granicus.if.org Git - postgresql/blob - src/backend/utils/misc/guc.c

   1 /*--------------------------------------------------------------------
   2  * guc.c
   3  *
   4  * Support for grand unified configuration scheme, including SET
   5  * command, configuration file, and command line options.
   6  * See src/backend/utils/misc/README for more information.
   7  *
   8  *
   9  * Copyright (c) 2000-2006, PostgreSQL Global Development Group
  10  * Written by Peter Eisentraut <peter_e@gmx.net>.
  11  *
  12  * IDENTIFICATION
  13  *        $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.333 2006/07/29 03:02:56 tgl Exp $
  14  *
  15  *--------------------------------------------------------------------
  16  */
  17 #include "postgres.h"
  18
  19 #include <ctype.h>
  20 #include <float.h>
  21 #include <limits.h>
  22 #include <unistd.h>
  23 #include <sys/stat.h>
  24 #ifdef HAVE_SYSLOG
  25 #include <syslog.h>
  26 #endif
  27
  28
  29 #include "access/gin.h"
  30 #include "access/twophase.h"
  31 #include "access/xact.h"
  32 #include "catalog/namespace.h"
  33 #include "commands/async.h"
  34 #include "commands/vacuum.h"
  35 #include "commands/variable.h"
  36 #include "funcapi.h"
  37 #include "libpq/auth.h"
  38 #include "libpq/pqformat.h"
  39 #include "miscadmin.h"
  40 #include "optimizer/cost.h"
  41 #include "optimizer/geqo.h"
  42 #include "optimizer/paths.h"
  43 #include "optimizer/planmain.h"
  44 #include "parser/gramparse.h"
  45 #include "parser/parse_expr.h"
  46 #include "parser/parse_relation.h"
  47 #include "parser/scansup.h"
  48 #include "pgstat.h"
  49 #include "postmaster/autovacuum.h"
  50 #include "postmaster/bgwriter.h"
  51 #include "postmaster/postmaster.h"
  52 #include "postmaster/syslogger.h"
  53 #include "storage/fd.h"
  54 #include "storage/freespace.h"
  55 #include "tcop/tcopprot.h"
  56 #include "utils/builtins.h"
  57 #include "utils/guc_tables.h"
  58 #include "utils/memutils.h"
  59 #include "utils/pg_locale.h"
  60 #include "utils/ps_status.h"
  61 #include "utils/tzparser.h"
  62
  63 #ifndef PG_KRB_SRVTAB
  64 #define PG_KRB_SRVTAB ""
  65 #endif
  66 #ifndef PG_KRB_SRVNAM
  67 #define PG_KRB_SRVNAM ""
  68 #endif
  69
  70 #define CONFIG_FILENAME "postgresql.conf"
  71 #define HBA_FILENAME    "pg_hba.conf"
  72 #define IDENT_FILENAME  "pg_ident.conf"
  73
  74 #ifdef EXEC_BACKEND
  75 #define CONFIG_EXEC_PARAMS "global/config_exec_params"
  76 #define CONFIG_EXEC_PARAMS_NEW "global/config_exec_params.new"
  77 #endif
  78
  79 /* upper limit for GUC variables measured in kilobytes of memory */
  80 #if SIZEOF_SIZE_T > 4
  81 #define MAX_KILOBYTES   INT_MAX
  82 #else
  83 #define MAX_KILOBYTES   (INT_MAX / 1024)
  84 #endif
  85
  86 #define KB_PER_MB (1024)
  87 #define KB_PER_GB (1024*1024)
  88
  89 #define MS_PER_S 1000
  90 #define MS_PER_MIN (1000 * 60)
  91 #define MS_PER_H (1000 * 60 * 60)
  92 #define MS_PER_D (1000 * 60 * 60 * 24)
  93
  94 /* XXX these should appear in other modules' header files */
  95 extern bool Log_disconnections;
  96 extern bool check_function_bodies;
  97 extern int      CommitDelay;
  98 extern int      CommitSiblings;
  99 extern char *default_tablespace;
 100 extern bool fullPageWrites;
 101
 102 #ifdef TRACE_SORT
 103 extern bool trace_sort;
 104 #endif
 105
 106 static const char *assign_log_destination(const char *value,
 107                                            bool doit, GucSource source);
 108
 109 #ifdef HAVE_SYSLOG
 110 static int      syslog_facility = LOG_LOCAL0;
 111
 112 static const char *assign_syslog_facility(const char *facility,
 113                                            bool doit, GucSource source);
 114 static const char *assign_syslog_ident(const char *ident,
 115                                         bool doit, GucSource source);
 116 #endif
 117
 118 static const char *assign_defaultxactisolevel(const char *newval, bool doit,
 119                                                    GucSource source);
 120 static const char *assign_log_min_messages(const char *newval, bool doit,
 121                                                 GucSource source);
 122 static const char *assign_client_min_messages(const char *newval,
 123                                                    bool doit, GucSource source);
 124 static const char *assign_min_error_statement(const char *newval, bool doit,
 125                                                    GucSource source);
 126 static const char *assign_msglvl(int *var, const char *newval, bool doit,
 127                           GucSource source);
 128 static const char *assign_log_error_verbosity(const char *newval, bool doit,
 129                                                    GucSource source);
 130 static const char *assign_log_statement(const char *newval, bool doit,
 131                                          GucSource source);
 132 static const char *show_num_temp_buffers(void);
 133 static bool assign_phony_autocommit(bool newval, bool doit, GucSource source);
 134 static const char *assign_custom_variable_classes(const char *newval, bool doit,
 135                                                            GucSource source);
 136 static bool assign_debug_assertions(bool newval, bool doit, GucSource source);
 137 static bool assign_ssl(bool newval, bool doit, GucSource source);
 138 static bool assign_stage_log_stats(bool newval, bool doit, GucSource source);
 139 static bool assign_log_stats(bool newval, bool doit, GucSource source);
 140 static bool assign_transaction_read_only(bool newval, bool doit, GucSource source);
 141 static const char *assign_canonical_path(const char *newval, bool doit, GucSource source);
 142 static const char *assign_backslash_quote(const char *newval, bool doit, GucSource source);
 143 static const char *assign_timezone_abbreviations(const char *newval, bool doit, GucSource source);
 144
 145 static bool assign_tcp_keepalives_idle(int newval, bool doit, GucSource source);
 146 static bool assign_tcp_keepalives_interval(int newval, bool doit, GucSource source);
 147 static bool assign_tcp_keepalives_count(int newval, bool doit, GucSource source);
 148 static const char *show_tcp_keepalives_idle(void);
 149 static const char *show_tcp_keepalives_interval(void);
 150 static const char *show_tcp_keepalives_count(void);
 151
 152 /*
 153  * GUC option variables that are exported from this module
 154  */
 155 #ifdef USE_ASSERT_CHECKING
 156 bool            assert_enabled = true;
 157 #else
 158 bool            assert_enabled = false;
 159 #endif
 160 bool            log_duration = false;
 161 bool            Debug_print_plan = false;
 162 bool            Debug_print_parse = false;
 163 bool            Debug_print_rewritten = false;
 164 bool            Debug_pretty_print = false;
 165 bool            Explain_pretty_print = true;
 166
 167 bool            log_parser_stats = false;
 168 bool            log_planner_stats = false;
 169 bool            log_executor_stats = false;
 170 bool            log_statement_stats = false;            /* this is sort of all three
 171                                                                                                  * above together */
 172 bool            log_btree_build_stats = false;
 173
 174 bool            SQL_inheritance = true;
 175
 176 bool            Password_encryption = true;
 177
 178 bool            default_with_oids = false;
 179
 180 int                     log_min_error_statement = PANIC;
 181 int                     log_min_messages = NOTICE;
 182 int                     client_min_messages = NOTICE;
 183 int                     log_min_duration_statement = -1;
 184
 185 int                     num_temp_buffers = 1000;
 186
 187 char       *ConfigFileName;
 188 char       *HbaFileName;
 189 char       *IdentFileName;
 190 char       *external_pid_file;
 191
 192 int                     tcp_keepalives_idle;
 193 int                     tcp_keepalives_interval;
 194 int                     tcp_keepalives_count;
 195
 196 /*
 197  * These variables are all dummies that don't do anything, except in some
 198  * cases provide the value for SHOW to display.  The real state is elsewhere
 199  * and is kept in sync by assign_hooks.
 200  */
 201 static char *client_min_messages_str;
 202 static char *log_min_messages_str;
 203 static char *log_error_verbosity_str;
 204 static char *log_statement_str;
 205 static char *log_min_error_statement_str;
 206 static char *log_destination_string;
 207 #ifdef HAVE_SYSLOG
 208 static char *syslog_facility_str;
 209 static char *syslog_ident_str;
 210 #endif
 211 static bool phony_autocommit;
 212 static bool session_auth_is_superuser;
 213 static double phony_random_seed;
 214 static char *backslash_quote_string;
 215 static char *client_encoding_string;
 216 static char *datestyle_string;
 217 static char *default_iso_level_string;
 218 static char *locale_collate;
 219 static char *locale_ctype;
 220 static char *regex_flavor_string;
 221 static char *server_encoding_string;
 222 static char *server_version_string;
 223 static char *timezone_string;
 224 static char *timezone_abbreviations_string;
 225 static char *XactIsoLevel_string;
 226 static char *data_directory;
 227 static char *custom_variable_classes;
 228 static int      max_function_args;
 229 static int      max_index_keys;
 230 static int      max_identifier_length;
 231 static int      block_size;
 232 static bool integer_datetimes;
 233
 234 /* should be static, but commands/variable.c needs to get at these */
 235 char       *role_string;
 236 char       *session_authorization_string;
 237
 238
 239 /*
 240  * Displayable names for context types (enum GucContext)
 241  *
 242  * Note: these strings are deliberately not localized.
 243  */
 244 const char *const GucContext_Names[] =
 245 {
 246          /* PGC_INTERNAL */ "internal",
 247          /* PGC_POSTMASTER */ "postmaster",
 248          /* PGC_SIGHUP */ "sighup",
 249          /* PGC_BACKEND */ "backend",
 250          /* PGC_SUSET */ "superuser",
 251          /* PGC_USERSET */ "user"
 252 };
 253
 254 /*
 255  * Displayable names for source types (enum GucSource)
 256  *
 257  * Note: these strings are deliberately not localized.
 258  */
 259 const char *const GucSource_Names[] =
 260 {
 261          /* PGC_S_DEFAULT */ "default",
 262          /* PGC_S_ENV_VAR */ "environment variable",
 263          /* PGC_S_FILE */ "configuration file",
 264          /* PGC_S_ARGV */ "command line",
 265          /* PGC_S_DATABASE */ "database",
 266          /* PGC_S_USER */ "user",
 267          /* PGC_S_CLIENT */ "client",
 268          /* PGC_S_OVERRIDE */ "override",
 269          /* PGC_S_INTERACTIVE */ "interactive",
 270          /* PGC_S_TEST */ "test",
 271          /* PGC_S_SESSION */ "session"
 272 };
 273
 274 /*
 275  * Displayable names for the groupings defined in enum config_group
 276  */
 277 const char *const config_group_names[] =
 278 {
 279         /* UNGROUPED */
 280         gettext_noop("Ungrouped"),
 281         /* FILE_LOCATIONS */
 282         gettext_noop("File Locations"),
 283         /* CONN_AUTH */
 284         gettext_noop("Connections and Authentication"),
 285         /* CONN_AUTH_SETTINGS */
 286         gettext_noop("Connections and Authentication / Connection Settings"),
 287         /* CONN_AUTH_SECURITY */
 288         gettext_noop("Connections and Authentication / Security and Authentication"),
 289         /* RESOURCES */
 290         gettext_noop("Resource Usage"),
 291         /* RESOURCES_MEM */
 292         gettext_noop("Resource Usage / Memory"),
 293         /* RESOURCES_FSM */
 294         gettext_noop("Resource Usage / Free Space Map"),
 295         /* RESOURCES_KERNEL */
 296         gettext_noop("Resource Usage / Kernel Resources"),
 297         /* WAL */
 298         gettext_noop("Write-Ahead Log"),
 299         /* WAL_SETTINGS */
 300         gettext_noop("Write-Ahead Log / Settings"),
 301         /* WAL_CHECKPOINTS */
 302         gettext_noop("Write-Ahead Log / Checkpoints"),
 303         /* QUERY_TUNING */
 304         gettext_noop("Query Tuning"),
 305         /* QUERY_TUNING_METHOD */
 306         gettext_noop("Query Tuning / Planner Method Configuration"),
 307         /* QUERY_TUNING_COST */
 308         gettext_noop("Query Tuning / Planner Cost Constants"),
 309         /* QUERY_TUNING_GEQO */
 310         gettext_noop("Query Tuning / Genetic Query Optimizer"),
 311         /* QUERY_TUNING_OTHER */
 312         gettext_noop("Query Tuning / Other Planner Options"),
 313         /* LOGGING */
 314         gettext_noop("Reporting and Logging"),
 315         /* LOGGING_WHERE */
 316         gettext_noop("Reporting and Logging / Where to Log"),
 317         /* LOGGING_WHEN */
 318         gettext_noop("Reporting and Logging / When to Log"),
 319         /* LOGGING_WHAT */
 320         gettext_noop("Reporting and Logging / What to Log"),
 321         /* STATS */
 322         gettext_noop("Statistics"),
 323         /* STATS_MONITORING */
 324         gettext_noop("Statistics / Monitoring"),
 325         /* STATS_COLLECTOR */
 326         gettext_noop("Statistics / Query and Index Statistics Collector"),
 327         /* AUTOVACUUM */
 328         gettext_noop("Autovacuum"),
 329         /* CLIENT_CONN */
 330         gettext_noop("Client Connection Defaults"),
 331         /* CLIENT_CONN_STATEMENT */
 332         gettext_noop("Client Connection Defaults / Statement Behavior"),
 333         /* CLIENT_CONN_LOCALE */
 334         gettext_noop("Client Connection Defaults / Locale and Formatting"),
 335         /* CLIENT_CONN_OTHER */
 336         gettext_noop("Client Connection Defaults / Other Defaults"),
 337         /* LOCK_MANAGEMENT */
 338         gettext_noop("Lock Management"),
 339         /* COMPAT_OPTIONS */
 340         gettext_noop("Version and Platform Compatibility"),
 341         /* COMPAT_OPTIONS_PREVIOUS */
 342         gettext_noop("Version and Platform Compatibility / Previous PostgreSQL Versions"),
 343         /* COMPAT_OPTIONS_CLIENT */
 344         gettext_noop("Version and Platform Compatibility / Other Platforms and Clients"),
 345         /* PRESET_OPTIONS */
 346         gettext_noop("Preset Options"),
 347         /* CUSTOM_OPTIONS */
 348         gettext_noop("Customized Options"),
 349         /* DEVELOPER_OPTIONS */
 350         gettext_noop("Developer Options"),
 351         /* help_config wants this array to be null-terminated */
 352         NULL
 353 };
 354
 355 /*
 356  * Displayable names for GUC variable types (enum config_type)
 357  *
 358  * Note: these strings are deliberately not localized.
 359  */
 360 const char *const config_type_names[] =
 361 {
 362          /* PGC_BOOL */ "bool",
 363          /* PGC_INT */ "integer",
 364          /* PGC_REAL */ "real",
 365          /* PGC_STRING */ "string"
 366 };
 367
 368
 369 /*
 370  * Contents of GUC tables
 371  *
 372  * See src/backend/utils/misc/README for design notes.
 373  *
 374  * TO ADD AN OPTION:
 375  *
 376  * 1. Declare a global variable of type bool, int, double, or char*
 377  *        and make use of it.
 378  *
 379  * 2. Decide at what times it's safe to set the option. See guc.h for
 380  *        details.
 381  *
 382  * 3. Decide on a name, a default value, upper and lower bounds (if
 383  *        applicable), etc.
 384  *
 385  * 4. Add a record below.
 386  *
 387  * 5. Add it to src/backend/utils/misc/postgresql.conf.sample, if
 388  *        appropriate
 389  *
 390  * 6. Add it to src/bin/psql/tab-complete.c, if it's a USERSET option.
 391  *
 392  * 7. Don't forget to document the option.
 393  *
 394  * 8. If it's a new GUC_LIST option you must edit pg_dumpall.c to ensure
 395  *        it is not single quoted at dump time.
 396  */
 397
 398
 399 /******** option records follow ********/
 400
 401 static struct config_bool ConfigureNamesBool[] =
 402 {
 403         {
 404                 {"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
 405                         gettext_noop("Enables the planner's use of sequential-scan plans."),
 406                         NULL
 407                 },
 408                 &enable_seqscan,
 409                 true, NULL, NULL
 410         },
 411         {
 412                 {"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
 413                         gettext_noop("Enables the planner's use of index-scan plans."),
 414                         NULL
 415                 },
 416                 &enable_indexscan,
 417                 true, NULL, NULL
 418         },
 419         {
 420                 {"enable_bitmapscan", PGC_USERSET, QUERY_TUNING_METHOD,
 421                         gettext_noop("Enables the planner's use of bitmap-scan plans."),
 422                         NULL
 423                 },
 424                 &enable_bitmapscan,
 425                 true, NULL, NULL
 426         },
 427         {
 428                 {"enable_tidscan", PGC_USERSET, QUERY_TUNING_METHOD,
 429                         gettext_noop("Enables the planner's use of TID scan plans."),
 430                         NULL
 431                 },
 432                 &enable_tidscan,
 433                 true, NULL, NULL
 434         },
 435         {
 436                 {"enable_sort", PGC_USERSET, QUERY_TUNING_METHOD,
 437                         gettext_noop("Enables the planner's use of explicit sort steps."),
 438                         NULL
 439                 },
 440                 &enable_sort,
 441                 true, NULL, NULL
 442         },
 443         {
 444                 {"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
 445                         gettext_noop("Enables the planner's use of hashed aggregation plans."),
 446                         NULL
 447                 },
 448                 &enable_hashagg,
 449                 true, NULL, NULL
 450         },
 451         {
 452                 {"enable_nestloop", PGC_USERSET, QUERY_TUNING_METHOD,
 453                         gettext_noop("Enables the planner's use of nested-loop join plans."),
 454                         NULL
 455                 },
 456                 &enable_nestloop,
 457                 true, NULL, NULL
 458         },
 459         {
 460                 {"enable_mergejoin", PGC_USERSET, QUERY_TUNING_METHOD,
 461                         gettext_noop("Enables the planner's use of merge join plans."),
 462                         NULL
 463                 },
 464                 &enable_mergejoin,
 465                 true, NULL, NULL
 466         },
 467         {
 468                 {"enable_hashjoin", PGC_USERSET, QUERY_TUNING_METHOD,
 469                         gettext_noop("Enables the planner's use of hash join plans."),
 470                         NULL
 471                 },
 472                 &enable_hashjoin,
 473                 true, NULL, NULL
 474         },
 475         {
 476                 {"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
 477                         gettext_noop("Enables the planner to use constraints to optimize queries."),
 478                         gettext_noop("Child table scans will be skipped if their "
 479                                            "constraints guarantee that no rows match the query.")
 480                 },
 481                 &constraint_exclusion,
 482                 false, NULL, NULL
 483         },
 484         {
 485                 {"geqo", PGC_USERSET, QUERY_TUNING_GEQO,
 486                         gettext_noop("Enables genetic query optimization."),
 487                         gettext_noop("This algorithm attempts to do planning without "
 488                                                  "exhaustive searching.")
 489                 },
 490                 &enable_geqo,
 491                 true, NULL, NULL
 492         },
 493         {
 494                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
 495                 {"is_superuser", PGC_INTERNAL, UNGROUPED,
 496                         gettext_noop("Shows whether the current user is a superuser."),
 497                         NULL,
 498                         GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 499                 },
 500                 &session_auth_is_superuser,
 501                 false, NULL, NULL
 502         },
 503         {
 504                 {"ssl", PGC_POSTMASTER, CONN_AUTH_SECURITY,
 505                         gettext_noop("Enables SSL connections."),
 506                         NULL
 507                 },
 508                 &EnableSSL,
 509                 false, assign_ssl, NULL
 510         },
 511         {
 512                 {"fsync", PGC_SIGHUP, WAL_SETTINGS,
 513                         gettext_noop("Forces synchronization of updates to disk."),
 514                         gettext_noop("The server will use the fsync() system call in several places to make "
 515                         "sure that updates are physically written to disk. This insures "
 516                                                  "that a database cluster will recover to a consistent state after "
 517                                                  "an operating system or hardware crash.")
 518                 },
 519                 &enableFsync,
 520                 true, NULL, NULL
 521         },
 522         {
 523                 {"zero_damaged_pages", PGC_SUSET, DEVELOPER_OPTIONS,
 524                         gettext_noop("Continues processing past damaged page headers."),
 525                         gettext_noop("Detection of a damaged page header normally causes PostgreSQL to "
 526                                 "report an error, aborting the current transaction. Setting "
 527                                                  "zero_damaged_pages to true causes the system to instead report a "
 528                                                  "warning, zero out the damaged page, and continue processing. This "
 529                                                  "behavior will destroy data, namely all the rows on the damaged page."),
 530                         GUC_NOT_IN_SAMPLE
 531                 },
 532                 &zero_damaged_pages,
 533                 false, NULL, NULL
 534         },
 535         {
 536                 {"full_page_writes", PGC_SIGHUP, WAL_SETTINGS,
 537                         gettext_noop("Writes full pages to WAL when first modified after a checkpoint."),
 538                         gettext_noop("A page write in process during an operating system crash might be "
 539                                                  "only partially written to disk.  During recovery, the row changes "
 540                           "stored in WAL are not enough to recover.  This option writes "
 541                                                  "pages when first modified after a checkpoint to WAL so full recovery "
 542                                                  "is possible.")
 543                 },
 544                 &fullPageWrites,
 545                 true, NULL, NULL
 546         },
 547         {
 548                 {"silent_mode", PGC_POSTMASTER, LOGGING_WHEN,
 549                         gettext_noop("Runs the server silently."),
 550                         gettext_noop("If this parameter is set, the server will automatically run in the "
 551                                  "background and any controlling terminals are dissociated.")
 552                 },
 553                 &SilentMode,
 554                 false, NULL, NULL
 555         },
 556         {
 557                 {"log_connections", PGC_BACKEND, LOGGING_WHAT,
 558                         gettext_noop("Logs each successful connection."),
 559                         NULL
 560                 },
 561                 &Log_connections,
 562                 false, NULL, NULL
 563         },
 564         {
 565                 {"log_disconnections", PGC_BACKEND, LOGGING_WHAT,
 566                         gettext_noop("Logs end of a session, including duration."),
 567                         NULL
 568                 },
 569                 &Log_disconnections,
 570                 false, NULL, NULL
 571         },
 572         {
 573                 {"debug_assertions", PGC_USERSET, DEVELOPER_OPTIONS,
 574                         gettext_noop("Turns on various assertion checks."),
 575                         gettext_noop("This is a debugging aid."),
 576                         GUC_NOT_IN_SAMPLE
 577                 },
 578                 &assert_enabled,
 579 #ifdef USE_ASSERT_CHECKING
 580                 true,
 581 #else
 582                 false,
 583 #endif
 584                 assign_debug_assertions, NULL
 585         },
 586         {
 587                 /* currently undocumented, so don't show in SHOW ALL */
 588                 {"exit_on_error", PGC_USERSET, UNGROUPED,
 589                         gettext_noop("no description available"),
 590                         NULL,
 591                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
 592                 },
 593                 &ExitOnAnyError,
 594                 false, NULL, NULL
 595         },
 596         {
 597                 {"log_duration", PGC_SUSET, LOGGING_WHAT,
 598                         gettext_noop("Logs the duration of each completed SQL statement."),
 599                         NULL
 600                 },
 601                 &log_duration,
 602                 false, NULL, NULL
 603         },
 604         {
 605                 {"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
 606                         gettext_noop("Prints the parse tree to the server log."),
 607                         NULL
 608                 },
 609                 &Debug_print_parse,
 610                 false, NULL, NULL
 611         },
 612         {
 613                 {"debug_print_rewritten", PGC_USERSET, LOGGING_WHAT,
 614                         gettext_noop("Prints the parse tree after rewriting to server log."),
 615                         NULL
 616                 },
 617                 &Debug_print_rewritten,
 618                 false, NULL, NULL
 619         },
 620         {
 621                 {"debug_print_plan", PGC_USERSET, LOGGING_WHAT,
 622                         gettext_noop("Prints the execution plan to server log."),
 623                         NULL
 624                 },
 625                 &Debug_print_plan,
 626                 false, NULL, NULL
 627         },
 628         {
 629                 {"debug_pretty_print", PGC_USERSET, LOGGING_WHAT,
 630                         gettext_noop("Indents parse and plan tree displays."),
 631                         NULL
 632                 },
 633                 &Debug_pretty_print,
 634                 false, NULL, NULL
 635         },
 636         {
 637                 {"log_parser_stats", PGC_SUSET, STATS_MONITORING,
 638                         gettext_noop("Writes parser performance statistics to the server log."),
 639                         NULL
 640                 },
 641                 &log_parser_stats,
 642                 false, assign_stage_log_stats, NULL
 643         },
 644         {
 645                 {"log_planner_stats", PGC_SUSET, STATS_MONITORING,
 646                         gettext_noop("Writes planner performance statistics to the server log."),
 647                         NULL
 648                 },
 649                 &log_planner_stats,
 650                 false, assign_stage_log_stats, NULL
 651         },
 652         {
 653                 {"log_executor_stats", PGC_SUSET, STATS_MONITORING,
 654                         gettext_noop("Writes executor performance statistics to the server log."),
 655                         NULL
 656                 },
 657                 &log_executor_stats,
 658                 false, assign_stage_log_stats, NULL
 659         },
 660         {
 661                 {"log_statement_stats", PGC_SUSET, STATS_MONITORING,
 662                         gettext_noop("Writes cumulative performance statistics to the server log."),
 663                         NULL
 664                 },
 665                 &log_statement_stats,
 666                 false, assign_log_stats, NULL
 667         },
 668 #ifdef BTREE_BUILD_STATS
 669         {
 670                 {"log_btree_build_stats", PGC_SUSET, DEVELOPER_OPTIONS,
 671                         gettext_noop("no description available"),
 672                         NULL,
 673                         GUC_NOT_IN_SAMPLE
 674                 },
 675                 &log_btree_build_stats,
 676                 false, NULL, NULL
 677         },
 678 #endif
 679
 680         {
 681                 {"explain_pretty_print", PGC_USERSET, CLIENT_CONN_OTHER,
 682                         gettext_noop("Uses the indented output format for EXPLAIN VERBOSE."),
 683                         NULL
 684                 },
 685                 &Explain_pretty_print,
 686                 true, NULL, NULL
 687         },
 688         {
 689                 {"stats_start_collector", PGC_POSTMASTER, STATS_COLLECTOR,
 690                         gettext_noop("Starts the server statistics-collection subprocess."),
 691                         NULL
 692                 },
 693                 &pgstat_collect_startcollector,
 694                 true, NULL, NULL
 695         },
 696         {
 697                 {"stats_reset_on_server_start", PGC_POSTMASTER, STATS_COLLECTOR,
 698                         gettext_noop("Zeroes collected statistics on server restart."),
 699                         NULL
 700                 },
 701                 &pgstat_collect_resetonpmstart,
 702                 false, NULL, NULL
 703         },
 704         {
 705                 {"stats_row_level", PGC_SUSET, STATS_COLLECTOR,
 706                         gettext_noop("Collects row-level statistics on database activity."),
 707                         NULL
 708                 },
 709                 &pgstat_collect_tuplelevel,
 710                 false, NULL, NULL
 711         },
 712         {
 713                 {"stats_block_level", PGC_SUSET, STATS_COLLECTOR,
 714                         gettext_noop("Collects block-level statistics on database activity."),
 715                         NULL
 716                 },
 717                 &pgstat_collect_blocklevel,
 718                 false, NULL, NULL
 719         },
 720
 721         {
 722                 {"stats_command_string", PGC_SUSET, STATS_COLLECTOR,
 723                         gettext_noop("Collects information about executing commands."),
 724                         gettext_noop("Enables the collection of information on the currently "
 725                                         "executing command of each session, along with the time "
 726                                                  "at which that command began execution.")
 727                 },
 728                 &pgstat_collect_querystring,
 729                 true, NULL, NULL
 730         },
 731
 732         {
 733                 {"update_process_title", PGC_SUSET, STATS_COLLECTOR,
 734                         gettext_noop("Updates the process title to show the active SQL command."),
 735                         gettext_noop("Enables updating of the process title every time a new SQL command is received by the server.")
 736                 },
 737                 &update_process_title,
 738                 true, NULL, NULL
 739         },
 740
 741         {
 742                 {"autovacuum", PGC_SIGHUP, AUTOVACUUM,
 743                         gettext_noop("Starts the autovacuum subprocess."),
 744                         NULL
 745                 },
 746                 &autovacuum_start_daemon,
 747                 false, NULL, NULL
 748         },
 749
 750         {
 751                 {"trace_notify", PGC_USERSET, DEVELOPER_OPTIONS,
 752                         gettext_noop("Generates debugging output for LISTEN and NOTIFY."),
 753                         NULL,
 754                         GUC_NOT_IN_SAMPLE
 755                 },
 756                 &Trace_notify,
 757                 false, NULL, NULL
 758         },
 759
 760 #ifdef LOCK_DEBUG
 761         {
 762                 {"trace_locks", PGC_SUSET, DEVELOPER_OPTIONS,
 763                         gettext_noop("no description available"),
 764                         NULL,
 765                         GUC_NOT_IN_SAMPLE
 766                 },
 767                 &Trace_locks,
 768                 false, NULL, NULL
 769         },
 770         {
 771                 {"trace_userlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 772                         gettext_noop("no description available"),
 773                         NULL,
 774                         GUC_NOT_IN_SAMPLE
 775                 },
 776                 &Trace_userlocks,
 777                 false, NULL, NULL
 778         },
 779         {
 780                 {"trace_lwlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 781                         gettext_noop("no description available"),
 782                         NULL,
 783                         GUC_NOT_IN_SAMPLE
 784                 },
 785                 &Trace_lwlocks,
 786                 false, NULL, NULL
 787         },
 788         {
 789                 {"debug_deadlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 790                         gettext_noop("no description available"),
 791                         NULL,
 792                         GUC_NOT_IN_SAMPLE
 793                 },
 794                 &Debug_deadlocks,
 795                 false, NULL, NULL
 796         },
 797 #endif
 798
 799         {
 800                 {"log_hostname", PGC_SIGHUP, LOGGING_WHAT,
 801                         gettext_noop("Logs the host name in the connection logs."),
 802                         gettext_noop("By default, connection logs only show the IP address "
 803                                                  "of the connecting host. If you want them to show the host name you "
 804                           "can turn this on, but depending on your host name resolution "
 805                            "setup it might impose a non-negligible performance penalty.")
 806                 },
 807                 &log_hostname,
 808                 false, NULL, NULL
 809         },
 810         {
 811                 {"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 812                         gettext_noop("Causes subtables to be included by default in various commands."),
 813                         NULL
 814                 },
 815                 &SQL_inheritance,
 816                 true, NULL, NULL
 817         },
 818         {
 819                 {"password_encryption", PGC_USERSET, CONN_AUTH_SECURITY,
 820                         gettext_noop("Encrypt passwords."),
 821                         gettext_noop("When a password is specified in CREATE USER or "
 822                            "ALTER USER without writing either ENCRYPTED or UNENCRYPTED, "
 823                                                  "this parameter determines whether the password is to be encrypted.")
 824                 },
 825                 &Password_encryption,
 826                 true, NULL, NULL
 827         },
 828         {
 829                 {"transform_null_equals", PGC_USERSET, COMPAT_OPTIONS_CLIENT,
 830                         gettext_noop("Treats \"expr=NULL\" as \"expr IS NULL\"."),
 831                         gettext_noop("When turned on, expressions of the form expr = NULL "
 832                            "(or NULL = expr) are treated as expr IS NULL, that is, they "
 833                                 "return true if expr evaluates to the null value, and false "
 834                            "otherwise. The correct behavior of expr = NULL is to always "
 835                                                  "return null (unknown).")
 836                 },
 837                 &Transform_null_equals,
 838                 false, NULL, NULL
 839         },
 840         {
 841                 {"db_user_namespace", PGC_SIGHUP, CONN_AUTH_SECURITY,
 842                         gettext_noop("Enables per-database user names."),
 843                         NULL
 844                 },
 845                 &Db_user_namespace,
 846                 false, NULL, NULL
 847         },
 848         {
 849                 /* only here for backwards compatibility */
 850                 {"autocommit", PGC_USERSET, CLIENT_CONN_STATEMENT,
 851                         gettext_noop("This parameter doesn't do anything."),
 852                         gettext_noop("It's just here so that we won't choke on SET AUTOCOMMIT TO ON from 7.3-vintage clients."),
 853                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
 854                 },
 855                 &phony_autocommit,
 856                 true, assign_phony_autocommit, NULL
 857         },
 858         {
 859                 {"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
 860                         gettext_noop("Sets the default read-only status of new transactions."),
 861                         NULL
 862                 },
 863                 &DefaultXactReadOnly,
 864                 false, NULL, NULL
 865         },
 866         {
 867                 {"transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
 868                         gettext_noop("Sets the current transaction's read-only status."),
 869                         NULL,
 870                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 871                 },
 872                 &XactReadOnly,
 873                 false, assign_transaction_read_only, NULL
 874         },
 875         {
 876                 {"add_missing_from", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 877                         gettext_noop("Automatically adds missing table references to FROM clauses."),
 878                         NULL
 879                 },
 880                 &add_missing_from,
 881                 false, NULL, NULL
 882         },
 883         {
 884                 {"check_function_bodies", PGC_USERSET, CLIENT_CONN_STATEMENT,
 885                         gettext_noop("Check function bodies during CREATE FUNCTION."),
 886                         NULL
 887                 },
 888                 &check_function_bodies,
 889                 true, NULL, NULL
 890         },
 891         {
 892                 {"array_nulls", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 893                         gettext_noop("Enable input of NULL elements in arrays."),
 894                         gettext_noop("When turned on, unquoted NULL in an array input "
 895                                                  "value means a NULL value; "
 896                                                  "otherwise it is taken literally.")
 897                 },
 898                 &Array_nulls,
 899                 true, NULL, NULL
 900         },
 901         {
 902                 {"default_with_oids", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 903                         gettext_noop("Create new tables with OIDs by default."),
 904                         NULL
 905                 },
 906                 &default_with_oids,
 907                 false, NULL, NULL
 908         },
 909         {
 910                 {"redirect_stderr", PGC_POSTMASTER, LOGGING_WHERE,
 911                         gettext_noop("Start a subprocess to capture stderr output into log files."),
 912                         NULL
 913                 },
 914                 &Redirect_stderr,
 915                 false, NULL, NULL
 916         },
 917         {
 918                 {"log_truncate_on_rotation", PGC_SIGHUP, LOGGING_WHERE,
 919                         gettext_noop("Truncate existing log files of same name during log rotation."),
 920                         NULL
 921                 },
 922                 &Log_truncate_on_rotation,
 923                 false, NULL, NULL
 924         },
 925
 926 #ifdef TRACE_SORT
 927         {
 928                 {"trace_sort", PGC_USERSET, DEVELOPER_OPTIONS,
 929                         gettext_noop("Emit information about resource usage in sorting."),
 930                         NULL,
 931                         GUC_NOT_IN_SAMPLE
 932                 },
 933                 &trace_sort,
 934                 false, NULL, NULL
 935         },
 936 #endif
 937
 938 #ifdef WAL_DEBUG
 939         {
 940                 {"wal_debug", PGC_SUSET, DEVELOPER_OPTIONS,
 941                         gettext_noop("Emit WAL-related debugging output."),
 942                         NULL,
 943                         GUC_NOT_IN_SAMPLE
 944                 },
 945                 &XLOG_DEBUG,
 946                 false, NULL, NULL
 947         },
 948 #endif
 949
 950         {
 951                 {"integer_datetimes", PGC_INTERNAL, PRESET_OPTIONS,
 952                         gettext_noop("Datetimes are integer based."),
 953                         NULL,
 954                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 955                 },
 956                 &integer_datetimes,
 957 #ifdef HAVE_INT64_TIMESTAMP
 958                 true, NULL, NULL
 959 #else
 960                 false, NULL, NULL
 961 #endif
 962         },
 963
 964         {
 965                 {"krb_caseins_users", PGC_POSTMASTER, CONN_AUTH_SECURITY,
 966                         gettext_noop("Sets whether Kerberos user names should be treated as case-insensitive."),
 967                         NULL
 968                 },
 969                 &pg_krb_caseins_users,
 970                 false, NULL, NULL
 971         },
 972
 973         {
 974                 {"escape_string_warning", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 975                         gettext_noop("Warn about backslash escapes in ordinary string literals."),
 976                         NULL
 977                 },
 978                 &escape_string_warning,
 979                 true, NULL, NULL
 980         },
 981
 982         {
 983                 {"standard_conforming_strings", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 984                         gettext_noop("'...' strings treat backslashes literally."),
 985                         NULL,
 986                         GUC_REPORT
 987                 },
 988                 &standard_conforming_strings,
 989                 false, NULL, NULL
 990         },
 991
 992         {
 993                 {"allow_system_table_mods", PGC_POSTMASTER, DEVELOPER_OPTIONS,
 994                  gettext_noop("Allows modifications of the structure of system tables."),
 995                  NULL,
 996                  GUC_NOT_IN_SAMPLE
 997                 },
 998                 &allowSystemTableMods,
 999                 false, NULL, NULL
1000         },
1001
1002         {
1003                 {"ignore_system_indexes", PGC_BACKEND, DEVELOPER_OPTIONS,
1004                  gettext_noop("Disabled reading from system indexes."),
1005                  gettext_noop("It does not prevent updating the indexes, so it is safe "
1006                                           "to use.  The worst consequence is slowness."),
1007                  GUC_NOT_IN_SAMPLE
1008                 },
1009                 &IgnoreSystemIndexes,
1010                 false, NULL, NULL
1011         },
1012
1013         /* End-of-list marker */
1014         {
1015                 {NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL
1016         }
1017 };
1018
1019
1020 static struct config_int ConfigureNamesInt[] =
1021 {
1022         {
1023                 {"post_auth_delay", PGC_BACKEND, DEVELOPER_OPTIONS,
1024                  gettext_noop("Waits N seconds on connection startup after authentication."),
1025                  gettext_noop("This allows attaching a debugger to the process."),
1026                  GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1027                 },
1028                 &PostAuthDelay,
1029                 0, 0, INT_MAX, NULL, NULL
1030         },
1031         {
1032                 {"default_statistics_target", PGC_USERSET, QUERY_TUNING_OTHER,
1033                         gettext_noop("Sets the default statistics target."),
1034                         gettext_noop("This applies to table columns that have not had a "
1035                                 "column-specific target set via ALTER TABLE SET STATISTICS.")
1036                 },
1037                 &default_statistics_target,
1038                 10, 1, 1000, NULL, NULL
1039         },
1040         {
1041                 {"from_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1042                         gettext_noop("Sets the FROM-list size beyond which subqueries are not "
1043                                                  "collapsed."),
1044                         gettext_noop("The planner will merge subqueries into upper "
1045                                 "queries if the resulting FROM list would have no more than "
1046                                                  "this many items.")
1047                 },
1048                 &from_collapse_limit,
1049                 8, 1, INT_MAX, NULL, NULL
1050         },
1051         {
1052                 {"join_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1053                         gettext_noop("Sets the FROM-list size beyond which JOIN constructs are not "
1054                                                  "flattened."),
1055                         gettext_noop("The planner will flatten explicit JOIN "
1056                         "constructs into lists of FROM items whenever a list of no more "
1057                                                  "than this many items would result.")
1058                 },
1059                 &join_collapse_limit,
1060                 8, 1, INT_MAX, NULL, NULL
1061         },
1062         {
1063                 {"geqo_threshold", PGC_USERSET, QUERY_TUNING_GEQO,
1064                         gettext_noop("Sets the threshold of FROM items beyond which GEQO is used."),
1065                         NULL
1066                 },
1067                 &geqo_threshold,
1068                 12, 2, INT_MAX, NULL, NULL
1069         },
1070         {
1071                 {"geqo_effort", PGC_USERSET, QUERY_TUNING_GEQO,
1072                         gettext_noop("GEQO: effort is used to set the default for other GEQO parameters."),
1073                         NULL
1074                 },
1075                 &Geqo_effort,
1076                 DEFAULT_GEQO_EFFORT, MIN_GEQO_EFFORT, MAX_GEQO_EFFORT, NULL, NULL
1077         },
1078         {
1079                 {"geqo_pool_size", PGC_USERSET, QUERY_TUNING_GEQO,
1080                         gettext_noop("GEQO: number of individuals in the population."),
1081                         gettext_noop("Zero selects a suitable default value.")
1082                 },
1083                 &Geqo_pool_size,
1084                 0, 0, INT_MAX, NULL, NULL
1085         },
1086         {
1087                 {"geqo_generations", PGC_USERSET, QUERY_TUNING_GEQO,
1088                         gettext_noop("GEQO: number of iterations of the algorithm."),
1089                         gettext_noop("Zero selects a suitable default value.")
1090                 },
1091                 &Geqo_generations,
1092                 0, 0, INT_MAX, NULL, NULL
1093         },
1094
1095         {
1096                 {"deadlock_timeout", PGC_SIGHUP, LOCK_MANAGEMENT,
1097                         gettext_noop("The time in milliseconds to wait on lock before checking for deadlock."),
1098                         NULL,
1099                         GUC_UNIT_MS
1100                 },
1101                 &DeadlockTimeout,
1102                 1000, 0, INT_MAX, NULL, NULL
1103         },
1104
1105         /*
1106          * Note: There is some postprocessing done in PostmasterMain() to make
1107          * sure the buffers are at least twice the number of backends, so the
1108          * constraints here are partially unused. Similarly, the superuser
1109          * reserved number is checked to ensure it is less than the max backends
1110          * number.
1111          *
1112          * MaxBackends is limited to INT_MAX/4 because some places compute
1113          * 4*MaxBackends without any overflow check.  Likewise we have to limit
1114          * NBuffers to INT_MAX/2.
1115          */
1116         {
1117                 {"max_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1118                         gettext_noop("Sets the maximum number of concurrent connections."),
1119                         NULL
1120                 },
1121                 &MaxBackends,
1122                 100, 1, INT_MAX / 4, NULL, NULL
1123         },
1124
1125         {
1126                 {"superuser_reserved_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1127                         gettext_noop("Sets the number of connection slots reserved for superusers."),
1128                         NULL
1129                 },
1130                 &ReservedBackends,
1131                 2, 0, INT_MAX / 4, NULL, NULL
1132         },
1133
1134         {
1135                 {"shared_buffers", PGC_POSTMASTER, RESOURCES_MEM,
1136                         gettext_noop("Sets the number of shared memory buffers used by the server."),
1137                         NULL,
1138                         GUC_UNIT_BLOCKS
1139                 },
1140                 &NBuffers,
1141                 1000, 16, INT_MAX / 2, NULL, NULL
1142         },
1143
1144         {
1145                 {"temp_buffers", PGC_USERSET, RESOURCES_MEM,
1146                         gettext_noop("Sets the maximum number of temporary buffers used by each session."),
1147                         NULL,
1148                         GUC_UNIT_BLOCKS
1149                 },
1150                 &num_temp_buffers,
1151                 1000, 100, INT_MAX / 2, NULL, show_num_temp_buffers
1152         },
1153
1154         {
1155                 {"port", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1156                         gettext_noop("Sets the TCP port the server listens on."),
1157                         NULL
1158                 },
1159                 &PostPortNumber,
1160                 DEF_PGPORT, 1, 65535, NULL, NULL
1161         },
1162
1163         {
1164                 {"unix_socket_permissions", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1165                         gettext_noop("Sets the access permissions of the Unix-domain socket."),
1166                         gettext_noop("Unix-domain sockets use the usual Unix file system "
1167                                                  "permission set. The parameter value is expected to be an numeric mode "
1168                                                  "specification in the form accepted by the chmod and umask system "
1169                                                  "calls. (To use the customary octal format the number must start with "
1170                                                  "a 0 (zero).)")
1171                 },
1172                 &Unix_socket_permissions,
1173                 0777, 0000, 0777, NULL, NULL
1174         },
1175
1176         {
1177                 {"work_mem", PGC_USERSET, RESOURCES_MEM,
1178                         gettext_noop("Sets the maximum memory to be used for query workspaces."),
1179                         gettext_noop("This much memory may be used by each internal "
1180                                                  "sort operation and hash table before switching to "
1181                                                  "temporary disk files."),
1182                         GUC_UNIT_KB
1183                 },
1184                 &work_mem,
1185                 1024, 8 * BLCKSZ / 1024, MAX_KILOBYTES, NULL, NULL
1186         },
1187
1188         {
1189                 {"maintenance_work_mem", PGC_USERSET, RESOURCES_MEM,
1190                         gettext_noop("Sets the maximum memory to be used for maintenance operations."),
1191                         gettext_noop("This includes operations such as VACUUM and CREATE INDEX."),
1192                         GUC_UNIT_KB
1193                 },
1194                 &maintenance_work_mem,
1195                 16384, 1024, MAX_KILOBYTES, NULL, NULL
1196         },
1197
1198         {
1199                 {"max_stack_depth", PGC_SUSET, RESOURCES_MEM,
1200                         gettext_noop("Sets the maximum stack depth, in kilobytes."),
1201                         NULL,
1202                         GUC_UNIT_KB
1203                 },
1204                 &max_stack_depth,
1205                 2048, 100, MAX_KILOBYTES, assign_max_stack_depth, NULL
1206         },
1207
1208         {
1209                 {"vacuum_cost_page_hit", PGC_USERSET, RESOURCES,
1210                         gettext_noop("Vacuum cost for a page found in the buffer cache."),
1211                         NULL
1212                 },
1213                 &VacuumCostPageHit,
1214                 1, 0, 10000, NULL, NULL
1215         },
1216
1217         {
1218                 {"vacuum_cost_page_miss", PGC_USERSET, RESOURCES,
1219                         gettext_noop("Vacuum cost for a page not found in the buffer cache."),
1220                         NULL
1221                 },
1222                 &VacuumCostPageMiss,
1223                 10, 0, 10000, NULL, NULL
1224         },
1225
1226         {
1227                 {"vacuum_cost_page_dirty", PGC_USERSET, RESOURCES,
1228                         gettext_noop("Vacuum cost for a page dirtied by vacuum."),
1229                         NULL
1230                 },
1231                 &VacuumCostPageDirty,
1232                 20, 0, 10000, NULL, NULL
1233         },
1234
1235         {
1236                 {"vacuum_cost_limit", PGC_USERSET, RESOURCES,
1237                         gettext_noop("Vacuum cost amount available before napping."),
1238                         NULL
1239                 },
1240                 &VacuumCostLimit,
1241                 200, 1, 10000, NULL, NULL
1242         },
1243
1244         {
1245                 {"vacuum_cost_delay", PGC_USERSET, RESOURCES,
1246                         gettext_noop("Vacuum cost delay in milliseconds."),
1247                         NULL,
1248                         GUC_UNIT_MS
1249                 },
1250                 &VacuumCostDelay,
1251                 0, 0, 1000, NULL, NULL
1252         },
1253
1254         {
1255                 {"autovacuum_vacuum_cost_delay", PGC_SIGHUP, AUTOVACUUM,
1256                         gettext_noop("Vacuum cost delay in milliseconds, for autovacuum."),
1257                         NULL,
1258                         GUC_UNIT_MS
1259                 },
1260                 &autovacuum_vac_cost_delay,
1261                 -1, -1, 1000, NULL, NULL
1262         },
1263
1264         {
1265                 {"autovacuum_vacuum_cost_limit", PGC_SIGHUP, AUTOVACUUM,
1266                         gettext_noop("Vacuum cost amount available before napping, for autovacuum."),
1267                         NULL
1268                 },
1269                 &autovacuum_vac_cost_limit,
1270                 -1, -1, 10000, NULL, NULL
1271         },
1272
1273         {
1274                 {"max_files_per_process", PGC_POSTMASTER, RESOURCES_KERNEL,
1275                         gettext_noop("Sets the maximum number of simultaneously open files for each server process."),
1276                         NULL
1277                 },
1278                 &max_files_per_process,
1279                 1000, 25, INT_MAX, NULL, NULL
1280         },
1281
1282         {
1283                 {"max_prepared_transactions", PGC_POSTMASTER, RESOURCES,
1284                         gettext_noop("Sets the maximum number of simultaneously prepared transactions."),
1285                         NULL
1286                 },
1287                 &max_prepared_xacts,
1288                 5, 0, INT_MAX, NULL, NULL
1289         },
1290
1291 #ifdef LOCK_DEBUG
1292         {
1293                 {"trace_lock_oidmin", PGC_SUSET, DEVELOPER_OPTIONS,
1294                         gettext_noop("no description available"),
1295                         NULL,
1296                         GUC_NOT_IN_SAMPLE
1297                 },
1298                 &Trace_lock_oidmin,
1299                 FirstNormalObjectId, 0, INT_MAX, NULL, NULL
1300         },
1301         {
1302                 {"trace_lock_table", PGC_SUSET, DEVELOPER_OPTIONS,
1303                         gettext_noop("no description available"),
1304                         NULL,
1305                         GUC_NOT_IN_SAMPLE
1306                 },
1307                 &Trace_lock_table,
1308                 0, 0, INT_MAX, NULL, NULL
1309         },
1310 #endif
1311
1312         {
1313                 {"statement_timeout", PGC_USERSET, CLIENT_CONN_STATEMENT,
1314                         gettext_noop("Sets the maximum allowed duration (in milliseconds) of any statement."),
1315                         gettext_noop("A value of 0 turns off the timeout."),
1316                         GUC_UNIT_MS
1317                 },
1318                 &StatementTimeout,
1319                 0, 0, INT_MAX, NULL, NULL
1320         },
1321
1322         {
1323                 {"max_fsm_relations", PGC_POSTMASTER, RESOURCES_FSM,
1324                         gettext_noop("Sets the maximum number of tables and indexes for which free space is tracked."),
1325                         NULL
1326                 },
1327                 &MaxFSMRelations,
1328                 1000, 100, INT_MAX, NULL, NULL
1329         },
1330         {
1331                 {"max_fsm_pages", PGC_POSTMASTER, RESOURCES_FSM,
1332                         gettext_noop("Sets the maximum number of disk pages for which free space is tracked."),
1333                         NULL
1334                 },
1335                 &MaxFSMPages,
1336                 20000, 1000, INT_MAX, NULL, NULL
1337         },
1338
1339         {
1340                 {"max_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
1341                         gettext_noop("Sets the maximum number of locks per transaction."),
1342                         gettext_noop("The shared lock table is sized on the assumption that "
1343                           "at most max_locks_per_transaction * max_connections distinct "
1344                                                  "objects will need to be locked at any one time.")
1345                 },
1346                 &max_locks_per_xact,
1347                 64, 10, INT_MAX, NULL, NULL
1348         },
1349
1350         {
1351                 {"authentication_timeout", PGC_SIGHUP, CONN_AUTH_SECURITY,
1352                         gettext_noop("Sets the maximum time in seconds to complete client authentication."),
1353                         NULL,
1354                         GUC_UNIT_S
1355                 },
1356                 &AuthenticationTimeout,
1357                 60, 1, 600, NULL, NULL
1358         },
1359
1360         {
1361                 /* Not for general use */
1362                 {"pre_auth_delay", PGC_SIGHUP, DEVELOPER_OPTIONS,
1363                         gettext_noop("no description available"),
1364                         NULL,
1365                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1366                 },
1367                 &PreAuthDelay,
1368                 0, 0, 60, NULL, NULL
1369         },
1370
1371         {
1372                 {"checkpoint_segments", PGC_SIGHUP, WAL_CHECKPOINTS,
1373                         gettext_noop("Sets the maximum distance in log segments between automatic WAL checkpoints."),
1374                         NULL
1375                 },
1376                 &CheckPointSegments,
1377                 3, 1, INT_MAX, NULL, NULL
1378         },
1379
1380         {
1381                 {"checkpoint_timeout", PGC_SIGHUP, WAL_CHECKPOINTS,
1382                         gettext_noop("Sets the maximum time in seconds between automatic WAL checkpoints."),
1383                         NULL,
1384                         GUC_UNIT_S
1385                 },
1386                 &CheckPointTimeout,
1387                 300, 30, 3600, NULL, NULL
1388         },
1389
1390         {
1391                 {"checkpoint_warning", PGC_SIGHUP, WAL_CHECKPOINTS,
1392                         gettext_noop("Logs if filling of checkpoint segments happens more "
1393                                                  "frequently than this (in seconds)."),
1394                         gettext_noop("Write a message to the server log if checkpoints "
1395                         "caused by the filling of checkpoint segment files happens more "
1396                                                  "frequently than this number of seconds. Zero turns off the warning.")
1397                 },
1398                 &CheckPointWarning,
1399                 30, 0, INT_MAX, NULL, NULL
1400         },
1401
1402         {
1403                 {"wal_buffers", PGC_POSTMASTER, WAL_SETTINGS,
1404                         gettext_noop("Sets the number of disk-page buffers in shared memory for WAL."),
1405                         NULL
1406                 },
1407                 &XLOGbuffers,
1408                 8, 4, INT_MAX, NULL, NULL
1409         },
1410
1411         {
1412                 {"commit_delay", PGC_USERSET, WAL_CHECKPOINTS,
1413                         gettext_noop("Sets the delay in microseconds between transaction commit and "
1414                                                  "flushing WAL to disk."),
1415                         NULL
1416                 },
1417                 &CommitDelay,
1418                 0, 0, 100000, NULL, NULL
1419         },
1420
1421         {
1422                 {"commit_siblings", PGC_USERSET, WAL_CHECKPOINTS,
1423                         gettext_noop("Sets the minimum concurrent open transactions before performing "
1424                                                  "commit_delay."),
1425                         NULL
1426                 },
1427                 &CommitSiblings,
1428                 5, 1, 1000, NULL, NULL
1429         },
1430
1431         {
1432                 {"extra_float_digits", PGC_USERSET, CLIENT_CONN_LOCALE,
1433                         gettext_noop("Sets the number of digits displayed for floating-point values."),
1434                         gettext_noop("This affects real, double precision, and geometric data types. "
1435                          "The parameter value is added to the standard number of digits "
1436                                                  "(FLT_DIG or DBL_DIG as appropriate).")
1437                 },
1438                 &extra_float_digits,
1439                 0, -15, 2, NULL, NULL
1440         },
1441
1442         {
1443                 {"log_min_duration_statement", PGC_SUSET, LOGGING_WHEN,
1444                         gettext_noop("Sets the minimum execution time in milliseconds above which statements will "
1445                                                  "be logged."),
1446                         gettext_noop("Zero prints all queries. The default is -1 (turning this feature off)."),
1447                         GUC_UNIT_MS
1448                 },
1449                 &log_min_duration_statement,
1450                 -1, -1, INT_MAX / 1000, NULL, NULL
1451         },
1452
1453         {
1454                 {"bgwriter_delay", PGC_SIGHUP, RESOURCES,
1455                         gettext_noop("Background writer sleep time between rounds in milliseconds"),
1456                         NULL,
1457                         GUC_UNIT_MS
1458                 },
1459                 &BgWriterDelay,
1460                 200, 10, 10000, NULL, NULL
1461         },
1462
1463         {
1464                 {"bgwriter_lru_maxpages", PGC_SIGHUP, RESOURCES,
1465                         gettext_noop("Background writer maximum number of LRU pages to flush per round"),
1466                         NULL
1467                 },
1468                 &bgwriter_lru_maxpages,
1469                 5, 0, 1000, NULL, NULL
1470         },
1471
1472         {
1473                 {"bgwriter_all_maxpages", PGC_SIGHUP, RESOURCES,
1474                         gettext_noop("Background writer maximum number of all pages to flush per round"),
1475                         NULL
1476                 },
1477                 &bgwriter_all_maxpages,
1478                 5, 0, 1000, NULL, NULL
1479         },
1480
1481         {
1482                 {"log_rotation_age", PGC_SIGHUP, LOGGING_WHERE,
1483                         gettext_noop("Automatic log file rotation will occur after N minutes"),
1484                         NULL,
1485                         GUC_UNIT_MIN
1486                 },
1487                 &Log_RotationAge,
1488                 HOURS_PER_DAY * MINS_PER_HOUR, 0, INT_MAX / MINS_PER_HOUR, NULL, NULL
1489         },
1490
1491         {
1492                 {"log_rotation_size", PGC_SIGHUP, LOGGING_WHERE,
1493                         gettext_noop("Automatic log file rotation will occur after N kilobytes"),
1494                         NULL,
1495                         GUC_UNIT_KB
1496                 },
1497                 &Log_RotationSize,
1498                 10 * 1024, 0, INT_MAX / 1024, NULL, NULL
1499         },
1500
1501         {
1502                 {"max_function_args", PGC_INTERNAL, PRESET_OPTIONS,
1503                         gettext_noop("Shows the maximum number of function arguments."),
1504                         NULL,
1505                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1506                 },
1507                 &max_function_args,
1508                 FUNC_MAX_ARGS, FUNC_MAX_ARGS, FUNC_MAX_ARGS, NULL, NULL
1509         },
1510
1511         {
1512                 {"max_index_keys", PGC_INTERNAL, PRESET_OPTIONS,
1513                         gettext_noop("Shows the maximum number of index keys."),
1514                         NULL,
1515                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1516                 },
1517                 &max_index_keys,
1518                 INDEX_MAX_KEYS, INDEX_MAX_KEYS, INDEX_MAX_KEYS, NULL, NULL
1519         },
1520
1521         {
1522                 {"max_identifier_length", PGC_INTERNAL, PRESET_OPTIONS,
1523                         gettext_noop("Shows the maximum identifier length"),
1524                         NULL,
1525                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1526                 },
1527                 &max_identifier_length,
1528                 NAMEDATALEN - 1, NAMEDATALEN - 1, NAMEDATALEN - 1, NULL, NULL
1529         },
1530
1531         {
1532                 {"block_size", PGC_INTERNAL, PRESET_OPTIONS,
1533                         gettext_noop("Shows size of a disk block"),
1534                         NULL,
1535                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1536                 },
1537                 &block_size,
1538                 BLCKSZ, BLCKSZ, BLCKSZ, NULL, NULL
1539         },
1540
1541         {
1542                 {"autovacuum_naptime", PGC_SIGHUP, AUTOVACUUM,
1543                         gettext_noop("Time to sleep between autovacuum runs, in seconds."),
1544                         NULL,
1545                         GUC_UNIT_S
1546                 },
1547                 &autovacuum_naptime,
1548                 60, 1, INT_MAX, NULL, NULL
1549         },
1550         {
1551                 {"autovacuum_vacuum_threshold", PGC_SIGHUP, AUTOVACUUM,
1552                         gettext_noop("Minimum number of tuple updates or deletes prior to vacuum."),
1553                         NULL
1554                 },
1555                 &autovacuum_vac_thresh,
1556                 1000, 0, INT_MAX, NULL, NULL
1557         },
1558         {
1559                 {"autovacuum_analyze_threshold", PGC_SIGHUP, AUTOVACUUM,
1560                         gettext_noop("Minimum number of tuple inserts, updates or deletes prior to analyze."),
1561                         NULL
1562                 },
1563                 &autovacuum_anl_thresh,
1564                 500, 0, INT_MAX, NULL, NULL
1565         },
1566
1567         {
1568                 {"tcp_keepalives_idle", PGC_USERSET, CLIENT_CONN_OTHER,
1569                         gettext_noop("Seconds between issuing TCP keepalives."),
1570                         gettext_noop("A value of 0 uses the system default."),
1571                         GUC_UNIT_S
1572                 },
1573                 &tcp_keepalives_idle,
1574                 0, 0, INT_MAX, assign_tcp_keepalives_idle, show_tcp_keepalives_idle
1575         },
1576
1577         {
1578                 {"tcp_keepalives_interval", PGC_USERSET, CLIENT_CONN_OTHER,
1579                         gettext_noop("Seconds between TCP keepalive retransmits."),
1580                         gettext_noop("A value of 0 uses the system default."),
1581                         GUC_UNIT_S
1582                 },
1583                 &tcp_keepalives_interval,
1584                 0, 0, INT_MAX, assign_tcp_keepalives_interval, show_tcp_keepalives_interval
1585         },
1586
1587         {
1588                 {"tcp_keepalives_count", PGC_USERSET, CLIENT_CONN_OTHER,
1589                         gettext_noop("Maximum number of TCP keepalive retransmits."),
1590                         gettext_noop("This controls the number of consecutive keepalive retransmits that can be "
1591                                                  "lost before a connection is considered dead. A value of 0 uses the "
1592                                                  "system default."),
1593                 },
1594                 &tcp_keepalives_count,
1595                 0, 0, INT_MAX, assign_tcp_keepalives_count, show_tcp_keepalives_count
1596         },
1597
1598         {
1599                 {"gin_fuzzy_search_limit", PGC_USERSET, UNGROUPED,
1600                         gettext_noop("Sets the maximum allowed result for exact search by gin."),
1601                         NULL,
1602                         0
1603                 },
1604                 &GinFuzzySearchLimit,
1605                 0, 0, INT_MAX, NULL, NULL
1606         },
1607
1608         {
1609                 {"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST,
1610                         gettext_noop("Sets the planner's assumption about size of the disk cache."),
1611                         gettext_noop("That is, the portion of the kernel's disk cache that "
1612                                                  "will be used for PostgreSQL data files. This is measured in disk "
1613                                                  "pages, which are normally 8 kB each."),
1614                         GUC_UNIT_BLOCKS,
1615                 },
1616                 &effective_cache_size,
1617                 DEFAULT_EFFECTIVE_CACHE_SIZE, 1, INT_MAX, NULL, NULL
1618         },
1619
1620         /* End-of-list marker */
1621         {
1622                 {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL
1623         }
1624 };
1625
1626
1627 static struct config_real ConfigureNamesReal[] =
1628 {
1629         {
1630                 {"seq_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1631                         gettext_noop("Sets the planner's estimate of the cost of a "
1632                                                  "sequentially fetched disk page."),
1633                         NULL
1634                 },
1635                 &seq_page_cost,
1636                 DEFAULT_SEQ_PAGE_COST, 0, DBL_MAX, NULL, NULL
1637         },
1638         {
1639                 {"random_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1640                         gettext_noop("Sets the planner's estimate of the cost of a "
1641                                                  "nonsequentially fetched disk page."),
1642                         NULL
1643                 },
1644                 &random_page_cost,
1645                 DEFAULT_RANDOM_PAGE_COST, 0, DBL_MAX, NULL, NULL
1646         },
1647         {
1648                 {"cpu_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
1649                         gettext_noop("Sets the planner's estimate of the cost of "
1650                                                  "processing each tuple (row)."),
1651                         NULL
1652                 },
1653                 &cpu_tuple_cost,
1654                 DEFAULT_CPU_TUPLE_COST, 0, DBL_MAX, NULL, NULL
1655         },
1656         {
1657                 {"cpu_index_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
1658                         gettext_noop("Sets the planner's estimate of the cost of "
1659                                                  "processing each index entry during an index scan."),
1660                         NULL
1661                 },
1662                 &cpu_index_tuple_cost,
1663                 DEFAULT_CPU_INDEX_TUPLE_COST, 0, DBL_MAX, NULL, NULL
1664         },
1665         {
1666                 {"cpu_operator_cost", PGC_USERSET, QUERY_TUNING_COST,
1667                         gettext_noop("Sets the planner's estimate of the cost of "
1668                                                  "processing each operator or function call."),
1669                         NULL
1670                 },
1671                 &cpu_operator_cost,
1672                 DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX, NULL, NULL
1673         },
1674
1675         {
1676                 {"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO,
1677                         gettext_noop("GEQO: selective pressure within the population."),
1678                         NULL
1679                 },
1680                 &Geqo_selection_bias,
1681                 DEFAULT_GEQO_SELECTION_BIAS, MIN_GEQO_SELECTION_BIAS,
1682                 MAX_GEQO_SELECTION_BIAS, NULL, NULL
1683         },
1684
1685         {
1686                 {"bgwriter_lru_percent", PGC_SIGHUP, RESOURCES,
1687                         gettext_noop("Background writer percentage of LRU buffers to flush per round"),
1688                         NULL
1689                 },
1690                 &bgwriter_lru_percent,
1691                 1.0, 0.0, 100.0, NULL, NULL
1692         },
1693
1694         {
1695                 {"bgwriter_all_percent", PGC_SIGHUP, RESOURCES,
1696                         gettext_noop("Background writer percentage of all buffers to flush per round"),
1697                         NULL
1698                 },
1699                 &bgwriter_all_percent,
1700                 0.333, 0.0, 100.0, NULL, NULL
1701         },
1702
1703         {
1704                 {"seed", PGC_USERSET, UNGROUPED,
1705                         gettext_noop("Sets the seed for random-number generation."),
1706                         NULL,
1707                         GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1708                 },
1709                 &phony_random_seed,
1710                 0.5, 0.0, 1.0, assign_random_seed, show_random_seed
1711         },
1712
1713         {
1714                 {"autovacuum_vacuum_scale_factor", PGC_SIGHUP, AUTOVACUUM,
1715                         gettext_noop("Number of tuple updates or deletes prior to vacuum as a fraction of reltuples."),
1716                         NULL
1717                 },
1718                 &autovacuum_vac_scale,
1719                 0.4, 0.0, 100.0, NULL, NULL
1720         },
1721         {
1722                 {"autovacuum_analyze_scale_factor", PGC_SIGHUP, AUTOVACUUM,
1723                         gettext_noop("Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples."),
1724                         NULL
1725                 },
1726                 &autovacuum_anl_scale,
1727                 0.2, 0.0, 100.0, NULL, NULL
1728         },
1729
1730         /* End-of-list marker */
1731         {
1732                 {NULL, 0, 0, NULL, NULL}, NULL, 0.0, 0.0, 0.0, NULL, NULL
1733         }
1734 };
1735
1736
1737 static struct config_string ConfigureNamesString[] =
1738 {
1739         {
1740                 {"archive_command", PGC_SIGHUP, WAL_SETTINGS,
1741                         gettext_noop("WAL archiving command."),
1742                         gettext_noop("The shell command that will be called to archive a WAL file.")
1743                 },
1744                 &XLogArchiveCommand,
1745                 "", NULL, NULL
1746         },
1747
1748         {
1749                 {"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1750                         gettext_noop("Sets whether \"\\'\" is allowed in string literals."),
1751                         gettext_noop("Valid values are ON, OFF, and SAFE_ENCODING.")
1752                 },
1753                 &backslash_quote_string,
1754                 "safe_encoding", assign_backslash_quote, NULL
1755         },
1756
1757         {
1758                 {"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE,
1759                         gettext_noop("Sets the client's character set encoding."),
1760                         NULL,
1761                         GUC_IS_NAME | GUC_REPORT
1762                 },
1763                 &client_encoding_string,
1764                 "SQL_ASCII", assign_client_encoding, NULL
1765         },
1766
1767         {
1768                 {"client_min_messages", PGC_USERSET, LOGGING_WHEN,
1769                         gettext_noop("Sets the message levels that are sent to the client."),
1770                         gettext_noop("Valid values are DEBUG5, DEBUG4, DEBUG3, DEBUG2, "
1771                                                  "DEBUG1, LOG, NOTICE, WARNING, and ERROR. Each level includes all the "
1772                                                  "levels that follow it. The later the level, the fewer messages are "
1773                                                  "sent.")
1774                 },
1775                 &client_min_messages_str,
1776                 "notice", assign_client_min_messages, NULL
1777         },
1778
1779         {
1780                 {"log_min_messages", PGC_SUSET, LOGGING_WHEN,
1781                         gettext_noop("Sets the message levels that are logged."),
1782                         gettext_noop("Valid values are DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1, "
1783                         "INFO, NOTICE, WARNING, ERROR, LOG, FATAL, and PANIC. Each level "
1784                                                  "includes all the levels that follow it.")
1785                 },
1786                 &log_min_messages_str,
1787                 "notice", assign_log_min_messages, NULL
1788         },
1789
1790         {
1791                 {"log_error_verbosity", PGC_SUSET, LOGGING_WHEN,
1792                         gettext_noop("Sets the verbosity of logged messages."),
1793                         gettext_noop("Valid values are \"terse\", \"default\", and \"verbose\".")
1794                 },
1795                 &log_error_verbosity_str,
1796                 "default", assign_log_error_verbosity, NULL
1797         },
1798         {
1799                 {"log_statement", PGC_SUSET, LOGGING_WHAT,
1800                         gettext_noop("Sets the type of statements logged."),
1801                         gettext_noop("Valid values are \"none\", \"ddl\", \"mod\", and \"all\".")
1802                 },
1803                 &log_statement_str,
1804                 "none", assign_log_statement, NULL
1805         },
1806
1807         {
1808                 {"log_min_error_statement", PGC_SUSET, LOGGING_WHEN,
1809                         gettext_noop("Causes all statements generating error at or above this level to be logged."),
1810                         gettext_noop("All SQL statements that cause an error of the "
1811                                                  "specified level or a higher level are logged.")
1812                 },
1813                 &log_min_error_statement_str,
1814                 "panic", assign_min_error_statement, NULL
1815         },
1816
1817         {
1818                 {"log_line_prefix", PGC_SIGHUP, LOGGING_WHAT,
1819                         gettext_noop("Controls information prefixed to each log line"),
1820                         gettext_noop("if blank no prefix is used")
1821                 },
1822                 &Log_line_prefix,
1823                 "", NULL, NULL
1824         },
1825
1826
1827         {
1828                 {"DateStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
1829                         gettext_noop("Sets the display format for date and time values."),
1830                         gettext_noop("Also controls interpretation of ambiguous "
1831                                                  "date inputs."),
1832                         GUC_LIST_INPUT | GUC_REPORT
1833                 },
1834                 &datestyle_string,
1835                 "ISO, MDY", assign_datestyle, NULL
1836         },
1837
1838         {
1839                 {"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
1840                         gettext_noop("Sets the default tablespace to create tables and indexes in."),
1841                         gettext_noop("An empty string selects the database's default tablespace."),
1842                         GUC_IS_NAME
1843                 },
1844                 &default_tablespace,
1845                 "", assign_default_tablespace, NULL
1846         },
1847
1848         {
1849                 {"default_transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
1850                         gettext_noop("Sets the transaction isolation level of each new transaction."),
1851                         gettext_noop("Each SQL transaction has an isolation level, which "
1852                                                  "can be either \"read uncommitted\", \"read committed\", \"repeatable read\", or \"serializable\".")
1853                 },
1854                 &default_iso_level_string,
1855                 "read committed", assign_defaultxactisolevel, NULL
1856         },
1857
1858         {
1859                 {"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
1860                         gettext_noop("Sets the path for dynamically loadable modules."),
1861                         gettext_noop("If a dynamically loadable module needs to be opened and "
1862                                                  "the specified name does not have a directory component (i.e., the "
1863                                                  "name does not contain a slash), the system will search this path for "
1864                                                  "the specified file."),
1865                         GUC_SUPERUSER_ONLY
1866                 },
1867                 &Dynamic_library_path,
1868                 "$libdir", NULL, NULL
1869         },
1870
1871         {
1872                 {"krb_server_keyfile", PGC_POSTMASTER, CONN_AUTH_SECURITY,
1873                         gettext_noop("Sets the location of the Kerberos server key file."),
1874                         NULL,
1875                         GUC_SUPERUSER_ONLY
1876                 },
1877                 &pg_krb_server_keyfile,
1878                 PG_KRB_SRVTAB, NULL, NULL
1879         },
1880
1881         {
1882                 {"krb_srvname", PGC_POSTMASTER, CONN_AUTH_SECURITY,
1883                         gettext_noop("Sets the name of the Kerberos service."),
1884                         NULL
1885                 },
1886                 &pg_krb_srvnam,
1887                 PG_KRB_SRVNAM, NULL, NULL
1888         },
1889
1890         {
1891                 {"krb_server_hostname", PGC_POSTMASTER, CONN_AUTH_SECURITY,
1892                         gettext_noop("Sets the hostname of the Kerberos server."),
1893                         NULL
1894                 },
1895                 &pg_krb_server_hostname,
1896                 NULL, NULL, NULL
1897         },
1898
1899         {
1900                 {"bonjour_name", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1901                         gettext_noop("Sets the Bonjour broadcast service name."),
1902                         NULL
1903                 },
1904                 &bonjour_name,
1905                 "", NULL, NULL
1906         },
1907
1908         /* See main.c about why defaults for LC_foo are not all alike */
1909
1910         {
1911                 {"lc_collate", PGC_INTERNAL, CLIENT_CONN_LOCALE,
1912                         gettext_noop("Shows the collation order locale."),
1913                         NULL,
1914                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1915                 },
1916                 &locale_collate,
1917                 "C", NULL, NULL
1918         },
1919
1920         {
1921                 {"lc_ctype", PGC_INTERNAL, CLIENT_CONN_LOCALE,
1922                         gettext_noop("Shows the character classification and case conversion locale."),
1923                         NULL,
1924                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1925                 },
1926                 &locale_ctype,
1927                 "C", NULL, NULL
1928         },
1929
1930         {
1931                 {"lc_messages", PGC_SUSET, CLIENT_CONN_LOCALE,
1932                         gettext_noop("Sets the language in which messages are displayed."),
1933                         NULL
1934                 },
1935                 &locale_messages,
1936                 "", locale_messages_assign, NULL
1937         },
1938
1939         {
1940                 {"lc_monetary", PGC_USERSET, CLIENT_CONN_LOCALE,
1941                         gettext_noop("Sets the locale for formatting monetary amounts."),
1942                         NULL
1943                 },
1944                 &locale_monetary,
1945                 "C", locale_monetary_assign, NULL
1946         },
1947
1948         {
1949                 {"lc_numeric", PGC_USERSET, CLIENT_CONN_LOCALE,
1950                         gettext_noop("Sets the locale for formatting numbers."),
1951                         NULL
1952                 },
1953                 &locale_numeric,
1954                 "C", locale_numeric_assign, NULL
1955         },
1956
1957         {
1958                 {"lc_time", PGC_USERSET, CLIENT_CONN_LOCALE,
1959                         gettext_noop("Sets the locale for formatting date and time values."),
1960                         NULL
1961                 },
1962                 &locale_time,
1963                 "C", locale_time_assign, NULL
1964         },
1965
1966         {
1967                 {"preload_libraries", PGC_POSTMASTER, RESOURCES_KERNEL,
1968                         gettext_noop("Lists shared libraries to preload into server."),
1969                         NULL,
1970                         GUC_LIST_INPUT | GUC_LIST_QUOTE | GUC_SUPERUSER_ONLY
1971                 },
1972                 &preload_libraries_string,
1973                 "", NULL, NULL
1974         },
1975
1976         {
1977                 {"regex_flavor", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1978                         gettext_noop("Sets the regular expression \"flavor\"."),
1979                         gettext_noop("This can be set to advanced, extended, or basic.")
1980                 },
1981                 &regex_flavor_string,
1982                 "advanced", assign_regex_flavor, NULL
1983         },
1984
1985         {
1986                 {"search_path", PGC_USERSET, CLIENT_CONN_STATEMENT,
1987                         gettext_noop("Sets the schema search order for names that are not schema-qualified."),
1988                         NULL,
1989                         GUC_LIST_INPUT | GUC_LIST_QUOTE
1990                 },
1991                 &namespace_search_path,
1992                 "\"$user\",public", assign_search_path, NULL
1993         },
1994
1995         {
1996                 /* Can't be set in postgresql.conf */
1997                 {"server_encoding", PGC_INTERNAL, CLIENT_CONN_LOCALE,
1998                         gettext_noop("Sets the server (database) character set encoding."),
1999                         NULL,
2000                         GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2001                 },
2002                 &server_encoding_string,
2003                 "SQL_ASCII", NULL, NULL
2004         },
2005
2006         {
2007                 /* Can't be set in postgresql.conf */
2008                 {"server_version", PGC_INTERNAL, PRESET_OPTIONS,
2009                         gettext_noop("Shows the server version."),
2010                         NULL,
2011                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2012                 },
2013                 &server_version_string,
2014                 PG_VERSION, NULL, NULL
2015         },
2016
2017         {
2018                 /* Not for general use --- used by SET ROLE */
2019                 {"role", PGC_USERSET, UNGROUPED,
2020                         gettext_noop("Sets the current role."),
2021                         NULL,
2022                         GUC_IS_NAME | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2023                 },
2024                 &role_string,
2025                 "none", assign_role, show_role
2026         },
2027
2028         {
2029                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
2030                 {"session_authorization", PGC_USERSET, UNGROUPED,
2031                         gettext_noop("Sets the session user name."),
2032                         NULL,
2033                         GUC_IS_NAME | GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2034                 },
2035                 &session_authorization_string,
2036                 NULL, assign_session_authorization, show_session_authorization
2037         },
2038
2039         {
2040                 {"log_destination", PGC_SIGHUP, LOGGING_WHERE,
2041                         gettext_noop("Sets the destination for server log output."),
2042                         gettext_noop("Valid values are combinations of \"stderr\", \"syslog\", "
2043                                                  "and \"eventlog\", depending on the platform."),
2044                         GUC_LIST_INPUT
2045                 },
2046                 &log_destination_string,
2047                 "stderr", assign_log_destination, NULL
2048         },
2049         {
2050                 {"log_directory", PGC_SIGHUP, LOGGING_WHERE,
2051                         gettext_noop("Sets the destination directory for log files."),
2052                         gettext_noop("May be specified as relative to the data directory "
2053                                                  "or as absolute path."),
2054                         GUC_SUPERUSER_ONLY
2055                 },
2056                 &Log_directory,
2057                 "pg_log", assign_canonical_path, NULL
2058         },
2059         {
2060                 {"log_filename", PGC_SIGHUP, LOGGING_WHERE,
2061                         gettext_noop("Sets the file name pattern for log files."),
2062                         NULL,
2063                         GUC_SUPERUSER_ONLY
2064                 },
2065                 &Log_filename,
2066                 "postgresql-%Y-%m-%d_%H%M%S.log", NULL, NULL
2067         },
2068
2069 #ifdef HAVE_SYSLOG
2070         {
2071                 {"syslog_facility", PGC_SIGHUP, LOGGING_WHERE,
2072                         gettext_noop("Sets the syslog \"facility\" to be used when syslog enabled."),
2073                         gettext_noop("Valid values are LOCAL0, LOCAL1, LOCAL2, LOCAL3, "
2074                                                  "LOCAL4, LOCAL5, LOCAL6, LOCAL7.")
2075                 },
2076                 &syslog_facility_str,
2077                 "LOCAL0", assign_syslog_facility, NULL
2078         },
2079         {
2080                 {"syslog_ident", PGC_SIGHUP, LOGGING_WHERE,
2081                         gettext_noop("Sets the program name used to identify PostgreSQL "
2082                                                  "messages in syslog."),
2083                         NULL
2084                 },
2085                 &syslog_ident_str,
2086                 "postgres", assign_syslog_ident, NULL
2087         },
2088 #endif
2089
2090         {
2091                 {"TimeZone", PGC_USERSET, CLIENT_CONN_LOCALE,
2092                         gettext_noop("Sets the time zone for displaying and interpreting time stamps."),
2093                         NULL,
2094                         GUC_REPORT
2095                 },
2096                 &timezone_string,
2097                 "UNKNOWN", assign_timezone, show_timezone
2098         },
2099         {
2100                 {"timezone_abbreviations", PGC_USERSET, CLIENT_CONN_LOCALE,
2101                         gettext_noop("Selects a file of timezone abbreviations"),
2102                         NULL,
2103                 },
2104                 &timezone_abbreviations_string,
2105                 "UNKNOWN", assign_timezone_abbreviations, NULL
2106         },
2107
2108         {
2109                 {"transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2110                         gettext_noop("Sets the current transaction's isolation level."),
2111                         NULL,
2112                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2113                 },
2114                 &XactIsoLevel_string,
2115                 NULL, assign_XactIsoLevel, show_XactIsoLevel
2116         },
2117
2118         {
2119                 {"unix_socket_group", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2120                         gettext_noop("Sets the owning group of the Unix-domain socket."),
2121                         gettext_noop("(The owning user of the socket is always the user "
2122                                                  "that starts the server.)")
2123                 },
2124                 &Unix_socket_group,
2125                 "", NULL, NULL
2126         },
2127
2128         {
2129                 {"unix_socket_directory", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2130                         gettext_noop("Sets the directory where the Unix-domain socket will be created."),
2131                         NULL,
2132                         GUC_SUPERUSER_ONLY
2133                 },
2134                 &UnixSocketDir,
2135                 "", assign_canonical_path, NULL
2136         },
2137
2138         {
2139                 {"listen_addresses", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2140                         gettext_noop("Sets the host name or IP address(es) to listen to."),
2141                         NULL,
2142                         GUC_LIST_INPUT
2143                 },
2144                 &ListenAddresses,
2145                 "localhost", NULL, NULL
2146         },
2147
2148         {
2149                 {"wal_sync_method", PGC_SIGHUP, WAL_SETTINGS,
2150                         gettext_noop("Selects the method used for forcing WAL updates out to disk."),
2151                         NULL
2152                 },
2153                 &XLOG_sync_method,
2154                 XLOG_sync_method_default, assign_xlog_sync_method, NULL
2155         },
2156
2157         {
2158                 {"custom_variable_classes", PGC_SIGHUP, CUSTOM_OPTIONS,
2159                         gettext_noop("Sets the list of known custom variable classes."),
2160                         NULL,
2161                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2162                 },
2163                 &custom_variable_classes,
2164                 NULL, assign_custom_variable_classes, NULL
2165         },
2166
2167         {
2168                 {"data_directory", PGC_POSTMASTER, FILE_LOCATIONS,
2169                         gettext_noop("Sets the server's data directory."),
2170                         NULL,
2171                         GUC_SUPERUSER_ONLY
2172                 },
2173                 &data_directory,
2174                 NULL, NULL, NULL
2175         },
2176
2177         {
2178                 {"config_file", PGC_POSTMASTER, FILE_LOCATIONS,
2179                         gettext_noop("Sets the server's main configuration file."),
2180                         NULL,
2181                         GUC_DISALLOW_IN_FILE | GUC_SUPERUSER_ONLY
2182                 },
2183                 &ConfigFileName,
2184                 NULL, NULL, NULL
2185         },
2186
2187         {
2188                 {"hba_file", PGC_POSTMASTER, FILE_LOCATIONS,
2189                         gettext_noop("Sets the server's \"hba\" configuration file"),
2190                         NULL,
2191                         GUC_SUPERUSER_ONLY
2192                 },
2193                 &HbaFileName,
2194                 NULL, NULL, NULL
2195         },
2196
2197         {
2198                 {"ident_file", PGC_POSTMASTER, FILE_LOCATIONS,
2199                         gettext_noop("Sets the server's \"ident\" configuration file"),
2200                         NULL,
2201                         GUC_SUPERUSER_ONLY
2202                 },
2203                 &IdentFileName,
2204                 NULL, NULL, NULL
2205         },
2206
2207         {
2208                 {"external_pid_file", PGC_POSTMASTER, FILE_LOCATIONS,
2209                         gettext_noop("Writes the postmaster PID to the specified file."),
2210                         NULL,
2211                         GUC_SUPERUSER_ONLY
2212                 },
2213                 &external_pid_file,
2214                 NULL, assign_canonical_path, NULL
2215         },
2216
2217         /* End-of-list marker */
2218         {
2219                 {NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
2220         }
2221 };
2222
2223
2224 /******** end of options list ********/
2225
2226
2227 /*
2228  * To allow continued support of obsolete names for GUC variables, we apply
2229  * the following mappings to any unrecognized name.  Note that an old name
2230  * should be mapped to a new one only if the new variable has very similar
2231  * semantics to the old.
2232  */
2233 static const char *const map_old_guc_names[] = {
2234         "sort_mem", "work_mem",
2235         "vacuum_mem", "maintenance_work_mem",
2236         NULL
2237 };
2238
2239
2240 /*
2241  * Actual lookup of variables is done through this single, sorted array.
2242  */
2243 static struct config_generic **guc_variables;
2244
2245 /* Current number of variables contained in the vector */
2246 static int      num_guc_variables;
2247
2248 /* Vector capacity */
2249 static int      size_guc_variables;
2250
2251
2252 static bool guc_dirty;                  /* TRUE if need to do commit/abort work */
2253
2254 static bool reporting_enabled;  /* TRUE to enable GUC_REPORT */
2255
2256
2257 static int      guc_var_compare(const void *a, const void *b);
2258 static int      guc_name_compare(const char *namea, const char *nameb);
2259 static void push_old_value(struct config_generic * gconf);
2260 static void ReportGUCOption(struct config_generic * record);
2261 static void ShowGUCConfigOption(const char *name, DestReceiver *dest);
2262 static void ShowAllGUCConfig(DestReceiver *dest);
2263 static char *_ShowOption(struct config_generic * record, bool use_units);
2264 static bool is_newvalue_equal(struct config_generic *record, const char *newvalue);
2265
2266
2267 /*
2268  * Some infrastructure for checking malloc/strdup/realloc calls
2269  */
2270 static void *
2271 guc_malloc(int elevel, size_t size)
2272 {
2273         void       *data;
2274
2275         data = malloc(size);
2276         if (data == NULL)
2277                 ereport(elevel,
2278                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2279                                  errmsg("out of memory")));
2280         return data;
2281 }
2282
2283 static void *
2284 guc_realloc(int elevel, void *old, size_t size)
2285 {
2286         void       *data;
2287
2288         data = realloc(old, size);
2289         if (data == NULL)
2290                 ereport(elevel,
2291                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2292                                  errmsg("out of memory")));
2293         return data;
2294 }
2295
2296 static char *
2297 guc_strdup(int elevel, const char *src)
2298 {
2299         char       *data;
2300
2301         data = strdup(src);
2302         if (data == NULL)
2303                 ereport(elevel,
2304                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2305                                  errmsg("out of memory")));
2306         return data;
2307 }
2308
2309
2310 /*
2311  * Support for assigning to a field of a string GUC item.  Free the prior
2312  * value if it's not referenced anywhere else in the item (including stacked
2313  * states).
2314  */
2315 static void
2316 set_string_field(struct config_string * conf, char **field, char *newval)
2317 {
2318         char       *oldval = *field;
2319         GucStack   *stack;
2320
2321         /* Do the assignment */
2322         *field = newval;
2323
2324         /* Exit if any duplicate references, or if old value was NULL anyway */
2325         if (oldval == NULL ||
2326                 oldval == *(conf->variable) ||
2327                 oldval == conf->reset_val ||
2328                 oldval == conf->tentative_val)
2329                 return;
2330         for (stack = conf->gen.stack; stack; stack = stack->prev)
2331         {
2332                 if (oldval == stack->tentative_val.stringval ||
2333                         oldval == stack->value.stringval)
2334                         return;
2335         }
2336
2337         /* Not used anymore, so free it */
2338         free(oldval);
2339 }
2340
2341 /*
2342  * Detect whether strval is referenced anywhere in a GUC string item
2343  */
2344 static bool
2345 string_field_used(struct config_string * conf, char *strval)
2346 {
2347         GucStack   *stack;
2348
2349         if (strval == *(conf->variable) ||
2350                 strval == conf->reset_val ||
2351                 strval == conf->tentative_val)
2352                 return true;
2353         for (stack = conf->gen.stack; stack; stack = stack->prev)
2354         {
2355                 if (strval == stack->tentative_val.stringval ||
2356                         strval == stack->value.stringval)
2357                         return true;
2358         }
2359         return false;
2360 }
2361
2362
2363 struct config_generic **
2364 get_guc_variables(void)
2365 {
2366         return guc_variables;
2367 }
2368
2369
2370 /*
2371  * Build the sorted array.      This is split out so that it could be
2372  * re-executed after startup (eg, we could allow loadable modules to
2373  * add vars, and then we'd need to re-sort).
2374  */
2375 void
2376 build_guc_variables(void)
2377 {
2378         int                     size_vars;
2379         int                     num_vars = 0;
2380         struct config_generic **guc_vars;
2381         int                     i;
2382
2383         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2384         {
2385                 struct config_bool *conf = &ConfigureNamesBool[i];
2386
2387                 /* Rather than requiring vartype to be filled in by hand, do this: */
2388                 conf->gen.vartype = PGC_BOOL;
2389                 num_vars++;
2390         }
2391
2392         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2393         {
2394                 struct config_int *conf = &ConfigureNamesInt[i];
2395
2396                 conf->gen.vartype = PGC_INT;
2397                 num_vars++;
2398         }
2399
2400         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2401         {
2402                 struct config_real *conf = &ConfigureNamesReal[i];
2403
2404                 conf->gen.vartype = PGC_REAL;
2405                 num_vars++;
2406         }
2407
2408         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2409         {
2410                 struct config_string *conf = &ConfigureNamesString[i];
2411
2412                 conf->gen.vartype = PGC_STRING;
2413                 num_vars++;
2414         }
2415
2416         /*
2417          * Create table with 20% slack
2418          */
2419         size_vars = num_vars + num_vars / 4;
2420
2421         guc_vars = (struct config_generic **)
2422                 guc_malloc(FATAL, size_vars * sizeof(struct config_generic *));
2423
2424         num_vars = 0;
2425
2426         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2427                 guc_vars[num_vars++] = &ConfigureNamesBool[i].gen;
2428
2429         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2430                 guc_vars[num_vars++] = &ConfigureNamesInt[i].gen;
2431
2432         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2433                 guc_vars[num_vars++] = &ConfigureNamesReal[i].gen;
2434
2435         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2436                 guc_vars[num_vars++] = &ConfigureNamesString[i].gen;
2437
2438         if (guc_variables)
2439                 free(guc_variables);
2440         guc_variables = guc_vars;
2441         num_guc_variables = num_vars;
2442         size_guc_variables = size_vars;
2443         qsort((void *) guc_variables, num_guc_variables,
2444                   sizeof(struct config_generic *), guc_var_compare);
2445 }
2446
2447 static bool
2448 is_custom_class(const char *name, int dotPos)
2449 {
2450         /*
2451          * assign_custom_variable_classes() has made sure no empty identifiers or
2452          * whitespace exists in the variable
2453          */
2454         bool            result = false;
2455         const char *ccs = GetConfigOption("custom_variable_classes");
2456
2457         if (ccs != NULL)
2458         {
2459                 const char *start = ccs;
2460
2461                 for (;; ++ccs)
2462                 {
2463                         int                     c = *ccs;
2464
2465                         if (c == 0 || c == ',')
2466                         {
2467                                 if (dotPos == ccs - start && strncmp(start, name, dotPos) == 0)
2468                                 {
2469                                         result = true;
2470                                         break;
2471                                 }
2472                                 if (c == 0)
2473                                         break;
2474                                 start = ccs + 1;
2475                         }
2476                 }
2477         }
2478         return result;
2479 }
2480
2481 /*
2482  * Add a new GUC variable to the list of known variables. The
2483  * list is expanded if needed.
2484  */
2485 static bool
2486 add_guc_variable(struct config_generic * var, int elevel)
2487 {
2488         if (num_guc_variables + 1 >= size_guc_variables)
2489         {
2490                 /*
2491                  * Increase the vector by 25%
2492                  */
2493                 int                     size_vars = size_guc_variables + size_guc_variables / 4;
2494                 struct config_generic **guc_vars;
2495
2496                 if (size_vars == 0)
2497                 {
2498                         size_vars = 100;
2499                         guc_vars = (struct config_generic **)
2500                                 guc_malloc(elevel, size_vars * sizeof(struct config_generic *));
2501                 }
2502                 else
2503                 {
2504                         guc_vars = (struct config_generic **)
2505                                 guc_realloc(elevel, guc_variables, size_vars * sizeof(struct config_generic *));
2506                 }
2507
2508                 if (guc_vars == NULL)
2509                         return false;           /* out of memory */
2510
2511                 guc_variables = guc_vars;
2512                 size_guc_variables = size_vars;
2513         }
2514         guc_variables[num_guc_variables++] = var;
2515         qsort((void *) guc_variables, num_guc_variables,
2516                   sizeof(struct config_generic *), guc_var_compare);
2517         return true;
2518 }
2519
2520 /*
2521  * Create and add a placeholder variable. It's presumed to belong
2522  * to a valid custom variable class at this point.
2523  */
2524 static struct config_string *
2525 add_placeholder_variable(const char *name, int elevel)
2526 {
2527         size_t          sz = sizeof(struct config_string) + sizeof(char *);
2528         struct config_string *var;
2529         struct config_generic *gen;
2530
2531         var = (struct config_string *) guc_malloc(elevel, sz);
2532         if (var == NULL)
2533                 return NULL;
2534
2535         gen = &var->gen;
2536         memset(var, 0, sz);
2537
2538         gen->name = guc_strdup(elevel, name);
2539         if (gen->name == NULL)
2540         {
2541                 free(var);
2542                 return NULL;
2543         }
2544
2545         gen->context = PGC_USERSET;
2546         gen->group = CUSTOM_OPTIONS;
2547         gen->short_desc = "GUC placeholder variable";
2548         gen->flags = GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE | GUC_CUSTOM_PLACEHOLDER;
2549         gen->vartype = PGC_STRING;
2550
2551         /*
2552          * The char* is allocated at the end of the struct since we have no
2553          * 'static' place to point to.
2554          */
2555         var->variable = (char **) (var + 1);
2556
2557         if (!add_guc_variable((struct config_generic *) var, elevel))
2558         {
2559                 free((void *) gen->name);
2560                 free(var);
2561                 return NULL;
2562         }
2563
2564         return var;
2565 }
2566
2567 /*
2568  * Look up option NAME. If it exists, return a pointer to its record,
2569  * else return NULL.
2570  */
2571 static struct config_generic *
2572 find_option(const char *name, int elevel)
2573 {
2574         const char *dot;
2575         const char **key = &name;
2576         struct config_generic **res;
2577         int                     i;
2578
2579         Assert(name);
2580
2581         /*
2582          * By equating const char ** with struct config_generic *, we are assuming
2583          * the name field is first in config_generic.
2584          */
2585         res = (struct config_generic **) bsearch((void *) &key,
2586                                                                                          (void *) guc_variables,
2587                                                                                          num_guc_variables,
2588                                                                                          sizeof(struct config_generic *),
2589                                                                                          guc_var_compare);
2590         if (res)
2591                 return *res;
2592
2593         /*
2594          * See if the name is an obsolete name for a variable.  We assume that the
2595          * set of supported old names is short enough that a brute-force search is
2596          * the best way.
2597          */
2598         for (i = 0; map_old_guc_names[i] != NULL; i += 2)
2599         {
2600                 if (guc_name_compare(name, map_old_guc_names[i]) == 0)
2601                         return find_option(map_old_guc_names[i + 1], elevel);
2602         }
2603
2604         /*
2605          * Check if the name is qualified, and if so, check if the qualifier maps
2606          * to a custom variable class.
2607          */
2608         dot = strchr(name, GUC_QUALIFIER_SEPARATOR);
2609         if (dot != NULL && is_custom_class(name, dot - name))
2610                 /* Add a placeholder variable for this name */
2611                 return (struct config_generic *) add_placeholder_variable(name, elevel);
2612
2613         /* Unknown name */
2614         return NULL;
2615 }
2616
2617
2618 /*
2619  * comparator for qsorting and bsearching guc_variables array
2620  */
2621 static int
2622 guc_var_compare(const void *a, const void *b)
2623 {
2624         struct config_generic *confa = *(struct config_generic **) a;
2625         struct config_generic *confb = *(struct config_generic **) b;
2626
2627         return guc_name_compare(confa->name, confb->name);
2628 }
2629
2630
2631 static int
2632 guc_name_compare(const char *namea, const char *nameb)
2633 {
2634         /*
2635          * The temptation to use strcasecmp() here must be resisted, because the
2636          * array ordering has to remain stable across setlocale() calls. So, build
2637          * our own with a simple ASCII-only downcasing.
2638          */
2639         while (*namea && *nameb)
2640         {
2641                 char            cha = *namea++;
2642                 char            chb = *nameb++;
2643
2644                 if (cha >= 'A' && cha <= 'Z')
2645                         cha += 'a' - 'A';
2646                 if (chb >= 'A' && chb <= 'Z')
2647                         chb += 'a' - 'A';
2648                 if (cha != chb)
2649                         return cha - chb;
2650         }
2651         if (*namea)
2652                 return 1;                               /* a is longer */
2653         if (*nameb)
2654                 return -1;                              /* b is longer */
2655         return 0;
2656 }
2657
2658
2659 /*
2660  * Initialize GUC options during program startup.
2661  *
2662  * Note that we cannot read the config file yet, since we have not yet
2663  * processed command-line switches.
2664  */
2665 void
2666 InitializeGUCOptions(void)
2667 {
2668         int                     i;
2669         char       *env;
2670
2671         /*
2672          * Build sorted array of all GUC variables.
2673          */
2674         build_guc_variables();
2675
2676         /*
2677          * Load all variables with their compiled-in defaults, and initialize
2678          * status fields as needed.
2679          */
2680         for (i = 0; i < num_guc_variables; i++)
2681         {
2682                 struct config_generic *gconf = guc_variables[i];
2683
2684                 gconf->status = 0;
2685                 gconf->reset_source = PGC_S_DEFAULT;
2686                 gconf->tentative_source = PGC_S_DEFAULT;
2687                 gconf->source = PGC_S_DEFAULT;
2688                 gconf->stack = NULL;
2689
2690                 switch (gconf->vartype)
2691                 {
2692                         case PGC_BOOL:
2693                                 {
2694                                         struct config_bool *conf = (struct config_bool *) gconf;
2695
2696                                         if (conf->assign_hook)
2697                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
2698                                                                                                    PGC_S_DEFAULT))
2699                                                         elog(FATAL, "failed to initialize %s to %d",
2700                                                                  conf->gen.name, (int) conf->reset_val);
2701                                         *conf->variable = conf->reset_val;
2702                                         break;
2703                                 }
2704                         case PGC_INT:
2705                                 {
2706                                         struct config_int *conf = (struct config_int *) gconf;
2707
2708                                         Assert(conf->reset_val >= conf->min);
2709                                         Assert(conf->reset_val <= conf->max);
2710                                         if (conf->assign_hook)
2711                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
2712                                                                                                    PGC_S_DEFAULT))
2713                                                         elog(FATAL, "failed to initialize %s to %d",
2714                                                                  conf->gen.name, conf->reset_val);
2715                                         *conf->variable = conf->reset_val;
2716                                         break;
2717                                 }
2718                         case PGC_REAL:
2719                                 {
2720                                         struct config_real *conf = (struct config_real *) gconf;
2721
2722                                         Assert(conf->reset_val >= conf->min);
2723                                         Assert(conf->reset_val <= conf->max);
2724                                         if (conf->assign_hook)
2725                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
2726                                                                                                    PGC_S_DEFAULT))
2727                                                         elog(FATAL, "failed to initialize %s to %g",
2728                                                                  conf->gen.name, conf->reset_val);
2729                                         *conf->variable = conf->reset_val;
2730                                         break;
2731                                 }
2732                         case PGC_STRING:
2733                                 {
2734                                         struct config_string *conf = (struct config_string *) gconf;
2735                                         char       *str;
2736
2737                                         *conf->variable = NULL;
2738                                         conf->reset_val = NULL;
2739                                         conf->tentative_val = NULL;
2740
2741                                         if (conf->boot_val == NULL)
2742                                         {
2743                                                 /* Cannot set value yet */
2744                                                 break;
2745                                         }
2746
2747                                         str = guc_strdup(FATAL, conf->boot_val);
2748                                         conf->reset_val = str;
2749
2750                                         if (conf->assign_hook)
2751                                         {
2752                                                 const char *newstr;
2753
2754                                                 newstr = (*conf->assign_hook) (str, true,
2755                                                                                                            PGC_S_DEFAULT);
2756                                                 if (newstr == NULL)
2757                                                 {
2758                                                         elog(FATAL, "failed to initialize %s to \"%s\"",
2759                                                                  conf->gen.name, str);
2760                                                 }
2761                                                 else if (newstr != str)
2762                                                 {
2763                                                         free(str);
2764
2765                                                         /*
2766                                                          * See notes in set_config_option about casting
2767                                                          */
2768                                                         str = (char *) newstr;
2769                                                         conf->reset_val = str;
2770                                                 }
2771                                         }
2772                                         *conf->variable = str;
2773                                         break;
2774                                 }
2775                 }
2776         }
2777
2778         guc_dirty = false;
2779
2780         reporting_enabled = false;
2781
2782         /*
2783          * Prevent any attempt to override the transaction modes from
2784          * non-interactive sources.
2785          */
2786         SetConfigOption("transaction_isolation", "default",
2787                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
2788         SetConfigOption("transaction_read_only", "no",
2789                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
2790
2791         /*
2792          * For historical reasons, some GUC parameters can receive defaults from
2793          * environment variables.  Process those settings.
2794          */
2795
2796         env = getenv("PGPORT");
2797         if (env != NULL)
2798                 SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
2799
2800         env = getenv("PGDATESTYLE");
2801         if (env != NULL)
2802                 SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
2803
2804         env = getenv("PGCLIENTENCODING");
2805         if (env != NULL)
2806                 SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
2807 }
2808
2809
2810 /*
2811  * Select the configuration files and data directory to be used, and
2812  * do the initial read of postgresql.conf.
2813  *
2814  * This is called after processing command-line switches.
2815  *              userDoption is the -D switch value if any (NULL if unspecified).
2816  *              progname is just for use in error messages.
2817  *
2818  * Returns true on success; on failure, prints a suitable error message
2819  * to stderr and returns false.
2820  */
2821 bool
2822 SelectConfigFiles(const char *userDoption, const char *progname)
2823 {
2824         char       *configdir;
2825         char       *fname;
2826         struct stat stat_buf;
2827
2828         /* configdir is -D option, or $PGDATA if no -D */
2829         if (userDoption)
2830                 configdir = make_absolute_path(userDoption);
2831         else
2832                 configdir = make_absolute_path(getenv("PGDATA"));
2833
2834         /*
2835          * Find the configuration file: if config_file was specified on the
2836          * command line, use it, else use configdir/postgresql.conf.  In any case
2837          * ensure the result is an absolute path, so that it will be interpreted
2838          * the same way by future backends.
2839          */
2840         if (ConfigFileName)
2841                 fname = make_absolute_path(ConfigFileName);
2842         else if (configdir)
2843         {
2844                 fname = guc_malloc(FATAL,
2845                                                    strlen(configdir) + strlen(CONFIG_FILENAME) + 2);
2846                 sprintf(fname, "%s/%s", configdir, CONFIG_FILENAME);
2847         }
2848         else
2849         {
2850                 write_stderr("%s does not know where to find the server configuration file.\n"
2851                                          "You must specify the --config-file or -D invocation "
2852                                          "option or set the PGDATA environment variable.\n",
2853                                          progname);
2854                 return false;
2855         }
2856
2857         /*
2858          * Set the ConfigFileName GUC variable to its final value, ensuring that
2859          * it can't be overridden later.
2860          */
2861         SetConfigOption("config_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
2862         free(fname);
2863
2864         /*
2865          * Now read the config file for the first time.
2866          */
2867         if (stat(ConfigFileName, &stat_buf) != 0)
2868         {
2869                 write_stderr("%s cannot access the server configuration file \"%s\": %s\n",
2870                                          progname, ConfigFileName, strerror(errno));
2871                 return false;
2872         }
2873
2874         ProcessConfigFile(PGC_POSTMASTER);
2875
2876         /*
2877          * If the data_directory GUC variable has been set, use that as DataDir;
2878          * otherwise use configdir if set; else punt.
2879          *
2880          * Note: SetDataDir will copy and absolute-ize its argument, so we don't
2881          * have to.
2882          */
2883         if (data_directory)
2884                 SetDataDir(data_directory);
2885         else if (configdir)
2886                 SetDataDir(configdir);
2887         else
2888         {
2889                 write_stderr("%s does not know where to find the database system data.\n"
2890                                          "This can be specified as \"data_directory\" in \"%s\", "
2891                                          "or by the -D invocation option, or by the "
2892                                          "PGDATA environment variable.\n",
2893                                          progname, ConfigFileName);
2894                 return false;
2895         }
2896
2897         /*
2898          * Reflect the final DataDir value back into the data_directory GUC var.
2899          * (If you are wondering why we don't just make them a single variable,
2900          * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
2901          * child backends specially.  XXX is that still true?  Given that we now
2902          * chdir to DataDir, EXEC_BACKEND can read the config file without knowing
2903          * DataDir in advance.)
2904          */
2905         SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
2906
2907         /*
2908          * Figure out where pg_hba.conf is, and make sure the path is absolute.
2909          */
2910         if (HbaFileName)
2911                 fname = make_absolute_path(HbaFileName);
2912         else if (configdir)
2913         {
2914                 fname = guc_malloc(FATAL,
2915                                                    strlen(configdir) + strlen(HBA_FILENAME) + 2);
2916                 sprintf(fname, "%s/%s", configdir, HBA_FILENAME);
2917         }
2918         else
2919         {
2920                 write_stderr("%s does not know where to find the \"hba\" configuration file.\n"
2921                                          "This can be specified as \"hba_file\" in \"%s\", "
2922                                          "or by the -D invocation option, or by the "
2923                                          "PGDATA environment variable.\n",
2924                                          progname, ConfigFileName);
2925                 return false;
2926         }
2927         SetConfigOption("hba_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
2928         free(fname);
2929
2930         /*
2931          * Likewise for pg_ident.conf.
2932          */
2933         if (IdentFileName)
2934                 fname = make_absolute_path(IdentFileName);
2935         else if (configdir)
2936         {
2937                 fname = guc_malloc(FATAL,
2938                                                    strlen(configdir) + strlen(IDENT_FILENAME) + 2);
2939                 sprintf(fname, "%s/%s", configdir, IDENT_FILENAME);
2940         }
2941         else
2942         {
2943                 write_stderr("%s does not know where to find the \"ident\" configuration file.\n"
2944                                          "This can be specified as \"ident_file\" in \"%s\", "
2945                                          "or by the -D invocation option, or by the "
2946                                          "PGDATA environment variable.\n",
2947                                          progname, ConfigFileName);
2948                 return false;
2949         }
2950         SetConfigOption("ident_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
2951         free(fname);
2952
2953         free(configdir);
2954
2955         return true;
2956 }
2957
2958
2959 /*
2960  * Reset all options to their saved default values (implements RESET ALL)
2961  */
2962 void
2963 ResetAllOptions(void)
2964 {
2965         int                     i;
2966
2967         for (i = 0; i < num_guc_variables; i++)
2968         {
2969                 struct config_generic *gconf = guc_variables[i];
2970
2971                 /* Don't reset non-SET-able values */
2972                 if (gconf->context != PGC_SUSET &&
2973                         gconf->context != PGC_USERSET)
2974                         continue;
2975                 /* Don't reset if special exclusion from RESET ALL */
2976                 if (gconf->flags & GUC_NO_RESET_ALL)
2977                         continue;
2978                 /* No need to reset if wasn't SET */
2979                 if (gconf->source <= PGC_S_OVERRIDE)
2980                         continue;
2981
2982                 /* Save old value to support transaction abort */
2983                 push_old_value(gconf);
2984
2985                 switch (gconf->vartype)
2986                 {
2987                         case PGC_BOOL:
2988                                 {
2989                                         struct config_bool *conf = (struct config_bool *) gconf;
2990
2991                                         if (conf->assign_hook)
2992                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
2993                                                                                                    PGC_S_SESSION))
2994                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
2995                                         *conf->variable = conf->reset_val;
2996                                         conf->tentative_val = conf->reset_val;
2997                                         conf->gen.source = conf->gen.reset_source;
2998                                         conf->gen.tentative_source = conf->gen.reset_source;
2999                                         conf->gen.status |= GUC_HAVE_TENTATIVE;
3000                                         guc_dirty = true;
3001                                         break;
3002                                 }
3003                         case PGC_INT:
3004                                 {
3005                                         struct config_int *conf = (struct config_int *) gconf;
3006
3007                                         if (conf->assign_hook)
3008                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3009                                                                                                    PGC_S_SESSION))
3010                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3011                                         *conf->variable = conf->reset_val;
3012                                         conf->tentative_val = conf->reset_val;
3013                                         conf->gen.source = conf->gen.reset_source;
3014                                         conf->gen.tentative_source = conf->gen.reset_source;
3015                                         conf->gen.status |= GUC_HAVE_TENTATIVE;
3016                                         guc_dirty = true;
3017                                         break;
3018                                 }
3019                         case PGC_REAL:
3020                                 {
3021                                         struct config_real *conf = (struct config_real *) gconf;
3022
3023                                         if (conf->assign_hook)
3024                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3025                                                                                                    PGC_S_SESSION))
3026                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3027                                         *conf->variable = conf->reset_val;
3028                                         conf->tentative_val = conf->reset_val;
3029                                         conf->gen.source = conf->gen.reset_source;
3030                                         conf->gen.tentative_source = conf->gen.reset_source;
3031                                         conf->gen.status |= GUC_HAVE_TENTATIVE;
3032                                         guc_dirty = true;
3033                                         break;
3034                                 }
3035                         case PGC_STRING:
3036                                 {
3037                                         struct config_string *conf = (struct config_string *) gconf;
3038                                         char       *str;
3039
3040                                         if (conf->reset_val == NULL)
3041                                         {
3042                                                 /* Nothing to reset to, as yet; so do nothing */
3043                                                 break;
3044                                         }
3045
3046                                         /* We need not strdup here */
3047                                         str = conf->reset_val;
3048
3049                                         if (conf->assign_hook)
3050                                         {
3051                                                 const char *newstr;
3052
3053                                                 newstr = (*conf->assign_hook) (str, true,
3054                                                                                                            PGC_S_SESSION);
3055                                                 if (newstr == NULL)
3056                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3057                                                 else if (newstr != str)
3058                                                 {
3059                                                         /*
3060                                                          * See notes in set_config_option about casting
3061                                                          */
3062                                                         str = (char *) newstr;
3063                                                 }
3064                                         }
3065
3066                                         set_string_field(conf, conf->variable, str);
3067                                         set_string_field(conf, &conf->tentative_val, str);
3068                                         conf->gen.source = conf->gen.reset_source;
3069                                         conf->gen.tentative_source = conf->gen.reset_source;
3070                                         conf->gen.status |= GUC_HAVE_TENTATIVE;
3071                                         guc_dirty = true;
3072                                         break;
3073                                 }
3074                 }
3075
3076                 if (gconf->flags & GUC_REPORT)
3077                         ReportGUCOption(gconf);
3078         }
3079 }
3080
3081
3082 /*
3083  * push_old_value
3084  *              Push previous state during first assignment to a GUC variable
3085  *              within a particular transaction.
3086  *
3087  * We have to be willing to "back-fill" the state stack if the first
3088  * assignment occurs within a subtransaction nested several levels deep.
3089  * This ensures that if an intermediate transaction aborts, it will have
3090  * the proper value available to restore the setting to.
3091  */
3092 static void
3093 push_old_value(struct config_generic * gconf)
3094 {
3095         int                     my_level = GetCurrentTransactionNestLevel();
3096         GucStack   *stack;
3097
3098         /* If we're not inside a transaction, do nothing */
3099         if (my_level == 0)
3100                 return;
3101
3102         for (;;)
3103         {
3104                 /* Done if we already pushed it at this nesting depth */
3105                 if (gconf->stack && gconf->stack->nest_level >= my_level)
3106                         return;
3107
3108                 /*
3109                  * We keep all the stack entries in TopTransactionContext so as to
3110                  * avoid allocation problems when a subtransaction back-fills stack
3111                  * entries for upper transaction levels.
3112                  */
3113                 stack = (GucStack *) MemoryContextAlloc(TopTransactionContext,
3114                                                                                                 sizeof(GucStack));
3115
3116                 stack->prev = gconf->stack;
3117                 stack->nest_level = stack->prev ? stack->prev->nest_level + 1 : 1;
3118                 stack->status = gconf->status;
3119                 stack->tentative_source = gconf->tentative_source;
3120                 stack->source = gconf->source;
3121
3122                 switch (gconf->vartype)
3123                 {
3124                         case PGC_BOOL:
3125                                 stack->tentative_val.boolval =
3126                                         ((struct config_bool *) gconf)->tentative_val;
3127                                 stack->value.boolval =
3128                                         *((struct config_bool *) gconf)->variable;
3129                                 break;
3130
3131                         case PGC_INT:
3132                                 stack->tentative_val.intval =
3133                                         ((struct config_int *) gconf)->tentative_val;
3134                                 stack->value.intval =
3135                                         *((struct config_int *) gconf)->variable;
3136                                 break;
3137
3138                         case PGC_REAL:
3139                                 stack->tentative_val.realval =
3140                                         ((struct config_real *) gconf)->tentative_val;
3141                                 stack->value.realval =
3142                                         *((struct config_real *) gconf)->variable;
3143                                 break;
3144
3145                         case PGC_STRING:
3146                                 stack->tentative_val.stringval =
3147                                         ((struct config_string *) gconf)->tentative_val;
3148                                 stack->value.stringval =
3149                                         *((struct config_string *) gconf)->variable;
3150                                 break;
3151                 }
3152
3153                 gconf->stack = stack;
3154
3155                 /* Set state to indicate nothing happened yet within this level */
3156                 gconf->status = GUC_HAVE_STACK;
3157
3158                 /* Ensure we remember to pop at end of xact */
3159                 guc_dirty = true;
3160         }
3161 }
3162
3163 /*
3164  * Do GUC processing at transaction or subtransaction commit or abort.
3165  */
3166 void
3167 AtEOXact_GUC(bool isCommit, bool isSubXact)
3168 {
3169         int                     my_level;
3170         int                     i;
3171
3172         /* Quick exit if nothing's changed in this transaction */
3173         if (!guc_dirty)
3174                 return;
3175
3176         my_level = GetCurrentTransactionNestLevel();
3177         Assert(isSubXact ? (my_level > 1) : (my_level == 1));
3178
3179         for (i = 0; i < num_guc_variables; i++)
3180         {
3181                 struct config_generic *gconf = guc_variables[i];
3182                 int                     my_status = gconf->status;
3183                 GucStack   *stack = gconf->stack;
3184                 bool            useTentative;
3185                 bool            changed;
3186
3187                 /*
3188                  * Skip if nothing's happened to this var in this transaction
3189                  */
3190                 if (my_status == 0)
3191                 {
3192                         Assert(stack == NULL);
3193                         continue;
3194                 }
3195                 /* Assert that we stacked old value before changing it */
3196                 Assert(stack != NULL && (my_status & GUC_HAVE_STACK));
3197                 /* However, the last change may have been at an outer xact level */
3198                 if (stack->nest_level < my_level)
3199                         continue;
3200                 Assert(stack->nest_level == my_level);
3201
3202                 /*
3203                  * We will pop the stack entry.  Start by restoring outer xact status
3204                  * (since we may want to modify it below).      Be careful to use
3205                  * my_status to reference the inner xact status below this point...
3206                  */
3207                 gconf->status = stack->status;
3208
3209                 /*
3210                  * We have two cases:
3211                  *
3212                  * If commit and HAVE_TENTATIVE, set actual value to tentative (this
3213                  * is to override a SET LOCAL if one occurred later than SET). We keep
3214                  * the tentative value and propagate HAVE_TENTATIVE to the parent
3215                  * status, allowing the SET's effect to percolate up. (But if we're
3216                  * exiting the outermost transaction, we'll drop the HAVE_TENTATIVE
3217                  * bit below.)
3218                  *
3219                  * Otherwise, we have a transaction that aborted or executed only SET
3220                  * LOCAL (or no SET at all).  In either case it should have no further
3221                  * effect, so restore both tentative and actual values from the stack
3222                  * entry.
3223                  */
3224
3225                 useTentative = isCommit && (my_status & GUC_HAVE_TENTATIVE) != 0;
3226                 changed = false;
3227
3228                 switch (gconf->vartype)
3229                 {
3230                         case PGC_BOOL:
3231                                 {
3232                                         struct config_bool *conf = (struct config_bool *) gconf;
3233                                         bool            newval;
3234                                         GucSource       newsource;
3235
3236                                         if (useTentative)
3237                                         {
3238                                                 newval = conf->tentative_val;
3239                                                 newsource = conf->gen.tentative_source;
3240                                                 conf->gen.status |= GUC_HAVE_TENTATIVE;
3241                                         }
3242                                         else
3243                                         {
3244                                                 newval = stack->value.boolval;
3245                                                 newsource = stack->source;
3246                                                 conf->tentative_val = stack->tentative_val.boolval;
3247                                                 conf->gen.tentative_source = stack->tentative_source;
3248                                         }
3249
3250                                         if (*conf->variable != newval)
3251                                         {
3252                                                 if (conf->assign_hook)
3253                                                         if (!(*conf->assign_hook) (newval,
3254                                                                                                            true, PGC_S_OVERRIDE))
3255                                                                 elog(LOG, "failed to commit %s",
3256                                                                          conf->gen.name);
3257                                                 *conf->variable = newval;
3258                                                 changed = true;
3259                                         }
3260                                         conf->gen.source = newsource;
3261                                         break;
3262                                 }
3263                         case PGC_INT:
3264                                 {
3265                                         struct config_int *conf = (struct config_int *) gconf;
3266                                         int                     newval;
3267                                         GucSource       newsource;
3268
3269                                         if (useTentative)
3270                                         {
3271                                                 newval = conf->tentative_val;
3272                                                 newsource = conf->gen.tentative_source;
3273                                                 conf->gen.status |= GUC_HAVE_TENTATIVE;
3274                                         }
3275                                         else
3276                                         {
3277                                                 newval = stack->value.intval;
3278                                                 newsource = stack->source;
3279                                                 conf->tentative_val = stack->tentative_val.intval;
3280                                                 conf->gen.tentative_source = stack->tentative_source;
3281                                         }
3282
3283                                         if (*conf->variable != newval)
3284                                         {
3285                                                 if (conf->assign_hook)
3286                                                         if (!(*conf->assign_hook) (newval,
3287                                                                                                            true, PGC_S_OVERRIDE))
3288                                                                 elog(LOG, "failed to commit %s",
3289                                                                          conf->gen.name);
3290                                                 *conf->variable = newval;
3291                                                 changed = true;
3292                                         }
3293                                         conf->gen.source = newsource;
3294                                         break;
3295                                 }
3296                         case PGC_REAL:
3297                                 {
3298                                         struct config_real *conf = (struct config_real *) gconf;
3299                                         double          newval;
3300                                         GucSource       newsource;
3301
3302                                         if (useTentative)
3303                                         {
3304                                                 newval = conf->tentative_val;
3305                                                 newsource = conf->gen.tentative_source;
3306                                                 conf->gen.status |= GUC_HAVE_TENTATIVE;
3307                                         }
3308                                         else
3309                                         {
3310                                                 newval = stack->value.realval;
3311                                                 newsource = stack->source;
3312                                                 conf->tentative_val = stack->tentative_val.realval;
3313                                                 conf->gen.tentative_source = stack->tentative_source;
3314                                         }
3315
3316                                         if (*conf->variable != newval)
3317                                         {
3318                                                 if (conf->assign_hook)
3319                                                         if (!(*conf->assign_hook) (newval,
3320                                                                                                            true, PGC_S_OVERRIDE))
3321                                                                 elog(LOG, "failed to commit %s",
3322                                                                          conf->gen.name);
3323                                                 *conf->variable = newval;
3324                                                 changed = true;
3325                                         }
3326                                         conf->gen.source = newsource;
3327                                         break;
3328                                 }
3329                         case PGC_STRING:
3330                                 {
3331                                         struct config_string *conf = (struct config_string *) gconf;
3332                                         char       *newval;
3333                                         GucSource       newsource;
3334
3335                                         if (useTentative)
3336                                         {
3337                                                 newval = conf->tentative_val;
3338                                                 newsource = conf->gen.tentative_source;
3339                                                 conf->gen.status |= GUC_HAVE_TENTATIVE;
3340                                         }
3341                                         else
3342                                         {
3343                                                 newval = stack->value.stringval;
3344                                                 newsource = stack->source;
3345                                                 set_string_field(conf, &conf->tentative_val,
3346                                                                                  stack->tentative_val.stringval);
3347                                                 conf->gen.tentative_source = stack->tentative_source;
3348                                         }
3349
3350                                         if (*conf->variable != newval)
3351                                         {
3352                                                 if (conf->assign_hook)
3353                                                 {
3354                                                         const char *newstr;
3355
3356                                                         newstr = (*conf->assign_hook) (newval, true,
3357                                                                                                                    PGC_S_OVERRIDE);
3358                                                         if (newstr == NULL)
3359                                                                 elog(LOG, "failed to commit %s",
3360                                                                          conf->gen.name);
3361                                                         else if (newstr != newval)
3362                                                         {
3363                                                                 /*
3364                                                                  * If newval should now be freed, it'll be
3365                                                                  * taken care of below.
3366                                                                  *
3367                                                                  * See notes in set_config_option about
3368                                                                  * casting
3369                                                                  */
3370                                                                 newval = (char *) newstr;
3371                                                         }
3372                                                 }
3373
3374                                                 set_string_field(conf, conf->variable, newval);
3375                                                 changed = true;
3376                                         }
3377                                         conf->gen.source = newsource;
3378                                         /* Release stacked values if not used anymore */
3379                                         set_string_field(conf, &stack->value.stringval,
3380                                                                          NULL);
3381                                         set_string_field(conf, &stack->tentative_val.stringval,
3382                                                                          NULL);
3383                                         /* Don't store tentative value separately after commit */
3384                                         if (!isSubXact)
3385                                                 set_string_field(conf, &conf->tentative_val, NULL);
3386                                         break;
3387                                 }
3388                 }
3389
3390                 /* Finish popping the state stack */
3391                 gconf->stack = stack->prev;
3392                 pfree(stack);
3393
3394                 /*
3395                  * If we're now out of all xact levels, forget TENTATIVE status bit;
3396                  * there's nothing tentative about the value anymore.
3397                  */
3398                 if (!isSubXact)
3399                 {
3400                         Assert(gconf->stack == NULL);
3401                         gconf->status = 0;
3402                 }
3403
3404                 /* Report new value if we changed it */
3405                 if (changed && (gconf->flags & GUC_REPORT))
3406                         ReportGUCOption(gconf);
3407         }
3408
3409         /*
3410          * If we're now out of all xact levels, we can clear guc_dirty. (Note: we
3411          * cannot reset guc_dirty when exiting a subtransaction, because we know
3412          * that all outer transaction levels will have stacked values to deal
3413          * with.)
3414          */
3415         if (!isSubXact)
3416                 guc_dirty = false;
3417 }
3418
3419
3420 /*
3421  * Start up automatic reporting of changes to variables marked GUC_REPORT.
3422  * This is executed at completion of backend startup.
3423  */
3424 void
3425 BeginReportingGUCOptions(void)
3426 {
3427         int                     i;
3428
3429         /*
3430          * Don't do anything unless talking to an interactive frontend of protocol
3431          * 3.0 or later.
3432          */
3433         if (whereToSendOutput != DestRemote ||
3434                 PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
3435                 return;
3436
3437         reporting_enabled = true;
3438
3439         /* Transmit initial values of interesting variables */
3440         for (i = 0; i < num_guc_variables; i++)
3441         {
3442                 struct config_generic *conf = guc_variables[i];
3443
3444                 if (conf->flags & GUC_REPORT)
3445                         ReportGUCOption(conf);
3446         }
3447 }
3448
3449 /*
3450  * ReportGUCOption: if appropriate, transmit option value to frontend
3451  */
3452 static void
3453 ReportGUCOption(struct config_generic * record)
3454 {
3455         if (reporting_enabled && (record->flags & GUC_REPORT))
3456         {
3457                 char       *val = _ShowOption(record, false);
3458                 StringInfoData msgbuf;
3459
3460                 pq_beginmessage(&msgbuf, 'S');
3461                 pq_sendstring(&msgbuf, record->name);
3462                 pq_sendstring(&msgbuf, val);
3463                 pq_endmessage(&msgbuf);
3464
3465                 pfree(val);
3466         }
3467 }
3468
3469
3470 /*
3471  * Try to interpret value as boolean value.  Valid values are: true,
3472  * false, yes, no, on, off, 1, 0.  If the string parses okay, return
3473  * true, else false.  If result is not NULL, return the parsing result
3474  * there.
3475  */
3476 static bool
3477 parse_bool(const char *value, bool *result)
3478 {
3479         size_t          len = strlen(value);
3480
3481         if (pg_strncasecmp(value, "true", len) == 0)
3482         {
3483                 if (result)
3484                         *result = true;
3485         }
3486         else if (pg_strncasecmp(value, "false", len) == 0)
3487         {
3488                 if (result)
3489                         *result = false;
3490         }
3491
3492         else if (pg_strncasecmp(value, "yes", len) == 0)
3493         {
3494                 if (result)
3495                         *result = true;
3496         }
3497         else if (pg_strncasecmp(value, "no", len) == 0)
3498         {
3499                 if (result)
3500                         *result = false;
3501         }
3502
3503         else if (pg_strcasecmp(value, "on") == 0)
3504         {
3505                 if (result)
3506                         *result = true;
3507         }
3508         else if (pg_strcasecmp(value, "off") == 0)
3509         {
3510                 if (result)
3511                         *result = false;
3512         }
3513
3514         else if (pg_strcasecmp(value, "1") == 0)
3515         {
3516                 if (result)
3517                         *result = true;
3518         }
3519         else if (pg_strcasecmp(value, "0") == 0)
3520         {
3521                 if (result)
3522                         *result = false;
3523         }
3524
3525         else
3526         {
3527                 if (result)
3528                         *result = false;        /* suppress compiler warning */
3529                 return false;
3530         }
3531         return true;
3532 }
3533
3534
3535
3536 /*
3537  * Try to parse value as an integer.  The accepted formats are the
3538  * usual decimal, octal, or hexadecimal formats.  If the string parses
3539  * okay, return true, else false.  If result is not NULL, return the
3540  * value there.
3541  */
3542 static bool
3543 parse_int(const char *value, int *result, int flags)
3544 {
3545         long            val;
3546         char       *endptr;
3547
3548         errno = 0;
3549         val = strtol(value, &endptr, 0);
3550
3551         if ((flags & GUC_UNIT_MEMORY) && endptr != value)
3552         {
3553                 bool used = false;
3554
3555                 while (*endptr == ' ')
3556                         endptr++;
3557
3558                 if (strcmp(endptr, "kB") == 0)
3559                 {
3560                         used = true;
3561                         endptr += 2;
3562                 }
3563                 else if (strcmp(endptr, "MB") == 0)
3564                 {
3565                         val *= KB_PER_MB;
3566                         used = true;
3567                         endptr += 2;
3568                 }
3569                 else if (strcmp(endptr, "GB") == 0)
3570                 {
3571                         val *= KB_PER_MB;
3572                         used = true;
3573                         endptr += 2;
3574                 }
3575
3576                 if (used && (flags & GUC_UNIT_BLOCKS))
3577                         val /= (BLCKSZ/1024);
3578         }
3579
3580         if ((flags & GUC_UNIT_TIME) && endptr != value)
3581         {
3582                 bool used = false;
3583
3584                 while (*endptr == ' ')
3585                         endptr++;
3586
3587                 if (strcmp(endptr, "ms") == 0)
3588                 {
3589                         used = true;
3590                         endptr += 2;
3591                 }
3592                 else if (strcmp(endptr, "s") == 0)
3593                 {
3594                         val *= MS_PER_S;
3595                         used = true;
3596                         endptr += 1;
3597                 }
3598                 else if (strcmp(endptr, "min") == 0)
3599                 {
3600                         val *= MS_PER_MIN;
3601                         used = true;
3602                         endptr += 3;
3603                 }
3604                 else if (strcmp(endptr, "h") == 0)
3605                 {
3606                         val *= MS_PER_H;
3607                         used = true;
3608                         endptr += 1;
3609                 }
3610                 else if (strcmp(endptr, "d") == 0)
3611                 {
3612                         val *= MS_PER_D;
3613                         used = true;
3614                         endptr += 1;
3615                 }
3616
3617                 if (used && (flags & GUC_UNIT_S))
3618                         val /= MS_PER_S;
3619                 else if (used && (flags & GUC_UNIT_MIN))
3620                         val /= MS_PER_MIN;
3621         }
3622
3623         if (endptr == value || *endptr != '\0' || errno == ERANGE
3624 #ifdef HAVE_LONG_INT_64
3625         /* if long > 32 bits, check for overflow of int4 */
3626                 || val != (long) ((int32) val)
3627 #endif
3628                 )
3629         {
3630                 if (result)
3631                         *result = 0;            /* suppress compiler warning */
3632                 return false;
3633         }
3634         if (result)
3635                 *result = (int) val;
3636         return true;
3637 }
3638
3639
3640
3641 /*
3642  * Try to parse value as a floating point constant in the usual
3643  * format.      If the value parsed okay return true, else false.  If
3644  * result is not NULL, return the semantic value there.
3645  */
3646 static bool
3647 parse_real(const char *value, double *result)
3648 {
3649         double          val;
3650         char       *endptr;
3651
3652         errno = 0;
3653         val = strtod(value, &endptr);
3654         if (endptr == value || *endptr != '\0' || errno == ERANGE)
3655         {
3656                 if (result)
3657                         *result = 0;            /* suppress compiler warning */
3658                 return false;
3659         }
3660         if (result)
3661                 *result = val;
3662         return true;
3663 }
3664
3665
3666 /*
3667  * Call a GucStringAssignHook function, being careful to free the
3668  * "newval" string if the hook ereports.
3669  *
3670  * This is split out of set_config_option just to avoid the "volatile"
3671  * qualifiers that would otherwise have to be plastered all over.
3672  */
3673 static const char *
3674 call_string_assign_hook(GucStringAssignHook assign_hook,
3675                                                 char *newval, bool doit, GucSource source)
3676 {
3677         const char *result;
3678
3679         PG_TRY();
3680         {
3681                 result = (*assign_hook) (newval, doit, source);
3682         }
3683         PG_CATCH();
3684         {
3685                 free(newval);
3686                 PG_RE_THROW();
3687         }
3688         PG_END_TRY();
3689
3690         return result;
3691 }
3692
3693
3694 /*
3695  * Sets option `name' to given value. The value should be a string
3696  * which is going to be parsed and converted to the appropriate data
3697  * type.  The context and source parameters indicate in which context this
3698  * function is being called so it can apply the access restrictions
3699  * properly.
3700  *
3701  * If value is NULL, set the option to its default value. If the
3702  * parameter changeVal is false then don't really set the option but do all
3703  * the checks to see if it would work.
3704  *
3705  * If there is an error (non-existing option, invalid value) then an
3706  * ereport(ERROR) is thrown *unless* this is called in a context where we
3707  * don't want to ereport (currently, startup or SIGHUP config file reread).
3708  * In that case we write a suitable error message via ereport(DEBUG) and
3709  * return false. This is working around the deficiencies in the ereport
3710  * mechanism, so don't blame me.  In all other cases, the function
3711  * returns true, including cases where the input is valid but we chose
3712  * not to apply it because of context or source-priority considerations.
3713  *
3714  * See also SetConfigOption for an external interface.
3715  */
3716 bool
3717 set_config_option(const char *name, const char *value,
3718                                   GucContext context, GucSource source,
3719                                   bool isLocal, bool changeVal)
3720 {
3721         struct config_generic *record;
3722         int                     elevel;
3723         bool            makeDefault;
3724
3725         if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
3726         {
3727                 /*
3728                  * To avoid cluttering the log, only the postmaster bleats loudly
3729                  * about problems with the config file.
3730                  */
3731                 elevel = IsUnderPostmaster ? DEBUG2 : LOG;
3732         }
3733         else if (source == PGC_S_DATABASE || source == PGC_S_USER)
3734                 elevel = INFO;
3735         else
3736                 elevel = ERROR;
3737
3738         record = find_option(name, elevel);
3739         if (record == NULL)
3740         {
3741                 ereport(elevel,
3742                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
3743                            errmsg("unrecognized configuration parameter \"%s\"", name)));
3744                 return false;
3745         }
3746
3747         /*
3748          * Check if the option can be set at this time. See guc.h for the precise
3749          * rules. Note that we don't want to throw errors if we're in the SIGHUP
3750          * context. In that case we just ignore the attempt and return true.
3751          */
3752         switch (record->context)
3753         {
3754                 case PGC_INTERNAL:
3755                         if (context == PGC_SIGHUP)
3756                                 return true;
3757                         if (context != PGC_INTERNAL)
3758                         {
3759                                 ereport(elevel,
3760                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
3761                                                  errmsg("parameter \"%s\" cannot be changed",
3762                                                                 name)));
3763                                 return false;
3764                         }
3765                         break;
3766                 case PGC_POSTMASTER:
3767                         if (context == PGC_SIGHUP)
3768                         {
3769                                 if (changeVal && !is_newvalue_equal(record, value))
3770                                         ereport(elevel,
3771                                                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
3772                                                          errmsg("parameter \"%s\" cannot be changed after server start; configuration file change ignored",
3773                                                                         name)));
3774
3775                                 return true;
3776                         }
3777                         if (context != PGC_POSTMASTER)
3778                         {
3779                                 ereport(elevel,
3780                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
3781                                                  errmsg("parameter \"%s\" cannot be changed after server start",
3782                                                                 name)));
3783                                 return false;
3784                         }
3785                         break;
3786                 case PGC_SIGHUP:
3787                         if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
3788                         {
3789                                 ereport(elevel,
3790                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
3791                                                  errmsg("parameter \"%s\" cannot be changed now",
3792                                                                 name)));
3793                                 return false;
3794                         }
3795
3796                         /*
3797                          * Hmm, the idea of the SIGHUP context is "ought to be global, but
3798                          * can be changed after postmaster start". But there's nothing
3799                          * that prevents a crafty administrator from sending SIGHUP
3800                          * signals to individual backends only.
3801                          */
3802                         break;
3803                 case PGC_BACKEND:
3804                         if (context == PGC_SIGHUP)
3805                         {
3806                                 /*
3807                                  * If a PGC_BACKEND parameter is changed in the config file,
3808                                  * we want to accept the new value in the postmaster (whence
3809                                  * it will propagate to subsequently-started backends), but
3810                                  * ignore it in existing backends.      This is a tad klugy, but
3811                                  * necessary because we don't re-read the config file during
3812                                  * backend start.
3813                                  */
3814                                 if (IsUnderPostmaster)
3815                                         return true;
3816                         }
3817                         else if (context != PGC_BACKEND && context != PGC_POSTMASTER)
3818                         {
3819                                 ereport(elevel,
3820                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
3821                                                  errmsg("parameter \"%s\" cannot be set after connection start",
3822                                                                 name)));
3823                                 return false;
3824                         }
3825                         break;
3826                 case PGC_SUSET:
3827                         if (context == PGC_USERSET || context == PGC_BACKEND)
3828                         {
3829                                 ereport(elevel,
3830                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
3831                                                  errmsg("permission denied to set parameter \"%s\"",
3832                                                                 name)));
3833                                 return false;
3834                         }
3835                         break;
3836                 case PGC_USERSET:
3837                         /* always okay */
3838                         break;
3839         }
3840
3841         /*
3842          * Should we set reset/stacked values?  (If so, the behavior is not
3843          * transactional.)
3844          */
3845         makeDefault = changeVal && (source <= PGC_S_OVERRIDE) && (value != NULL);
3846
3847         /*
3848          * Ignore attempted set if overridden by previously processed setting.
3849          * However, if changeVal is false then plow ahead anyway since we are
3850          * trying to find out if the value is potentially good, not actually use
3851          * it. Also keep going if makeDefault is true, since we may want to set
3852          * the reset/stacked values even if we can't set the variable itself.
3853          */
3854         if (record->source > source)
3855         {
3856                 if (changeVal && !makeDefault)
3857                 {
3858                         elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
3859                                  name);
3860                         return true;
3861                 }
3862                 changeVal = false;
3863         }
3864
3865         /*
3866          * Evaluate value and set variable.
3867          */
3868         switch (record->vartype)
3869         {
3870                 case PGC_BOOL:
3871                         {
3872                                 struct config_bool *conf = (struct config_bool *) record;
3873                                 bool            newval;
3874
3875                                 if (value)
3876                                 {
3877                                         if (!parse_bool(value, &newval))
3878                                         {
3879                                                 ereport(elevel,
3880                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
3881                                                   errmsg("parameter \"%s\" requires a Boolean value",
3882                                                                  name)));
3883                                                 return false;
3884                                         }
3885                                 }
3886                                 else
3887                                 {
3888                                         newval = conf->reset_val;
3889                                         source = conf->gen.reset_source;
3890                                 }
3891
3892                                 if (conf->assign_hook)
3893                                         if (!(*conf->assign_hook) (newval, changeVal, source))
3894                                         {
3895                                                 ereport(elevel,
3896                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
3897                                                          errmsg("invalid value for parameter \"%s\": %d",
3898                                                                         name, (int) newval)));
3899                                                 return false;
3900                                         }
3901
3902                                 if (changeVal || makeDefault)
3903                                 {
3904                                         /* Save old value to support transaction abort */
3905                                         if (!makeDefault)
3906                                                 push_old_value(&conf->gen);
3907                                         if (changeVal)
3908                                         {
3909                                                 *conf->variable = newval;
3910                                                 conf->gen.source = source;
3911                                         }
3912                                         if (makeDefault)
3913                                         {
3914                                                 GucStack   *stack;
3915
3916                                                 if (conf->gen.reset_source <= source)
3917                                                 {
3918                                                         conf->reset_val = newval;
3919                                                         conf->gen.reset_source = source;
3920                                                 }
3921                                                 for (stack = conf->gen.stack; stack; stack = stack->prev)
3922                                                 {
3923                                                         if (stack->source <= source)
3924                                                         {
3925                                                                 stack->value.boolval = newval;
3926                                                                 stack->source = source;
3927                                                         }
3928                                                 }
3929                                         }
3930                                         else if (isLocal)
3931                                         {
3932                                                 conf->gen.status |= GUC_HAVE_LOCAL;
3933                                                 guc_dirty = true;
3934                                         }
3935                                         else
3936                                         {
3937                                                 conf->tentative_val = newval;
3938                                                 conf->gen.tentative_source = source;
3939                                                 conf->gen.status |= GUC_HAVE_TENTATIVE;
3940                                                 guc_dirty = true;
3941                                         }
3942                                 }
3943                                 break;
3944                         }
3945
3946                 case PGC_INT:
3947                         {
3948                                 struct config_int *conf = (struct config_int *) record;
3949                                 int                     newval;
3950
3951                                 if (value)
3952                                 {
3953                                         if (!parse_int(value, &newval, conf->gen.flags))
3954                                         {
3955                                                 ereport(elevel,
3956                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
3957                                                  errmsg("parameter \"%s\" requires an integer value",
3958                                                                 name)));
3959                                                 return false;
3960                                         }
3961                                         if (newval < conf->min || newval > conf->max)
3962                                         {
3963                                                 ereport(elevel,
3964                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
3965                                                                  errmsg("%d is outside the valid range for parameter \"%s\" (%d .. %d)",
3966                                                                                 newval, name, conf->min, conf->max)));
3967                                                 return false;
3968                                         }
3969                                 }
3970                                 else
3971                                 {
3972                                         newval = conf->reset_val;
3973                                         source = conf->gen.reset_source;
3974                                 }
3975
3976                                 if (conf->assign_hook)
3977                                         if (!(*conf->assign_hook) (newval, changeVal, source))
3978                                         {
3979                                                 ereport(elevel,
3980                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
3981                                                          errmsg("invalid value for parameter \"%s\": %d",
3982                                                                         name, newval)));
3983                                                 return false;
3984                                         }
3985
3986                                 if (changeVal || makeDefault)
3987                                 {
3988                                         /* Save old value to support transaction abort */
3989                                         if (!makeDefault)
3990                                                 push_old_value(&conf->gen);
3991                                         if (changeVal)
3992                                         {
3993                                                 *conf->variable = newval;
3994                                                 conf->gen.source = source;
3995                                         }
3996                                         if (makeDefault)
3997                                         {
3998                                                 GucStack   *stack;
3999
4000                                                 if (conf->gen.reset_source <= source)
4001                                                 {
4002                                                         conf->reset_val = newval;
4003                                                         conf->gen.reset_source = source;
4004                                                 }
4005                                                 for (stack = conf->gen.stack; stack; stack = stack->prev)
4006                                                 {
4007                                                         if (stack->source <= source)
4008                                                         {
4009                                                                 stack->value.intval = newval;
4010                                                                 stack->source = source;
4011                                                         }
4012                                                 }
4013                                         }
4014                                         else if (isLocal)
4015                                         {
4016                                                 conf->gen.status |= GUC_HAVE_LOCAL;
4017                                                 guc_dirty = true;
4018                                         }
4019                                         else
4020                                         {
4021                                                 conf->tentative_val = newval;
4022                                                 conf->gen.tentative_source = source;
4023                                                 conf->gen.status |= GUC_HAVE_TENTATIVE;
4024                                                 guc_dirty = true;
4025                                         }
4026                                 }
4027                                 break;
4028                         }
4029
4030                 case PGC_REAL:
4031                         {
4032                                 struct config_real *conf = (struct config_real *) record;
4033                                 double          newval;
4034
4035                                 if (value)
4036                                 {
4037                                         if (!parse_real(value, &newval))
4038                                         {
4039                                                 ereport(elevel,
4040                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4041                                                   errmsg("parameter \"%s\" requires a numeric value",
4042                                                                  name)));
4043                                                 return false;
4044                                         }
4045                                         if (newval < conf->min || newval > conf->max)
4046                                         {
4047                                                 ereport(elevel,
4048                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4049                                                                  errmsg("%g is outside the valid range for parameter \"%s\" (%g .. %g)",
4050                                                                                 newval, name, conf->min, conf->max)));
4051                                                 return false;
4052                                         }
4053                                 }
4054                                 else
4055                                 {
4056                                         newval = conf->reset_val;
4057                                         source = conf->gen.reset_source;
4058                                 }
4059
4060                                 if (conf->assign_hook)
4061                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4062                                         {
4063                                                 ereport(elevel,
4064                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4065                                                          errmsg("invalid value for parameter \"%s\": %g",
4066                                                                         name, newval)));
4067                                                 return false;
4068                                         }
4069
4070                                 if (changeVal || makeDefault)
4071                                 {
4072                                         /* Save old value to support transaction abort */
4073                                         if (!makeDefault)
4074                                                 push_old_value(&conf->gen);
4075                                         if (changeVal)
4076                                         {
4077                                                 *conf->variable = newval;
4078                                                 conf->gen.source = source;
4079                                         }
4080                                         if (makeDefault)
4081                                         {
4082                                                 GucStack   *stack;
4083
4084                                                 if (conf->gen.reset_source <= source)
4085                                                 {
4086                                                         conf->reset_val = newval;
4087                                                         conf->gen.reset_source = source;
4088                                                 }
4089                                                 for (stack = conf->gen.stack; stack; stack = stack->prev)
4090                                                 {
4091                                                         if (stack->source <= source)
4092                                                         {
4093                                                                 stack->value.realval = newval;
4094                                                                 stack->source = source;
4095                                                         }
4096                                                 }
4097                                         }
4098                                         else if (isLocal)
4099                                         {
4100                                                 conf->gen.status |= GUC_HAVE_LOCAL;
4101                                                 guc_dirty = true;
4102                                         }
4103                                         else
4104                                         {
4105                                                 conf->tentative_val = newval;
4106                                                 conf->gen.tentative_source = source;
4107                                                 conf->gen.status |= GUC_HAVE_TENTATIVE;
4108                                                 guc_dirty = true;
4109                                         }
4110                                 }
4111                                 break;
4112                         }
4113
4114                 case PGC_STRING:
4115                         {
4116                                 struct config_string *conf = (struct config_string *) record;
4117                                 char       *newval;
4118
4119                                 if (value)
4120                                 {
4121                                         newval = guc_strdup(elevel, value);
4122                                         if (newval == NULL)
4123                                                 return false;
4124                                         /*
4125                                          * The only sort of "parsing" check we need to do is
4126                                          * apply truncation if GUC_IS_NAME.
4127                                          */
4128                                         if (conf->gen.flags & GUC_IS_NAME)
4129                                                 truncate_identifier(newval, strlen(newval), true);
4130                                 }
4131                                 else if (conf->reset_val)
4132                                 {
4133                                         /*
4134                                          * We could possibly avoid strdup here, but easier to make
4135                                          * this case work the same as the normal assignment case.
4136                                          */
4137                                         newval = guc_strdup(elevel, conf->reset_val);
4138                                         if (newval == NULL)
4139                                                 return false;
4140                                         source = conf->gen.reset_source;
4141                                 }
4142                                 else
4143                                 {
4144                                         /* Nothing to reset to, as yet; so do nothing */
4145                                         break;
4146                                 }
4147
4148                                 if (conf->assign_hook)
4149                                 {
4150                                         const char *hookresult;
4151
4152                                         /*
4153                                          * If the hook ereports, we have to make sure we free
4154                                          * newval, else it will be a permanent memory leak.
4155                                          */
4156                                         hookresult = call_string_assign_hook(conf->assign_hook,
4157                                                                                                                  newval,
4158                                                                                                                  changeVal,
4159                                                                                                                  source);
4160                                         if (hookresult == NULL)
4161                                         {
4162                                                 free(newval);
4163                                                 ereport(elevel,
4164                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4165                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4166                                                                 name, value ? value : "")));
4167                                                 return false;
4168                                         }
4169                                         else if (hookresult != newval)
4170                                         {
4171                                                 free(newval);
4172
4173                                                 /*
4174                                                  * Having to cast away const here is annoying, but the
4175                                                  * alternative is to declare assign_hooks as returning
4176                                                  * char*, which would mean they'd have to cast away
4177                                                  * const, or as both taking and returning char*, which
4178                                                  * doesn't seem attractive either --- we don't want
4179                                                  * them to scribble on the passed str.
4180                                                  */
4181                                                 newval = (char *) hookresult;
4182                                         }
4183                                 }
4184
4185                                 if (changeVal || makeDefault)
4186                                 {
4187                                         /* Save old value to support transaction abort */
4188                                         if (!makeDefault)
4189                                                 push_old_value(&conf->gen);
4190                                         if (changeVal)
4191                                         {
4192                                                 set_string_field(conf, conf->variable, newval);
4193                                                 conf->gen.source = source;
4194                                         }
4195                                         if (makeDefault)
4196                                         {
4197                                                 GucStack   *stack;
4198
4199                                                 if (conf->gen.reset_source <= source)
4200                                                 {
4201                                                         set_string_field(conf, &conf->reset_val, newval);
4202                                                         conf->gen.reset_source = source;
4203                                                 }
4204                                                 for (stack = conf->gen.stack; stack; stack = stack->prev)
4205                                                 {
4206                                                         if (stack->source <= source)
4207                                                         {
4208                                                                 set_string_field(conf, &stack->value.stringval,
4209                                                                                                  newval);
4210                                                                 stack->source = source;
4211                                                         }
4212                                                 }
4213                                                 /* Perhaps we didn't install newval anywhere */
4214                                                 if (!string_field_used(conf, newval))
4215                                                         free(newval);
4216                                         }
4217                                         else if (isLocal)
4218                                         {
4219                                                 conf->gen.status |= GUC_HAVE_LOCAL;
4220                                                 guc_dirty = true;
4221                                         }
4222                                         else
4223                                         {
4224                                                 set_string_field(conf, &conf->tentative_val, newval);
4225                                                 conf->gen.tentative_source = source;
4226                                                 conf->gen.status |= GUC_HAVE_TENTATIVE;
4227                                                 guc_dirty = true;
4228                                         }
4229                                 }
4230                                 else
4231                                         free(newval);
4232                                 break;
4233                         }
4234         }
4235
4236         if (changeVal && (record->flags & GUC_REPORT))
4237                 ReportGUCOption(record);
4238
4239         return true;
4240 }
4241
4242
4243 /*
4244  * Set a config option to the given value. See also set_config_option,
4245  * this is just the wrapper to be called from outside GUC.      NB: this
4246  * is used only for non-transactional operations.
4247  */
4248 void
4249 SetConfigOption(const char *name, const char *value,
4250                                 GucContext context, GucSource source)
4251 {
4252         (void) set_config_option(name, value, context, source, false, true);
4253 }
4254
4255
4256
4257 /*
4258  * Fetch the current value of the option `name'. If the option doesn't exist,
4259  * throw an ereport and don't return.
4260  *
4261  * The string is *not* allocated for modification and is really only
4262  * valid until the next call to configuration related functions.
4263  */
4264 const char *
4265 GetConfigOption(const char *name)
4266 {
4267         struct config_generic *record;
4268         static char buffer[256];
4269
4270         record = find_option(name, ERROR);
4271         if (record == NULL)
4272                 ereport(ERROR,
4273                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4274                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4275         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
4276                 ereport(ERROR,
4277                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4278                                  errmsg("must be superuser to examine \"%s\"", name)));
4279
4280         switch (record->vartype)
4281         {
4282                 case PGC_BOOL:
4283                         return *((struct config_bool *) record)->variable ? "on" : "off";
4284
4285                 case PGC_INT:
4286                         snprintf(buffer, sizeof(buffer), "%d",
4287                                          *((struct config_int *) record)->variable);
4288                         return buffer;
4289
4290                 case PGC_REAL:
4291                         snprintf(buffer, sizeof(buffer), "%g",
4292                                          *((struct config_real *) record)->variable);
4293                         return buffer;
4294
4295                 case PGC_STRING:
4296                         return *((struct config_string *) record)->variable;
4297         }
4298         return NULL;
4299 }
4300
4301 /*
4302  * Get the RESET value associated with the given option.
4303  */
4304 const char *
4305 GetConfigOptionResetString(const char *name)
4306 {
4307         struct config_generic *record;
4308         static char buffer[256];
4309
4310         record = find_option(name, ERROR);
4311         if (record == NULL)
4312                 ereport(ERROR,
4313                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4314                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4315         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
4316                 ereport(ERROR,
4317                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4318                                  errmsg("must be superuser to examine \"%s\"", name)));
4319
4320         switch (record->vartype)
4321         {
4322                 case PGC_BOOL:
4323                         return ((struct config_bool *) record)->reset_val ? "on" : "off";
4324
4325                 case PGC_INT:
4326                         snprintf(buffer, sizeof(buffer), "%d",
4327                                          ((struct config_int *) record)->reset_val);
4328                         return buffer;
4329
4330                 case PGC_REAL:
4331                         snprintf(buffer, sizeof(buffer), "%g",
4332                                          ((struct config_real *) record)->reset_val);
4333                         return buffer;
4334
4335                 case PGC_STRING:
4336                         return ((struct config_string *) record)->reset_val;
4337         }
4338         return NULL;
4339 }
4340
4341 /*
4342  * Detect whether the given configuration option can only be set by
4343  * a superuser.
4344  */
4345 bool
4346 IsSuperuserConfigOption(const char *name)
4347 {
4348         struct config_generic *record;
4349
4350         record = find_option(name, ERROR);
4351         /* On an unrecognized name, don't error, just return false. */
4352         if (record == NULL)
4353                 return false;
4354         return (record->context == PGC_SUSET);
4355 }
4356
4357
4358 /*
4359  * flatten_set_variable_args
4360  *              Given a parsenode List as emitted by the grammar for SET,
4361  *              convert to the flat string representation used by GUC.
4362  *
4363  * We need to be told the name of the variable the args are for, because
4364  * the flattening rules vary (ugh).
4365  *
4366  * The result is NULL if input is NIL (ie, SET ... TO DEFAULT), otherwise
4367  * a palloc'd string.
4368  */
4369 char *
4370 flatten_set_variable_args(const char *name, List *args)
4371 {
4372         struct config_generic *record;
4373         int                     flags;
4374         StringInfoData buf;
4375         ListCell   *l;
4376
4377         /*
4378          * Fast path if just DEFAULT.  We do not check the variable name in this
4379          * case --- necessary for RESET ALL to work correctly.
4380          */
4381         if (args == NIL)
4382                 return NULL;
4383
4384         /* Else get flags for the variable */
4385         record = find_option(name, ERROR);
4386         if (record == NULL)
4387                 ereport(ERROR,
4388                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4389                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4390
4391         flags = record->flags;
4392
4393         /* Complain if list input and non-list variable */
4394         if ((flags & GUC_LIST_INPUT) == 0 &&
4395                 list_length(args) != 1)
4396                 ereport(ERROR,
4397                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4398                                  errmsg("SET %s takes only one argument", name)));
4399
4400         initStringInfo(&buf);
4401
4402         foreach(l, args)
4403         {
4404                 A_Const    *arg = (A_Const *) lfirst(l);
4405                 char       *val;
4406
4407                 if (l != list_head(args))
4408                         appendStringInfo(&buf, ", ");
4409
4410                 if (!IsA(arg, A_Const))
4411                         elog(ERROR, "unrecognized node type: %d", (int) nodeTag(arg));
4412
4413                 switch (nodeTag(&arg->val))
4414                 {
4415                         case T_Integer:
4416                                 appendStringInfo(&buf, "%ld", intVal(&arg->val));
4417                                 break;
4418                         case T_Float:
4419                                 /* represented as a string, so just copy it */
4420                                 appendStringInfoString(&buf, strVal(&arg->val));
4421                                 break;
4422                         case T_String:
4423                                 val = strVal(&arg->val);
4424                                 if (arg->typename != NULL)
4425                                 {
4426                                         /*
4427                                          * Must be a ConstInterval argument for TIME ZONE. Coerce
4428                                          * to interval and back to normalize the value and account
4429                                          * for any typmod.
4430                                          */
4431                                         Datum           interval;
4432                                         char       *intervalout;
4433
4434                                         interval =
4435                                                 DirectFunctionCall3(interval_in,
4436                                                                                         CStringGetDatum(val),
4437                                                                                         ObjectIdGetDatum(InvalidOid),
4438                                                                            Int32GetDatum(arg->typename->typmod));
4439
4440                                         intervalout =
4441                                                 DatumGetCString(DirectFunctionCall1(interval_out,
4442                                                                                                                         interval));
4443                                         appendStringInfo(&buf, "INTERVAL '%s'", intervalout);
4444                                 }
4445                                 else
4446                                 {
4447                                         /*
4448                                          * Plain string literal or identifier.  For quote mode,
4449                                          * quote it if it's not a vanilla identifier.
4450                                          */
4451                                         if (flags & GUC_LIST_QUOTE)
4452                                                 appendStringInfoString(&buf, quote_identifier(val));
4453                                         else
4454                                                 appendStringInfoString(&buf, val);
4455                                 }
4456                                 break;
4457                         default:
4458                                 elog(ERROR, "unrecognized node type: %d",
4459                                          (int) nodeTag(&arg->val));
4460                                 break;
4461                 }
4462         }
4463
4464         return buf.data;
4465 }
4466
4467
4468 /*
4469  * SET command
4470  */
4471 void
4472 SetPGVariable(const char *name, List *args, bool is_local)
4473 {
4474         char       *argstring = flatten_set_variable_args(name, args);
4475
4476         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
4477         set_config_option(name,
4478                                           argstring,
4479                                           (superuser() ? PGC_SUSET : PGC_USERSET),
4480                                           PGC_S_SESSION,
4481                                           is_local,
4482                                           true);
4483 }
4484
4485 /*
4486  * SET command wrapped as a SQL callable function.
4487  */
4488 Datum
4489 set_config_by_name(PG_FUNCTION_ARGS)
4490 {
4491         char       *name;
4492         char       *value;
4493         char       *new_value;
4494         bool            is_local;
4495         text       *result_text;
4496
4497         if (PG_ARGISNULL(0))
4498                 ereport(ERROR,
4499                                 (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
4500                                  errmsg("SET requires parameter name")));
4501
4502         /* Get the GUC variable name */
4503         name = DatumGetCString(DirectFunctionCall1(textout, PG_GETARG_DATUM(0)));
4504
4505         /* Get the desired value or set to NULL for a reset request */
4506         if (PG_ARGISNULL(1))
4507                 value = NULL;
4508         else
4509                 value = DatumGetCString(DirectFunctionCall1(textout, PG_GETARG_DATUM(1)));
4510
4511         /*
4512          * Get the desired state of is_local. Default to false if provided value
4513          * is NULL
4514          */
4515         if (PG_ARGISNULL(2))
4516                 is_local = false;
4517         else
4518                 is_local = PG_GETARG_BOOL(2);
4519
4520         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
4521         set_config_option(name,
4522                                           value,
4523                                           (superuser() ? PGC_SUSET : PGC_USERSET),
4524                                           PGC_S_SESSION,
4525                                           is_local,
4526                                           true);
4527
4528         /* get the new current value */
4529         new_value = GetConfigOptionByName(name, NULL);
4530
4531         /* Convert return string to text */
4532         result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(new_value)));
4533
4534         /* return it */
4535         PG_RETURN_TEXT_P(result_text);
4536 }
4537
4538 static void
4539 define_custom_variable(struct config_generic * variable)
4540 {
4541         const char *name = variable->name;
4542         const char **nameAddr = &name;
4543         const char *value;
4544         struct config_string *pHolder;
4545         struct config_generic **res = (struct config_generic **) bsearch(
4546                                                                                                                   (void *) &nameAddr,
4547                                                                                                           (void *) guc_variables,
4548                                                                                                                    num_guc_variables,
4549                                                                                          sizeof(struct config_generic *),
4550                                                                                                                         guc_var_compare);
4551
4552         if (res == NULL)
4553         {
4554                 add_guc_variable(variable, ERROR);
4555                 return;
4556         }
4557
4558         /*
4559          * This better be a placeholder
4560          */
4561         if (((*res)->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
4562                 ereport(ERROR,
4563                                 (errcode(ERRCODE_INTERNAL_ERROR),
4564                                  errmsg("attempt to redefine parameter \"%s\"", name)));
4565
4566         Assert((*res)->vartype == PGC_STRING);
4567         pHolder = (struct config_string *) * res;
4568
4569         /* We have the same name, no sorting is necessary */
4570         *res = variable;
4571
4572         value = *pHolder->variable;
4573
4574         /*
4575          * Assign the string value stored in the placeholder to the real variable.
4576          *
4577          * XXX this is not really good enough --- it should be a nontransactional
4578          * assignment, since we don't want it to roll back if the current xact
4579          * fails later.
4580          */
4581         set_config_option(name, value,
4582                                           pHolder->gen.context, pHolder->gen.source,
4583                                           false, true);
4584
4585         /*
4586          * Free up as much as we conveniently can of the placeholder structure
4587          * (this neglects any stack items...)
4588          */
4589         set_string_field(pHolder, pHolder->variable, NULL);
4590         set_string_field(pHolder, &pHolder->reset_val, NULL);
4591         set_string_field(pHolder, &pHolder->tentative_val, NULL);
4592
4593         free(pHolder);
4594 }
4595
4596 static void
4597 init_custom_variable(struct config_generic * gen,
4598                                          const char *name,
4599                                          const char *short_desc,
4600                                          const char *long_desc,
4601                                          GucContext context,
4602                                          enum config_type type)
4603 {
4604         gen->name = guc_strdup(ERROR, name);
4605         gen->context = context;
4606         gen->group = CUSTOM_OPTIONS;
4607         gen->short_desc = short_desc;
4608         gen->long_desc = long_desc;
4609         gen->vartype = type;
4610 }
4611
4612 void
4613 DefineCustomBoolVariable(const char *name,
4614                                                  const char *short_desc,
4615                                                  const char *long_desc,
4616                                                  bool *valueAddr,
4617                                                  GucContext context,
4618                                                  GucBoolAssignHook assign_hook,
4619                                                  GucShowHook show_hook)
4620 {
4621         size_t          sz = sizeof(struct config_bool);
4622         struct config_bool *var = (struct config_bool *) guc_malloc(ERROR, sz);
4623
4624         memset(var, 0, sz);
4625         init_custom_variable(&var->gen, name, short_desc, long_desc, context, PGC_BOOL);
4626
4627         var->variable = valueAddr;
4628         var->reset_val = *valueAddr;
4629         var->assign_hook = assign_hook;
4630         var->show_hook = show_hook;
4631         define_custom_variable(&var->gen);
4632 }
4633
4634 void
4635 DefineCustomIntVariable(const char *name,
4636                                                 const char *short_desc,
4637                                                 const char *long_desc,
4638                                                 int *valueAddr,
4639                                                 int minValue,
4640                                                 int maxValue,
4641                                                 GucContext context,
4642                                                 GucIntAssignHook assign_hook,
4643                                                 GucShowHook show_hook)
4644 {
4645         size_t          sz = sizeof(struct config_int);
4646         struct config_int *var = (struct config_int *) guc_malloc(ERROR, sz);
4647
4648         memset(var, 0, sz);
4649         init_custom_variable(&var->gen, name, short_desc, long_desc, context, PGC_INT);
4650
4651         var->variable = valueAddr;
4652         var->reset_val = *valueAddr;
4653         var->min = minValue;
4654         var->max = maxValue;
4655         var->assign_hook = assign_hook;
4656         var->show_hook = show_hook;
4657         define_custom_variable(&var->gen);
4658 }
4659
4660 void
4661 DefineCustomRealVariable(const char *name,
4662                                                  const char *short_desc,
4663                                                  const char *long_desc,
4664                                                  double *valueAddr,
4665                                                  double minValue,
4666                                                  double maxValue,
4667                                                  GucContext context,
4668                                                  GucRealAssignHook assign_hook,
4669                                                  GucShowHook show_hook)
4670 {
4671         size_t          sz = sizeof(struct config_real);
4672         struct config_real *var = (struct config_real *) guc_malloc(ERROR, sz);
4673
4674         memset(var, 0, sz);
4675         init_custom_variable(&var->gen, name, short_desc, long_desc, context, PGC_REAL);
4676
4677         var->variable = valueAddr;
4678         var->reset_val = *valueAddr;
4679         var->min = minValue;
4680         var->max = maxValue;
4681         var->assign_hook = assign_hook;
4682         var->show_hook = show_hook;
4683         define_custom_variable(&var->gen);
4684 }
4685
4686 void
4687 DefineCustomStringVariable(const char *name,
4688                                                    const char *short_desc,
4689                                                    const char *long_desc,
4690                                                    char **valueAddr,
4691                                                    GucContext context,
4692                                                    GucStringAssignHook assign_hook,
4693                                                    GucShowHook show_hook)
4694 {
4695         size_t          sz = sizeof(struct config_string);
4696         struct config_string *var = (struct config_string *) guc_malloc(ERROR, sz);
4697
4698         memset(var, 0, sz);
4699         init_custom_variable(&var->gen, name, short_desc, long_desc, context, PGC_STRING);
4700
4701         var->variable = valueAddr;
4702         var->reset_val = *valueAddr;
4703         var->assign_hook = assign_hook;
4704         var->show_hook = show_hook;
4705         define_custom_variable(&var->gen);
4706 }
4707
4708 void
4709 EmitWarningsOnPlaceholders(const char *className)
4710 {
4711         struct config_generic **vars = guc_variables;
4712         struct config_generic **last = vars + num_guc_variables;
4713
4714         int                     nameLen = strlen(className);
4715
4716         while (vars < last)
4717         {
4718                 struct config_generic *var = *vars++;
4719
4720                 if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
4721                         strncmp(className, var->name, nameLen) == 0 &&
4722                         var->name[nameLen] == GUC_QUALIFIER_SEPARATOR)
4723                 {
4724                         ereport(INFO,
4725                                         (errcode(ERRCODE_UNDEFINED_OBJECT),
4726                                          errmsg("unrecognized configuration parameter \"%s\"", var->name)));
4727                 }
4728         }
4729 }
4730
4731
4732 /*
4733  * SHOW command
4734  */
4735 void
4736 GetPGVariable(const char *name, DestReceiver *dest)
4737 {
4738         if (pg_strcasecmp(name, "all") == 0)
4739                 ShowAllGUCConfig(dest);
4740         else
4741                 ShowGUCConfigOption(name, dest);
4742 }
4743
4744 TupleDesc
4745 GetPGVariableResultDesc(const char *name)
4746 {
4747         TupleDesc       tupdesc;
4748
4749         if (pg_strcasecmp(name, "all") == 0)
4750         {
4751                 /* need a tuple descriptor representing three TEXT columns */
4752                 tupdesc = CreateTemplateTupleDesc(3, false);
4753                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
4754                                                    TEXTOID, -1, 0);
4755                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
4756                                                    TEXTOID, -1, 0);
4757                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
4758                                                    TEXTOID, -1, 0);
4759
4760         }
4761         else
4762         {
4763                 const char *varname;
4764
4765                 /* Get the canonical spelling of name */
4766                 (void) GetConfigOptionByName(name, &varname);
4767
4768                 /* need a tuple descriptor representing a single TEXT column */
4769                 tupdesc = CreateTemplateTupleDesc(1, false);
4770                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
4771                                                    TEXTOID, -1, 0);
4772         }
4773         return tupdesc;
4774 }
4775
4776 /*
4777  * RESET command
4778  */
4779 void
4780 ResetPGVariable(const char *name)
4781 {
4782         if (pg_strcasecmp(name, "all") == 0)
4783                 ResetAllOptions();
4784         else
4785                 set_config_option(name,
4786                                                   NULL,
4787                                                   (superuser() ? PGC_SUSET : PGC_USERSET),
4788                                                   PGC_S_SESSION,
4789                                                   false,
4790                                                   true);
4791 }
4792
4793
4794 /*
4795  * SHOW command
4796  */
4797 static void
4798 ShowGUCConfigOption(const char *name, DestReceiver *dest)
4799 {
4800         TupOutputState *tstate;
4801         TupleDesc       tupdesc;
4802         const char *varname;
4803         char       *value;
4804
4805         /* Get the value and canonical spelling of name */
4806         value = GetConfigOptionByName(name, &varname);
4807
4808         /* need a tuple descriptor representing a single TEXT column */
4809         tupdesc = CreateTemplateTupleDesc(1, false);
4810         TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
4811                                            TEXTOID, -1, 0);
4812
4813         /* prepare for projection of tuples */
4814         tstate = begin_tup_output_tupdesc(dest, tupdesc);
4815
4816         /* Send it */
4817         do_text_output_oneline(tstate, value);
4818
4819         end_tup_output(tstate);
4820 }
4821
4822 /*
4823  * SHOW ALL command
4824  */
4825 static void
4826 ShowAllGUCConfig(DestReceiver *dest)
4827 {
4828         bool            am_superuser = superuser();
4829         int                     i;
4830         TupOutputState *tstate;
4831         TupleDesc       tupdesc;
4832         char       *values[3];
4833
4834         /* need a tuple descriptor representing three TEXT columns */
4835         tupdesc = CreateTemplateTupleDesc(3, false);
4836         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
4837                                            TEXTOID, -1, 0);
4838         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
4839                                            TEXTOID, -1, 0);
4840         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
4841                                            TEXTOID, -1, 0);
4842
4843
4844         /* prepare for projection of tuples */
4845         tstate = begin_tup_output_tupdesc(dest, tupdesc);
4846
4847         for (i = 0; i < num_guc_variables; i++)
4848         {
4849                 struct config_generic *conf = guc_variables[i];
4850
4851                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
4852                         ((conf->flags & GUC_SUPERUSER_ONLY) && !am_superuser))
4853                         continue;
4854
4855                 /* assign to the values array */
4856                 values[0] = (char *) conf->name;
4857                 values[1] = _ShowOption(conf, true);
4858                 values[2] = (char *) conf->short_desc;
4859
4860                 /* send it to dest */
4861                 do_tup_output(tstate, values);
4862
4863                 /* clean up */
4864                 if (values[1] != NULL)
4865                         pfree(values[1]);
4866         }
4867
4868         end_tup_output(tstate);
4869 }
4870
4871 /*
4872  * Return GUC variable value by name; optionally return canonical
4873  * form of name.  Return value is palloc'd.
4874  */
4875 char *
4876 GetConfigOptionByName(const char *name, const char **varname)
4877 {
4878         struct config_generic *record;
4879
4880         record = find_option(name, ERROR);
4881         if (record == NULL)
4882                 ereport(ERROR,
4883                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4884                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4885         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
4886                 ereport(ERROR,
4887                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4888                                  errmsg("must be superuser to examine \"%s\"", name)));
4889
4890         if (varname)
4891                 *varname = record->name;
4892
4893         return _ShowOption(record, true);
4894 }
4895
4896 /*
4897  * Return GUC variable value by variable number; optionally return canonical
4898  * form of name.  Return value is palloc'd.
4899  */
4900 void
4901 GetConfigOptionByNum(int varnum, const char **values, bool *noshow)
4902 {
4903         char            buffer[256];
4904         struct config_generic *conf;
4905
4906         /* check requested variable number valid */
4907         Assert((varnum >= 0) && (varnum < num_guc_variables));
4908
4909         conf = guc_variables[varnum];
4910
4911         if (noshow)
4912         {
4913                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
4914                         ((conf->flags & GUC_SUPERUSER_ONLY) && !superuser()))
4915                         *noshow = true;
4916                 else
4917                         *noshow = false;
4918         }
4919
4920         /* first get the generic attributes */
4921
4922         /* name */
4923         values[0] = conf->name;
4924
4925         /* setting : use _ShowOption in order to avoid duplicating the logic */
4926         values[1] = _ShowOption(conf, false);
4927
4928         /* unit */
4929         if (conf->vartype == PGC_INT)
4930         {
4931                 if (conf->flags & GUC_UNIT_KB)
4932                         values[2] = "kB";
4933                 else if (conf->flags & GUC_UNIT_BLOCKS)
4934                 {
4935                         static char buf[8];
4936
4937                         snprintf(buf, sizeof(buf), "%dkB", BLCKSZ/1024);
4938                         values[2] = buf;
4939                 }
4940                 else if (conf->flags & GUC_UNIT_MS)
4941                         values[2] = "ms";
4942                 else if (conf->flags & GUC_UNIT_S)
4943                         values[2] = "s";
4944                 else if (conf->flags & GUC_UNIT_MIN)
4945                         values[2] = "min";
4946                 else
4947                         values[2] = "";
4948         }
4949         else
4950                 values[2] = NULL;
4951
4952         /* group */
4953         values[3] = config_group_names[conf->group];
4954
4955         /* short_desc */
4956         values[4] = conf->short_desc;
4957
4958         /* extra_desc */
4959         values[5] = conf->long_desc;
4960
4961         /* context */
4962         values[6] = GucContext_Names[conf->context];
4963
4964         /* vartype */
4965         values[7] = config_type_names[conf->vartype];
4966
4967         /* source */
4968         values[8] = GucSource_Names[conf->source];
4969
4970         /* now get the type specifc attributes */
4971         switch (conf->vartype)
4972         {
4973                 case PGC_BOOL:
4974                         {
4975                                 /* min_val */
4976                                 values[9] = NULL;
4977
4978                                 /* max_val */
4979                                 values[10] = NULL;
4980                         }
4981                         break;
4982
4983                 case PGC_INT:
4984                         {
4985                                 struct config_int *lconf = (struct config_int *) conf;
4986
4987                                 /* min_val */
4988                                 snprintf(buffer, sizeof(buffer), "%d", lconf->min);
4989                                 values[9] = pstrdup(buffer);
4990
4991                                 /* max_val */
4992                                 snprintf(buffer, sizeof(buffer), "%d", lconf->max);
4993                                 values[10] = pstrdup(buffer);
4994                         }
4995                         break;
4996
4997                 case PGC_REAL:
4998                         {
4999                                 struct config_real *lconf = (struct config_real *) conf;
5000
5001                                 /* min_val */
5002                                 snprintf(buffer, sizeof(buffer), "%g", lconf->min);
5003                                 values[9] = pstrdup(buffer);
5004
5005                                 /* max_val */
5006                                 snprintf(buffer, sizeof(buffer), "%g", lconf->max);
5007                                 values[10] = pstrdup(buffer);
5008                         }
5009                         break;
5010
5011                 case PGC_STRING:
5012                         {
5013                                 /* min_val */
5014                                 values[9] = NULL;
5015
5016                                 /* max_val */
5017                                 values[10] = NULL;
5018                         }
5019                         break;
5020
5021                 default:
5022                         {
5023                                 /*
5024                                  * should never get here, but in case we do, set 'em to NULL
5025                                  */
5026
5027                                 /* min_val */
5028                                 values[9] = NULL;
5029
5030                                 /* max_val */
5031                                 values[10] = NULL;
5032                         }
5033                         break;
5034         }
5035 }
5036
5037 /*
5038  * Return the total number of GUC variables
5039  */
5040 int
5041 GetNumConfigOptions(void)
5042 {
5043         return num_guc_variables;
5044 }
5045
5046 /*
5047  * show_config_by_name - equiv to SHOW X command but implemented as
5048  * a function.
5049  */
5050 Datum
5051 show_config_by_name(PG_FUNCTION_ARGS)
5052 {
5053         char       *varname;
5054         char       *varval;
5055         text       *result_text;
5056
5057         /* Get the GUC variable name */
5058         varname = DatumGetCString(DirectFunctionCall1(textout, PG_GETARG_DATUM(0)));
5059
5060         /* Get the value */
5061         varval = GetConfigOptionByName(varname, NULL);
5062
5063         /* Convert to text */
5064         result_text = DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(varval)));
5065
5066         /* return it */
5067         PG_RETURN_TEXT_P(result_text);
5068 }
5069
5070 /*
5071  * show_all_settings - equiv to SHOW ALL command but implemented as
5072  * a Table Function.
5073  */
5074 #define NUM_PG_SETTINGS_ATTS    11
5075
5076 Datum
5077 show_all_settings(PG_FUNCTION_ARGS)
5078 {
5079         FuncCallContext *funcctx;
5080         TupleDesc       tupdesc;
5081         int                     call_cntr;
5082         int                     max_calls;
5083         AttInMetadata *attinmeta;
5084         MemoryContext oldcontext;
5085
5086         /* stuff done only on the first call of the function */
5087         if (SRF_IS_FIRSTCALL())
5088         {
5089                 /* create a function context for cross-call persistence */
5090                 funcctx = SRF_FIRSTCALL_INIT();
5091
5092                 /*
5093                  * switch to memory context appropriate for multiple function calls
5094                  */
5095                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
5096
5097                 /*
5098                  * need a tuple descriptor representing NUM_PG_SETTINGS_ATTS columns
5099                  * of the appropriate types
5100                  */
5101                 tupdesc = CreateTemplateTupleDesc(NUM_PG_SETTINGS_ATTS, false);
5102                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5103                                                    TEXTOID, -1, 0);
5104                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5105                                                    TEXTOID, -1, 0);
5106                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "unit",
5107                                                    TEXTOID, -1, 0);
5108                 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "category",
5109                                                    TEXTOID, -1, 0);
5110                 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "short_desc",
5111                                                    TEXTOID, -1, 0);
5112                 TupleDescInitEntry(tupdesc, (AttrNumber) 6, "extra_desc",
5113                                                    TEXTOID, -1, 0);
5114                 TupleDescInitEntry(tupdesc, (AttrNumber) 7, "context",
5115                                                    TEXTOID, -1, 0);
5116                 TupleDescInitEntry(tupdesc, (AttrNumber) 8, "vartype",
5117                                                    TEXTOID, -1, 0);
5118                 TupleDescInitEntry(tupdesc, (AttrNumber) 9, "source",
5119                                                    TEXTOID, -1, 0);
5120                 TupleDescInitEntry(tupdesc, (AttrNumber) 10, "min_val",
5121                                                    TEXTOID, -1, 0);
5122                 TupleDescInitEntry(tupdesc, (AttrNumber) 11, "max_val",
5123                                                    TEXTOID, -1, 0);
5124
5125                 /*
5126                  * Generate attribute metadata needed later to produce tuples from raw
5127                  * C strings
5128                  */
5129                 attinmeta = TupleDescGetAttInMetadata(tupdesc);
5130                 funcctx->attinmeta = attinmeta;
5131
5132                 /* total number of tuples to be returned */
5133                 funcctx->max_calls = GetNumConfigOptions();
5134
5135                 MemoryContextSwitchTo(oldcontext);
5136         }
5137
5138         /* stuff done on every call of the function */
5139         funcctx = SRF_PERCALL_SETUP();
5140
5141         call_cntr = funcctx->call_cntr;
5142         max_calls = funcctx->max_calls;
5143         attinmeta = funcctx->attinmeta;
5144
5145         if (call_cntr < max_calls)      /* do when there is more left to send */
5146         {
5147                 char       *values[NUM_PG_SETTINGS_ATTS];
5148                 bool            noshow;
5149                 HeapTuple       tuple;
5150                 Datum           result;
5151
5152                 /*
5153                  * Get the next visible GUC variable name and value
5154                  */
5155                 do
5156                 {
5157                         GetConfigOptionByNum(call_cntr, (const char **) values, &noshow);
5158                         if (noshow)
5159                         {
5160                                 /* bump the counter and get the next config setting */
5161                                 call_cntr = ++funcctx->call_cntr;
5162
5163                                 /* make sure we haven't gone too far now */
5164                                 if (call_cntr >= max_calls)
5165                                         SRF_RETURN_DONE(funcctx);
5166                         }
5167                 } while (noshow);
5168
5169                 /* build a tuple */
5170                 tuple = BuildTupleFromCStrings(attinmeta, values);
5171
5172                 /* make the tuple into a datum */
5173                 result = HeapTupleGetDatum(tuple);
5174
5175                 SRF_RETURN_NEXT(funcctx, result);
5176         }
5177         else
5178         {
5179                 /* do when there is no more left */
5180                 SRF_RETURN_DONE(funcctx);
5181         }
5182 }
5183
5184 static char *
5185 _ShowOption(struct config_generic * record, bool use_units)
5186 {
5187         char            buffer[256];
5188         const char *val;
5189
5190         switch (record->vartype)
5191         {
5192                 case PGC_BOOL:
5193                         {
5194                                 struct config_bool *conf = (struct config_bool *) record;
5195
5196                                 if (conf->show_hook)
5197                                         val = (*conf->show_hook) ();
5198                                 else
5199                                         val = *conf->variable ? "on" : "off";
5200                         }
5201                         break;
5202
5203                 case PGC_INT:
5204                         {
5205                                 struct config_int *conf = (struct config_int *) record;
5206
5207                                 if (conf->show_hook)
5208                                         val = (*conf->show_hook) ();
5209                                 else
5210                                 {
5211                                         char unit[4];
5212                                         int result = *conf->variable;
5213
5214                                         if (use_units && result > 0 && (record->flags & GUC_UNIT_MEMORY))
5215                                         {
5216                                                 if (record->flags & GUC_UNIT_BLOCKS)
5217                                                         result *= BLCKSZ/1024;
5218
5219                                                 if (result % KB_PER_GB == 0)
5220                                                 {
5221                                                         result /= KB_PER_GB;
5222                                                         strcpy(unit, "GB");
5223                                                 }
5224                                                 else if (result % KB_PER_MB == 0)
5225                                                 {
5226                                                         result /= KB_PER_MB;
5227                                                         strcpy(unit, "MB");
5228                                                 }
5229                                                 else
5230                                                 {
5231                                                         strcpy(unit, "kB");
5232                                                 }
5233                                         }
5234                                         else if (use_units && result > 0 && (record->flags & GUC_UNIT_TIME))
5235                                         {
5236                                                 if (record->flags & GUC_UNIT_S)
5237                                                         result = result * MS_PER_S;
5238                                                 else if (record->flags & GUC_UNIT_MIN)
5239                                                         result = result * MS_PER_MIN;
5240
5241                                                 if (result % MS_PER_D == 0)
5242                                                 {
5243                                                         result /= MS_PER_D;
5244                                                         strcpy(unit, "d");
5245                                                 }
5246                                                 else if (result % MS_PER_H == 0)
5247                                                 {
5248                                                         result /= MS_PER_H;
5249                                                         strcpy(unit, "h");
5250                                                 }
5251                                                 else if (result % MS_PER_MIN == 0)
5252                                                 {
5253                                                         result /= MS_PER_MIN;
5254                                                         strcpy(unit, "min");
5255                                                 }
5256                                                 else if (result % MS_PER_S == 0)
5257                                                 {
5258                                                         result /= MS_PER_S;
5259                                                         strcpy(unit, "s");
5260                                                 }
5261                                                 else
5262                                                 {
5263                                                         strcpy(unit, "ms");
5264                                                 }
5265                                         }
5266                                         else
5267                                                 strcpy(unit, "");
5268
5269                                         snprintf(buffer, sizeof(buffer), "%d%s",
5270                                                          (int)result, unit);
5271                                         val = buffer;
5272                                 }
5273                         }
5274                         break;
5275
5276                 case PGC_REAL:
5277                         {
5278                                 struct config_real *conf = (struct config_real *) record;
5279
5280                                 if (conf->show_hook)
5281                                         val = (*conf->show_hook) ();
5282                                 else
5283                                 {
5284                                         snprintf(buffer, sizeof(buffer), "%g",
5285                                                          *conf->variable);
5286                                         val = buffer;
5287                                 }
5288                         }
5289                         break;
5290
5291                 case PGC_STRING:
5292                         {
5293                                 struct config_string *conf = (struct config_string *) record;
5294
5295                                 if (conf->show_hook)
5296                                         val = (*conf->show_hook) ();
5297                                 else if (*conf->variable && **conf->variable)
5298                                         val = *conf->variable;
5299                                 else
5300                                         val = "";
5301                         }
5302                         break;
5303
5304                 default:
5305                         /* just to keep compiler quiet */
5306                         val = "???";
5307                         break;
5308         }
5309
5310         return pstrdup(val);
5311 }
5312
5313
5314 static bool
5315 is_newvalue_equal(struct config_generic *record, const char *newvalue)
5316 {
5317         switch (record->vartype)
5318         {
5319                 case PGC_BOOL:
5320                 {
5321                         struct config_bool *conf = (struct config_bool *) record;
5322                         bool newval;
5323
5324                         return parse_bool(newvalue, &newval) && *conf->variable == newval;
5325                 }
5326                 case PGC_INT:
5327                 {
5328                         struct config_int *conf = (struct config_int *) record;
5329                         int newval;
5330
5331                         return parse_int(newvalue, &newval, record->flags) && *conf->variable == newval;
5332                 }
5333                 case PGC_REAL:
5334                 {
5335                         struct config_real *conf = (struct config_real *) record;
5336                         double newval;
5337
5338                         return parse_real(newvalue, &newval) && *conf->variable == newval;
5339                 }
5340                 case PGC_STRING:
5341                 {
5342                         struct config_string *conf = (struct config_string *) record;
5343
5344                         return strcmp(*conf->variable, newvalue) == 0;
5345                 }
5346         }
5347
5348         return false;
5349 }
5350
5351
5352 #ifdef EXEC_BACKEND
5353
5354 /*
5355  *      This routine dumps out all non-default GUC options into a binary
5356  *      file that is read by all exec'ed backends.  The format is:
5357  *
5358  *              variable name, string, null terminated
5359  *              variable value, string, null terminated
5360  *              variable source, integer
5361  */
5362 void
5363 write_nondefault_variables(GucContext context)
5364 {
5365         int                     i;
5366         int                     elevel;
5367         FILE       *fp;
5368
5369         Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
5370
5371         elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
5372
5373         /*
5374          * Open file
5375          */
5376         fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
5377         if (!fp)
5378         {
5379                 ereport(elevel,
5380                                 (errcode_for_file_access(),
5381                                  errmsg("could not write to file \"%s\": %m",
5382                                                 CONFIG_EXEC_PARAMS_NEW)));
5383                 return;
5384         }
5385
5386         for (i = 0; i < num_guc_variables; i++)
5387         {
5388                 struct config_generic *gconf = guc_variables[i];
5389
5390                 if (gconf->source != PGC_S_DEFAULT)
5391                 {
5392                         fprintf(fp, "%s", gconf->name);
5393                         fputc(0, fp);
5394
5395                         switch (gconf->vartype)
5396                         {
5397                                 case PGC_BOOL:
5398                                         {
5399                                                 struct config_bool *conf = (struct config_bool *) gconf;
5400
5401                                                 if (*conf->variable == 0)
5402                                                         fprintf(fp, "false");
5403                                                 else
5404                                                         fprintf(fp, "true");
5405                                         }
5406                                         break;
5407
5408                                 case PGC_INT:
5409                                         {
5410                                                 struct config_int *conf = (struct config_int *) gconf;
5411
5412                                                 fprintf(fp, "%d", *conf->variable);
5413                                         }
5414                                         break;
5415
5416                                 case PGC_REAL:
5417                                         {
5418                                                 struct config_real *conf = (struct config_real *) gconf;
5419
5420                                                 /* Could lose precision here? */
5421                                                 fprintf(fp, "%f", *conf->variable);
5422                                         }
5423                                         break;
5424
5425                                 case PGC_STRING:
5426                                         {
5427                                                 struct config_string *conf = (struct config_string *) gconf;
5428
5429                                                 fprintf(fp, "%s", *conf->variable);
5430                                         }
5431                                         break;
5432                         }
5433
5434                         fputc(0, fp);
5435
5436                         fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
5437                 }
5438         }
5439
5440         if (FreeFile(fp))
5441         {
5442                 ereport(elevel,
5443                                 (errcode_for_file_access(),
5444                                  errmsg("could not write to file \"%s\": %m",
5445                                                 CONFIG_EXEC_PARAMS_NEW)));
5446                 return;
5447         }
5448
5449         /*
5450          * Put new file in place.  This could delay on Win32, but we don't hold
5451          * any exclusive locks.
5452          */
5453         rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
5454 }
5455
5456
5457 /*
5458  *      Read string, including null byte from file
5459  *
5460  *      Return NULL on EOF and nothing read
5461  */
5462 static char *
5463 read_string_with_null(FILE *fp)
5464 {
5465         int                     i = 0,
5466                                 ch,
5467                                 maxlen = 256;
5468         char       *str = NULL;
5469
5470         do
5471         {
5472                 if ((ch = fgetc(fp)) == EOF)
5473                 {
5474                         if (i == 0)
5475                                 return NULL;
5476                         else
5477                                 elog(FATAL, "invalid format of exec config params file");
5478                 }
5479                 if (i == 0)
5480                         str = guc_malloc(FATAL, maxlen);
5481                 else if (i == maxlen)
5482                         str = guc_realloc(FATAL, str, maxlen *= 2);
5483                 str[i++] = ch;
5484         } while (ch != 0);
5485
5486         return str;
5487 }
5488
5489
5490 /*
5491  *      This routine loads a previous postmaster dump of its non-default
5492  *      settings.
5493  */
5494 void
5495 read_nondefault_variables(void)
5496 {
5497         FILE       *fp;
5498         char       *varname,
5499                            *varvalue;
5500         int                     varsource;
5501
5502         /*
5503          * Open file
5504          */
5505         fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
5506         if (!fp)
5507         {
5508                 /* File not found is fine */
5509                 if (errno != ENOENT)
5510                         ereport(FATAL,
5511                                         (errcode_for_file_access(),
5512                                          errmsg("could not read from file \"%s\": %m",
5513                                                         CONFIG_EXEC_PARAMS)));
5514                 return;
5515         }
5516
5517         for (;;)
5518         {
5519                 struct config_generic *record;
5520
5521                 if ((varname = read_string_with_null(fp)) == NULL)
5522                         break;
5523
5524                 if ((record = find_option(varname, FATAL)) == NULL)
5525                         elog(FATAL, "failed to locate variable %s in exec config params file", varname);
5526                 if ((varvalue = read_string_with_null(fp)) == NULL)
5527                         elog(FATAL, "invalid format of exec config params file");
5528                 if (fread(&varsource, sizeof(varsource), 1, fp) == 0)
5529                         elog(FATAL, "invalid format of exec config params file");
5530
5531                 (void) set_config_option(varname, varvalue, record->context,
5532                                                                  varsource, false, true);
5533                 free(varname);
5534                 free(varvalue);
5535         }
5536
5537         FreeFile(fp);
5538 }
5539 #endif   /* EXEC_BACKEND */
5540
5541
5542 /*
5543  * A little "long argument" simulation, although not quite GNU
5544  * compliant. Takes a string of the form "some-option=some value" and
5545  * returns name = "some_option" and value = "some value" in malloc'ed
5546  * storage. Note that '-' is converted to '_' in the option name. If
5547  * there is no '=' in the input string then value will be NULL.
5548  */
5549 void
5550 ParseLongOption(const char *string, char **name, char **value)
5551 {
5552         size_t          equal_pos;
5553         char       *cp;
5554
5555         AssertArg(string);
5556         AssertArg(name);
5557         AssertArg(value);
5558
5559         equal_pos = strcspn(string, "=");
5560
5561         if (string[equal_pos] == '=')
5562         {
5563                 *name = guc_malloc(FATAL, equal_pos + 1);
5564                 strncpy(*name, string, equal_pos);
5565                 (*name)[equal_pos] = '\0';
5566
5567                 *value = guc_strdup(FATAL, &string[equal_pos + 1]);
5568         }
5569         else
5570         {
5571                 /* no equal sign in string */
5572                 *name = guc_strdup(FATAL, string);
5573                 *value = NULL;
5574         }
5575
5576         for (cp = *name; *cp; cp++)
5577                 if (*cp == '-')
5578                         *cp = '_';
5579 }
5580
5581
5582 /*
5583  * Handle options fetched from pg_database.datconfig or pg_authid.rolconfig.
5584  * The array parameter must be an array of TEXT (it must not be NULL).
5585  */
5586 void
5587 ProcessGUCArray(ArrayType *array, GucSource source)
5588 {
5589         int                     i;
5590
5591         Assert(array != NULL);
5592         Assert(ARR_ELEMTYPE(array) == TEXTOID);
5593         Assert(ARR_NDIM(array) == 1);
5594         Assert(ARR_LBOUND(array)[0] == 1);
5595         Assert(source == PGC_S_DATABASE || source == PGC_S_USER);
5596
5597         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
5598         {
5599                 Datum           d;
5600                 bool            isnull;
5601                 char       *s;
5602                 char       *name;
5603                 char       *value;
5604
5605                 d = array_ref(array, 1, &i,
5606                                           -1 /* varlenarray */ ,
5607                                           -1 /* TEXT's typlen */ ,
5608                                           false /* TEXT's typbyval */ ,
5609                                           'i' /* TEXT's typalign */ ,
5610                                           &isnull);
5611
5612                 if (isnull)
5613                         continue;
5614
5615                 s = DatumGetCString(DirectFunctionCall1(textout, d));
5616
5617                 ParseLongOption(s, &name, &value);
5618                 if (!value)
5619                 {
5620                         ereport(WARNING,
5621                                         (errcode(ERRCODE_SYNTAX_ERROR),
5622                           errmsg("could not parse setting for parameter \"%s\"", name)));
5623                         free(name);
5624                         continue;
5625                 }
5626
5627                 /*
5628                  * We process all these options at SUSET level.  We assume that the
5629                  * right to insert an option into pg_database or pg_authid was checked
5630                  * when it was inserted.
5631                  */
5632                 SetConfigOption(name, value, PGC_SUSET, source);
5633
5634                 free(name);
5635                 if (value)
5636                         free(value);
5637         }
5638 }
5639
5640
5641 /*
5642  * Add an entry to an option array.  The array parameter may be NULL
5643  * to indicate the current table entry is NULL.
5644  */
5645 ArrayType *
5646 GUCArrayAdd(ArrayType *array, const char *name, const char *value)
5647 {
5648         const char *varname;
5649         Datum           datum;
5650         char       *newval;
5651         ArrayType  *a;
5652
5653         Assert(name);
5654         Assert(value);
5655
5656         /* test if the option is valid */
5657         set_config_option(name, value,
5658                                           superuser() ? PGC_SUSET : PGC_USERSET,
5659                                           PGC_S_TEST, false, false);
5660
5661         /* convert name to canonical spelling, so we can use plain strcmp */
5662         (void) GetConfigOptionByName(name, &varname);
5663         name = varname;
5664
5665         newval = palloc(strlen(name) + 1 + strlen(value) + 1);
5666         sprintf(newval, "%s=%s", name, value);
5667         datum = DirectFunctionCall1(textin, CStringGetDatum(newval));
5668
5669         if (array)
5670         {
5671                 int                     index;
5672                 bool            isnull;
5673                 int                     i;
5674
5675                 Assert(ARR_ELEMTYPE(array) == TEXTOID);
5676                 Assert(ARR_NDIM(array) == 1);
5677                 Assert(ARR_LBOUND(array)[0] == 1);
5678
5679                 index = ARR_DIMS(array)[0] + 1; /* add after end */
5680
5681                 for (i = 1; i <= ARR_DIMS(array)[0]; i++)
5682                 {
5683                         Datum           d;
5684                         char       *current;
5685
5686                         d = array_ref(array, 1, &i,
5687                                                   -1 /* varlenarray */ ,
5688                                                   -1 /* TEXT's typlen */ ,
5689                                                   false /* TEXT's typbyval */ ,
5690                                                   'i' /* TEXT's typalign */ ,
5691                                                   &isnull);
5692                         if (isnull)
5693                                 continue;
5694                         current = DatumGetCString(DirectFunctionCall1(textout, d));
5695                         if (strncmp(current, newval, strlen(name) + 1) == 0)
5696                         {
5697                                 index = i;
5698                                 break;
5699                         }
5700                 }
5701
5702                 a = array_set(array, 1, &index,
5703                                           datum,
5704                                           false,
5705                                           -1 /* varlena array */ ,
5706                                           -1 /* TEXT's typlen */ ,
5707                                           false /* TEXT's typbyval */ ,
5708                                           'i' /* TEXT's typalign */ );
5709         }
5710         else
5711                 a = construct_array(&datum, 1,
5712                                                         TEXTOID,
5713                                                         -1, false, 'i');
5714
5715         return a;
5716 }
5717
5718
5719 /*
5720  * Delete an entry from an option array.  The array parameter may be NULL
5721  * to indicate the current table entry is NULL.  Also, if the return value
5722  * is NULL then a null should be stored.
5723  */
5724 ArrayType *
5725 GUCArrayDelete(ArrayType *array, const char *name)
5726 {
5727         const char *varname;
5728         ArrayType  *newarray;
5729         int                     i;
5730         int                     index;
5731
5732         Assert(name);
5733
5734         /* test if the option is valid */
5735         set_config_option(name, NULL,
5736                                           superuser() ? PGC_SUSET : PGC_USERSET,
5737                                           PGC_S_TEST, false, false);
5738
5739         /* convert name to canonical spelling, so we can use plain strcmp */
5740         (void) GetConfigOptionByName(name, &varname);
5741         name = varname;
5742
5743         /* if array is currently null, then surely nothing to delete */
5744         if (!array)
5745                 return NULL;
5746
5747         newarray = NULL;
5748         index = 1;
5749
5750         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
5751         {
5752                 Datum           d;
5753                 char       *val;
5754                 bool            isnull;
5755
5756                 d = array_ref(array, 1, &i,
5757                                           -1 /* varlenarray */ ,
5758                                           -1 /* TEXT's typlen */ ,
5759                                           false /* TEXT's typbyval */ ,
5760                                           'i' /* TEXT's typalign */ ,
5761                                           &isnull);
5762                 if (isnull)
5763                         continue;
5764                 val = DatumGetCString(DirectFunctionCall1(textout, d));
5765
5766                 /* ignore entry if it's what we want to delete */
5767                 if (strncmp(val, name, strlen(name)) == 0
5768                         && val[strlen(name)] == '=')
5769                         continue;
5770
5771                 /* else add it to the output array */
5772                 if (newarray)
5773                 {
5774                         newarray = array_set(newarray, 1, &index,
5775                                                                  d,
5776                                                                  false,
5777                                                                  -1 /* varlenarray */ ,
5778                                                                  -1 /* TEXT's typlen */ ,
5779                                                                  false /* TEXT's typbyval */ ,
5780                                                                  'i' /* TEXT's typalign */ );
5781                 }
5782                 else
5783                         newarray = construct_array(&d, 1,
5784                                                                            TEXTOID,
5785                                                                            -1, false, 'i');
5786
5787                 index++;
5788         }
5789
5790         return newarray;
5791 }
5792
5793
5794 /*
5795  * assign_hook subroutines
5796  */
5797
5798 static const char *
5799 assign_log_destination(const char *value, bool doit, GucSource source)
5800 {
5801         char       *rawstring;
5802         List       *elemlist;
5803         ListCell   *l;
5804         int                     newlogdest = 0;
5805
5806         /* Need a modifiable copy of string */
5807         rawstring = pstrdup(value);
5808
5809         /* Parse string into list of identifiers */
5810         if (!SplitIdentifierString(rawstring, ',', &elemlist))
5811         {
5812                 /* syntax error in list */
5813                 pfree(rawstring);
5814                 list_free(elemlist);
5815                 if (source >= PGC_S_INTERACTIVE)
5816                         ereport(ERROR,
5817                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5818                         errmsg("invalid list syntax for parameter \"log_destination\"")));
5819                 return NULL;
5820         }
5821
5822         foreach(l, elemlist)
5823         {
5824                 char       *tok = (char *) lfirst(l);
5825
5826                 if (pg_strcasecmp(tok, "stderr") == 0)
5827                         newlogdest |= LOG_DESTINATION_STDERR;
5828 #ifdef HAVE_SYSLOG
5829                 else if (pg_strcasecmp(tok, "syslog") == 0)
5830                         newlogdest |= LOG_DESTINATION_SYSLOG;
5831 #endif
5832 #ifdef WIN32
5833                 else if (pg_strcasecmp(tok, "eventlog") == 0)
5834                         newlogdest |= LOG_DESTINATION_EVENTLOG;
5835 #endif
5836                 else
5837                 {
5838                         if (source >= PGC_S_INTERACTIVE)
5839                                 ereport(ERROR,
5840                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5841                                   errmsg("unrecognized \"log_destination\" key word: \"%s\"",
5842                                                  tok)));
5843                         pfree(rawstring);
5844                         list_free(elemlist);
5845                         return NULL;
5846                 }
5847         }
5848
5849         if (doit)
5850                 Log_destination = newlogdest;
5851
5852         pfree(rawstring);
5853         list_free(elemlist);
5854
5855         return value;
5856 }
5857
5858 #ifdef HAVE_SYSLOG
5859
5860 static const char *
5861 assign_syslog_facility(const char *facility, bool doit, GucSource source)
5862 {
5863         int                     syslog_fac;
5864
5865         if (pg_strcasecmp(facility, "LOCAL0") == 0)
5866                 syslog_fac = LOG_LOCAL0;
5867         else if (pg_strcasecmp(facility, "LOCAL1") == 0)
5868                 syslog_fac = LOG_LOCAL1;
5869         else if (pg_strcasecmp(facility, "LOCAL2") == 0)
5870                 syslog_fac = LOG_LOCAL2;
5871         else if (pg_strcasecmp(facility, "LOCAL3") == 0)
5872                 syslog_fac = LOG_LOCAL3;
5873         else if (pg_strcasecmp(facility, "LOCAL4") == 0)
5874                 syslog_fac = LOG_LOCAL4;
5875         else if (pg_strcasecmp(facility, "LOCAL5") == 0)
5876                 syslog_fac = LOG_LOCAL5;
5877         else if (pg_strcasecmp(facility, "LOCAL6") == 0)
5878                 syslog_fac = LOG_LOCAL6;
5879         else if (pg_strcasecmp(facility, "LOCAL7") == 0)
5880                 syslog_fac = LOG_LOCAL7;
5881         else
5882                 return NULL;                    /* reject */
5883
5884         if (doit)
5885         {
5886                 syslog_facility = syslog_fac;
5887                 set_syslog_parameters(syslog_ident_str ? syslog_ident_str : "postgres",
5888                                                           syslog_facility);
5889         }
5890
5891         return facility;
5892 }
5893
5894 static const char *
5895 assign_syslog_ident(const char *ident, bool doit, GucSource source)
5896 {
5897         if (doit)
5898                 set_syslog_parameters(ident, syslog_facility);
5899
5900         return ident;
5901 }
5902 #endif   /* HAVE_SYSLOG */
5903
5904
5905 static const char *
5906 assign_defaultxactisolevel(const char *newval, bool doit, GucSource source)
5907 {
5908         if (pg_strcasecmp(newval, "serializable") == 0)
5909         {
5910                 if (doit)
5911                         DefaultXactIsoLevel = XACT_SERIALIZABLE;
5912         }
5913         else if (pg_strcasecmp(newval, "repeatable read") == 0)
5914         {
5915                 if (doit)
5916                         DefaultXactIsoLevel = XACT_REPEATABLE_READ;
5917         }
5918         else if (pg_strcasecmp(newval, "read committed") == 0)
5919         {
5920                 if (doit)
5921                         DefaultXactIsoLevel = XACT_READ_COMMITTED;
5922         }
5923         else if (pg_strcasecmp(newval, "read uncommitted") == 0)
5924         {
5925                 if (doit)
5926                         DefaultXactIsoLevel = XACT_READ_UNCOMMITTED;
5927         }
5928         else
5929                 return NULL;
5930         return newval;
5931 }
5932
5933 static const char *
5934 assign_log_min_messages(const char *newval,
5935                                                 bool doit, GucSource source)
5936 {
5937         return (assign_msglvl(&log_min_messages, newval, doit, source));
5938 }
5939
5940 static const char *
5941 assign_client_min_messages(const char *newval, bool doit, GucSource source)
5942 {
5943         return (assign_msglvl(&client_min_messages, newval, doit, source));
5944 }
5945
5946 static const char *
5947 assign_min_error_statement(const char *newval, bool doit, GucSource source)
5948 {
5949         return (assign_msglvl(&log_min_error_statement, newval, doit, source));
5950 }
5951
5952 static const char *
5953 assign_msglvl(int *var, const char *newval, bool doit, GucSource source)
5954 {
5955         if (pg_strcasecmp(newval, "debug") == 0)
5956         {
5957                 if (doit)
5958                         (*var) = DEBUG2;
5959         }
5960         else if (pg_strcasecmp(newval, "debug5") == 0)
5961         {
5962                 if (doit)
5963                         (*var) = DEBUG5;
5964         }
5965         else if (pg_strcasecmp(newval, "debug4") == 0)
5966         {
5967                 if (doit)
5968                         (*var) = DEBUG4;
5969         }
5970         else if (pg_strcasecmp(newval, "debug3") == 0)
5971         {
5972                 if (doit)
5973                         (*var) = DEBUG3;
5974         }
5975         else if (pg_strcasecmp(newval, "debug2") == 0)
5976         {
5977                 if (doit)
5978                         (*var) = DEBUG2;
5979         }
5980         else if (pg_strcasecmp(newval, "debug1") == 0)
5981         {
5982                 if (doit)
5983                         (*var) = DEBUG1;
5984         }
5985         else if (pg_strcasecmp(newval, "log") == 0)
5986         {
5987                 if (doit)
5988                         (*var) = LOG;
5989         }
5990
5991         /*
5992          * Client_min_messages always prints 'info', but we allow it as a value
5993          * anyway.
5994          */
5995         else if (pg_strcasecmp(newval, "info") == 0)
5996         {
5997                 if (doit)
5998                         (*var) = INFO;
5999         }
6000         else if (pg_strcasecmp(newval, "notice") == 0)
6001         {
6002                 if (doit)
6003                         (*var) = NOTICE;
6004         }
6005         else if (pg_strcasecmp(newval, "warning") == 0)
6006         {
6007                 if (doit)
6008                         (*var) = WARNING;
6009         }
6010         else if (pg_strcasecmp(newval, "error") == 0)
6011         {
6012                 if (doit)
6013                         (*var) = ERROR;
6014         }
6015         /* We allow FATAL/PANIC for client-side messages too. */
6016         else if (pg_strcasecmp(newval, "fatal") == 0)
6017         {
6018                 if (doit)
6019                         (*var) = FATAL;
6020         }
6021         else if (pg_strcasecmp(newval, "panic") == 0)
6022         {
6023                 if (doit)
6024                         (*var) = PANIC;
6025         }
6026         else
6027                 return NULL;                    /* fail */
6028         return newval;                          /* OK */
6029 }
6030
6031 static const char *
6032 assign_log_error_verbosity(const char *newval, bool doit, GucSource source)
6033 {
6034         if (pg_strcasecmp(newval, "terse") == 0)
6035         {
6036                 if (doit)
6037                         Log_error_verbosity = PGERROR_TERSE;
6038         }
6039         else if (pg_strcasecmp(newval, "default") == 0)
6040         {
6041                 if (doit)
6042                         Log_error_verbosity = PGERROR_DEFAULT;
6043         }
6044         else if (pg_strcasecmp(newval, "verbose") == 0)
6045         {
6046                 if (doit)
6047                         Log_error_verbosity = PGERROR_VERBOSE;
6048         }
6049         else
6050                 return NULL;                    /* fail */
6051         return newval;                          /* OK */
6052 }
6053
6054 static const char *
6055 assign_log_statement(const char *newval, bool doit, GucSource source)
6056 {
6057         if (pg_strcasecmp(newval, "none") == 0)
6058         {
6059                 if (doit)
6060                         log_statement = LOGSTMT_NONE;
6061         }
6062         else if (pg_strcasecmp(newval, "ddl") == 0)
6063         {
6064                 if (doit)
6065                         log_statement = LOGSTMT_DDL;
6066         }
6067         else if (pg_strcasecmp(newval, "mod") == 0)
6068         {
6069                 if (doit)
6070                         log_statement = LOGSTMT_MOD;
6071         }
6072         else if (pg_strcasecmp(newval, "all") == 0)
6073         {
6074                 if (doit)
6075                         log_statement = LOGSTMT_ALL;
6076         }
6077         else
6078                 return NULL;                    /* fail */
6079         return newval;                          /* OK */
6080 }
6081
6082 static const char *
6083 show_num_temp_buffers(void)
6084 {
6085         /*
6086          * We show the GUC var until local buffers have been initialized, and
6087          * NLocBuffer afterwards.
6088          */
6089         static char nbuf[32];
6090
6091         sprintf(nbuf, "%d", NLocBuffer ? NLocBuffer : num_temp_buffers);
6092         return nbuf;
6093 }
6094
6095 static bool
6096 assign_phony_autocommit(bool newval, bool doit, GucSource source)
6097 {
6098         if (!newval)
6099         {
6100                 if (doit && source >= PGC_S_INTERACTIVE)
6101                         ereport(ERROR,
6102                                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
6103                                          errmsg("SET AUTOCOMMIT TO OFF is no longer supported")));
6104                 return false;
6105         }
6106         return true;
6107 }
6108
6109 static const char *
6110 assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
6111 {
6112         /*
6113          * Check syntax. newval must be a comma separated list of identifiers.
6114          * Whitespace is allowed but skipped.
6115          */
6116         bool            hasSpaceAfterToken = false;
6117         const char *cp = newval;
6118         int                     symLen = 0;
6119         int                     c;
6120         StringInfoData buf;
6121
6122         initStringInfo(&buf);
6123         while ((c = *cp++) != 0)
6124         {
6125                 if (isspace(c))
6126                 {
6127                         if (symLen > 0)
6128                                 hasSpaceAfterToken = true;
6129                         continue;
6130                 }
6131
6132                 if (c == ',')
6133                 {
6134                         hasSpaceAfterToken = false;
6135                         if (symLen > 0)
6136                         {
6137                                 symLen = 0;
6138                                 appendStringInfoChar(&buf, ',');
6139                         }
6140                         continue;
6141                 }
6142
6143                 if (hasSpaceAfterToken || !isalnum(c))
6144                 {
6145                         /*
6146                          * Syntax error due to token following space after token or non
6147                          * alpha numeric character
6148                          */
6149                         ereport(LOG,
6150                                         (errcode(ERRCODE_SYNTAX_ERROR),
6151                                          errmsg("invalid syntax for \"custom_variable_classes\": \"%s\"", newval)));
6152                         pfree(buf.data);
6153                         return NULL;
6154                 }
6155                 symLen++;
6156                 appendStringInfoChar(&buf, (char) c);
6157         }
6158
6159         /* Remove stray ',' at end */
6160         if (symLen == 0 && buf.len > 0)
6161                 buf.data[--buf.len] = '\0';
6162
6163         if (buf.len == 0)
6164                 newval = NULL;
6165         else if (doit)
6166                 newval = strdup(buf.data);
6167
6168         pfree(buf.data);
6169         return newval;
6170 }
6171
6172 static bool
6173 assign_debug_assertions(bool newval, bool doit, GucSource source)
6174 {
6175 #ifndef USE_ASSERT_CHECKING
6176         if (newval)
6177                 ereport(ERROR,
6178                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
6179                                  errmsg("assertion checking is not supported by this build")));
6180 #endif
6181         return true;
6182 }
6183
6184 static bool
6185 assign_ssl(bool newval, bool doit, GucSource source)
6186 {
6187 #ifndef USE_SSL
6188         if (newval)
6189                 ereport(ERROR,
6190                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
6191                                  errmsg("SSL is not supported by this build")));
6192 #endif
6193         return true;
6194 }
6195
6196 static bool
6197 assign_stage_log_stats(bool newval, bool doit, GucSource source)
6198 {
6199         if (newval && log_statement_stats)
6200         {
6201                 if (source >= PGC_S_INTERACTIVE)
6202                         ereport(ERROR,
6203                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
6204                                          errmsg("cannot enable parameter when \"log_statement_stats\" is true")));
6205                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
6206                 else if (source != PGC_S_OVERRIDE)
6207                         return false;
6208         }
6209         return true;
6210 }
6211
6212 static bool
6213 assign_log_stats(bool newval, bool doit, GucSource source)
6214 {
6215         if (newval &&
6216                 (log_parser_stats || log_planner_stats || log_executor_stats))
6217         {
6218                 if (source >= PGC_S_INTERACTIVE)
6219                         ereport(ERROR,
6220                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
6221                                          errmsg("cannot enable \"log_statement_stats\" when "
6222                                                         "\"log_parser_stats\", \"log_planner_stats\", "
6223                                                         "or \"log_executor_stats\" is true")));
6224                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
6225                 else if (source != PGC_S_OVERRIDE)
6226                         return false;
6227         }
6228         return true;
6229 }
6230
6231 static bool
6232 assign_transaction_read_only(bool newval, bool doit, GucSource source)
6233 {
6234         /* Can't go to r/w mode inside a r/o transaction */
6235         if (newval == false && XactReadOnly && IsSubTransaction())
6236         {
6237                 if (source >= PGC_S_INTERACTIVE)
6238                         ereport(ERROR,
6239                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
6240                                          errmsg("cannot set transaction read-write mode inside a read-only transaction")));
6241                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
6242                 else if (source != PGC_S_OVERRIDE)
6243                         return false;
6244         }
6245         return true;
6246 }
6247
6248 static const char *
6249 assign_canonical_path(const char *newval, bool doit, GucSource source)
6250 {
6251         if (doit)
6252         {
6253                 char       *canon_val = guc_strdup(ERROR, newval);
6254
6255                 canonicalize_path(canon_val);
6256                 return canon_val;
6257         }
6258         else
6259                 return newval;
6260 }
6261
6262 static const char *
6263 assign_backslash_quote(const char *newval, bool doit, GucSource source)
6264 {
6265         BackslashQuoteType bq;
6266         bool    bqbool;
6267
6268         /*
6269          * Although only "on", "off", and "safe_encoding" are documented,
6270          * we use parse_bool so we can accept all the likely variants of
6271          * "on" and "off".
6272          */
6273         if (pg_strcasecmp(newval, "safe_encoding") == 0)
6274                 bq = BACKSLASH_QUOTE_SAFE_ENCODING;
6275         else if (parse_bool(newval, &bqbool))
6276         {
6277                 bq = bqbool ? BACKSLASH_QUOTE_ON : BACKSLASH_QUOTE_OFF;
6278         }
6279         else
6280                 return NULL;                    /* reject */
6281
6282         if (doit)
6283                 backslash_quote = bq;
6284
6285         return newval;
6286 }
6287
6288 static const char *
6289 assign_timezone_abbreviations(const char *newval, bool doit, GucSource source)
6290 {
6291         /*
6292          * The powerup value shown above for timezone_abbreviations is "UNKNOWN".
6293          * When we see this we just do nothing.  If this value isn't overridden
6294          * from the config file then pg_timezone_abbrev_initialize() will
6295          * eventually replace it with "Default".  This hack has two purposes:
6296          * to avoid wasting cycles loading values that might soon be overridden
6297          * from the config file, and to avoid trying to read the timezone abbrev
6298          * files during InitializeGUCOptions().  The latter doesn't work in an
6299          * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet and
6300          * so we can't locate PGSHAREDIR.  (Essentially the same hack is used
6301          * to delay initializing TimeZone ... if we have any more, we should
6302          * try to clean up and centralize this mechanism ...)
6303          */
6304         if (strcmp(newval, "UNKNOWN") == 0)
6305         {
6306                 return newval;
6307         }
6308
6309         /* Loading abbrev file is expensive, so only do it when value changes */
6310         if (timezone_abbreviations_string == NULL ||
6311                 strcmp(timezone_abbreviations_string, newval) != 0)
6312         {
6313                 int             elevel;
6314
6315                 /*
6316                  * If reading config file, only the postmaster should bleat loudly
6317                  * about problems.  Otherwise, it's just this one process doing it,
6318                  * and we use WARNING message level.
6319                  */
6320                 if (source == PGC_S_FILE)
6321                         elevel = IsUnderPostmaster ? DEBUG2 : LOG;
6322                 else
6323                         elevel = WARNING;
6324                 if (!load_tzoffsets(newval, doit, elevel))
6325                         return NULL;
6326         }
6327         return newval;
6328 }
6329
6330 /*
6331  * pg_timezone_abbrev_initialize --- set default value if not done already
6332  *
6333  * This is called after initial loading of postgresql.conf.  If no
6334  * timezone_abbreviations setting was found therein, select default.
6335  */
6336 void
6337 pg_timezone_abbrev_initialize(void)
6338 {
6339         if (strcmp(timezone_abbreviations_string, "UNKNOWN") == 0)
6340         {
6341                 SetConfigOption("timezone_abbreviations", "Default",
6342                                                 PGC_POSTMASTER, PGC_S_ARGV);
6343         }
6344 }
6345
6346 static bool
6347 assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
6348 {
6349         if (doit)
6350                 return (pq_setkeepalivesidle(newval, MyProcPort) == STATUS_OK);
6351
6352         return true;
6353 }
6354
6355 static const char *
6356 show_tcp_keepalives_idle(void)
6357 {
6358         static char nbuf[16];
6359
6360         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
6361         return nbuf;
6362 }
6363
6364 static bool
6365 assign_tcp_keepalives_interval(int newval, bool doit, GucSource source)
6366 {
6367         if (doit)
6368                 return (pq_setkeepalivesinterval(newval, MyProcPort) == STATUS_OK);
6369
6370         return true;
6371 }
6372
6373 static const char *
6374 show_tcp_keepalives_interval(void)
6375 {
6376         static char nbuf[16];
6377
6378         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
6379         return nbuf;
6380 }
6381
6382 static bool
6383 assign_tcp_keepalives_count(int newval, bool doit, GucSource source)
6384 {
6385         if (doit)
6386                 return (pq_setkeepalivescount(newval, MyProcPort) == STATUS_OK);
6387
6388         return true;
6389 }
6390
6391 static const char *
6392 show_tcp_keepalives_count(void)
6393 {
6394         static char nbuf[16];
6395
6396         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
6397         return nbuf;
6398 }
6399
6400
6401 #include "guc-file.c"