granicus.if.org Git - postgresql/blob - contrib/tablefunc/tablefunc.c

   1 /*
   2  * contrib/tablefunc/tablefunc.c
   3  *
   4  *
   5  * tablefunc
   6  *
   7  * Sample to demonstrate C functions which return setof scalar
   8  * and setof composite.
   9  * Joe Conway <mail@joeconway.com>
  10  * And contributors:
  11  * Nabil Sayegh <postgresql@e-trolley.de>
  12  *
  13  * Copyright (c) 2002-2012, PostgreSQL Global Development Group
  14  *
  15  * Permission to use, copy, modify, and distribute this software and its
  16  * documentation for any purpose, without fee, and without a written agreement
  17  * is hereby granted, provided that the above copyright notice and this
  18  * paragraph and the following two paragraphs appear in all copies.
  19  *
  20  * IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
  21  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
  22  * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
  23  * DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE
  24  * POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
  27  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  28  * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  29  * ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO
  30  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  31  *
  32  */
  33 #include "postgres.h"
  34
  35 #include <math.h>
  36
  37 #include "access/htup_details.h"
  38 #include "catalog/pg_type.h"
  39 #include "executor/spi.h"
  40 #include "funcapi.h"
  41 #include "lib/stringinfo.h"
  42 #include "miscadmin.h"
  43 #include "utils/builtins.h"
  44
  45 #include "tablefunc.h"
  46
  47 PG_MODULE_MAGIC;
  48
  49 static HTAB *load_categories_hash(char *cats_sql, MemoryContext per_query_ctx);
  50 static Tuplestorestate *get_crosstab_tuplestore(char *sql,
  51                                                 HTAB *crosstab_hash,
  52                                                 TupleDesc tupdesc,
  53                                                 MemoryContext per_query_ctx,
  54                                                 bool randomAccess);
  55 static void validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch, bool show_serial);
  56 static bool compatCrosstabTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
  57 static bool compatConnectbyTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
  58 static void get_normal_pair(float8 *x1, float8 *x2);
  59 static Tuplestorestate *connectby(char *relname,
  60                   char *key_fld,
  61                   char *parent_key_fld,
  62                   char *orderby_fld,
  63                   char *branch_delim,
  64                   char *start_with,
  65                   int max_depth,
  66                   bool show_branch,
  67                   bool show_serial,
  68                   MemoryContext per_query_ctx,
  69                   bool randomAccess,
  70                   AttInMetadata *attinmeta);
  71 static Tuplestorestate *build_tuplestore_recursively(char *key_fld,
  72                                                          char *parent_key_fld,
  73                                                          char *relname,
  74                                                          char *orderby_fld,
  75                                                          char *branch_delim,
  76                                                          char *start_with,
  77                                                          char *branch,
  78                                                          int level,
  79                                                          int *serial,
  80                                                          int max_depth,
  81                                                          bool show_branch,
  82                                                          bool show_serial,
  83                                                          MemoryContext per_query_ctx,
  84                                                          AttInMetadata *attinmeta,
  85                                                          Tuplestorestate *tupstore);
  86
  87 typedef struct
  88 {
  89         float8          mean;                   /* mean of the distribution */
  90         float8          stddev;                 /* stddev of the distribution */
  91         float8          carry_val;              /* hold second generated value */
  92         bool            use_carry;              /* use second generated value */
  93 } normal_rand_fctx;
  94
  95 #define xpfree(var_) \
  96         do { \
  97                 if (var_ != NULL) \
  98                 { \
  99                         pfree(var_); \
 100                         var_ = NULL; \
 101                 } \
 102         } while (0)
 103
 104 #define xpstrdup(tgtvar_, srcvar_) \
 105         do { \
 106                 if (srcvar_) \
 107                         tgtvar_ = pstrdup(srcvar_); \
 108                 else \
 109                         tgtvar_ = NULL; \
 110         } while (0)
 111
 112 #define xstreq(tgtvar_, srcvar_) \
 113         (((tgtvar_ == NULL) && (srcvar_ == NULL)) || \
 114          ((tgtvar_ != NULL) && (srcvar_ != NULL) && (strcmp(tgtvar_, srcvar_) == 0)))
 115
 116 /* sign, 10 digits, '\0' */
 117 #define INT32_STRLEN    12
 118
 119 /* stored info for a crosstab category */
 120 typedef struct crosstab_cat_desc
 121 {
 122         char       *catname;            /* full category name */
 123         int                     attidx;                 /* zero based */
 124 } crosstab_cat_desc;
 125
 126 #define MAX_CATNAME_LEN                 NAMEDATALEN
 127 #define INIT_CATS                               64
 128
 129 #define crosstab_HashTableLookup(HASHTAB, CATNAME, CATDESC) \
 130 do { \
 131         crosstab_HashEnt *hentry; char key[MAX_CATNAME_LEN]; \
 132         \
 133         MemSet(key, 0, MAX_CATNAME_LEN); \
 134         snprintf(key, MAX_CATNAME_LEN - 1, "%s", CATNAME); \
 135         hentry = (crosstab_HashEnt*) hash_search(HASHTAB, \
 136                                                                                  key, HASH_FIND, NULL); \
 137         if (hentry) \
 138                 CATDESC = hentry->catdesc; \
 139         else \
 140                 CATDESC = NULL; \
 141 } while(0)
 142
 143 #define crosstab_HashTableInsert(HASHTAB, CATDESC) \
 144 do { \
 145         crosstab_HashEnt *hentry; bool found; char key[MAX_CATNAME_LEN]; \
 146         \
 147         MemSet(key, 0, MAX_CATNAME_LEN); \
 148         snprintf(key, MAX_CATNAME_LEN - 1, "%s", CATDESC->catname); \
 149         hentry = (crosstab_HashEnt*) hash_search(HASHTAB, \
 150                                                                                  key, HASH_ENTER, &found); \
 151         if (found) \
 152                 ereport(ERROR, \
 153                                 (errcode(ERRCODE_DUPLICATE_OBJECT), \
 154                                  errmsg("duplicate category name"))); \
 155         hentry->catdesc = CATDESC; \
 156 } while(0)
 157
 158 /* hash table */
 159 typedef struct crosstab_hashent
 160 {
 161         char            internal_catname[MAX_CATNAME_LEN];
 162         crosstab_cat_desc *catdesc;
 163 } crosstab_HashEnt;
 164
 165 /*
 166  * normal_rand - return requested number of random values
 167  * with a Gaussian (Normal) distribution.
 168  *
 169  * inputs are int numvals, float8 mean, and float8 stddev
 170  * returns setof float8
 171  */
 172 PG_FUNCTION_INFO_V1(normal_rand);
 173 Datum
 174 normal_rand(PG_FUNCTION_ARGS)
 175 {
 176         FuncCallContext *funcctx;
 177         int                     call_cntr;
 178         int                     max_calls;
 179         normal_rand_fctx *fctx;
 180         float8          mean;
 181         float8          stddev;
 182         float8          carry_val;
 183         bool            use_carry;
 184         MemoryContext oldcontext;
 185
 186         /* stuff done only on the first call of the function */
 187         if (SRF_IS_FIRSTCALL())
 188         {
 189                 /* create a function context for cross-call persistence */
 190                 funcctx = SRF_FIRSTCALL_INIT();
 191
 192                 /*
 193                  * switch to memory context appropriate for multiple function calls
 194                  */
 195                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
 196
 197                 /* total number of tuples to be returned */
 198                 funcctx->max_calls = PG_GETARG_UINT32(0);
 199
 200                 /* allocate memory for user context */
 201                 fctx = (normal_rand_fctx *) palloc(sizeof(normal_rand_fctx));
 202
 203                 /*
 204                  * Use fctx to keep track of upper and lower bounds from call to call.
 205                  * It will also be used to carry over the spare value we get from the
 206                  * Box-Muller algorithm so that we only actually calculate a new value
 207                  * every other call.
 208                  */
 209                 fctx->mean = PG_GETARG_FLOAT8(1);
 210                 fctx->stddev = PG_GETARG_FLOAT8(2);
 211                 fctx->carry_val = 0;
 212                 fctx->use_carry = false;
 213
 214                 funcctx->user_fctx = fctx;
 215
 216                 MemoryContextSwitchTo(oldcontext);
 217         }
 218
 219         /* stuff done on every call of the function */
 220         funcctx = SRF_PERCALL_SETUP();
 221
 222         call_cntr = funcctx->call_cntr;
 223         max_calls = funcctx->max_calls;
 224         fctx = funcctx->user_fctx;
 225         mean = fctx->mean;
 226         stddev = fctx->stddev;
 227         carry_val = fctx->carry_val;
 228         use_carry = fctx->use_carry;
 229
 230         if (call_cntr < max_calls)      /* do when there is more left to send */
 231         {
 232                 float8          result;
 233
 234                 if (use_carry)
 235                 {
 236                         /*
 237                          * reset use_carry and use second value obtained on last pass
 238                          */
 239                         fctx->use_carry = false;
 240                         result = carry_val;
 241                 }
 242                 else
 243                 {
 244                         float8          normval_1;
 245                         float8          normval_2;
 246
 247                         /* Get the next two normal values */
 248                         get_normal_pair(&normval_1, &normval_2);
 249
 250                         /* use the first */
 251                         result = mean + (stddev * normval_1);
 252
 253                         /* and save the second */
 254                         fctx->carry_val = mean + (stddev * normval_2);
 255                         fctx->use_carry = true;
 256                 }
 257
 258                 /* send the result */
 259                 SRF_RETURN_NEXT(funcctx, Float8GetDatum(result));
 260         }
 261         else
 262                 /* do when there is no more left */
 263                 SRF_RETURN_DONE(funcctx);
 264 }
 265
 266 /*
 267  * get_normal_pair()
 268  * Assigns normally distributed (Gaussian) values to a pair of provided
 269  * parameters, with mean 0, standard deviation 1.
 270  *
 271  * This routine implements Algorithm P (Polar method for normal deviates)
 272  * from Knuth's _The_Art_of_Computer_Programming_, Volume 2, 3rd ed., pages
 273  * 122-126. Knuth cites his source as "The polar method", G. E. P. Box, M. E.
 274  * Muller, and G. Marsaglia, _Annals_Math,_Stat._ 29 (1958), 610-611.
 275  *
 276  */
 277 static void
 278 get_normal_pair(float8 *x1, float8 *x2)
 279 {
 280         float8          u1,
 281                                 u2,
 282                                 v1,
 283                                 v2,
 284                                 s;
 285
 286         do
 287         {
 288                 u1 = (float8) random() / (float8) MAX_RANDOM_VALUE;
 289                 u2 = (float8) random() / (float8) MAX_RANDOM_VALUE;
 290
 291                 v1 = (2.0 * u1) - 1.0;
 292                 v2 = (2.0 * u2) - 1.0;
 293
 294                 s = v1 * v1 + v2 * v2;
 295         } while (s >= 1.0);
 296
 297         if (s == 0)
 298         {
 299                 *x1 = 0;
 300                 *x2 = 0;
 301         }
 302         else
 303         {
 304                 s = sqrt((-2.0 * log(s)) / s);
 305                 *x1 = v1 * s;
 306                 *x2 = v2 * s;
 307         }
 308 }
 309
 310 /*
 311  * crosstab - create a crosstab of rowids and values columns from a
 312  * SQL statement returning one rowid column, one category column,
 313  * and one value column.
 314  *
 315  * e.g. given sql which produces:
 316  *
 317  *                      rowid   cat             value
 318  *                      ------+-------+-------
 319  *                      row1    cat1    val1
 320  *                      row1    cat2    val2
 321  *                      row1    cat3    val3
 322  *                      row1    cat4    val4
 323  *                      row2    cat1    val5
 324  *                      row2    cat2    val6
 325  *                      row2    cat3    val7
 326  *                      row2    cat4    val8
 327  *
 328  * crosstab returns:
 329  *                                      <===== values columns =====>
 330  *                      rowid   cat1    cat2    cat3    cat4
 331  *                      ------+-------+-------+-------+-------
 332  *                      row1    val1    val2    val3    val4
 333  *                      row2    val5    val6    val7    val8
 334  *
 335  * NOTES:
 336  * 1. SQL result must be ordered by 1,2.
 337  * 2. The number of values columns depends on the tuple description
 338  *        of the function's declared return type.  The return type's columns
 339  *        must match the datatypes of the SQL query's result.  The datatype
 340  *        of the category column can be anything, however.
 341  * 3. Missing values (i.e. not enough adjacent rows of same rowid to
 342  *        fill the number of result values columns) are filled in with nulls.
 343  * 4. Extra values (i.e. too many adjacent rows of same rowid to fill
 344  *        the number of result values columns) are skipped.
 345  * 5. Rows with all nulls in the values columns are skipped.
 346  */
 347 PG_FUNCTION_INFO_V1(crosstab);
 348 Datum
 349 crosstab(PG_FUNCTION_ARGS)
 350 {
 351         char       *sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
 352         ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
 353         Tuplestorestate *tupstore;
 354         TupleDesc       tupdesc;
 355         int                     call_cntr;
 356         int                     max_calls;
 357         AttInMetadata *attinmeta;
 358         SPITupleTable *spi_tuptable;
 359         TupleDesc       spi_tupdesc;
 360         bool            firstpass;
 361         char       *lastrowid;
 362         int                     i;
 363         int                     num_categories;
 364         MemoryContext per_query_ctx;
 365         MemoryContext oldcontext;
 366         int                     ret;
 367         int                     proc;
 368
 369         /* check to see if caller supports us returning a tuplestore */
 370         if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
 371                 ereport(ERROR,
 372                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 373                                  errmsg("set-valued function called in context that cannot accept a set")));
 374         if (!(rsinfo->allowedModes & SFRM_Materialize))
 375                 ereport(ERROR,
 376                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 377                                  errmsg("materialize mode required, but it is not " \
 378                                                 "allowed in this context")));
 379
 380         per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
 381
 382         /* Connect to SPI manager */
 383         if ((ret = SPI_connect()) < 0)
 384                 /* internal error */
 385                 elog(ERROR, "crosstab: SPI_connect returned %d", ret);
 386
 387         /* Retrieve the desired rows */
 388         ret = SPI_execute(sql, true, 0);
 389         proc = SPI_processed;
 390
 391         /* If no qualifying tuples, fall out early */
 392         if (ret != SPI_OK_SELECT || proc <= 0)
 393         {
 394                 SPI_finish();
 395                 rsinfo->isDone = ExprEndResult;
 396                 PG_RETURN_NULL();
 397         }
 398
 399         spi_tuptable = SPI_tuptable;
 400         spi_tupdesc = spi_tuptable->tupdesc;
 401
 402         /*----------
 403          * The provided SQL query must always return three columns.
 404          *
 405          * 1. rowname
 406          *      the label or identifier for each row in the final result
 407          * 2. category
 408          *      the label or identifier for each column in the final result
 409          * 3. values
 410          *      the value for each column in the final result
 411          *----------
 412          */
 413         if (spi_tupdesc->natts != 3)
 414                 ereport(ERROR,
 415                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 416                                  errmsg("invalid source data SQL statement"),
 417                                  errdetail("The provided SQL must return 3 "
 418                                                    "columns: rowid, category, and values.")));
 419
 420         /* get a tuple descriptor for our result type */
 421         switch (get_call_result_type(fcinfo, NULL, &tupdesc))
 422         {
 423                 case TYPEFUNC_COMPOSITE:
 424                         /* success */
 425                         break;
 426                 case TYPEFUNC_RECORD:
 427                         /* failed to determine actual type of RECORD */
 428                         ereport(ERROR,
 429                                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 430                                          errmsg("function returning record called in context "
 431                                                         "that cannot accept type record")));
 432                         break;
 433                 default:
 434                         /* result type isn't composite */
 435                         elog(ERROR, "return type must be a row type");
 436                         break;
 437         }
 438
 439         /*
 440          * Check that return tupdesc is compatible with the data we got from SPI,
 441          * at least based on number and type of attributes
 442          */
 443         if (!compatCrosstabTupleDescs(tupdesc, spi_tupdesc))
 444                 ereport(ERROR,
 445                                 (errcode(ERRCODE_SYNTAX_ERROR),
 446                                  errmsg("return and sql tuple descriptions are " \
 447                                                 "incompatible")));
 448
 449         /*
 450          * switch to long-lived memory context
 451          */
 452         oldcontext = MemoryContextSwitchTo(per_query_ctx);
 453
 454         /* make sure we have a persistent copy of the result tupdesc */
 455         tupdesc = CreateTupleDescCopy(tupdesc);
 456
 457         /* initialize our tuplestore in long-lived context */
 458         tupstore =
 459                 tuplestore_begin_heap(rsinfo->allowedModes & SFRM_Materialize_Random,
 460                                                           false, work_mem);
 461
 462         MemoryContextSwitchTo(oldcontext);
 463
 464         /*
 465          * Generate attribute metadata needed later to produce tuples from raw C
 466          * strings
 467          */
 468         attinmeta = TupleDescGetAttInMetadata(tupdesc);
 469
 470         /* total number of tuples to be examined */
 471         max_calls = proc;
 472
 473         /* the return tuple always must have 1 rowid + num_categories columns */
 474         num_categories = tupdesc->natts - 1;
 475
 476         firstpass = true;
 477         lastrowid = NULL;
 478
 479         for (call_cntr = 0; call_cntr < max_calls; call_cntr++)
 480         {
 481                 bool            skip_tuple = false;
 482                 char      **values;
 483
 484                 /* allocate and zero space */
 485                 values = (char **) palloc0((1 + num_categories) * sizeof(char *));
 486
 487                 /*
 488                  * now loop through the sql results and assign each value in sequence
 489                  * to the next category
 490                  */
 491                 for (i = 0; i < num_categories; i++)
 492                 {
 493                         HeapTuple       spi_tuple;
 494                         char       *rowid;
 495
 496                         /* see if we've gone too far already */
 497                         if (call_cntr >= max_calls)
 498                                 break;
 499
 500                         /* get the next sql result tuple */
 501                         spi_tuple = spi_tuptable->vals[call_cntr];
 502
 503                         /* get the rowid from the current sql result tuple */
 504                         rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
 505
 506                         /*
 507                          * If this is the first pass through the values for this rowid,
 508                          * set the first column to rowid
 509                          */
 510                         if (i == 0)
 511                         {
 512                                 xpstrdup(values[0], rowid);
 513
 514                                 /*
 515                                  * Check to see if the rowid is the same as that of the last
 516                                  * tuple sent -- if so, skip this tuple entirely
 517                                  */
 518                                 if (!firstpass && xstreq(lastrowid, rowid))
 519                                 {
 520                                         xpfree(rowid);
 521                                         skip_tuple = true;
 522                                         break;
 523                                 }
 524                         }
 525
 526                         /*
 527                          * If rowid hasn't changed on us, continue building the output
 528                          * tuple.
 529                          */
 530                         if (xstreq(rowid, values[0]))
 531                         {
 532                                 /*
 533                                  * Get the next category item value, which is always attribute
 534                                  * number three.
 535                                  *
 536                                  * Be careful to assign the value to the array index based on
 537                                  * which category we are presently processing.
 538                                  */
 539                                 values[1 + i] = SPI_getvalue(spi_tuple, spi_tupdesc, 3);
 540
 541                                 /*
 542                                  * increment the counter since we consume a row for each
 543                                  * category, but not for last pass because the outer loop will
 544                                  * do that for us
 545                                  */
 546                                 if (i < (num_categories - 1))
 547                                         call_cntr++;
 548                                 xpfree(rowid);
 549                         }
 550                         else
 551                         {
 552                                 /*
 553                                  * We'll fill in NULLs for the missing values, but we need to
 554                                  * decrement the counter since this sql result row doesn't
 555                                  * belong to the current output tuple.
 556                                  */
 557                                 call_cntr--;
 558                                 xpfree(rowid);
 559                                 break;
 560                         }
 561                 }
 562
 563                 if (!skip_tuple)
 564                 {
 565                         HeapTuple       tuple;
 566
 567                         /* build the tuple and store it */
 568                         tuple = BuildTupleFromCStrings(attinmeta, values);
 569                         tuplestore_puttuple(tupstore, tuple);
 570                         heap_freetuple(tuple);
 571                 }
 572
 573                 /* Remember current rowid */
 574                 xpfree(lastrowid);
 575                 xpstrdup(lastrowid, values[0]);
 576                 firstpass = false;
 577
 578                 /* Clean up */
 579                 for (i = 0; i < num_categories + 1; i++)
 580                         if (values[i] != NULL)
 581                                 pfree(values[i]);
 582                 pfree(values);
 583         }
 584
 585         /* let the caller know we're sending back a tuplestore */
 586         rsinfo->returnMode = SFRM_Materialize;
 587         rsinfo->setResult = tupstore;
 588         rsinfo->setDesc = tupdesc;
 589
 590         /* release SPI related resources (and return to caller's context) */
 591         SPI_finish();
 592
 593         return (Datum) 0;
 594 }
 595
 596 /*
 597  * crosstab_hash - reimplement crosstab as materialized function and
 598  * properly deal with missing values (i.e. don't pack remaining
 599  * values to the left)
 600  *
 601  * crosstab - create a crosstab of rowids and values columns from a
 602  * SQL statement returning one rowid column, one category column,
 603  * and one value column.
 604  *
 605  * e.g. given sql which produces:
 606  *
 607  *                      rowid   cat             value
 608  *                      ------+-------+-------
 609  *                      row1    cat1    val1
 610  *                      row1    cat2    val2
 611  *                      row1    cat4    val4
 612  *                      row2    cat1    val5
 613  *                      row2    cat2    val6
 614  *                      row2    cat3    val7
 615  *                      row2    cat4    val8
 616  *
 617  * crosstab returns:
 618  *                                      <===== values columns =====>
 619  *                      rowid   cat1    cat2    cat3    cat4
 620  *                      ------+-------+-------+-------+-------
 621  *                      row1    val1    val2    null    val4
 622  *                      row2    val5    val6    val7    val8
 623  *
 624  * NOTES:
 625  * 1. SQL result must be ordered by 1.
 626  * 2. The number of values columns depends on the tuple description
 627  *        of the function's declared return type.
 628  * 3. Missing values (i.e. missing category) are filled in with nulls.
 629  * 4. Extra values (i.e. not in category results) are skipped.
 630  */
 631 PG_FUNCTION_INFO_V1(crosstab_hash);
 632 Datum
 633 crosstab_hash(PG_FUNCTION_ARGS)
 634 {
 635         char       *sql = text_to_cstring(PG_GETARG_TEXT_PP(0));
 636         char       *cats_sql = text_to_cstring(PG_GETARG_TEXT_PP(1));
 637         ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
 638         TupleDesc       tupdesc;
 639         MemoryContext per_query_ctx;
 640         MemoryContext oldcontext;
 641         HTAB       *crosstab_hash;
 642
 643         /* check to see if caller supports us returning a tuplestore */
 644         if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
 645                 ereport(ERROR,
 646                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 647                                  errmsg("set-valued function called in context that cannot accept a set")));
 648         if (!(rsinfo->allowedModes & SFRM_Materialize) ||
 649                 rsinfo->expectedDesc == NULL)
 650                 ereport(ERROR,
 651                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 652                                  errmsg("materialize mode required, but it is not " \
 653                                                 "allowed in this context")));
 654
 655         per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
 656         oldcontext = MemoryContextSwitchTo(per_query_ctx);
 657
 658         /* get the requested return tuple description */
 659         tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
 660
 661         /*
 662          * Check to make sure we have a reasonable tuple descriptor
 663          *
 664          * Note we will attempt to coerce the values into whatever the return
 665          * attribute type is and depend on the "in" function to complain if
 666          * needed.
 667          */
 668         if (tupdesc->natts < 2)
 669                 ereport(ERROR,
 670                                 (errcode(ERRCODE_SYNTAX_ERROR),
 671                                  errmsg("query-specified return tuple and " \
 672                                                 "crosstab function are not compatible")));
 673
 674         /* load up the categories hash table */
 675         crosstab_hash = load_categories_hash(cats_sql, per_query_ctx);
 676
 677         /* let the caller know we're sending back a tuplestore */
 678         rsinfo->returnMode = SFRM_Materialize;
 679
 680         /* now go build it */
 681         rsinfo->setResult = get_crosstab_tuplestore(sql,
 682                                                                                                 crosstab_hash,
 683                                                                                                 tupdesc,
 684                                                                                                 per_query_ctx,
 685                                                          rsinfo->allowedModes & SFRM_Materialize_Random);
 686
 687         /*
 688          * SFRM_Materialize mode expects us to return a NULL Datum. The actual
 689          * tuples are in our tuplestore and passed back through rsinfo->setResult.
 690          * rsinfo->setDesc is set to the tuple description that we actually used
 691          * to build our tuples with, so the caller can verify we did what it was
 692          * expecting.
 693          */
 694         rsinfo->setDesc = tupdesc;
 695         MemoryContextSwitchTo(oldcontext);
 696
 697         return (Datum) 0;
 698 }
 699
 700 /*
 701  * load up the categories hash table
 702  */
 703 static HTAB *
 704 load_categories_hash(char *cats_sql, MemoryContext per_query_ctx)
 705 {
 706         HTAB       *crosstab_hash;
 707         HASHCTL         ctl;
 708         int                     ret;
 709         int                     proc;
 710         MemoryContext SPIcontext;
 711
 712         /* initialize the category hash table */
 713         MemSet(&ctl, 0, sizeof(ctl));
 714         ctl.keysize = MAX_CATNAME_LEN;
 715         ctl.entrysize = sizeof(crosstab_HashEnt);
 716         ctl.hcxt = per_query_ctx;
 717
 718         /*
 719          * use INIT_CATS, defined above as a guess of how many hash table entries
 720          * to create, initially
 721          */
 722         crosstab_hash = hash_create("crosstab hash",
 723                                                                 INIT_CATS,
 724                                                                 &ctl,
 725                                                                 HASH_ELEM | HASH_CONTEXT);
 726
 727         /* Connect to SPI manager */
 728         if ((ret = SPI_connect()) < 0)
 729                 /* internal error */
 730                 elog(ERROR, "load_categories_hash: SPI_connect returned %d", ret);
 731
 732         /* Retrieve the category name rows */
 733         ret = SPI_execute(cats_sql, true, 0);
 734         proc = SPI_processed;
 735
 736         /* Check for qualifying tuples */
 737         if ((ret == SPI_OK_SELECT) && (proc > 0))
 738         {
 739                 SPITupleTable *spi_tuptable = SPI_tuptable;
 740                 TupleDesc       spi_tupdesc = spi_tuptable->tupdesc;
 741                 int                     i;
 742
 743                 /*
 744                  * The provided categories SQL query must always return one column:
 745                  * category - the label or identifier for each column
 746                  */
 747                 if (spi_tupdesc->natts != 1)
 748                         ereport(ERROR,
 749                                         (errcode(ERRCODE_SYNTAX_ERROR),
 750                                          errmsg("provided \"categories\" SQL must " \
 751                                                         "return 1 column of at least one row")));
 752
 753                 for (i = 0; i < proc; i++)
 754                 {
 755                         crosstab_cat_desc *catdesc;
 756                         char       *catname;
 757                         HeapTuple       spi_tuple;
 758
 759                         /* get the next sql result tuple */
 760                         spi_tuple = spi_tuptable->vals[i];
 761
 762                         /* get the category from the current sql result tuple */
 763                         catname = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
 764
 765                         SPIcontext = MemoryContextSwitchTo(per_query_ctx);
 766
 767                         catdesc = (crosstab_cat_desc *) palloc(sizeof(crosstab_cat_desc));
 768                         catdesc->catname = catname;
 769                         catdesc->attidx = i;
 770
 771                         /* Add the proc description block to the hashtable */
 772                         crosstab_HashTableInsert(crosstab_hash, catdesc);
 773
 774                         MemoryContextSwitchTo(SPIcontext);
 775                 }
 776         }
 777
 778         if (SPI_finish() != SPI_OK_FINISH)
 779                 /* internal error */
 780                 elog(ERROR, "load_categories_hash: SPI_finish() failed");
 781
 782         return crosstab_hash;
 783 }
 784
 785 /*
 786  * create and populate the crosstab tuplestore using the provided source query
 787  */
 788 static Tuplestorestate *
 789 get_crosstab_tuplestore(char *sql,
 790                                                 HTAB *crosstab_hash,
 791                                                 TupleDesc tupdesc,
 792                                                 MemoryContext per_query_ctx,
 793                                                 bool randomAccess)
 794 {
 795         Tuplestorestate *tupstore;
 796         int                     num_categories = hash_get_num_entries(crosstab_hash);
 797         AttInMetadata *attinmeta = TupleDescGetAttInMetadata(tupdesc);
 798         char      **values;
 799         HeapTuple       tuple;
 800         int                     ret;
 801         int                     proc;
 802
 803         /* initialize our tuplestore (while still in query context!) */
 804         tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
 805
 806         /* Connect to SPI manager */
 807         if ((ret = SPI_connect()) < 0)
 808                 /* internal error */
 809                 elog(ERROR, "get_crosstab_tuplestore: SPI_connect returned %d", ret);
 810
 811         /* Now retrieve the crosstab source rows */
 812         ret = SPI_execute(sql, true, 0);
 813         proc = SPI_processed;
 814
 815         /* Check for qualifying tuples */
 816         if ((ret == SPI_OK_SELECT) && (proc > 0))
 817         {
 818                 SPITupleTable *spi_tuptable = SPI_tuptable;
 819                 TupleDesc       spi_tupdesc = spi_tuptable->tupdesc;
 820                 int                     ncols = spi_tupdesc->natts;
 821                 char       *rowid;
 822                 char       *lastrowid = NULL;
 823                 bool            firstpass = true;
 824                 int                     i,
 825                                         j;
 826                 int                     result_ncols;
 827
 828                 if (num_categories == 0)
 829                 {
 830                         /* no qualifying category tuples */
 831                         ereport(ERROR,
 832                                         (errcode(ERRCODE_SYNTAX_ERROR),
 833                                          errmsg("provided \"categories\" SQL must " \
 834                                                         "return 1 column of at least one row")));
 835                 }
 836
 837                 /*
 838                  * The provided SQL query must always return at least three columns:
 839                  *
 840                  * 1. rowname   the label for each row - column 1 in the final result
 841                  * 2. category  the label for each value-column in the final result 3.
 842                  * value         the values used to populate the value-columns
 843                  *
 844                  * If there are more than three columns, the last two are taken as
 845                  * "category" and "values". The first column is taken as "rowname".
 846                  * Additional columns (2 thru N-2) are assumed the same for the same
 847                  * "rowname", and are copied into the result tuple from the first time
 848                  * we encounter a particular rowname.
 849                  */
 850                 if (ncols < 3)
 851                         ereport(ERROR,
 852                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 853                                          errmsg("invalid source data SQL statement"),
 854                                          errdetail("The provided SQL must return 3 " \
 855                                                            " columns; rowid, category, and values.")));
 856
 857                 result_ncols = (ncols - 2) + num_categories;
 858
 859                 /* Recheck to make sure we tuple descriptor still looks reasonable */
 860                 if (tupdesc->natts != result_ncols)
 861                         ereport(ERROR,
 862                                         (errcode(ERRCODE_SYNTAX_ERROR),
 863                                          errmsg("invalid return type"),
 864                                          errdetail("Query-specified return " \
 865                                                            "tuple has %d columns but crosstab " \
 866                                                            "returns %d.", tupdesc->natts, result_ncols)));
 867
 868                 /* allocate space */
 869                 values = (char **) palloc(result_ncols * sizeof(char *));
 870
 871                 /* and make sure it's clear */
 872                 memset(values, '\0', result_ncols * sizeof(char *));
 873
 874                 for (i = 0; i < proc; i++)
 875                 {
 876                         HeapTuple       spi_tuple;
 877                         crosstab_cat_desc *catdesc;
 878                         char       *catname;
 879
 880                         /* get the next sql result tuple */
 881                         spi_tuple = spi_tuptable->vals[i];
 882
 883                         /* get the rowid from the current sql result tuple */
 884                         rowid = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
 885
 886                         /*
 887                          * if we're on a new output row, grab the column values up to
 888                          * column N-2 now
 889                          */
 890                         if (firstpass || !xstreq(lastrowid, rowid))
 891                         {
 892                                 /*
 893                                  * a new row means we need to flush the old one first, unless
 894                                  * we're on the very first row
 895                                  */
 896                                 if (!firstpass)
 897                                 {
 898                                         /* rowid changed, flush the previous output row */
 899                                         tuple = BuildTupleFromCStrings(attinmeta, values);
 900
 901                                         tuplestore_puttuple(tupstore, tuple);
 902
 903                                         for (j = 0; j < result_ncols; j++)
 904                                                 xpfree(values[j]);
 905                                 }
 906
 907                                 values[0] = rowid;
 908                                 for (j = 1; j < ncols - 2; j++)
 909                                         values[j] = SPI_getvalue(spi_tuple, spi_tupdesc, j + 1);
 910
 911                                 /* we're no longer on the first pass */
 912                                 firstpass = false;
 913                         }
 914
 915                         /* look up the category and fill in the appropriate column */
 916                         catname = SPI_getvalue(spi_tuple, spi_tupdesc, ncols - 1);
 917
 918                         if (catname != NULL)
 919                         {
 920                                 crosstab_HashTableLookup(crosstab_hash, catname, catdesc);
 921
 922                                 if (catdesc)
 923                                         values[catdesc->attidx + ncols - 2] =
 924                                                 SPI_getvalue(spi_tuple, spi_tupdesc, ncols);
 925                         }
 926
 927                         xpfree(lastrowid);
 928                         xpstrdup(lastrowid, rowid);
 929                 }
 930
 931                 /* flush the last output row */
 932                 tuple = BuildTupleFromCStrings(attinmeta, values);
 933
 934                 tuplestore_puttuple(tupstore, tuple);
 935         }
 936
 937         if (SPI_finish() != SPI_OK_FINISH)
 938                 /* internal error */
 939                 elog(ERROR, "get_crosstab_tuplestore: SPI_finish() failed");
 940
 941         tuplestore_donestoring(tupstore);
 942
 943         return tupstore;
 944 }
 945
 946 /*
 947  * connectby_text - produce a result set from a hierarchical (parent/child)
 948  * table.
 949  *
 950  * e.g. given table foo:
 951  *
 952  *                      keyid   parent_keyid pos
 953  *                      ------+------------+--
 954  *                      row1    NULL             0
 955  *                      row2    row1             0
 956  *                      row3    row1             0
 957  *                      row4    row2             1
 958  *                      row5    row2             0
 959  *                      row6    row4             0
 960  *                      row7    row3             0
 961  *                      row8    row6             0
 962  *                      row9    row5             0
 963  *
 964  *
 965  * connectby(text relname, text keyid_fld, text parent_keyid_fld
 966  *                        [, text orderby_fld], text start_with, int max_depth
 967  *                        [, text branch_delim])
 968  * connectby('foo', 'keyid', 'parent_keyid', 'pos', 'row2', 0, '~') returns:
 969  *
 970  *              keyid   parent_id       level    branch                         serial
 971  *              ------+-----------+--------+-----------------------
 972  *              row2    NULL              0               row2                            1
 973  *              row5    row2              1               row2~row5                       2
 974  *              row9    row5              2               row2~row5~row9          3
 975  *              row4    row2              1               row2~row4                       4
 976  *              row6    row4              2               row2~row4~row6          5
 977  *              row8    row6              3               row2~row4~row6~row8 6
 978  *
 979  */
 980 PG_FUNCTION_INFO_V1(connectby_text);
 981
 982 #define CONNECTBY_NCOLS                                 4
 983 #define CONNECTBY_NCOLS_NOBRANCH                3
 984
 985 Datum
 986 connectby_text(PG_FUNCTION_ARGS)
 987 {
 988         char       *relname = text_to_cstring(PG_GETARG_TEXT_PP(0));
 989         char       *key_fld = text_to_cstring(PG_GETARG_TEXT_PP(1));
 990         char       *parent_key_fld = text_to_cstring(PG_GETARG_TEXT_PP(2));
 991         char       *start_with = text_to_cstring(PG_GETARG_TEXT_PP(3));
 992         int                     max_depth = PG_GETARG_INT32(4);
 993         char       *branch_delim = NULL;
 994         bool            show_branch = false;
 995         bool            show_serial = false;
 996         ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
 997         TupleDesc       tupdesc;
 998         AttInMetadata *attinmeta;
 999         MemoryContext per_query_ctx;
1000         MemoryContext oldcontext;
1001
1002         /* check to see if caller supports us returning a tuplestore */
1003         if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
1004                 ereport(ERROR,
1005                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1006                                  errmsg("set-valued function called in context that cannot accept a set")));
1007         if (!(rsinfo->allowedModes & SFRM_Materialize) ||
1008                 rsinfo->expectedDesc == NULL)
1009                 ereport(ERROR,
1010                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1011                                  errmsg("materialize mode required, but it is not " \
1012                                                 "allowed in this context")));
1013
1014         if (fcinfo->nargs == 6)
1015         {
1016                 branch_delim = text_to_cstring(PG_GETARG_TEXT_PP(5));
1017                 show_branch = true;
1018         }
1019         else
1020                 /* default is no show, tilde for the delimiter */
1021                 branch_delim = pstrdup("~");
1022
1023         per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
1024         oldcontext = MemoryContextSwitchTo(per_query_ctx);
1025
1026         /* get the requested return tuple description */
1027         tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
1028
1029         /* does it meet our needs */
1030         validateConnectbyTupleDesc(tupdesc, show_branch, show_serial);
1031
1032         /* OK, use it then */
1033         attinmeta = TupleDescGetAttInMetadata(tupdesc);
1034
1035         /* OK, go to work */
1036         rsinfo->returnMode = SFRM_Materialize;
1037         rsinfo->setResult = connectby(relname,
1038                                                                   key_fld,
1039                                                                   parent_key_fld,
1040                                                                   NULL,
1041                                                                   branch_delim,
1042                                                                   start_with,
1043                                                                   max_depth,
1044                                                                   show_branch,
1045                                                                   show_serial,
1046                                                                   per_query_ctx,
1047                                                           rsinfo->allowedModes & SFRM_Materialize_Random,
1048                                                                   attinmeta);
1049         rsinfo->setDesc = tupdesc;
1050
1051         MemoryContextSwitchTo(oldcontext);
1052
1053         /*
1054          * SFRM_Materialize mode expects us to return a NULL Datum. The actual
1055          * tuples are in our tuplestore and passed back through rsinfo->setResult.
1056          * rsinfo->setDesc is set to the tuple description that we actually used
1057          * to build our tuples with, so the caller can verify we did what it was
1058          * expecting.
1059          */
1060         return (Datum) 0;
1061 }
1062
1063 PG_FUNCTION_INFO_V1(connectby_text_serial);
1064 Datum
1065 connectby_text_serial(PG_FUNCTION_ARGS)
1066 {
1067         char       *relname = text_to_cstring(PG_GETARG_TEXT_PP(0));
1068         char       *key_fld = text_to_cstring(PG_GETARG_TEXT_PP(1));
1069         char       *parent_key_fld = text_to_cstring(PG_GETARG_TEXT_PP(2));
1070         char       *orderby_fld = text_to_cstring(PG_GETARG_TEXT_PP(3));
1071         char       *start_with = text_to_cstring(PG_GETARG_TEXT_PP(4));
1072         int                     max_depth = PG_GETARG_INT32(5);
1073         char       *branch_delim = NULL;
1074         bool            show_branch = false;
1075         bool            show_serial = true;
1076         ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
1077         TupleDesc       tupdesc;
1078         AttInMetadata *attinmeta;
1079         MemoryContext per_query_ctx;
1080         MemoryContext oldcontext;
1081
1082         /* check to see if caller supports us returning a tuplestore */
1083         if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
1084                 ereport(ERROR,
1085                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1086                                  errmsg("set-valued function called in context that cannot accept a set")));
1087         if (!(rsinfo->allowedModes & SFRM_Materialize) ||
1088                 rsinfo->expectedDesc == NULL)
1089                 ereport(ERROR,
1090                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1091                                  errmsg("materialize mode required, but it is not " \
1092                                                 "allowed in this context")));
1093
1094         if (fcinfo->nargs == 7)
1095         {
1096                 branch_delim = text_to_cstring(PG_GETARG_TEXT_PP(6));
1097                 show_branch = true;
1098         }
1099         else
1100                 /* default is no show, tilde for the delimiter */
1101                 branch_delim = pstrdup("~");
1102
1103         per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
1104         oldcontext = MemoryContextSwitchTo(per_query_ctx);
1105
1106         /* get the requested return tuple description */
1107         tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
1108
1109         /* does it meet our needs */
1110         validateConnectbyTupleDesc(tupdesc, show_branch, show_serial);
1111
1112         /* OK, use it then */
1113         attinmeta = TupleDescGetAttInMetadata(tupdesc);
1114
1115         /* OK, go to work */
1116         rsinfo->returnMode = SFRM_Materialize;
1117         rsinfo->setResult = connectby(relname,
1118                                                                   key_fld,
1119                                                                   parent_key_fld,
1120                                                                   orderby_fld,
1121                                                                   branch_delim,
1122                                                                   start_with,
1123                                                                   max_depth,
1124                                                                   show_branch,
1125                                                                   show_serial,
1126                                                                   per_query_ctx,
1127                                                           rsinfo->allowedModes & SFRM_Materialize_Random,
1128                                                                   attinmeta);
1129         rsinfo->setDesc = tupdesc;
1130
1131         MemoryContextSwitchTo(oldcontext);
1132
1133         /*
1134          * SFRM_Materialize mode expects us to return a NULL Datum. The actual
1135          * tuples are in our tuplestore and passed back through rsinfo->setResult.
1136          * rsinfo->setDesc is set to the tuple description that we actually used
1137          * to build our tuples with, so the caller can verify we did what it was
1138          * expecting.
1139          */
1140         return (Datum) 0;
1141 }
1142
1143
1144 /*
1145  * connectby - does the real work for connectby_text()
1146  */
1147 static Tuplestorestate *
1148 connectby(char *relname,
1149                   char *key_fld,
1150                   char *parent_key_fld,
1151                   char *orderby_fld,
1152                   char *branch_delim,
1153                   char *start_with,
1154                   int max_depth,
1155                   bool show_branch,
1156                   bool show_serial,
1157                   MemoryContext per_query_ctx,
1158                   bool randomAccess,
1159                   AttInMetadata *attinmeta)
1160 {
1161         Tuplestorestate *tupstore = NULL;
1162         int                     ret;
1163         MemoryContext oldcontext;
1164
1165         int                     serial = 1;
1166
1167         /* Connect to SPI manager */
1168         if ((ret = SPI_connect()) < 0)
1169                 /* internal error */
1170                 elog(ERROR, "connectby: SPI_connect returned %d", ret);
1171
1172         /* switch to longer term context to create the tuple store */
1173         oldcontext = MemoryContextSwitchTo(per_query_ctx);
1174
1175         /* initialize our tuplestore */
1176         tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
1177
1178         MemoryContextSwitchTo(oldcontext);
1179
1180         /* now go get the whole tree */
1181         tupstore = build_tuplestore_recursively(key_fld,
1182                                                                                         parent_key_fld,
1183                                                                                         relname,
1184                                                                                         orderby_fld,
1185                                                                                         branch_delim,
1186                                                                                         start_with,
1187                                                                                         start_with, /* current_branch */
1188                                                                                         0,      /* initial level is 0 */
1189                                                                                         &serial,        /* initial serial is 1 */
1190                                                                                         max_depth,
1191                                                                                         show_branch,
1192                                                                                         show_serial,
1193                                                                                         per_query_ctx,
1194                                                                                         attinmeta,
1195                                                                                         tupstore);
1196
1197         SPI_finish();
1198
1199         return tupstore;
1200 }
1201
1202 static Tuplestorestate *
1203 build_tuplestore_recursively(char *key_fld,
1204                                                          char *parent_key_fld,
1205                                                          char *relname,
1206                                                          char *orderby_fld,
1207                                                          char *branch_delim,
1208                                                          char *start_with,
1209                                                          char *branch,
1210                                                          int level,
1211                                                          int *serial,
1212                                                          int max_depth,
1213                                                          bool show_branch,
1214                                                          bool show_serial,
1215                                                          MemoryContext per_query_ctx,
1216                                                          AttInMetadata *attinmeta,
1217                                                          Tuplestorestate *tupstore)
1218 {
1219         TupleDesc       tupdesc = attinmeta->tupdesc;
1220         int                     ret;
1221         int                     proc;
1222         int                     serial_column;
1223         StringInfoData sql;
1224         char      **values;
1225         char       *current_key;
1226         char       *current_key_parent;
1227         char            current_level[INT32_STRLEN];
1228         char            serial_str[INT32_STRLEN];
1229         char       *current_branch;
1230         HeapTuple       tuple;
1231
1232         if (max_depth > 0 && level > max_depth)
1233                 return tupstore;
1234
1235         initStringInfo(&sql);
1236
1237         /* Build initial sql statement */
1238         if (!show_serial)
1239         {
1240                 appendStringInfo(&sql, "SELECT %s, %s FROM %s WHERE %s = %s AND %s IS NOT NULL AND %s <> %s",
1241                                                  key_fld,
1242                                                  parent_key_fld,
1243                                                  relname,
1244                                                  parent_key_fld,
1245                                                  quote_literal_cstr(start_with),
1246                                                  key_fld, key_fld, parent_key_fld);
1247                 serial_column = 0;
1248         }
1249         else
1250         {
1251                 appendStringInfo(&sql, "SELECT %s, %s FROM %s WHERE %s = %s AND %s IS NOT NULL AND %s <> %s ORDER BY %s",
1252                                                  key_fld,
1253                                                  parent_key_fld,
1254                                                  relname,
1255                                                  parent_key_fld,
1256                                                  quote_literal_cstr(start_with),
1257                                                  key_fld, key_fld, parent_key_fld,
1258                                                  orderby_fld);
1259                 serial_column = 1;
1260         }
1261
1262         if (show_branch)
1263                 values = (char **) palloc((CONNECTBY_NCOLS + serial_column) * sizeof(char *));
1264         else
1265                 values = (char **) palloc((CONNECTBY_NCOLS_NOBRANCH + serial_column) * sizeof(char *));
1266
1267         /* First time through, do a little setup */
1268         if (level == 0)
1269         {
1270                 /* root value is the one we initially start with */
1271                 values[0] = start_with;
1272
1273                 /* root value has no parent */
1274                 values[1] = NULL;
1275
1276                 /* root level is 0 */
1277                 sprintf(current_level, "%d", level);
1278                 values[2] = current_level;
1279
1280                 /* root branch is just starting root value */
1281                 if (show_branch)
1282                         values[3] = start_with;
1283
1284                 /* root starts the serial with 1 */
1285                 if (show_serial)
1286                 {
1287                         sprintf(serial_str, "%d", (*serial)++);
1288                         if (show_branch)
1289                                 values[4] = serial_str;
1290                         else
1291                                 values[3] = serial_str;
1292                 }
1293
1294                 /* construct the tuple */
1295                 tuple = BuildTupleFromCStrings(attinmeta, values);
1296
1297                 /* now store it */
1298                 tuplestore_puttuple(tupstore, tuple);
1299
1300                 /* increment level */
1301                 level++;
1302         }
1303
1304         /* Retrieve the desired rows */
1305         ret = SPI_execute(sql.data, true, 0);
1306         proc = SPI_processed;
1307
1308         /* Check for qualifying tuples */
1309         if ((ret == SPI_OK_SELECT) && (proc > 0))
1310         {
1311                 HeapTuple       spi_tuple;
1312                 SPITupleTable *tuptable = SPI_tuptable;
1313                 TupleDesc       spi_tupdesc = tuptable->tupdesc;
1314                 int                     i;
1315                 StringInfoData branchstr;
1316                 StringInfoData chk_branchstr;
1317                 StringInfoData chk_current_key;
1318
1319                 /* First time through, do a little more setup */
1320                 if (level == 0)
1321                 {
1322                         /*
1323                          * Check that return tupdesc is compatible with the one we got
1324                          * from the query, but only at level 0 -- no need to check more
1325                          * than once
1326                          */
1327
1328                         if (!compatConnectbyTupleDescs(tupdesc, spi_tupdesc))
1329                                 ereport(ERROR,
1330                                                 (errcode(ERRCODE_SYNTAX_ERROR),
1331                                                  errmsg("invalid return type"),
1332                                                  errdetail("Return and SQL tuple descriptions are " \
1333                                                                    "incompatible.")));
1334                 }
1335
1336                 initStringInfo(&branchstr);
1337                 initStringInfo(&chk_branchstr);
1338                 initStringInfo(&chk_current_key);
1339
1340                 for (i = 0; i < proc; i++)
1341                 {
1342                         /* initialize branch for this pass */
1343                         appendStringInfo(&branchstr, "%s", branch);
1344                         appendStringInfo(&chk_branchstr, "%s%s%s", branch_delim, branch, branch_delim);
1345
1346                         /* get the next sql result tuple */
1347                         spi_tuple = tuptable->vals[i];
1348
1349                         /* get the current key and parent */
1350                         current_key = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
1351                         appendStringInfo(&chk_current_key, "%s%s%s", branch_delim, current_key, branch_delim);
1352                         current_key_parent = pstrdup(SPI_getvalue(spi_tuple, spi_tupdesc, 2));
1353
1354                         /* get the current level */
1355                         sprintf(current_level, "%d", level);
1356
1357                         /* check to see if this key is also an ancestor */
1358                         if (strstr(chk_branchstr.data, chk_current_key.data))
1359                                 elog(ERROR, "infinite recursion detected");
1360
1361                         /* OK, extend the branch */
1362                         appendStringInfo(&branchstr, "%s%s", branch_delim, current_key);
1363                         current_branch = branchstr.data;
1364
1365                         /* build a tuple */
1366                         values[0] = pstrdup(current_key);
1367                         values[1] = current_key_parent;
1368                         values[2] = current_level;
1369                         if (show_branch)
1370                                 values[3] = current_branch;
1371                         if (show_serial)
1372                         {
1373                                 sprintf(serial_str, "%d", (*serial)++);
1374                                 if (show_branch)
1375                                         values[4] = serial_str;
1376                                 else
1377                                         values[3] = serial_str;
1378                         }
1379
1380                         tuple = BuildTupleFromCStrings(attinmeta, values);
1381
1382                         xpfree(current_key);
1383                         xpfree(current_key_parent);
1384
1385                         /* store the tuple for later use */
1386                         tuplestore_puttuple(tupstore, tuple);
1387
1388                         heap_freetuple(tuple);
1389
1390                         /* recurse using current_key_parent as the new start_with */
1391                         tupstore = build_tuplestore_recursively(key_fld,
1392                                                                                                         parent_key_fld,
1393                                                                                                         relname,
1394                                                                                                         orderby_fld,
1395                                                                                                         branch_delim,
1396                                                                                                         values[0],
1397                                                                                                         current_branch,
1398                                                                                                         level + 1,
1399                                                                                                         serial,
1400                                                                                                         max_depth,
1401                                                                                                         show_branch,
1402                                                                                                         show_serial,
1403                                                                                                         per_query_ctx,
1404                                                                                                         attinmeta,
1405                                                                                                         tupstore);
1406
1407                         /* reset branch for next pass */
1408                         resetStringInfo(&branchstr);
1409                         resetStringInfo(&chk_branchstr);
1410                         resetStringInfo(&chk_current_key);
1411                 }
1412
1413                 xpfree(branchstr.data);
1414                 xpfree(chk_branchstr.data);
1415                 xpfree(chk_current_key.data);
1416         }
1417
1418         return tupstore;
1419 }
1420
1421 /*
1422  * Check expected (query runtime) tupdesc suitable for Connectby
1423  */
1424 static void
1425 validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch, bool show_serial)
1426 {
1427         int                     serial_column = 0;
1428
1429         if (show_serial)
1430                 serial_column = 1;
1431
1432         /* are there the correct number of columns */
1433         if (show_branch)
1434         {
1435                 if (tupdesc->natts != (CONNECTBY_NCOLS + serial_column))
1436                         ereport(ERROR,
1437                                         (errcode(ERRCODE_SYNTAX_ERROR),
1438                                          errmsg("invalid return type"),
1439                                          errdetail("Query-specified return tuple has " \
1440                                                            "wrong number of columns.")));
1441         }
1442         else
1443         {
1444                 if (tupdesc->natts != CONNECTBY_NCOLS_NOBRANCH + serial_column)
1445                         ereport(ERROR,
1446                                         (errcode(ERRCODE_SYNTAX_ERROR),
1447                                          errmsg("invalid return type"),
1448                                          errdetail("Query-specified return tuple has " \
1449                                                            "wrong number of columns.")));
1450         }
1451
1452         /* check that the types of the first two columns match */
1453         if (tupdesc->attrs[0]->atttypid != tupdesc->attrs[1]->atttypid)
1454                 ereport(ERROR,
1455                                 (errcode(ERRCODE_SYNTAX_ERROR),
1456                                  errmsg("invalid return type"),
1457                                  errdetail("First two columns must be the same type.")));
1458
1459         /* check that the type of the third column is INT4 */
1460         if (tupdesc->attrs[2]->atttypid != INT4OID)
1461                 ereport(ERROR,
1462                                 (errcode(ERRCODE_SYNTAX_ERROR),
1463                                  errmsg("invalid return type"),
1464                                  errdetail("Third column must be type %s.",
1465                                                    format_type_be(INT4OID))));
1466
1467         /* check that the type of the fourth column is TEXT if applicable */
1468         if (show_branch && tupdesc->attrs[3]->atttypid != TEXTOID)
1469                 ereport(ERROR,
1470                                 (errcode(ERRCODE_SYNTAX_ERROR),
1471                                  errmsg("invalid return type"),
1472                                  errdetail("Fourth column must be type %s.",
1473                                                    format_type_be(TEXTOID))));
1474
1475         /* check that the type of the fifth column is INT4 */
1476         if (show_branch && show_serial && tupdesc->attrs[4]->atttypid != INT4OID)
1477                 elog(ERROR, "query-specified return tuple not valid for Connectby: "
1478                          "fifth column must be type %s", format_type_be(INT4OID));
1479
1480         /* check that the type of the fifth column is INT4 */
1481         if (!show_branch && show_serial && tupdesc->attrs[3]->atttypid != INT4OID)
1482                 elog(ERROR, "query-specified return tuple not valid for Connectby: "
1483                          "fourth column must be type %s", format_type_be(INT4OID));
1484
1485         /* OK, the tupdesc is valid for our purposes */
1486 }
1487
1488 /*
1489  * Check if spi sql tupdesc and return tupdesc are compatible
1490  */
1491 static bool
1492 compatConnectbyTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc)
1493 {
1494         Oid                     ret_atttypid;
1495         Oid                     sql_atttypid;
1496
1497         /* check the key_fld types match */
1498         ret_atttypid = ret_tupdesc->attrs[0]->atttypid;
1499         sql_atttypid = sql_tupdesc->attrs[0]->atttypid;
1500         if (ret_atttypid != sql_atttypid)
1501                 ereport(ERROR,
1502                                 (errcode(ERRCODE_SYNTAX_ERROR),
1503                                  errmsg("invalid return type"),
1504                                  errdetail("SQL key field datatype does " \
1505                                                    "not match return key field datatype.")));
1506
1507         /* check the parent_key_fld types match */
1508         ret_atttypid = ret_tupdesc->attrs[1]->atttypid;
1509         sql_atttypid = sql_tupdesc->attrs[1]->atttypid;
1510         if (ret_atttypid != sql_atttypid)
1511                 ereport(ERROR,
1512                                 (errcode(ERRCODE_SYNTAX_ERROR),
1513                                  errmsg("invalid return type"),
1514                                  errdetail("SQL parent key field datatype does " \
1515                                                    "not match return parent key field datatype.")));
1516
1517         /* OK, the two tupdescs are compatible for our purposes */
1518         return true;
1519 }
1520
1521 /*
1522  * Check if two tupdescs match in type of attributes
1523  */
1524 static bool
1525 compatCrosstabTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc)
1526 {
1527         int                     i;
1528         Form_pg_attribute ret_attr;
1529         Oid                     ret_atttypid;
1530         Form_pg_attribute sql_attr;
1531         Oid                     sql_atttypid;
1532
1533         if (ret_tupdesc->natts < 2 ||
1534                 sql_tupdesc->natts < 3)
1535                 return false;
1536
1537         /* check the rowid types match */
1538         ret_atttypid = ret_tupdesc->attrs[0]->atttypid;
1539         sql_atttypid = sql_tupdesc->attrs[0]->atttypid;
1540         if (ret_atttypid != sql_atttypid)
1541                 ereport(ERROR,
1542                                 (errcode(ERRCODE_SYNTAX_ERROR),
1543                                  errmsg("invalid return type"),
1544                                  errdetail("SQL rowid datatype does not match " \
1545                                                    "return rowid datatype.")));
1546
1547         /*
1548          * - attribute [1] of the sql tuple is the category; no need to check it -
1549          * attribute [2] of the sql tuple should match attributes [1] to [natts]
1550          * of the return tuple
1551          */
1552         sql_attr = sql_tupdesc->attrs[2];
1553         for (i = 1; i < ret_tupdesc->natts; i++)
1554         {
1555                 ret_attr = ret_tupdesc->attrs[i];
1556
1557                 if (ret_attr->atttypid != sql_attr->atttypid)
1558                         return false;
1559         }
1560
1561         /* OK, the two tupdescs are compatible for our purposes */
1562         return true;
1563 }