granicus.if.org Git - postgresql/blob - src/backend/utils/adt/json.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * json.c
   4  *              JSON data type support.
   5  *
   6  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  * IDENTIFICATION
  10  *        src/backend/utils/adt/json.c
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #include "postgres.h"
  15
  16 #include "access/htup_details.h"
  17 #include "access/transam.h"
  18 #include "catalog/pg_type.h"
  19 #include "executor/spi.h"
  20 #include "lib/stringinfo.h"
  21 #include "libpq/pqformat.h"
  22 #include "mb/pg_wchar.h"
  23 #include "miscadmin.h"
  24 #include "parser/parse_coerce.h"
  25 #include "utils/array.h"
  26 #include "utils/builtins.h"
  27 #include "utils/date.h"
  28 #include "utils/datetime.h"
  29 #include "utils/lsyscache.h"
  30 #include "utils/json.h"
  31 #include "utils/jsonapi.h"
  32 #include "utils/typcache.h"
  33 #include "utils/syscache.h"
  34
  35 /*
  36  * The context of the parser is maintained by the recursive descent
  37  * mechanism, but is passed explicitly to the error reporting routine
  38  * for better diagnostics.
  39  */
  40 typedef enum                                    /* contexts of JSON parser */
  41 {
  42         JSON_PARSE_VALUE,                       /* expecting a value */
  43         JSON_PARSE_STRING,                      /* expecting a string (for a field name) */
  44         JSON_PARSE_ARRAY_START,         /* saw '[', expecting value or ']' */
  45         JSON_PARSE_ARRAY_NEXT,          /* saw array element, expecting ',' or ']' */
  46         JSON_PARSE_OBJECT_START,        /* saw '{', expecting label or '}' */
  47         JSON_PARSE_OBJECT_LABEL,        /* saw object label, expecting ':' */
  48         JSON_PARSE_OBJECT_NEXT,         /* saw object value, expecting ',' or '}' */
  49         JSON_PARSE_OBJECT_COMMA,        /* saw object ',', expecting next label */
  50         JSON_PARSE_END                          /* saw the end of a document, expect nothing */
  51 } JsonParseContext;
  52
  53 typedef enum                                    /* type categories for datum_to_json */
  54 {
  55         JSONTYPE_NULL,                          /* null, so we didn't bother to identify */
  56         JSONTYPE_BOOL,                          /* boolean (built-in types only) */
  57         JSONTYPE_NUMERIC,                       /* numeric (ditto) */
  58         JSONTYPE_DATE,                          /* we use special formatting for datetimes */
  59         JSONTYPE_TIMESTAMP,
  60         JSONTYPE_TIMESTAMPTZ,
  61         JSONTYPE_JSON,                          /* JSON itself (and JSONB) */
  62         JSONTYPE_ARRAY,                         /* array */
  63         JSONTYPE_COMPOSITE,                     /* composite */
  64         JSONTYPE_CAST,                          /* something with an explicit cast to JSON */
  65         JSONTYPE_OTHER                          /* all else */
  66 } JsonTypeCategory;
  67
  68 typedef struct JsonAggState
  69 {
  70         StringInfo      str;
  71         JsonTypeCategory key_category;
  72         Oid                     key_output_func;
  73         JsonTypeCategory val_category;
  74         Oid                     val_output_func;
  75 } JsonAggState;
  76
  77 static inline void json_lex(JsonLexContext *lex);
  78 static inline void json_lex_string(JsonLexContext *lex);
  79 static inline void json_lex_number(JsonLexContext *lex, char *s,
  80                                 bool *num_err, int *total_len);
  81 static inline void parse_scalar(JsonLexContext *lex, JsonSemAction *sem);
  82 static void parse_object_field(JsonLexContext *lex, JsonSemAction *sem);
  83 static void parse_object(JsonLexContext *lex, JsonSemAction *sem);
  84 static void parse_array_element(JsonLexContext *lex, JsonSemAction *sem);
  85 static void parse_array(JsonLexContext *lex, JsonSemAction *sem);
  86 static void report_parse_error(JsonParseContext ctx, JsonLexContext *lex);
  87 static void report_invalid_token(JsonLexContext *lex);
  88 static int      report_json_context(JsonLexContext *lex);
  89 static char *extract_mb_char(char *s);
  90 static void composite_to_json(Datum composite, StringInfo result,
  91                                   bool use_line_feeds);
  92 static void array_dim_to_json(StringInfo result, int dim, int ndims, int *dims,
  93                                   Datum *vals, bool *nulls, int *valcount,
  94                                   JsonTypeCategory tcategory, Oid outfuncoid,
  95                                   bool use_line_feeds);
  96 static void array_to_json_internal(Datum array, StringInfo result,
  97                                            bool use_line_feeds);
  98 static void json_categorize_type(Oid typoid,
  99                                          JsonTypeCategory *tcategory,
 100                                          Oid *outfuncoid);
 101 static void datum_to_json(Datum val, bool is_null, StringInfo result,
 102                           JsonTypeCategory tcategory, Oid outfuncoid,
 103                           bool key_scalar);
 104 static void add_json(Datum val, bool is_null, StringInfo result,
 105                  Oid val_type, bool key_scalar);
 106 static text *catenate_stringinfo_string(StringInfo buffer, const char *addon);
 107
 108 /* the null action object used for pure validation */
 109 static JsonSemAction nullSemAction =
 110 {
 111         NULL, NULL, NULL, NULL, NULL,
 112         NULL, NULL, NULL, NULL, NULL
 113 };
 114
 115 /* Recursive Descent parser support routines */
 116
 117 /*
 118  * lex_peek
 119  *
 120  * what is the current look_ahead token?
 121 */
 122 static inline JsonTokenType
 123 lex_peek(JsonLexContext *lex)
 124 {
 125         return lex->token_type;
 126 }
 127
 128 /*
 129  * lex_accept
 130  *
 131  * accept the look_ahead token and move the lexer to the next token if the
 132  * look_ahead token matches the token parameter. In that case, and if required,
 133  * also hand back the de-escaped lexeme.
 134  *
 135  * returns true if the token matched, false otherwise.
 136  */
 137 static inline bool
 138 lex_accept(JsonLexContext *lex, JsonTokenType token, char **lexeme)
 139 {
 140         if (lex->token_type == token)
 141         {
 142                 if (lexeme != NULL)
 143                 {
 144                         if (lex->token_type == JSON_TOKEN_STRING)
 145                         {
 146                                 if (lex->strval != NULL)
 147                                         *lexeme = pstrdup(lex->strval->data);
 148                         }
 149                         else
 150                         {
 151                                 int                     len = (lex->token_terminator - lex->token_start);
 152                                 char       *tokstr = palloc(len + 1);
 153
 154                                 memcpy(tokstr, lex->token_start, len);
 155                                 tokstr[len] = '\0';
 156                                 *lexeme = tokstr;
 157                         }
 158                 }
 159                 json_lex(lex);
 160                 return true;
 161         }
 162         return false;
 163 }
 164
 165 /*
 166  * lex_accept
 167  *
 168  * move the lexer to the next token if the current look_ahead token matches
 169  * the parameter token. Otherwise, report an error.
 170  */
 171 static inline void
 172 lex_expect(JsonParseContext ctx, JsonLexContext *lex, JsonTokenType token)
 173 {
 174         if (!lex_accept(lex, token, NULL))
 175                 report_parse_error(ctx, lex);
 176 }
 177
 178 /* chars to consider as part of an alphanumeric token */
 179 #define JSON_ALPHANUMERIC_CHAR(c)  \
 180         (((c) >= 'a' && (c) <= 'z') || \
 181          ((c) >= 'A' && (c) <= 'Z') || \
 182          ((c) >= '0' && (c) <= '9') || \
 183          (c) == '_' || \
 184          IS_HIGHBIT_SET(c))
 185
 186 /*
 187  * Utility function to check if a string is a valid JSON number.
 188  *
 189  * str is of length len, and need not be null-terminated.
 190  */
 191 bool
 192 IsValidJsonNumber(const char *str, int len)
 193 {
 194         bool            numeric_error;
 195         int                     total_len;
 196         JsonLexContext dummy_lex;
 197
 198         if (len <= 0)
 199                 return false;
 200
 201         /*
 202          * json_lex_number expects a leading  '-' to have been eaten already.
 203          *
 204          * having to cast away the constness of str is ugly, but there's not much
 205          * easy alternative.
 206          */
 207         if (*str == '-')
 208         {
 209                 dummy_lex.input = (char *) str + 1;
 210                 dummy_lex.input_length = len - 1;
 211         }
 212         else
 213         {
 214                 dummy_lex.input = (char *) str;
 215                 dummy_lex.input_length = len;
 216         }
 217
 218         json_lex_number(&dummy_lex, dummy_lex.input, &numeric_error, &total_len);
 219
 220         return (!numeric_error) && (total_len == dummy_lex.input_length);
 221 }
 222
 223 /*
 224  * Input.
 225  */
 226 Datum
 227 json_in(PG_FUNCTION_ARGS)
 228 {
 229         char       *json = PG_GETARG_CSTRING(0);
 230         text       *result = cstring_to_text(json);
 231         JsonLexContext *lex;
 232
 233         /* validate it */
 234         lex = makeJsonLexContext(result, false);
 235         pg_parse_json(lex, &nullSemAction);
 236
 237         /* Internal representation is the same as text, for now */
 238         PG_RETURN_TEXT_P(result);
 239 }
 240
 241 /*
 242  * Output.
 243  */
 244 Datum
 245 json_out(PG_FUNCTION_ARGS)
 246 {
 247         /* we needn't detoast because text_to_cstring will handle that */
 248         Datum           txt = PG_GETARG_DATUM(0);
 249
 250         PG_RETURN_CSTRING(TextDatumGetCString(txt));
 251 }
 252
 253 /*
 254  * Binary send.
 255  */
 256 Datum
 257 json_send(PG_FUNCTION_ARGS)
 258 {
 259         text       *t = PG_GETARG_TEXT_PP(0);
 260         StringInfoData buf;
 261
 262         pq_begintypsend(&buf);
 263         pq_sendtext(&buf, VARDATA_ANY(t), VARSIZE_ANY_EXHDR(t));
 264         PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
 265 }
 266
 267 /*
 268  * Binary receive.
 269  */
 270 Datum
 271 json_recv(PG_FUNCTION_ARGS)
 272 {
 273         StringInfo      buf = (StringInfo) PG_GETARG_POINTER(0);
 274         char       *str;
 275         int                     nbytes;
 276         JsonLexContext *lex;
 277
 278         str = pq_getmsgtext(buf, buf->len - buf->cursor, &nbytes);
 279
 280         /* Validate it. */
 281         lex = makeJsonLexContextCstringLen(str, nbytes, false);
 282         pg_parse_json(lex, &nullSemAction);
 283
 284         PG_RETURN_TEXT_P(cstring_to_text_with_len(str, nbytes));
 285 }
 286
 287 /*
 288  * makeJsonLexContext
 289  *
 290  * lex constructor, with or without StringInfo object
 291  * for de-escaped lexemes.
 292  *
 293  * Without is better as it makes the processing faster, so only make one
 294  * if really required.
 295  *
 296  * If you already have the json as a text* value, use the first of these
 297  * functions, otherwise use  makeJsonLexContextCstringLen().
 298  */
 299 JsonLexContext *
 300 makeJsonLexContext(text *json, bool need_escapes)
 301 {
 302         return makeJsonLexContextCstringLen(VARDATA_ANY(json),
 303                                                                                 VARSIZE_ANY_EXHDR(json),
 304                                                                                 need_escapes);
 305 }
 306
 307 JsonLexContext *
 308 makeJsonLexContextCstringLen(char *json, int len, bool need_escapes)
 309 {
 310         JsonLexContext *lex = palloc0(sizeof(JsonLexContext));
 311
 312         lex->input = lex->token_terminator = lex->line_start = json;
 313         lex->line_number = 1;
 314         lex->input_length = len;
 315         if (need_escapes)
 316                 lex->strval = makeStringInfo();
 317         return lex;
 318 }
 319
 320 /*
 321  * pg_parse_json
 322  *
 323  * Publicly visible entry point for the JSON parser.
 324  *
 325  * lex is a lexing context, set up for the json to be processed by calling
 326  * makeJsonLexContext(). sem is a strucure of function pointers to semantic
 327  * action routines to be called at appropriate spots during parsing, and a
 328  * pointer to a state object to be passed to those routines.
 329  */
 330 void
 331 pg_parse_json(JsonLexContext *lex, JsonSemAction *sem)
 332 {
 333         JsonTokenType tok;
 334
 335         /* get the initial token */
 336         json_lex(lex);
 337
 338         tok = lex_peek(lex);
 339
 340         /* parse by recursive descent */
 341         switch (tok)
 342         {
 343                 case JSON_TOKEN_OBJECT_START:
 344                         parse_object(lex, sem);
 345                         break;
 346                 case JSON_TOKEN_ARRAY_START:
 347                         parse_array(lex, sem);
 348                         break;
 349                 default:
 350                         parse_scalar(lex, sem);         /* json can be a bare scalar */
 351         }
 352
 353         lex_expect(JSON_PARSE_END, lex, JSON_TOKEN_END);
 354
 355 }
 356
 357 /*
 358  * json_count_array_elements
 359  *
 360  * Returns number of array elements in lex context at start of array token
 361  * until end of array token at same nesting level.
 362  *
 363  * Designed to be called from array_start routines.
 364  */
 365 int
 366 json_count_array_elements(JsonLexContext *lex)
 367 {
 368         JsonLexContext copylex;
 369         int                     count;
 370
 371         /*
 372          * It's safe to do this with a shallow copy because the lexical routines
 373          * don't scribble on the input. They do scribble on the other pointers
 374          * etc, so doing this with a copy makes that safe.
 375          */
 376         memcpy(&copylex, lex, sizeof(JsonLexContext));
 377         copylex.strval = NULL;          /* not interested in values here */
 378         copylex.lex_level++;
 379
 380         count = 0;
 381         lex_expect(JSON_PARSE_ARRAY_START, &copylex, JSON_TOKEN_ARRAY_START);
 382         if (lex_peek(&copylex) != JSON_TOKEN_ARRAY_END)
 383         {
 384                 do
 385                 {
 386                         count++;
 387                         parse_array_element(&copylex, &nullSemAction);
 388                 }
 389                 while (lex_accept(&copylex, JSON_TOKEN_COMMA, NULL));
 390         }
 391         lex_expect(JSON_PARSE_ARRAY_NEXT, &copylex, JSON_TOKEN_ARRAY_END);
 392
 393         return count;
 394 }
 395
 396 /*
 397  *      Recursive Descent parse routines. There is one for each structural
 398  *      element in a json document:
 399  *        - scalar (string, number, true, false, null)
 400  *        - array  ( [ ] )
 401  *        - array element
 402  *        - object ( { } )
 403  *        - object field
 404  */
 405 static inline void
 406 parse_scalar(JsonLexContext *lex, JsonSemAction *sem)
 407 {
 408         char       *val = NULL;
 409         json_scalar_action sfunc = sem->scalar;
 410         char      **valaddr;
 411         JsonTokenType tok = lex_peek(lex);
 412
 413         valaddr = sfunc == NULL ? NULL : &val;
 414
 415         /* a scalar must be a string, a number, true, false, or null */
 416         switch (tok)
 417         {
 418                 case JSON_TOKEN_TRUE:
 419                         lex_accept(lex, JSON_TOKEN_TRUE, valaddr);
 420                         break;
 421                 case JSON_TOKEN_FALSE:
 422                         lex_accept(lex, JSON_TOKEN_FALSE, valaddr);
 423                         break;
 424                 case JSON_TOKEN_NULL:
 425                         lex_accept(lex, JSON_TOKEN_NULL, valaddr);
 426                         break;
 427                 case JSON_TOKEN_NUMBER:
 428                         lex_accept(lex, JSON_TOKEN_NUMBER, valaddr);
 429                         break;
 430                 case JSON_TOKEN_STRING:
 431                         lex_accept(lex, JSON_TOKEN_STRING, valaddr);
 432                         break;
 433                 default:
 434                         report_parse_error(JSON_PARSE_VALUE, lex);
 435         }
 436
 437         if (sfunc != NULL)
 438                 (*sfunc) (sem->semstate, val, tok);
 439 }
 440
 441 static void
 442 parse_object_field(JsonLexContext *lex, JsonSemAction *sem)
 443 {
 444         /*
 445          * An object field is "fieldname" : value where value can be a scalar,
 446          * object or array.  Note: in user-facing docs and error messages, we
 447          * generally call a field name a "key".
 448          */
 449
 450         char       *fname = NULL;       /* keep compiler quiet */
 451         json_ofield_action ostart = sem->object_field_start;
 452         json_ofield_action oend = sem->object_field_end;
 453         bool            isnull;
 454         char      **fnameaddr = NULL;
 455         JsonTokenType tok;
 456
 457         if (ostart != NULL || oend != NULL)
 458                 fnameaddr = &fname;
 459
 460         if (!lex_accept(lex, JSON_TOKEN_STRING, fnameaddr))
 461                 report_parse_error(JSON_PARSE_STRING, lex);
 462
 463         lex_expect(JSON_PARSE_OBJECT_LABEL, lex, JSON_TOKEN_COLON);
 464
 465         tok = lex_peek(lex);
 466         isnull = tok == JSON_TOKEN_NULL;
 467
 468         if (ostart != NULL)
 469                 (*ostart) (sem->semstate, fname, isnull);
 470
 471         switch (tok)
 472         {
 473                 case JSON_TOKEN_OBJECT_START:
 474                         parse_object(lex, sem);
 475                         break;
 476                 case JSON_TOKEN_ARRAY_START:
 477                         parse_array(lex, sem);
 478                         break;
 479                 default:
 480                         parse_scalar(lex, sem);
 481         }
 482
 483         if (oend != NULL)
 484                 (*oend) (sem->semstate, fname, isnull);
 485 }
 486
 487 static void
 488 parse_object(JsonLexContext *lex, JsonSemAction *sem)
 489 {
 490         /*
 491          * an object is a possibly empty sequence of object fields, separated by
 492          * commas and surrounded by curly braces.
 493          */
 494         json_struct_action ostart = sem->object_start;
 495         json_struct_action oend = sem->object_end;
 496         JsonTokenType tok;
 497
 498         check_stack_depth();
 499
 500         if (ostart != NULL)
 501                 (*ostart) (sem->semstate);
 502
 503         /*
 504          * Data inside an object is at a higher nesting level than the object
 505          * itself. Note that we increment this after we call the semantic routine
 506          * for the object start and restore it before we call the routine for the
 507          * object end.
 508          */
 509         lex->lex_level++;
 510
 511         /* we know this will succeed, just clearing the token */
 512         lex_expect(JSON_PARSE_OBJECT_START, lex, JSON_TOKEN_OBJECT_START);
 513
 514         tok = lex_peek(lex);
 515         switch (tok)
 516         {
 517                 case JSON_TOKEN_STRING:
 518                         parse_object_field(lex, sem);
 519                         while (lex_accept(lex, JSON_TOKEN_COMMA, NULL))
 520                                 parse_object_field(lex, sem);
 521                         break;
 522                 case JSON_TOKEN_OBJECT_END:
 523                         break;
 524                 default:
 525                         /* case of an invalid initial token inside the object */
 526                         report_parse_error(JSON_PARSE_OBJECT_START, lex);
 527         }
 528
 529         lex_expect(JSON_PARSE_OBJECT_NEXT, lex, JSON_TOKEN_OBJECT_END);
 530
 531         lex->lex_level--;
 532
 533         if (oend != NULL)
 534                 (*oend) (sem->semstate);
 535 }
 536
 537 static void
 538 parse_array_element(JsonLexContext *lex, JsonSemAction *sem)
 539 {
 540         json_aelem_action astart = sem->array_element_start;
 541         json_aelem_action aend = sem->array_element_end;
 542         JsonTokenType tok = lex_peek(lex);
 543
 544         bool            isnull;
 545
 546         isnull = tok == JSON_TOKEN_NULL;
 547
 548         if (astart != NULL)
 549                 (*astart) (sem->semstate, isnull);
 550
 551         /* an array element is any object, array or scalar */
 552         switch (tok)
 553         {
 554                 case JSON_TOKEN_OBJECT_START:
 555                         parse_object(lex, sem);
 556                         break;
 557                 case JSON_TOKEN_ARRAY_START:
 558                         parse_array(lex, sem);
 559                         break;
 560                 default:
 561                         parse_scalar(lex, sem);
 562         }
 563
 564         if (aend != NULL)
 565                 (*aend) (sem->semstate, isnull);
 566 }
 567
 568 static void
 569 parse_array(JsonLexContext *lex, JsonSemAction *sem)
 570 {
 571         /*
 572          * an array is a possibly empty sequence of array elements, separated by
 573          * commas and surrounded by square brackets.
 574          */
 575         json_struct_action astart = sem->array_start;
 576         json_struct_action aend = sem->array_end;
 577
 578         check_stack_depth();
 579
 580         if (astart != NULL)
 581                 (*astart) (sem->semstate);
 582
 583         /*
 584          * Data inside an array is at a higher nesting level than the array
 585          * itself. Note that we increment this after we call the semantic routine
 586          * for the array start and restore it before we call the routine for the
 587          * array end.
 588          */
 589         lex->lex_level++;
 590
 591         lex_expect(JSON_PARSE_ARRAY_START, lex, JSON_TOKEN_ARRAY_START);
 592         if (lex_peek(lex) != JSON_TOKEN_ARRAY_END)
 593         {
 594
 595                 parse_array_element(lex, sem);
 596
 597                 while (lex_accept(lex, JSON_TOKEN_COMMA, NULL))
 598                         parse_array_element(lex, sem);
 599         }
 600
 601         lex_expect(JSON_PARSE_ARRAY_NEXT, lex, JSON_TOKEN_ARRAY_END);
 602
 603         lex->lex_level--;
 604
 605         if (aend != NULL)
 606                 (*aend) (sem->semstate);
 607 }
 608
 609 /*
 610  * Lex one token from the input stream.
 611  */
 612 static inline void
 613 json_lex(JsonLexContext *lex)
 614 {
 615         char       *s;
 616         int                     len;
 617
 618         /* Skip leading whitespace. */
 619         s = lex->token_terminator;
 620         len = s - lex->input;
 621         while (len < lex->input_length &&
 622                    (*s == ' ' || *s == '\t' || *s == '\n' || *s == '\r'))
 623         {
 624                 if (*s == '\n')
 625                         ++lex->line_number;
 626                 ++s;
 627                 ++len;
 628         }
 629         lex->token_start = s;
 630
 631         /* Determine token type. */
 632         if (len >= lex->input_length)
 633         {
 634                 lex->token_start = NULL;
 635                 lex->prev_token_terminator = lex->token_terminator;
 636                 lex->token_terminator = s;
 637                 lex->token_type = JSON_TOKEN_END;
 638         }
 639         else
 640                 switch (*s)
 641                 {
 642                                 /* Single-character token, some kind of punctuation mark. */
 643                         case '{':
 644                                 lex->prev_token_terminator = lex->token_terminator;
 645                                 lex->token_terminator = s + 1;
 646                                 lex->token_type = JSON_TOKEN_OBJECT_START;
 647                                 break;
 648                         case '}':
 649                                 lex->prev_token_terminator = lex->token_terminator;
 650                                 lex->token_terminator = s + 1;
 651                                 lex->token_type = JSON_TOKEN_OBJECT_END;
 652                                 break;
 653                         case '[':
 654                                 lex->prev_token_terminator = lex->token_terminator;
 655                                 lex->token_terminator = s + 1;
 656                                 lex->token_type = JSON_TOKEN_ARRAY_START;
 657                                 break;
 658                         case ']':
 659                                 lex->prev_token_terminator = lex->token_terminator;
 660                                 lex->token_terminator = s + 1;
 661                                 lex->token_type = JSON_TOKEN_ARRAY_END;
 662                                 break;
 663                         case ',':
 664                                 lex->prev_token_terminator = lex->token_terminator;
 665                                 lex->token_terminator = s + 1;
 666                                 lex->token_type = JSON_TOKEN_COMMA;
 667                                 break;
 668                         case ':':
 669                                 lex->prev_token_terminator = lex->token_terminator;
 670                                 lex->token_terminator = s + 1;
 671                                 lex->token_type = JSON_TOKEN_COLON;
 672                                 break;
 673                         case '"':
 674                                 /* string */
 675                                 json_lex_string(lex);
 676                                 lex->token_type = JSON_TOKEN_STRING;
 677                                 break;
 678                         case '-':
 679                                 /* Negative number. */
 680                                 json_lex_number(lex, s + 1, NULL, NULL);
 681                                 lex->token_type = JSON_TOKEN_NUMBER;
 682                                 break;
 683                         case '0':
 684                         case '1':
 685                         case '2':
 686                         case '3':
 687                         case '4':
 688                         case '5':
 689                         case '6':
 690                         case '7':
 691                         case '8':
 692                         case '9':
 693                                 /* Positive number. */
 694                                 json_lex_number(lex, s, NULL, NULL);
 695                                 lex->token_type = JSON_TOKEN_NUMBER;
 696                                 break;
 697                         default:
 698                                 {
 699                                         char       *p;
 700
 701                                         /*
 702                                          * We're not dealing with a string, number, legal
 703                                          * punctuation mark, or end of string.  The only legal
 704                                          * tokens we might find here are true, false, and null,
 705                                          * but for error reporting purposes we scan until we see a
 706                                          * non-alphanumeric character.  That way, we can report
 707                                          * the whole word as an unexpected token, rather than just
 708                                          * some unintuitive prefix thereof.
 709                                          */
 710                                         for (p = s; p - s < lex->input_length - len && JSON_ALPHANUMERIC_CHAR(*p); p++)
 711                                                  /* skip */ ;
 712
 713                                         /*
 714                                          * We got some sort of unexpected punctuation or an
 715                                          * otherwise unexpected character, so just complain about
 716                                          * that one character.
 717                                          */
 718                                         if (p == s)
 719                                         {
 720                                                 lex->prev_token_terminator = lex->token_terminator;
 721                                                 lex->token_terminator = s + 1;
 722                                                 report_invalid_token(lex);
 723                                         }
 724
 725                                         /*
 726                                          * We've got a real alphanumeric token here.  If it
 727                                          * happens to be true, false, or null, all is well.  If
 728                                          * not, error out.
 729                                          */
 730                                         lex->prev_token_terminator = lex->token_terminator;
 731                                         lex->token_terminator = p;
 732                                         if (p - s == 4)
 733                                         {
 734                                                 if (memcmp(s, "true", 4) == 0)
 735                                                         lex->token_type = JSON_TOKEN_TRUE;
 736                                                 else if (memcmp(s, "null", 4) == 0)
 737                                                         lex->token_type = JSON_TOKEN_NULL;
 738                                                 else
 739                                                         report_invalid_token(lex);
 740                                         }
 741                                         else if (p - s == 5 && memcmp(s, "false", 5) == 0)
 742                                                 lex->token_type = JSON_TOKEN_FALSE;
 743                                         else
 744                                                 report_invalid_token(lex);
 745
 746                                 }
 747                 }                                               /* end of switch */
 748 }
 749
 750 /*
 751  * The next token in the input stream is known to be a string; lex it.
 752  */
 753 static inline void
 754 json_lex_string(JsonLexContext *lex)
 755 {
 756         char       *s;
 757         int                     len;
 758         int                     hi_surrogate = -1;
 759
 760         if (lex->strval != NULL)
 761                 resetStringInfo(lex->strval);
 762
 763         Assert(lex->input_length > 0);
 764         s = lex->token_start;
 765         len = lex->token_start - lex->input;
 766         for (;;)
 767         {
 768                 s++;
 769                 len++;
 770                 /* Premature end of the string. */
 771                 if (len >= lex->input_length)
 772                 {
 773                         lex->token_terminator = s;
 774                         report_invalid_token(lex);
 775                 }
 776                 else if (*s == '"')
 777                         break;
 778                 else if ((unsigned char) *s < 32)
 779                 {
 780                         /* Per RFC4627, these characters MUST be escaped. */
 781                         /* Since *s isn't printable, exclude it from the context string */
 782                         lex->token_terminator = s;
 783                         ereport(ERROR,
 784                                         (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 785                                          errmsg("invalid input syntax for type %s", "json"),
 786                                          errdetail("Character with value 0x%02x must be escaped.",
 787                                                            (unsigned char) *s),
 788                                          report_json_context(lex)));
 789                 }
 790                 else if (*s == '\\')
 791                 {
 792                         /* OK, we have an escape character. */
 793                         s++;
 794                         len++;
 795                         if (len >= lex->input_length)
 796                         {
 797                                 lex->token_terminator = s;
 798                                 report_invalid_token(lex);
 799                         }
 800                         else if (*s == 'u')
 801                         {
 802                                 int                     i;
 803                                 int                     ch = 0;
 804
 805                                 for (i = 1; i <= 4; i++)
 806                                 {
 807                                         s++;
 808                                         len++;
 809                                         if (len >= lex->input_length)
 810                                         {
 811                                                 lex->token_terminator = s;
 812                                                 report_invalid_token(lex);
 813                                         }
 814                                         else if (*s >= '0' && *s <= '9')
 815                                                 ch = (ch * 16) + (*s - '0');
 816                                         else if (*s >= 'a' && *s <= 'f')
 817                                                 ch = (ch * 16) + (*s - 'a') + 10;
 818                                         else if (*s >= 'A' && *s <= 'F')
 819                                                 ch = (ch * 16) + (*s - 'A') + 10;
 820                                         else
 821                                         {
 822                                                 lex->token_terminator = s + pg_mblen(s);
 823                                                 ereport(ERROR,
 824                                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 825                                                                  errmsg("invalid input syntax for type %s",
 826                                                                                 "json"),
 827                                                                  errdetail("\"\\u\" must be followed by four hexadecimal digits."),
 828                                                                  report_json_context(lex)));
 829                                         }
 830                                 }
 831                                 if (lex->strval != NULL)
 832                                 {
 833                                         char            utf8str[5];
 834                                         int                     utf8len;
 835
 836                                         if (ch >= 0xd800 && ch <= 0xdbff)
 837                                         {
 838                                                 if (hi_surrogate != -1)
 839                                                         ereport(ERROR,
 840                                                            (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 841                                                                 errmsg("invalid input syntax for type %s",
 842                                                                            "json"),
 843                                                                 errdetail("Unicode high surrogate must not follow a high surrogate."),
 844                                                                 report_json_context(lex)));
 845                                                 hi_surrogate = (ch & 0x3ff) << 10;
 846                                                 continue;
 847                                         }
 848                                         else if (ch >= 0xdc00 && ch <= 0xdfff)
 849                                         {
 850                                                 if (hi_surrogate == -1)
 851                                                         ereport(ERROR,
 852                                                            (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 853                                                                 errmsg("invalid input syntax for type %s", "json"),
 854                                                                 errdetail("Unicode low surrogate must follow a high surrogate."),
 855                                                                 report_json_context(lex)));
 856                                                 ch = 0x10000 + hi_surrogate + (ch & 0x3ff);
 857                                                 hi_surrogate = -1;
 858                                         }
 859
 860                                         if (hi_surrogate != -1)
 861                                                 ereport(ERROR,
 862                                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 863                                                   errmsg("invalid input syntax for type %s", "json"),
 864                                                                  errdetail("Unicode low surrogate must follow a high surrogate."),
 865                                                                  report_json_context(lex)));
 866
 867                                         /*
 868                                          * For UTF8, replace the escape sequence by the actual
 869                                          * utf8 character in lex->strval. Do this also for other
 870                                          * encodings if the escape designates an ASCII character,
 871                                          * otherwise raise an error.
 872                                          */
 873
 874                                         if (ch == 0)
 875                                         {
 876                                                 /* We can't allow this, since our TEXT type doesn't */
 877                                                 ereport(ERROR,
 878                                                                 (errcode(ERRCODE_UNTRANSLATABLE_CHARACTER),
 879                                                            errmsg("unsupported Unicode escape sequence"),
 880                                                    errdetail("\\u0000 cannot be converted to text."),
 881                                                                  report_json_context(lex)));
 882                                         }
 883                                         else if (GetDatabaseEncoding() == PG_UTF8)
 884                                         {
 885                                                 unicode_to_utf8(ch, (unsigned char *) utf8str);
 886                                                 utf8len = pg_utf_mblen((unsigned char *) utf8str);
 887                                                 appendBinaryStringInfo(lex->strval, utf8str, utf8len);
 888                                         }
 889                                         else if (ch <= 0x007f)
 890                                         {
 891                                                 /*
 892                                                  * This is the only way to designate things like a
 893                                                  * form feed character in JSON, so it's useful in all
 894                                                  * encodings.
 895                                                  */
 896                                                 appendStringInfoChar(lex->strval, (char) ch);
 897                                         }
 898                                         else
 899                                         {
 900                                                 ereport(ERROR,
 901                                                                 (errcode(ERRCODE_UNTRANSLATABLE_CHARACTER),
 902                                                            errmsg("unsupported Unicode escape sequence"),
 903                                                                  errdetail("Unicode escape values cannot be used for code point values above 007F when the server encoding is not UTF8."),
 904                                                                  report_json_context(lex)));
 905                                         }
 906
 907                                 }
 908                         }
 909                         else if (lex->strval != NULL)
 910                         {
 911                                 if (hi_surrogate != -1)
 912                                         ereport(ERROR,
 913                                                         (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 914                                                          errmsg("invalid input syntax for type %s",
 915                                                                         "json"),
 916                                                          errdetail("Unicode low surrogate must follow a high surrogate."),
 917                                                          report_json_context(lex)));
 918
 919                                 switch (*s)
 920                                 {
 921                                         case '"':
 922                                         case '\\':
 923                                         case '/':
 924                                                 appendStringInfoChar(lex->strval, *s);
 925                                                 break;
 926                                         case 'b':
 927                                                 appendStringInfoChar(lex->strval, '\b');
 928                                                 break;
 929                                         case 'f':
 930                                                 appendStringInfoChar(lex->strval, '\f');
 931                                                 break;
 932                                         case 'n':
 933                                                 appendStringInfoChar(lex->strval, '\n');
 934                                                 break;
 935                                         case 'r':
 936                                                 appendStringInfoChar(lex->strval, '\r');
 937                                                 break;
 938                                         case 't':
 939                                                 appendStringInfoChar(lex->strval, '\t');
 940                                                 break;
 941                                         default:
 942                                                 /* Not a valid string escape, so error out. */
 943                                                 lex->token_terminator = s + pg_mblen(s);
 944                                                 ereport(ERROR,
 945                                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 946                                                                  errmsg("invalid input syntax for type %s",
 947                                                                                 "json"),
 948                                                         errdetail("Escape sequence \"\\%s\" is invalid.",
 949                                                                           extract_mb_char(s)),
 950                                                                  report_json_context(lex)));
 951                                 }
 952                         }
 953                         else if (strchr("\"\\/bfnrt", *s) == NULL)
 954                         {
 955                                 /*
 956                                  * Simpler processing if we're not bothered about de-escaping
 957                                  *
 958                                  * It's very tempting to remove the strchr() call here and
 959                                  * replace it with a switch statement, but testing so far has
 960                                  * shown it's not a performance win.
 961                                  */
 962                                 lex->token_terminator = s + pg_mblen(s);
 963                                 ereport(ERROR,
 964                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 965                                                  errmsg("invalid input syntax for type %s", "json"),
 966                                                  errdetail("Escape sequence \"\\%s\" is invalid.",
 967                                                                    extract_mb_char(s)),
 968                                                  report_json_context(lex)));
 969                         }
 970
 971                 }
 972                 else if (lex->strval != NULL)
 973                 {
 974                         if (hi_surrogate != -1)
 975                                 ereport(ERROR,
 976                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 977                                                  errmsg("invalid input syntax for type %s", "json"),
 978                                                  errdetail("Unicode low surrogate must follow a high surrogate."),
 979                                                  report_json_context(lex)));
 980
 981                         appendStringInfoChar(lex->strval, *s);
 982                 }
 983
 984         }
 985
 986         if (hi_surrogate != -1)
 987                 ereport(ERROR,
 988                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
 989                                  errmsg("invalid input syntax for type %s", "json"),
 990                         errdetail("Unicode low surrogate must follow a high surrogate."),
 991                                  report_json_context(lex)));
 992
 993         /* Hooray, we found the end of the string! */
 994         lex->prev_token_terminator = lex->token_terminator;
 995         lex->token_terminator = s + 1;
 996 }
 997
 998 /*
 999  * The next token in the input stream is known to be a number; lex it.
1000  *
1001  * In JSON, a number consists of four parts:
1002  *
1003  * (1) An optional minus sign ('-').
1004  *
1005  * (2) Either a single '0', or a string of one or more digits that does not
1006  *         begin with a '0'.
1007  *
1008  * (3) An optional decimal part, consisting of a period ('.') followed by
1009  *         one or more digits.  (Note: While this part can be omitted
1010  *         completely, it's not OK to have only the decimal point without
1011  *         any digits afterwards.)
1012  *
1013  * (4) An optional exponent part, consisting of 'e' or 'E', optionally
1014  *         followed by '+' or '-', followed by one or more digits.  (Note:
1015  *         As with the decimal part, if 'e' or 'E' is present, it must be
1016  *         followed by at least one digit.)
1017  *
1018  * The 's' argument to this function points to the ostensible beginning
1019  * of part 2 - i.e. the character after any optional minus sign, or the
1020  * first character of the string if there is none.
1021  *
1022  * If num_err is not NULL, we return an error flag to *num_err rather than
1023  * raising an error for a badly-formed number.  Also, if total_len is not NULL
1024  * the distance from lex->input to the token end+1 is returned to *total_len.
1025  */
1026 static inline void
1027 json_lex_number(JsonLexContext *lex, char *s,
1028                                 bool *num_err, int *total_len)
1029 {
1030         bool            error = false;
1031         int                     len = s - lex->input;
1032
1033         /* Part (1): leading sign indicator. */
1034         /* Caller already did this for us; so do nothing. */
1035
1036         /* Part (2): parse main digit string. */
1037         if (len < lex->input_length && *s == '0')
1038         {
1039                 s++;
1040                 len++;
1041         }
1042         else if (len < lex->input_length && *s >= '1' && *s <= '9')
1043         {
1044                 do
1045                 {
1046                         s++;
1047                         len++;
1048                 } while (len < lex->input_length && *s >= '0' && *s <= '9');
1049         }
1050         else
1051                 error = true;
1052
1053         /* Part (3): parse optional decimal portion. */
1054         if (len < lex->input_length && *s == '.')
1055         {
1056                 s++;
1057                 len++;
1058                 if (len == lex->input_length || *s < '0' || *s > '9')
1059                         error = true;
1060                 else
1061                 {
1062                         do
1063                         {
1064                                 s++;
1065                                 len++;
1066                         } while (len < lex->input_length && *s >= '0' && *s <= '9');
1067                 }
1068         }
1069
1070         /* Part (4): parse optional exponent. */
1071         if (len < lex->input_length && (*s == 'e' || *s == 'E'))
1072         {
1073                 s++;
1074                 len++;
1075                 if (len < lex->input_length && (*s == '+' || *s == '-'))
1076                 {
1077                         s++;
1078                         len++;
1079                 }
1080                 if (len == lex->input_length || *s < '0' || *s > '9')
1081                         error = true;
1082                 else
1083                 {
1084                         do
1085                         {
1086                                 s++;
1087                                 len++;
1088                         } while (len < lex->input_length && *s >= '0' && *s <= '9');
1089                 }
1090         }
1091
1092         /*
1093          * Check for trailing garbage.  As in json_lex(), any alphanumeric stuff
1094          * here should be considered part of the token for error-reporting
1095          * purposes.
1096          */
1097         for (; len < lex->input_length && JSON_ALPHANUMERIC_CHAR(*s); s++, len++)
1098                 error = true;
1099
1100         if (total_len != NULL)
1101                 *total_len = len;
1102
1103         if (num_err != NULL)
1104         {
1105                 /* let the caller handle any error */
1106                 *num_err = error;
1107         }
1108         else
1109         {
1110                 /* return token endpoint */
1111                 lex->prev_token_terminator = lex->token_terminator;
1112                 lex->token_terminator = s;
1113                 /* handle error if any */
1114                 if (error)
1115                         report_invalid_token(lex);
1116         }
1117 }
1118
1119 /*
1120  * Report a parse error.
1121  *
1122  * lex->token_start and lex->token_terminator must identify the current token.
1123  */
1124 static void
1125 report_parse_error(JsonParseContext ctx, JsonLexContext *lex)
1126 {
1127         char       *token;
1128         int                     toklen;
1129
1130         /* Handle case where the input ended prematurely. */
1131         if (lex->token_start == NULL || lex->token_type == JSON_TOKEN_END)
1132                 ereport(ERROR,
1133                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
1134                                  errmsg("invalid input syntax for type %s", "json"),
1135                                  errdetail("The input string ended unexpectedly."),
1136                                  report_json_context(lex)));
1137
1138         /* Separate out the current token. */
1139         toklen = lex->token_terminator - lex->token_start;
1140         token = palloc(toklen + 1);
1141         memcpy(token, lex->token_start, toklen);
1142         token[toklen] = '\0';
1143
1144         /* Complain, with the appropriate detail message. */
1145         if (ctx == JSON_PARSE_END)
1146                 ereport(ERROR,
1147                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
1148                                  errmsg("invalid input syntax for type %s", "json"),
1149                                  errdetail("Expected end of input, but found \"%s\".",
1150                                                    token),
1151                                  report_json_context(lex)));
1152         else
1153         {
1154                 switch (ctx)
1155                 {
1156                         case JSON_PARSE_VALUE:
1157                                 ereport(ERROR,
1158                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
1159                                                  errmsg("invalid input syntax for type %s", "json"),
1160                                                  errdetail("Expected JSON value, but found \"%s\".",
1161                                                                    token),
1162                                                  report_json_context(lex)));
1163                                 break;
1164                         case JSON_PARSE_STRING:
1165                                 ereport(ERROR,
1166                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
1167                                                  errmsg("invalid input syntax for type %s", "json"),
1168                                                  errdetail("Expected string, but found \"%s\".",
1169                                                                    token),
1170                                                  report_json_context(lex)));
1171                                 break;
1172                         case JSON_PARSE_ARRAY_START:
1173                                 ereport(ERROR,
1174                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
1175                                                  errmsg("invalid input syntax for type %s", "json"),
1176                                                  errdetail("Expected array element or \"]\", but found \"%s\".",
1177                                                                    token),
1178                                                  report_json_context(lex)));
1179                                 break;
1180                         case JSON_PARSE_ARRAY_NEXT:
1181                                 ereport(ERROR,
1182                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
1183                                                  errmsg("invalid input syntax for type %s", "json"),
1184                                           errdetail("Expected \",\" or \"]\", but found \"%s\".",
1185                                                                 token),
1186                                                  report_json_context(lex)));
1187                                 break;
1188                         case JSON_PARSE_OBJECT_START:
1189                                 ereport(ERROR,
1190                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
1191                                                  errmsg("invalid input syntax for type %s", "json"),
1192                                          errdetail("Expected string or \"}\", but found \"%s\".",
1193                                                            token),
1194                                                  report_json_context(lex)));
1195                                 break;
1196                         case JSON_PARSE_OBJECT_LABEL:
1197                                 ereport(ERROR,
1198                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
1199                                                  errmsg("invalid input syntax for type %s", "json"),
1200                                                  errdetail("Expected \":\", but found \"%s\".",
1201                                                                    token),
1202                                                  report_json_context(lex)));
1203                                 break;
1204                         case JSON_PARSE_OBJECT_NEXT:
1205                                 ereport(ERROR,
1206                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
1207                                                  errmsg("invalid input syntax for type %s", "json"),
1208                                           errdetail("Expected \",\" or \"}\", but found \"%s\".",
1209                                                                 token),
1210                                                  report_json_context(lex)));
1211                                 break;
1212                         case JSON_PARSE_OBJECT_COMMA:
1213                                 ereport(ERROR,
1214                                                 (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
1215                                                  errmsg("invalid input syntax for type %s", "json"),
1216                                                  errdetail("Expected string, but found \"%s\".",
1217                                                                    token),
1218                                                  report_json_context(lex)));
1219                                 break;
1220                         default:
1221                                 elog(ERROR, "unexpected json parse state: %d", ctx);
1222                 }
1223         }
1224 }
1225
1226 /*
1227  * Report an invalid input token.
1228  *
1229  * lex->token_start and lex->token_terminator must identify the token.
1230  */
1231 static void
1232 report_invalid_token(JsonLexContext *lex)
1233 {
1234         char       *token;
1235         int                     toklen;
1236
1237         /* Separate out the offending token. */
1238         toklen = lex->token_terminator - lex->token_start;
1239         token = palloc(toklen + 1);
1240         memcpy(token, lex->token_start, toklen);
1241         token[toklen] = '\0';
1242
1243         ereport(ERROR,
1244                         (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
1245                          errmsg("invalid input syntax for type %s", "json"),
1246                          errdetail("Token \"%s\" is invalid.", token),
1247                          report_json_context(lex)));
1248 }
1249
1250 /*
1251  * Report a CONTEXT line for bogus JSON input.
1252  *
1253  * lex->token_terminator must be set to identify the spot where we detected
1254  * the error.  Note that lex->token_start might be NULL, in case we recognized
1255  * error at EOF.
1256  *
1257  * The return value isn't meaningful, but we make it non-void so that this
1258  * can be invoked inside ereport().
1259  */
1260 static int
1261 report_json_context(JsonLexContext *lex)
1262 {
1263         const char *context_start;
1264         const char *context_end;
1265         const char *line_start;
1266         int                     line_number;
1267         char       *ctxt;
1268         int                     ctxtlen;
1269         const char *prefix;
1270         const char *suffix;
1271
1272         /* Choose boundaries for the part of the input we will display */
1273         context_start = lex->input;
1274         context_end = lex->token_terminator;
1275         line_start = context_start;
1276         line_number = 1;
1277         for (;;)
1278         {
1279                 /* Always advance over newlines */
1280                 if (context_start < context_end && *context_start == '\n')
1281                 {
1282                         context_start++;
1283                         line_start = context_start;
1284                         line_number++;
1285                         continue;
1286                 }
1287                 /* Otherwise, done as soon as we are close enough to context_end */
1288                 if (context_end - context_start < 50)
1289                         break;
1290                 /* Advance to next multibyte character */
1291                 if (IS_HIGHBIT_SET(*context_start))
1292                         context_start += pg_mblen(context_start);
1293                 else
1294                         context_start++;
1295         }
1296
1297         /*
1298          * We add "..." to indicate that the excerpt doesn't start at the
1299          * beginning of the line ... but if we're within 3 characters of the
1300          * beginning of the line, we might as well just show the whole line.
1301          */
1302         if (context_start - line_start <= 3)
1303                 context_start = line_start;
1304
1305         /* Get a null-terminated copy of the data to present */
1306         ctxtlen = context_end - context_start;
1307         ctxt = palloc(ctxtlen + 1);
1308         memcpy(ctxt, context_start, ctxtlen);
1309         ctxt[ctxtlen] = '\0';
1310
1311         /*
1312          * Show the context, prefixing "..." if not starting at start of line, and
1313          * suffixing "..." if not ending at end of line.
1314          */
1315         prefix = (context_start > line_start) ? "..." : "";
1316         suffix = (lex->token_type != JSON_TOKEN_END && context_end - lex->input < lex->input_length && *context_end != '\n' && *context_end != '\r') ? "..." : "";
1317
1318         return errcontext("JSON data, line %d: %s%s%s",
1319                                           line_number, prefix, ctxt, suffix);
1320 }
1321
1322 /*
1323  * Extract a single, possibly multi-byte char from the input string.
1324  */
1325 static char *
1326 extract_mb_char(char *s)
1327 {
1328         char       *res;
1329         int                     len;
1330
1331         len = pg_mblen(s);
1332         res = palloc(len + 1);
1333         memcpy(res, s, len);
1334         res[len] = '\0';
1335
1336         return res;
1337 }
1338
1339 /*
1340  * Determine how we want to print values of a given type in datum_to_json.
1341  *
1342  * Given the datatype OID, return its JsonTypeCategory, as well as the type's
1343  * output function OID.  If the returned category is JSONTYPE_CAST, we
1344  * return the OID of the type->JSON cast function instead.
1345  */
1346 static void
1347 json_categorize_type(Oid typoid,
1348                                          JsonTypeCategory *tcategory,
1349                                          Oid *outfuncoid)
1350 {
1351         bool            typisvarlena;
1352
1353         /* Look through any domain */
1354         typoid = getBaseType(typoid);
1355
1356         *outfuncoid = InvalidOid;
1357
1358         /*
1359          * We need to get the output function for everything except date and
1360          * timestamp types, array and composite types, booleans, and non-builtin
1361          * types where there's a cast to json.
1362          */
1363
1364         switch (typoid)
1365         {
1366                 case BOOLOID:
1367                         *tcategory = JSONTYPE_BOOL;
1368                         break;
1369
1370                 case INT2OID:
1371                 case INT4OID:
1372                 case INT8OID:
1373                 case FLOAT4OID:
1374                 case FLOAT8OID:
1375                 case NUMERICOID:
1376                         getTypeOutputInfo(typoid, outfuncoid, &typisvarlena);
1377                         *tcategory = JSONTYPE_NUMERIC;
1378                         break;
1379
1380                 case DATEOID:
1381                         *tcategory = JSONTYPE_DATE;
1382                         break;
1383
1384                 case TIMESTAMPOID:
1385                         *tcategory = JSONTYPE_TIMESTAMP;
1386                         break;
1387
1388                 case TIMESTAMPTZOID:
1389                         *tcategory = JSONTYPE_TIMESTAMPTZ;
1390                         break;
1391
1392                 case JSONOID:
1393                 case JSONBOID:
1394                         getTypeOutputInfo(typoid, outfuncoid, &typisvarlena);
1395                         *tcategory = JSONTYPE_JSON;
1396                         break;
1397
1398                 default:
1399                         /* Check for arrays and composites */
1400                         if (OidIsValid(get_element_type(typoid)) || typoid == ANYARRAYOID
1401                                 || typoid == RECORDARRAYOID)
1402                                 *tcategory = JSONTYPE_ARRAY;
1403                         else if (type_is_rowtype(typoid)) /* includes RECORDOID */
1404                                 *tcategory = JSONTYPE_COMPOSITE;
1405                         else
1406                         {
1407                                 /* It's probably the general case ... */
1408                                 *tcategory = JSONTYPE_OTHER;
1409                                 /* but let's look for a cast to json, if it's not built-in */
1410                                 if (typoid >= FirstNormalObjectId)
1411                                 {
1412                                         Oid                     castfunc;
1413                                         CoercionPathType ctype;
1414
1415                                         ctype = find_coercion_pathway(JSONOID, typoid,
1416                                                                                                   COERCION_EXPLICIT,
1417                                                                                                   &castfunc);
1418                                         if (ctype == COERCION_PATH_FUNC && OidIsValid(castfunc))
1419                                         {
1420                                                 *tcategory = JSONTYPE_CAST;
1421                                                 *outfuncoid = castfunc;
1422                                         }
1423                                         else
1424                                         {
1425                                                 /* non builtin type with no cast */
1426                                                 getTypeOutputInfo(typoid, outfuncoid, &typisvarlena);
1427                                         }
1428                                 }
1429                                 else
1430                                 {
1431                                         /* any other builtin type */
1432                                         getTypeOutputInfo(typoid, outfuncoid, &typisvarlena);
1433                                 }
1434                         }
1435                         break;
1436         }
1437 }
1438
1439 /*
1440  * Turn a Datum into JSON text, appending the string to "result".
1441  *
1442  * tcategory and outfuncoid are from a previous call to json_categorize_type,
1443  * except that if is_null is true then they can be invalid.
1444  *
1445  * If key_scalar is true, the value is being printed as a key, so insist
1446  * it's of an acceptable type, and force it to be quoted.
1447  */
1448 static void
1449 datum_to_json(Datum val, bool is_null, StringInfo result,
1450                           JsonTypeCategory tcategory, Oid outfuncoid,
1451                           bool key_scalar)
1452 {
1453         char       *outputstr;
1454         text       *jsontext;
1455
1456         check_stack_depth();
1457
1458         /* callers are expected to ensure that null keys are not passed in */
1459         Assert(!(key_scalar && is_null));
1460
1461         if (is_null)
1462         {
1463                 appendStringInfoString(result, "null");
1464                 return;
1465         }
1466
1467         if (key_scalar &&
1468                 (tcategory == JSONTYPE_ARRAY ||
1469                  tcategory == JSONTYPE_COMPOSITE ||
1470                  tcategory == JSONTYPE_JSON ||
1471                  tcategory == JSONTYPE_CAST))
1472                 ereport(ERROR,
1473                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1474                  errmsg("key value must be scalar, not array, composite, or json")));
1475
1476         switch (tcategory)
1477         {
1478                 case JSONTYPE_ARRAY:
1479                         array_to_json_internal(val, result, false);
1480                         break;
1481                 case JSONTYPE_COMPOSITE:
1482                         composite_to_json(val, result, false);
1483                         break;
1484                 case JSONTYPE_BOOL:
1485                         outputstr = DatumGetBool(val) ? "true" : "false";
1486                         if (key_scalar)
1487                                 escape_json(result, outputstr);
1488                         else
1489                                 appendStringInfoString(result, outputstr);
1490                         break;
1491                 case JSONTYPE_NUMERIC:
1492                         outputstr = OidOutputFunctionCall(outfuncoid, val);
1493
1494                         /*
1495                          * Don't call escape_json for a non-key if it's a valid JSON
1496                          * number.
1497                          */
1498                         if (!key_scalar && IsValidJsonNumber(outputstr, strlen(outputstr)))
1499                                 appendStringInfoString(result, outputstr);
1500                         else
1501                                 escape_json(result, outputstr);
1502                         pfree(outputstr);
1503                         break;
1504                 case JSONTYPE_DATE:
1505                         {
1506                                 DateADT         date;
1507                                 struct pg_tm tm;
1508                                 char            buf[MAXDATELEN + 1];
1509
1510                                 date = DatumGetDateADT(val);
1511                                 /* Same as date_out(), but forcing DateStyle */
1512                                 if (DATE_NOT_FINITE(date))
1513                                         EncodeSpecialDate(date, buf);
1514                                 else
1515                                 {
1516                                         j2date(date + POSTGRES_EPOCH_JDATE,
1517                                                    &(tm.tm_year), &(tm.tm_mon), &(tm.tm_mday));
1518                                         EncodeDateOnly(&tm, USE_XSD_DATES, buf);
1519                                 }
1520                                 appendStringInfo(result, "\"%s\"", buf);
1521                         }
1522                         break;
1523                 case JSONTYPE_TIMESTAMP:
1524                         {
1525                                 Timestamp       timestamp;
1526                                 struct pg_tm tm;
1527                                 fsec_t          fsec;
1528                                 char            buf[MAXDATELEN + 1];
1529
1530                                 timestamp = DatumGetTimestamp(val);
1531                                 /* Same as timestamp_out(), but forcing DateStyle */
1532                                 if (TIMESTAMP_NOT_FINITE(timestamp))
1533                                         EncodeSpecialTimestamp(timestamp, buf);
1534                                 else if (timestamp2tm(timestamp, NULL, &tm, &fsec, NULL, NULL) == 0)
1535                                         EncodeDateTime(&tm, fsec, false, 0, NULL, USE_XSD_DATES, buf);
1536                                 else
1537                                         ereport(ERROR,
1538                                                         (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
1539                                                          errmsg("timestamp out of range")));
1540                                 appendStringInfo(result, "\"%s\"", buf);
1541                         }
1542                         break;
1543                 case JSONTYPE_TIMESTAMPTZ:
1544                         {
1545                                 TimestampTz timestamp;
1546                                 struct pg_tm tm;
1547                                 int                     tz;
1548                                 fsec_t          fsec;
1549                                 const char *tzn = NULL;
1550                                 char            buf[MAXDATELEN + 1];
1551
1552                                 timestamp = DatumGetTimestampTz(val);
1553                                 /* Same as timestamptz_out(), but forcing DateStyle */
1554                                 if (TIMESTAMP_NOT_FINITE(timestamp))
1555                                         EncodeSpecialTimestamp(timestamp, buf);
1556                                 else if (timestamp2tm(timestamp, &tz, &tm, &fsec, &tzn, NULL) == 0)
1557                                         EncodeDateTime(&tm, fsec, true, tz, tzn, USE_XSD_DATES, buf);
1558                                 else
1559                                         ereport(ERROR,
1560                                                         (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
1561                                                          errmsg("timestamp out of range")));
1562                                 appendStringInfo(result, "\"%s\"", buf);
1563                         }
1564                         break;
1565                 case JSONTYPE_JSON:
1566                         /* JSON and JSONB output will already be escaped */
1567                         outputstr = OidOutputFunctionCall(outfuncoid, val);
1568                         appendStringInfoString(result, outputstr);
1569                         pfree(outputstr);
1570                         break;
1571                 case JSONTYPE_CAST:
1572                         /* outfuncoid refers to a cast function, not an output function */
1573                         jsontext = DatumGetTextPP(OidFunctionCall1(outfuncoid, val));
1574                         outputstr = text_to_cstring(jsontext);
1575                         appendStringInfoString(result, outputstr);
1576                         pfree(outputstr);
1577                         pfree(jsontext);
1578                         break;
1579                 default:
1580                         outputstr = OidOutputFunctionCall(outfuncoid, val);
1581                         escape_json(result, outputstr);
1582                         pfree(outputstr);
1583                         break;
1584         }
1585 }
1586
1587 /*
1588  * Process a single dimension of an array.
1589  * If it's the innermost dimension, output the values, otherwise call
1590  * ourselves recursively to process the next dimension.
1591  */
1592 static void
1593 array_dim_to_json(StringInfo result, int dim, int ndims, int *dims, Datum *vals,
1594                                   bool *nulls, int *valcount, JsonTypeCategory tcategory,
1595                                   Oid outfuncoid, bool use_line_feeds)
1596 {
1597         int                     i;
1598         const char *sep;
1599
1600         Assert(dim < ndims);
1601
1602         sep = use_line_feeds ? ",\n " : ",";
1603
1604         appendStringInfoChar(result, '[');
1605
1606         for (i = 1; i <= dims[dim]; i++)
1607         {
1608                 if (i > 1)
1609                         appendStringInfoString(result, sep);
1610
1611                 if (dim + 1 == ndims)
1612                 {
1613                         datum_to_json(vals[*valcount], nulls[*valcount], result, tcategory,
1614                                                   outfuncoid, false);
1615                         (*valcount)++;
1616                 }
1617                 else
1618                 {
1619                         /*
1620                          * Do we want line feeds on inner dimensions of arrays? For now
1621                          * we'll say no.
1622                          */
1623                         array_dim_to_json(result, dim + 1, ndims, dims, vals, nulls,
1624                                                           valcount, tcategory, outfuncoid, false);
1625                 }
1626         }
1627
1628         appendStringInfoChar(result, ']');
1629 }
1630
1631 /*
1632  * Turn an array into JSON.
1633  */
1634 static void
1635 array_to_json_internal(Datum array, StringInfo result, bool use_line_feeds)
1636 {
1637         ArrayType  *v = DatumGetArrayTypeP(array);
1638         Oid                     element_type = ARR_ELEMTYPE(v);
1639         int                *dim;
1640         int                     ndim;
1641         int                     nitems;
1642         int                     count = 0;
1643         Datum      *elements;
1644         bool       *nulls;
1645         int16           typlen;
1646         bool            typbyval;
1647         char            typalign;
1648         JsonTypeCategory tcategory;
1649         Oid                     outfuncoid;
1650
1651         ndim = ARR_NDIM(v);
1652         dim = ARR_DIMS(v);
1653         nitems = ArrayGetNItems(ndim, dim);
1654
1655         if (nitems <= 0)
1656         {
1657                 appendStringInfoString(result, "[]");
1658                 return;
1659         }
1660
1661         get_typlenbyvalalign(element_type,
1662                                                  &typlen, &typbyval, &typalign);
1663
1664         json_categorize_type(element_type,
1665                                                  &tcategory, &outfuncoid);
1666
1667         deconstruct_array(v, element_type, typlen, typbyval,
1668                                           typalign, &elements, &nulls,
1669                                           &nitems);
1670
1671         array_dim_to_json(result, 0, ndim, dim, elements, nulls, &count, tcategory,
1672                                           outfuncoid, use_line_feeds);
1673
1674         pfree(elements);
1675         pfree(nulls);
1676 }
1677
1678 /*
1679  * Turn a composite / record into JSON.
1680  */
1681 static void
1682 composite_to_json(Datum composite, StringInfo result, bool use_line_feeds)
1683 {
1684         HeapTupleHeader td;
1685         Oid                     tupType;
1686         int32           tupTypmod;
1687         TupleDesc       tupdesc;
1688         HeapTupleData tmptup,
1689                            *tuple;
1690         int                     i;
1691         bool            needsep = false;
1692         const char *sep;
1693
1694         sep = use_line_feeds ? ",\n " : ",";
1695
1696         td = DatumGetHeapTupleHeader(composite);
1697
1698         /* Extract rowtype info and find a tupdesc */
1699         tupType = HeapTupleHeaderGetTypeId(td);
1700         tupTypmod = HeapTupleHeaderGetTypMod(td);
1701         tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
1702
1703         /* Build a temporary HeapTuple control structure */
1704         tmptup.t_len = HeapTupleHeaderGetDatumLength(td);
1705         tmptup.t_data = td;
1706         tuple = &tmptup;
1707
1708         appendStringInfoChar(result, '{');
1709
1710         for (i = 0; i < tupdesc->natts; i++)
1711         {
1712                 Datum           val;
1713                 bool            isnull;
1714                 char       *attname;
1715                 JsonTypeCategory tcategory;
1716                 Oid                     outfuncoid;
1717
1718                 if (tupdesc->attrs[i]->attisdropped)
1719                         continue;
1720
1721                 if (needsep)
1722                         appendStringInfoString(result, sep);
1723                 needsep = true;
1724
1725                 attname = NameStr(tupdesc->attrs[i]->attname);
1726                 escape_json(result, attname);
1727                 appendStringInfoChar(result, ':');
1728
1729                 val = heap_getattr(tuple, i + 1, tupdesc, &isnull);
1730
1731                 if (isnull)
1732                 {
1733                         tcategory = JSONTYPE_NULL;
1734                         outfuncoid = InvalidOid;
1735                 }
1736                 else
1737                         json_categorize_type(tupdesc->attrs[i]->atttypid,
1738                                                                  &tcategory, &outfuncoid);
1739
1740                 datum_to_json(val, isnull, result, tcategory, outfuncoid, false);
1741         }
1742
1743         appendStringInfoChar(result, '}');
1744         ReleaseTupleDesc(tupdesc);
1745 }
1746
1747 /*
1748  * Append JSON text for "val" to "result".
1749  *
1750  * This is just a thin wrapper around datum_to_json.  If the same type will be
1751  * printed many times, avoid using this; better to do the json_categorize_type
1752  * lookups only once.
1753  */
1754 static void
1755 add_json(Datum val, bool is_null, StringInfo result,
1756                  Oid val_type, bool key_scalar)
1757 {
1758         JsonTypeCategory tcategory;
1759         Oid                     outfuncoid;
1760
1761         if (val_type == InvalidOid)
1762                 ereport(ERROR,
1763                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1764                                  errmsg("could not determine input data type")));
1765
1766         if (is_null)
1767         {
1768                 tcategory = JSONTYPE_NULL;
1769                 outfuncoid = InvalidOid;
1770         }
1771         else
1772                 json_categorize_type(val_type,
1773                                                          &tcategory, &outfuncoid);
1774
1775         datum_to_json(val, is_null, result, tcategory, outfuncoid, key_scalar);
1776 }
1777
1778 /*
1779  * SQL function array_to_json(row)
1780  */
1781 extern Datum
1782 array_to_json(PG_FUNCTION_ARGS)
1783 {
1784         Datum           array = PG_GETARG_DATUM(0);
1785         StringInfo      result;
1786
1787         result = makeStringInfo();
1788
1789         array_to_json_internal(array, result, false);
1790
1791         PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
1792 }
1793
1794 /*
1795  * SQL function array_to_json(row, prettybool)
1796  */
1797 extern Datum
1798 array_to_json_pretty(PG_FUNCTION_ARGS)
1799 {
1800         Datum           array = PG_GETARG_DATUM(0);
1801         bool            use_line_feeds = PG_GETARG_BOOL(1);
1802         StringInfo      result;
1803
1804         result = makeStringInfo();
1805
1806         array_to_json_internal(array, result, use_line_feeds);
1807
1808         PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
1809 }
1810
1811 /*
1812  * SQL function row_to_json(row)
1813  */
1814 extern Datum
1815 row_to_json(PG_FUNCTION_ARGS)
1816 {
1817         Datum           array = PG_GETARG_DATUM(0);
1818         StringInfo      result;
1819
1820         result = makeStringInfo();
1821
1822         composite_to_json(array, result, false);
1823
1824         PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
1825 }
1826
1827 /*
1828  * SQL function row_to_json(row, prettybool)
1829  */
1830 extern Datum
1831 row_to_json_pretty(PG_FUNCTION_ARGS)
1832 {
1833         Datum           array = PG_GETARG_DATUM(0);
1834         bool            use_line_feeds = PG_GETARG_BOOL(1);
1835         StringInfo      result;
1836
1837         result = makeStringInfo();
1838
1839         composite_to_json(array, result, use_line_feeds);
1840
1841         PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
1842 }
1843
1844 /*
1845  * SQL function to_json(anyvalue)
1846  */
1847 Datum
1848 to_json(PG_FUNCTION_ARGS)
1849 {
1850         Datum           val = PG_GETARG_DATUM(0);
1851         Oid                     val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
1852         StringInfo      result;
1853         JsonTypeCategory tcategory;
1854         Oid                     outfuncoid;
1855
1856         if (val_type == InvalidOid)
1857                 ereport(ERROR,
1858                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1859                                  errmsg("could not determine input data type")));
1860
1861         json_categorize_type(val_type,
1862                                                  &tcategory, &outfuncoid);
1863
1864         result = makeStringInfo();
1865
1866         datum_to_json(val, false, result, tcategory, outfuncoid, false);
1867
1868         PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
1869 }
1870
1871 /*
1872  * json_agg transition function
1873  *
1874  * aggregate input column as a json array value.
1875  */
1876 Datum
1877 json_agg_transfn(PG_FUNCTION_ARGS)
1878 {
1879         MemoryContext aggcontext,
1880                                 oldcontext;
1881         JsonAggState *state;
1882         Datum           val;
1883
1884         if (!AggCheckCallContext(fcinfo, &aggcontext))
1885         {
1886                 /* cannot be called directly because of internal-type argument */
1887                 elog(ERROR, "json_agg_transfn called in non-aggregate context");
1888         }
1889
1890         if (PG_ARGISNULL(0))
1891         {
1892                 Oid                     arg_type = get_fn_expr_argtype(fcinfo->flinfo, 1);
1893
1894                 if (arg_type == InvalidOid)
1895                         ereport(ERROR,
1896                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1897                                          errmsg("could not determine input data type")));
1898
1899                 /*
1900                  * Make this state object in a context where it will persist for the
1901                  * duration of the aggregate call.  MemoryContextSwitchTo is only
1902                  * needed the first time, as the StringInfo routines make sure they
1903                  * use the right context to enlarge the object if necessary.
1904                  */
1905                 oldcontext = MemoryContextSwitchTo(aggcontext);
1906                 state = (JsonAggState *) palloc(sizeof(JsonAggState));
1907                 state->str = makeStringInfo();
1908                 MemoryContextSwitchTo(oldcontext);
1909
1910                 appendStringInfoChar(state->str, '[');
1911                 json_categorize_type(arg_type, &state->val_category,
1912                                                          &state->val_output_func);
1913         }
1914         else
1915         {
1916                 state = (JsonAggState *) PG_GETARG_POINTER(0);
1917                 appendStringInfoString(state->str, ", ");
1918         }
1919
1920         /* fast path for NULLs */
1921         if (PG_ARGISNULL(1))
1922         {
1923                 datum_to_json((Datum) 0, true, state->str, JSONTYPE_NULL,
1924                                           InvalidOid, false);
1925                 PG_RETURN_POINTER(state);
1926         }
1927
1928         val = PG_GETARG_DATUM(1);
1929
1930         /* add some whitespace if structured type and not first item */
1931         if (!PG_ARGISNULL(0) &&
1932                 (state->val_category == JSONTYPE_ARRAY ||
1933                  state->val_category == JSONTYPE_COMPOSITE))
1934         {
1935                 appendStringInfoString(state->str, "\n ");
1936         }
1937
1938         datum_to_json(val, false, state->str, state->val_category,
1939                                   state->val_output_func, false);
1940
1941         /*
1942          * The transition type for array_agg() is declared to be "internal", which
1943          * is a pass-by-value type the same size as a pointer.  So we can safely
1944          * pass the JsonAggState pointer through nodeAgg.c's machinations.
1945          */
1946         PG_RETURN_POINTER(state);
1947 }
1948
1949 /*
1950  * json_agg final function
1951  */
1952 Datum
1953 json_agg_finalfn(PG_FUNCTION_ARGS)
1954 {
1955         JsonAggState *state;
1956
1957         /* cannot be called directly because of internal-type argument */
1958         Assert(AggCheckCallContext(fcinfo, NULL));
1959
1960         state = PG_ARGISNULL(0) ?
1961                 NULL :
1962                 (JsonAggState *) PG_GETARG_POINTER(0);
1963
1964         /* NULL result for no rows in, as is standard with aggregates */
1965         if (state == NULL)
1966                 PG_RETURN_NULL();
1967
1968         /* Else return state with appropriate array terminator added */
1969         PG_RETURN_TEXT_P(catenate_stringinfo_string(state->str, "]"));
1970 }
1971
1972 /*
1973  * json_object_agg transition function.
1974  *
1975  * aggregate two input columns as a single json object value.
1976  */
1977 Datum
1978 json_object_agg_transfn(PG_FUNCTION_ARGS)
1979 {
1980         MemoryContext aggcontext,
1981                                 oldcontext;
1982         JsonAggState *state;
1983         Datum           arg;
1984
1985         if (!AggCheckCallContext(fcinfo, &aggcontext))
1986         {
1987                 /* cannot be called directly because of internal-type argument */
1988                 elog(ERROR, "json_object_agg_transfn called in non-aggregate context");
1989         }
1990
1991         if (PG_ARGISNULL(0))
1992         {
1993                 Oid                     arg_type;
1994
1995                 /*
1996                  * Make the StringInfo in a context where it will persist for the
1997                  * duration of the aggregate call. Switching context is only needed
1998                  * for this initial step, as the StringInfo routines make sure they
1999                  * use the right context to enlarge the object if necessary.
2000                  */
2001                 oldcontext = MemoryContextSwitchTo(aggcontext);
2002                 state = (JsonAggState *) palloc(sizeof(JsonAggState));
2003                 state->str = makeStringInfo();
2004                 MemoryContextSwitchTo(oldcontext);
2005
2006                 arg_type = get_fn_expr_argtype(fcinfo->flinfo, 1);
2007
2008                 if (arg_type == InvalidOid)
2009                         ereport(ERROR,
2010                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
2011                                          errmsg("could not determine data type for argument 1")));
2012
2013                 json_categorize_type(arg_type, &state->key_category,
2014                                                          &state->key_output_func);
2015
2016                 arg_type = get_fn_expr_argtype(fcinfo->flinfo, 2);
2017
2018                 if (arg_type == InvalidOid)
2019                         ereport(ERROR,
2020                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
2021                                          errmsg("could not determine data type for argument 2")));
2022
2023                 json_categorize_type(arg_type, &state->val_category,
2024                                                          &state->val_output_func);
2025
2026                 appendStringInfoString(state->str, "{ ");
2027         }
2028         else
2029         {
2030                 state = (JsonAggState *) PG_GETARG_POINTER(0);
2031                 appendStringInfoString(state->str, ", ");
2032         }
2033
2034         /*
2035          * Note: since json_object_agg() is declared as taking type "any", the
2036          * parser will not do any type conversion on unknown-type literals (that
2037          * is, undecorated strings or NULLs).  Such values will arrive here as
2038          * type UNKNOWN, which fortunately does not matter to us, since
2039          * unknownout() works fine.
2040          */
2041
2042         if (PG_ARGISNULL(1))
2043                 ereport(ERROR,
2044                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
2045                                  errmsg("field name must not be null")));
2046
2047         arg = PG_GETARG_DATUM(1);
2048
2049         datum_to_json(arg, false, state->str, state->key_category,
2050                                   state->key_output_func, true);
2051
2052         appendStringInfoString(state->str, " : ");
2053
2054         if (PG_ARGISNULL(2))
2055                 arg = (Datum) 0;
2056         else
2057                 arg = PG_GETARG_DATUM(2);
2058
2059         datum_to_json(arg, PG_ARGISNULL(2), state->str, state->val_category,
2060                                   state->val_output_func, false);
2061
2062         PG_RETURN_POINTER(state);
2063 }
2064
2065 /*
2066  * json_object_agg final function.
2067  */
2068 Datum
2069 json_object_agg_finalfn(PG_FUNCTION_ARGS)
2070 {
2071         JsonAggState *state;
2072
2073         /* cannot be called directly because of internal-type argument */
2074         Assert(AggCheckCallContext(fcinfo, NULL));
2075
2076         state = PG_ARGISNULL(0) ? NULL : (JsonAggState *) PG_GETARG_POINTER(0);
2077
2078         /* NULL result for no rows in, as is standard with aggregates */
2079         if (state == NULL)
2080                 PG_RETURN_NULL();
2081
2082         /* Else return state with appropriate object terminator added */
2083         PG_RETURN_TEXT_P(catenate_stringinfo_string(state->str, " }"));
2084 }
2085
2086 /*
2087  * Helper function for aggregates: return given StringInfo's contents plus
2088  * specified trailing string, as a text datum.  We need this because aggregate
2089  * final functions are not allowed to modify the aggregate state.
2090  */
2091 static text *
2092 catenate_stringinfo_string(StringInfo buffer, const char *addon)
2093 {
2094         /* custom version of cstring_to_text_with_len */
2095         int                     buflen = buffer->len;
2096         int                     addlen = strlen(addon);
2097         text       *result = (text *) palloc(buflen + addlen + VARHDRSZ);
2098
2099         SET_VARSIZE(result, buflen + addlen + VARHDRSZ);
2100         memcpy(VARDATA(result), buffer->data, buflen);
2101         memcpy(VARDATA(result) + buflen, addon, addlen);
2102
2103         return result;
2104 }
2105
2106 /*
2107  * SQL function json_build_object(variadic "any")
2108  */
2109 Datum
2110 json_build_object(PG_FUNCTION_ARGS)
2111 {
2112         int                     nargs = PG_NARGS();
2113         int                     i;
2114         Datum           arg;
2115         const char *sep = "";
2116         StringInfo      result;
2117         Oid                     val_type;
2118
2119         if (nargs % 2 != 0)
2120                 ereport(ERROR,
2121                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
2122                                  errmsg("argument list must have even number of elements"),
2123                                  errhint("The arguments of json_build_object() must consist of alternating keys and values.")));
2124
2125         result = makeStringInfo();
2126
2127         appendStringInfoChar(result, '{');
2128
2129         for (i = 0; i < nargs; i += 2)
2130         {
2131                 /*
2132                  * Note: since json_build_object() is declared as taking type "any",
2133                  * the parser will not do any type conversion on unknown-type literals
2134                  * (that is, undecorated strings or NULLs).  Such values will arrive
2135                  * here as type UNKNOWN, which fortunately does not matter to us,
2136                  * since unknownout() works fine.
2137                  */
2138                 appendStringInfoString(result, sep);
2139                 sep = ", ";
2140
2141                 /* process key */
2142                 val_type = get_fn_expr_argtype(fcinfo->flinfo, i);
2143
2144                 if (val_type == InvalidOid)
2145                         ereport(ERROR,
2146                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
2147                                          errmsg("could not determine data type for argument %d",
2148                                                         i + 1)));
2149
2150                 if (PG_ARGISNULL(i))
2151                         ereport(ERROR,
2152                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
2153                                          errmsg("argument %d cannot be null", i + 1),
2154                                          errhint("Object keys should be text.")));
2155
2156                 arg = PG_GETARG_DATUM(i);
2157
2158                 add_json(arg, false, result, val_type, true);
2159
2160                 appendStringInfoString(result, " : ");
2161
2162                 /* process value */
2163                 val_type = get_fn_expr_argtype(fcinfo->flinfo, i + 1);
2164
2165                 if (val_type == InvalidOid)
2166                         ereport(ERROR,
2167                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
2168                                          errmsg("could not determine data type for argument %d",
2169                                                         i + 2)));
2170
2171                 if (PG_ARGISNULL(i + 1))
2172                         arg = (Datum) 0;
2173                 else
2174                         arg = PG_GETARG_DATUM(i + 1);
2175
2176                 add_json(arg, PG_ARGISNULL(i + 1), result, val_type, false);
2177         }
2178
2179         appendStringInfoChar(result, '}');
2180
2181         PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
2182 }
2183
2184 /*
2185  * degenerate case of json_build_object where it gets 0 arguments.
2186  */
2187 Datum
2188 json_build_object_noargs(PG_FUNCTION_ARGS)
2189 {
2190         PG_RETURN_TEXT_P(cstring_to_text_with_len("{}", 2));
2191 }
2192
2193 /*
2194  * SQL function json_build_array(variadic "any")
2195  */
2196 Datum
2197 json_build_array(PG_FUNCTION_ARGS)
2198 {
2199         int                     nargs = PG_NARGS();
2200         int                     i;
2201         Datum           arg;
2202         const char *sep = "";
2203         StringInfo      result;
2204         Oid                     val_type;
2205
2206         result = makeStringInfo();
2207
2208         appendStringInfoChar(result, '[');
2209
2210         for (i = 0; i < nargs; i++)
2211         {
2212                 /*
2213                  * Note: since json_build_array() is declared as taking type "any",
2214                  * the parser will not do any type conversion on unknown-type literals
2215                  * (that is, undecorated strings or NULLs).  Such values will arrive
2216                  * here as type UNKNOWN, which fortunately does not matter to us,
2217                  * since unknownout() works fine.
2218                  */
2219                 appendStringInfoString(result, sep);
2220                 sep = ", ";
2221
2222                 val_type = get_fn_expr_argtype(fcinfo->flinfo, i);
2223
2224                 if (val_type == InvalidOid)
2225                         ereport(ERROR,
2226                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
2227                                          errmsg("could not determine data type for argument %d",
2228                                                         i + 1)));
2229
2230                 if (PG_ARGISNULL(i))
2231                         arg = (Datum) 0;
2232                 else
2233                         arg = PG_GETARG_DATUM(i);
2234
2235                 add_json(arg, PG_ARGISNULL(i), result, val_type, false);
2236         }
2237
2238         appendStringInfoChar(result, ']');
2239
2240         PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
2241 }
2242
2243 /*
2244  * degenerate case of json_build_array where it gets 0 arguments.
2245  */
2246 Datum
2247 json_build_array_noargs(PG_FUNCTION_ARGS)
2248 {
2249         PG_RETURN_TEXT_P(cstring_to_text_with_len("[]", 2));
2250 }
2251
2252 /*
2253  * SQL function json_object(text[])
2254  *
2255  * take a one or two dimensional array of text as key/value pairs
2256  * for a json object.
2257  */
2258 Datum
2259 json_object(PG_FUNCTION_ARGS)
2260 {
2261         ArrayType  *in_array = PG_GETARG_ARRAYTYPE_P(0);
2262         int                     ndims = ARR_NDIM(in_array);
2263         StringInfoData result;
2264         Datum      *in_datums;
2265         bool       *in_nulls;
2266         int                     in_count,
2267                                 count,
2268                                 i;
2269         text       *rval;
2270         char       *v;
2271
2272         switch (ndims)
2273         {
2274                 case 0:
2275                         PG_RETURN_DATUM(CStringGetTextDatum("{}"));
2276                         break;
2277
2278                 case 1:
2279                         if ((ARR_DIMS(in_array)[0]) % 2)
2280                                 ereport(ERROR,
2281                                                 (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
2282                                                  errmsg("array must have even number of elements")));
2283                         break;
2284
2285                 case 2:
2286                         if ((ARR_DIMS(in_array)[1]) != 2)
2287                                 ereport(ERROR,
2288                                                 (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
2289                                                  errmsg("array must have two columns")));
2290                         break;
2291
2292                 default:
2293                         ereport(ERROR,
2294                                         (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
2295                                          errmsg("wrong number of array subscripts")));
2296         }
2297
2298         deconstruct_array(in_array,
2299                                           TEXTOID, -1, false, 'i',
2300                                           &in_datums, &in_nulls, &in_count);
2301
2302         count = in_count / 2;
2303
2304         initStringInfo(&result);
2305
2306         appendStringInfoChar(&result, '{');
2307
2308         for (i = 0; i < count; ++i)
2309         {
2310                 if (in_nulls[i * 2])
2311                         ereport(ERROR,
2312                                         (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
2313                                          errmsg("null value not allowed for object key")));
2314
2315                 v = TextDatumGetCString(in_datums[i * 2]);
2316                 if (i > 0)
2317                         appendStringInfoString(&result, ", ");
2318                 escape_json(&result, v);
2319                 appendStringInfoString(&result, " : ");
2320                 pfree(v);
2321                 if (in_nulls[i * 2 + 1])
2322                         appendStringInfoString(&result, "null");
2323                 else
2324                 {
2325                         v = TextDatumGetCString(in_datums[i * 2 + 1]);
2326                         escape_json(&result, v);
2327                         pfree(v);
2328                 }
2329         }
2330
2331         appendStringInfoChar(&result, '}');
2332
2333         pfree(in_datums);
2334         pfree(in_nulls);
2335
2336         rval = cstring_to_text_with_len(result.data, result.len);
2337         pfree(result.data);
2338
2339         PG_RETURN_TEXT_P(rval);
2340
2341 }
2342
2343 /*
2344  * SQL function json_object(text[], text[])
2345  *
2346  * take separate key and value arrays of text to construct a json object
2347  * pairwise.
2348  */
2349 Datum
2350 json_object_two_arg(PG_FUNCTION_ARGS)
2351 {
2352         ArrayType  *key_array = PG_GETARG_ARRAYTYPE_P(0);
2353         ArrayType  *val_array = PG_GETARG_ARRAYTYPE_P(1);
2354         int                     nkdims = ARR_NDIM(key_array);
2355         int                     nvdims = ARR_NDIM(val_array);
2356         StringInfoData result;
2357         Datum      *key_datums,
2358                            *val_datums;
2359         bool       *key_nulls,
2360                            *val_nulls;
2361         int                     key_count,
2362                                 val_count,
2363                                 i;
2364         text       *rval;
2365         char       *v;
2366
2367         if (nkdims > 1 || nkdims != nvdims)
2368                 ereport(ERROR,
2369                                 (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
2370                                  errmsg("wrong number of array subscripts")));
2371
2372         if (nkdims == 0)
2373                 PG_RETURN_DATUM(CStringGetTextDatum("{}"));
2374
2375         deconstruct_array(key_array,
2376                                           TEXTOID, -1, false, 'i',
2377                                           &key_datums, &key_nulls, &key_count);
2378
2379         deconstruct_array(val_array,
2380                                           TEXTOID, -1, false, 'i',
2381                                           &val_datums, &val_nulls, &val_count);
2382
2383         if (key_count != val_count)
2384                 ereport(ERROR,
2385                                 (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
2386                                  errmsg("mismatched array dimensions")));
2387
2388         initStringInfo(&result);
2389
2390         appendStringInfoChar(&result, '{');
2391
2392         for (i = 0; i < key_count; ++i)
2393         {
2394                 if (key_nulls[i])
2395                         ereport(ERROR,
2396                                         (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
2397                                          errmsg("null value not allowed for object key")));
2398
2399                 v = TextDatumGetCString(key_datums[i]);
2400                 if (i > 0)
2401                         appendStringInfoString(&result, ", ");
2402                 escape_json(&result, v);
2403                 appendStringInfoString(&result, " : ");
2404                 pfree(v);
2405                 if (val_nulls[i])
2406                         appendStringInfoString(&result, "null");
2407                 else
2408                 {
2409                         v = TextDatumGetCString(val_datums[i]);
2410                         escape_json(&result, v);
2411                         pfree(v);
2412                 }
2413         }
2414
2415         appendStringInfoChar(&result, '}');
2416
2417         pfree(key_datums);
2418         pfree(key_nulls);
2419         pfree(val_datums);
2420         pfree(val_nulls);
2421
2422         rval = cstring_to_text_with_len(result.data, result.len);
2423         pfree(result.data);
2424
2425         PG_RETURN_TEXT_P(rval);
2426 }
2427
2428
2429 /*
2430  * Produce a JSON string literal, properly escaping characters in the text.
2431  */
2432 void
2433 escape_json(StringInfo buf, const char *str)
2434 {
2435         const char *p;
2436
2437         appendStringInfoCharMacro(buf, '"');
2438         for (p = str; *p; p++)
2439         {
2440                 switch (*p)
2441                 {
2442                         case '\b':
2443                                 appendStringInfoString(buf, "\\b");
2444                                 break;
2445                         case '\f':
2446                                 appendStringInfoString(buf, "\\f");
2447                                 break;
2448                         case '\n':
2449                                 appendStringInfoString(buf, "\\n");
2450                                 break;
2451                         case '\r':
2452                                 appendStringInfoString(buf, "\\r");
2453                                 break;
2454                         case '\t':
2455                                 appendStringInfoString(buf, "\\t");
2456                                 break;
2457                         case '"':
2458                                 appendStringInfoString(buf, "\\\"");
2459                                 break;
2460                         case '\\':
2461                                 appendStringInfoString(buf, "\\\\");
2462                                 break;
2463                         default:
2464                                 if ((unsigned char) *p < ' ')
2465                                         appendStringInfo(buf, "\\u%04x", (int) *p);
2466                                 else
2467                                         appendStringInfoCharMacro(buf, *p);
2468                                 break;
2469                 }
2470         }
2471         appendStringInfoCharMacro(buf, '"');
2472 }
2473
2474 /*
2475  * SQL function json_typeof(json) -> text
2476  *
2477  * Returns the type of the outermost JSON value as TEXT.  Possible types are
2478  * "object", "array", "string", "number", "boolean", and "null".
2479  *
2480  * Performs a single call to json_lex() to get the first token of the supplied
2481  * value.  This initial token uniquely determines the value's type.  As our
2482  * input must already have been validated by json_in() or json_recv(), the
2483  * initial token should never be JSON_TOKEN_OBJECT_END, JSON_TOKEN_ARRAY_END,
2484  * JSON_TOKEN_COLON, JSON_TOKEN_COMMA, or JSON_TOKEN_END.
2485  */
2486 Datum
2487 json_typeof(PG_FUNCTION_ARGS)
2488 {
2489         text       *json;
2490
2491         JsonLexContext *lex;
2492         JsonTokenType tok;
2493         char       *type;
2494
2495         json = PG_GETARG_TEXT_PP(0);
2496         lex = makeJsonLexContext(json, false);
2497
2498         /* Lex exactly one token from the input and check its type. */
2499         json_lex(lex);
2500         tok = lex_peek(lex);
2501         switch (tok)
2502         {
2503                 case JSON_TOKEN_OBJECT_START:
2504                         type = "object";
2505                         break;
2506                 case JSON_TOKEN_ARRAY_START:
2507                         type = "array";
2508                         break;
2509                 case JSON_TOKEN_STRING:
2510                         type = "string";
2511                         break;
2512                 case JSON_TOKEN_NUMBER:
2513                         type = "number";
2514                         break;
2515                 case JSON_TOKEN_TRUE:
2516                 case JSON_TOKEN_FALSE:
2517                         type = "boolean";
2518                         break;
2519                 case JSON_TOKEN_NULL:
2520                         type = "null";
2521                         break;
2522                 default:
2523                         elog(ERROR, "unexpected json token: %d", tok);
2524         }
2525
2526         PG_RETURN_TEXT_P(cstring_to_text(type));
2527 }