/*------------------------------------------------------------------------- * * json_extra.c * additional JSON data type support. * * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * adapted from src/backend/utils/adt/json.c and patch which adds to it * *------------------------------------------------------------------------- */ #include "postgres.h" /* #include "access/htup_details.h" */ #include "access/transam.h" #include "catalog/pg_cast.h" #include "catalog/pg_type.h" #include "executor/spi.h" #include "lib/stringinfo.h" #include "libpq/pqformat.h" #include "mb/pg_wchar.h" #include "parser/parse_coerce.h" #include "utils/array.h" #include "utils/builtins.h" #include "utils/lsyscache.h" #include "utils/json.h" #include "utils/typcache.h" #include "utils/syscache.h" #include "json_extra.h" #include "jsonapi.h" static void composite_to_json(Datum composite, StringInfo result, bool use_line_feeds); static void array_dim_to_json(StringInfo result, int dim, int ndims, int *dims, Datum *vals, bool *nulls, int *valcount, TYPCATEGORY tcategory, Oid typoutputfunc, bool use_line_feeds); static void array_to_json_internal(Datum array, StringInfo result, bool use_line_feeds); /* * All the defined type categories are upper case , so use lower case here * so we avoid any possible clash. */ /* fake type category for JSON so we can distinguish it in datum_to_json */ #define TYPCATEGORY_JSON 'j' /* fake category for types that have a cast to json */ #define TYPCATEGORY_JSON_CAST 'c' /* * The context of the parser is maintained by the recursive descent * mechanism, but is passed explicitly to the error reporting routine * for better diagnostics. */ typedef enum /* contexts of JSON parser */ { JSON_PARSE_VALUE, /* expecting a value */ JSON_PARSE_STRING, /* expecting a string (for a field name) */ JSON_PARSE_ARRAY_START, /* saw '[', expecting value or ']' */ JSON_PARSE_ARRAY_NEXT, /* saw array element, expecting ',' or ']' */ JSON_PARSE_OBJECT_START, /* saw '{', expecting label or '}' */ JSON_PARSE_OBJECT_LABEL, /* saw object label, expecting ':' */ JSON_PARSE_OBJECT_NEXT, /* saw object value, expecting ',' or '}' */ JSON_PARSE_OBJECT_COMMA, /* saw object ',', expecting next label */ JSON_PARSE_END /* saw the end of a document, expect nothing */ } JsonParseContext; static inline void json_lex(JsonLexContext *lex); static inline void json_lex_string(JsonLexContext *lex); static inline void json_lex_number(JsonLexContext *lex, char *s); static inline void parse_scalar(JsonLexContext *lex, JsonSemAction sem); static void parse_object_field(JsonLexContext *lex, JsonSemAction sem); static void parse_object(JsonLexContext *lex, JsonSemAction sem); static void parse_array_element(JsonLexContext *lex, JsonSemAction sem); static void parse_array(JsonLexContext *lex, JsonSemAction sem); static void report_parse_error(JsonParseContext ctx, JsonLexContext *lex); static void report_invalid_token(JsonLexContext *lex); static int report_json_context(JsonLexContext *lex); static char *extract_mb_char(char *s); /* Recursive Descent parser support routines */ /* * lex_peek * * what is the current look_ahead token? */ static inline JsonTokenType lex_peek(JsonLexContext *lex) { return lex->token_type; } /* * lex_accept * * accept the look_ahead token and move the lexer to the next token if the * look_ahead token matches the token parameter. In that case, and if required, * also hand back the de-escaped lexeme. * * returns true if the token matched, false otherwise. */ static inline bool lex_accept(JsonLexContext *lex, JsonTokenType token, char **lexeme) { if (lex->token_type == token) { if (lexeme != NULL) { if (lex->token_type == JSON_TOKEN_STRING) { if (lex->strval != NULL) *lexeme = pstrdup(lex->strval->data); } else { int len = (lex->token_terminator - lex->token_start); char *tokstr = palloc(len + 1); memcpy(tokstr, lex->token_start, len); tokstr[len] = '\0'; *lexeme = tokstr; } } json_lex(lex); return true; } return false; } /* * lex_accept * * move the lexer to the next token if the current look_ahead token matches * the parameter token. Otherwise, report an error. */ static inline void lex_expect(JsonParseContext ctx, JsonLexContext *lex, JsonTokenType token) { if (!lex_accept(lex, token, NULL)) report_parse_error(ctx, lex);; } /* fake type category for JSON so we can distinguish it in datum_to_json */ #define TYPCATEGORY_JSON 'j' /* letters appearing in numeric output that aren't valid in a JSON number */ #define NON_NUMERIC_LETTER "NnAaIiFfTtYy" /* chars to consider as part of an alphanumeric token */ #define JSON_ALPHANUMERIC_CHAR(c) \ (((c) >= 'a' && (c) <= 'z') || \ ((c) >= 'A' && (c) <= 'Z') || \ ((c) >= '0' && (c) <= '9') || \ (c) == '_' || \ IS_HIGHBIT_SET(c)) /* * makeJsonLexContext * * lex constructor, with or without StringInfo object * for de-escaped lexemes. * * Without is better as it makes the processing faster, so only make one * if really required. */ JsonLexContext * makeJsonLexContext(text *json, bool need_escapes) { JsonLexContext *lex = palloc0(sizeof(JsonLexContext)); lex->input = lex->token_terminator = lex->line_start = VARDATA(json); lex->line_number = 1; lex->input_length = VARSIZE(json) - VARHDRSZ; if (need_escapes) lex->strval = makeStringInfo(); return lex; } /* * pg_parse_json * * Publicly visible entry point for the JSON parser. * * lex is a lexing context, set up for the json to be processed by calling * makeJsonLexContext(). sem is a strucure of function pointers to semantic * action routines to be called at appropriate spots during parsing, and a * pointer to a state object to be passed to those routines. */ void pg_parse_json(JsonLexContext *lex, JsonSemAction sem) { JsonTokenType tok; /* get the initial token */ json_lex(lex); tok = lex_peek(lex); /* parse by recursive descent */ switch (tok) { case JSON_TOKEN_OBJECT_START: parse_object(lex, sem); break; case JSON_TOKEN_ARRAY_START: parse_array(lex, sem); break; default: parse_scalar(lex, sem); /* json can be a bare scalar */ } lex_expect(JSON_PARSE_END, lex, JSON_TOKEN_END); } /* * Recursive Descent parse routines. There is one for each structural * element in a json document: * - scalar (string, number, true, false, null) * - array ( [ ] ) * - array element * - object ( { } ) * - object field */ static inline void parse_scalar(JsonLexContext *lex, JsonSemAction sem) { char *val = NULL; json_scalar_action sfunc = sem->scalar; char **valaddr; JsonTokenType tok = lex_peek(lex); valaddr = sfunc == NULL ? NULL : &val; /* a scalar must be a string, a number, true, false, or null */ switch (tok) { case JSON_TOKEN_TRUE: lex_accept(lex, JSON_TOKEN_TRUE, valaddr); break; case JSON_TOKEN_FALSE: lex_accept(lex, JSON_TOKEN_FALSE, valaddr); break; case JSON_TOKEN_NULL: lex_accept(lex, JSON_TOKEN_NULL, valaddr); break; case JSON_TOKEN_NUMBER: lex_accept(lex, JSON_TOKEN_NUMBER, valaddr); break; case JSON_TOKEN_STRING: lex_accept(lex, JSON_TOKEN_STRING, valaddr); break; default: report_parse_error(JSON_PARSE_VALUE, lex); } if (sfunc != NULL) (*sfunc) (sem->semstate, val, tok); } static void parse_object_field(JsonLexContext *lex, JsonSemAction sem) { /* * an object field is "fieldname" : value where value can be a scalar, * object or array */ char *fname = NULL; /* keep compiler quiet */ json_ofield_action ostart = sem->object_field_start; json_ofield_action oend = sem->object_field_end; bool isnull; char **fnameaddr = NULL; JsonTokenType tok; if (ostart != NULL || oend != NULL) fnameaddr = &fname; if (!lex_accept(lex, JSON_TOKEN_STRING, fnameaddr)) report_parse_error(JSON_PARSE_STRING, lex); lex_expect(JSON_PARSE_OBJECT_LABEL, lex, JSON_TOKEN_COLON); tok = lex_peek(lex); isnull = tok == JSON_TOKEN_NULL; if (ostart != NULL) (*ostart) (sem->semstate, fname, isnull); switch (tok) { case JSON_TOKEN_OBJECT_START: parse_object(lex, sem); break; case JSON_TOKEN_ARRAY_START: parse_array(lex, sem); break; default: parse_scalar(lex, sem); } if (oend != NULL) (*oend) (sem->semstate, fname, isnull); if (fname != NULL) pfree(fname); } static void parse_object(JsonLexContext *lex, JsonSemAction sem) { /* * an object is a possibly empty sequence of object fields, separated by * commas and surrounde by curly braces. */ json_struct_action ostart = sem->object_start; json_struct_action oend = sem->object_end; JsonTokenType tok; if (ostart != NULL) (*ostart) (sem->semstate); /* * Data inside an object at at a higher nesting level than the object * itself. Note that we increment this after we call the semantic routine * for the object start and restore it before we call the routine for the * object end. */ lex->lex_level++; /* we know this will succeeed, just clearing the token */ lex_expect(JSON_PARSE_OBJECT_START, lex, JSON_TOKEN_OBJECT_START); tok = lex_peek(lex); switch (tok) { case JSON_TOKEN_STRING: parse_object_field(lex, sem); while (lex_accept(lex, JSON_TOKEN_COMMA, NULL)) parse_object_field(lex, sem); break; case JSON_TOKEN_OBJECT_END: break; default: /* case of an invalid initial token inside the object */ report_parse_error(JSON_PARSE_OBJECT_START, lex); } lex_expect(JSON_PARSE_OBJECT_NEXT, lex, JSON_TOKEN_OBJECT_END); lex->lex_level--; if (oend != NULL) (*oend) (sem->semstate); } static void parse_array_element(JsonLexContext *lex, JsonSemAction sem) { json_aelem_action astart = sem->array_element_start; json_aelem_action aend = sem->array_element_end; JsonTokenType tok = lex_peek(lex); bool isnull; isnull = tok == JSON_TOKEN_NULL; if (astart != NULL) (*astart) (sem->semstate, isnull); /* an array element is any object, array or scalar */ switch (tok) { case JSON_TOKEN_OBJECT_START: parse_object(lex, sem); break; case JSON_TOKEN_ARRAY_START: parse_array(lex, sem); break; default: parse_scalar(lex, sem); } if (aend != NULL) (*aend) (sem->semstate, isnull); } static void parse_array(JsonLexContext *lex, JsonSemAction sem) { /* * an array is a possibly empty sequence of array elements, separated by * commas and surrounded by square brackets. */ json_struct_action astart = sem->array_start; json_struct_action aend = sem->array_end; if (astart != NULL) (*astart) (sem->semstate); /* * Data inside an array at at a higher nesting level than the array * itself. Note that we increment this after we call the semantic routine * for the array start and restore it before we call the routine for the * array end. */ lex->lex_level++; lex_expect(JSON_PARSE_ARRAY_START, lex, JSON_TOKEN_ARRAY_START); if (lex_peek(lex) != JSON_TOKEN_ARRAY_END) { parse_array_element(lex, sem); while (lex_accept(lex, JSON_TOKEN_COMMA, NULL)) parse_array_element(lex, sem); } lex_expect(JSON_PARSE_ARRAY_NEXT, lex, JSON_TOKEN_ARRAY_END); lex->lex_level--; if (aend != NULL) (*aend) (sem->semstate); } /* * Lex one token from the input stream. */ static inline void json_lex(JsonLexContext *lex) { char *s; int len; /* Skip leading whitespace. */ s = lex->token_terminator; len = s - lex->input; while (len < lex->input_length && (*s == ' ' || *s == '\t' || *s == '\n' || *s == '\r')) { if (*s == '\n') ++lex->line_number; ++s; ++len; } lex->token_start = s; /* Determine token type. */ if (len >= lex->input_length) { lex->token_start = NULL; lex->prev_token_terminator = lex->token_terminator; lex->token_terminator = s; lex->token_type = JSON_TOKEN_END; } else switch (*s) { /* Single-character token, some kind of punctuation mark. */ case '{': lex->prev_token_terminator = lex->token_terminator; lex->token_terminator = s + 1; lex->token_type = JSON_TOKEN_OBJECT_START; break; case '}': lex->prev_token_terminator = lex->token_terminator; lex->token_terminator = s + 1; lex->token_type = JSON_TOKEN_OBJECT_END; break; case '[': lex->prev_token_terminator = lex->token_terminator; lex->token_terminator = s + 1; lex->token_type = JSON_TOKEN_ARRAY_START; break; case ']': lex->prev_token_terminator = lex->token_terminator; lex->token_terminator = s + 1; lex->token_type = JSON_TOKEN_ARRAY_END; break; case ',': lex->prev_token_terminator = lex->token_terminator; lex->token_terminator = s + 1; lex->token_type = JSON_TOKEN_COMMA; break; case ':': lex->prev_token_terminator = lex->token_terminator; lex->token_terminator = s + 1; lex->token_type = JSON_TOKEN_COLON; break; case '"': /* string */ json_lex_string(lex); lex->token_type = JSON_TOKEN_STRING; break; case '-': /* Negative number. */ json_lex_number(lex, s + 1); lex->token_type = JSON_TOKEN_NUMBER; break; case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': /* Positive number. */ json_lex_number(lex, s); lex->token_type = JSON_TOKEN_NUMBER; break; default: { char *p; /* * We're not dealing with a string, number, legal * punctuation mark, or end of string. The only legal * tokens we might find here are true, false, and null, * but for error reporting purposes we scan until we see a * non-alphanumeric character. That way, we can report * the whole word as an unexpected token, rather than just * some unintuitive prefix thereof. */ for (p = s; JSON_ALPHANUMERIC_CHAR(*p) && p - s < lex->input_length - len; p++) /* skip */ ; /* * We got some sort of unexpected punctuation or an * otherwise unexpected character, so just complain about * that one character. */ if (p == s) { lex->prev_token_terminator = lex->token_terminator; lex->token_terminator = s + 1; report_invalid_token(lex); } /* * We've got a real alphanumeric token here. If it * happens to be true, false, or null, all is well. If * not, error out. */ lex->prev_token_terminator = lex->token_terminator; lex->token_terminator = p; if (p - s == 4) { if (memcmp(s, "true", 4) == 0) lex->token_type = JSON_TOKEN_TRUE; else if (memcmp(s, "null", 4) == 0) lex->token_type = JSON_TOKEN_NULL; else report_invalid_token(lex); } else if (p - s == 5 && memcmp(s, "false", 5) == 0) lex->token_type = JSON_TOKEN_FALSE; else report_invalid_token(lex); } } /* end of switch */ } /* * The next token in the input stream is known to be a string; lex it. */ static inline void json_lex_string(JsonLexContext *lex) { char *s; int len; if (lex->strval != NULL) resetStringInfo(lex->strval); len = lex->token_start - lex->input; len++; for (s = lex->token_start + 1; *s != '"'; s++, len++) { /* Premature end of the string. */ if (len >= lex->input_length) { lex->token_terminator = s; report_invalid_token(lex); } else if ((unsigned char) *s < 32) { /* Per RFC4627, these characters MUST be escaped. */ /* Since *s isn't printable, exclude it from the context string */ lex->token_terminator = s; ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Character with value 0x%02x must be escaped.", (unsigned char) *s), report_json_context(lex))); } else if (*s == '\\') { /* OK, we have an escape character. */ s++; len++; if (len >= lex->input_length) { lex->token_terminator = s; report_invalid_token(lex); } else if (*s == 'u') { int i; int ch = 0; for (i = 1; i <= 4; i++) { s++; len++; if (len >= lex->input_length) { lex->token_terminator = s; report_invalid_token(lex); } else if (*s >= '0' && *s <= '9') ch = (ch * 16) + (*s - '0'); else if (*s >= 'a' && *s <= 'f') ch = (ch * 16) + (*s - 'a') + 10; else if (*s >= 'A' && *s <= 'F') ch = (ch * 16) + (*s - 'A') + 10; else { lex->token_terminator = s + pg_mblen(s); ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("\"\\u\" must be followed by four hexadecimal digits."), report_json_context(lex))); } } if (lex->strval != NULL) { char utf8str[5]; int utf8len; char *converted; unicode_to_utf8(ch, (unsigned char *) utf8str); utf8len = pg_utf_mblen((unsigned char *) utf8str); utf8str[utf8len] = '\0'; converted = pg_any_to_server(utf8str, 1, PG_UTF8); appendStringInfoString(lex->strval, converted); if (converted != utf8str) pfree(converted); } } else if (lex->strval != NULL) { switch (*s) { case '"': case '\\': case '/': appendStringInfoChar(lex->strval, *s); break; case 'b': appendStringInfoChar(lex->strval, '\b'); break; case 'f': appendStringInfoChar(lex->strval, '\f'); break; case 'n': appendStringInfoChar(lex->strval, '\n'); break; case 'r': appendStringInfoChar(lex->strval, '\r'); break; case 't': appendStringInfoChar(lex->strval, '\t'); break; default: /* Not a valid string escape, so error out. */ lex->token_terminator = s + pg_mblen(s); ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Escape sequence \"\\%s\" is invalid.", extract_mb_char(s)), report_json_context(lex))); } } else if (strchr("\"\\/bfnrt", *s) == NULL) { /* * Simpler processing if we're not bothered about de-escaping * * It's very tempting to remove the strchr() call here and * replace it with a switch statement, but testing so far has * shown it's not a performance win. */ lex->token_terminator = s + pg_mblen(s); ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Escape sequence \"\\%s\" is invalid.", extract_mb_char(s)), report_json_context(lex))); } } else if (lex->strval != NULL) { appendStringInfoChar(lex->strval, *s); } } /* Hooray, we found the end of the string! */ lex->prev_token_terminator = lex->token_terminator; lex->token_terminator = s + 1; } /*------------------------------------------------------------------------- * The next token in the input stream is known to be a number; lex it. * * In JSON, a number consists of four parts: * * (1) An optional minus sign ('-'). * * (2) Either a single '0', or a string of one or more digits that does not * begin with a '0'. * * (3) An optional decimal part, consisting of a period ('.') followed by * one or more digits. (Note: While this part can be omitted * completely, it's not OK to have only the decimal point without * any digits afterwards.) * * (4) An optional exponent part, consisting of 'e' or 'E', optionally * followed by '+' or '-', followed by one or more digits. (Note: * As with the decimal part, if 'e' or 'E' is present, it must be * followed by at least one digit.) * * The 's' argument to this function points to the ostensible beginning * of part 2 - i.e. the character after any optional minus sign, and the * first character of the string if there is none. * *------------------------------------------------------------------------- */ static inline void json_lex_number(JsonLexContext *lex, char *s) { bool error = false; char *p; int len; len = s - lex->input; /* Part (1): leading sign indicator. */ /* Caller already did this for us; so do nothing. */ /* Part (2): parse main digit string. */ if (*s == '0') { s++; len++; } else if (*s >= '1' && *s <= '9') { do { s++; len++; } while (*s >= '0' && *s <= '9' && len < lex->input_length); } else error = true; /* Part (3): parse optional decimal portion. */ if (len < lex->input_length && *s == '.') { s++; len++; if (len == lex->input_length || *s < '0' || *s > '9') error = true; else { do { s++; len++; } while (*s >= '0' && *s <= '9' && len < lex->input_length); } } /* Part (4): parse optional exponent. */ if (len < lex->input_length && (*s == 'e' || *s == 'E')) { s++; len++; if (len < lex->input_length && (*s == '+' || *s == '-')) { s++; len++; } if (len == lex->input_length || *s < '0' || *s > '9') error = true; else { do { s++; len++; } while (len < lex->input_length && *s >= '0' && *s <= '9'); } } /* * Check for trailing garbage. As in json_lex(), any alphanumeric stuff * here should be considered part of the token for error-reporting * purposes. */ for (p = s; JSON_ALPHANUMERIC_CHAR(*p) && len < lex->input_length; p++, len++) error = true; lex->prev_token_terminator = lex->token_terminator; lex->token_terminator = p; if (error) report_invalid_token(lex); } /* * Report a parse error. * * lex->token_start and lex->token_terminator must identify the current token. */ static void report_parse_error(JsonParseContext ctx, JsonLexContext *lex) { char *token; int toklen; /* Handle case where the input ended prematurely. */ if (lex->token_start == NULL || lex->token_type == JSON_TOKEN_END) ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("The input string ended unexpectedly."), report_json_context(lex))); /* Separate out the current token. */ toklen = lex->token_terminator - lex->token_start; token = palloc(toklen + 1); memcpy(token, lex->token_start, toklen); token[toklen] = '\0'; /* Complain, with the appropriate detail message. */ if (ctx == JSON_PARSE_END) ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Expected end of input, but found \"%s\".", token), report_json_context(lex))); else { switch (ctx) { case JSON_PARSE_VALUE: ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Expected JSON value, but found \"%s\".", token), report_json_context(lex))); break; case JSON_PARSE_STRING: ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Expected string, but found \"%s\".", token), report_json_context(lex))); break; case JSON_PARSE_ARRAY_START: ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Expected array element or \"]\", but found \"%s\".", token), report_json_context(lex))); break; case JSON_PARSE_ARRAY_NEXT: ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Expected \",\" or \"]\", but found \"%s\".", token), report_json_context(lex))); break; case JSON_PARSE_OBJECT_START: ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Expected string or \"}\", but found \"%s\".", token), report_json_context(lex))); break; case JSON_PARSE_OBJECT_LABEL: ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Expected \":\", but found \"%s\".", token), report_json_context(lex))); break; case JSON_PARSE_OBJECT_NEXT: ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Expected \",\" or \"}\", but found \"%s\".", token), report_json_context(lex))); break; case JSON_PARSE_OBJECT_COMMA: ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Expected string, but found \"%s\".", token), report_json_context(lex))); break; default: elog(ERROR, "unexpected json parse state: %d", ctx); } } } /* * Report an invalid input token. * * lex->token_start and lex->token_terminator must identify the token. */ static void report_invalid_token(JsonLexContext *lex) { char *token; int toklen; /* Separate out the offending token. */ toklen = lex->token_terminator - lex->token_start; token = palloc(toklen + 1); memcpy(token, lex->token_start, toklen); token[toklen] = '\0'; ereport(ERROR, (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION), errmsg("invalid input syntax for type json"), errdetail("Token \"%s\" is invalid.", token), report_json_context(lex))); } /* * Report a CONTEXT line for bogus JSON input. * * lex->token_terminator must be set to identify the spot where we detected * the error. Note that lex->token_start might be NULL, in case we recognized * error at EOF. * * The return value isn't meaningful, but we make it non-void so that this * can be invoked inside ereport(). */ static int report_json_context(JsonLexContext *lex) { const char *context_start; const char *context_end; const char *line_start; int line_number; char *ctxt; int ctxtlen; const char *prefix; const char *suffix; /* Choose boundaries for the part of the input we will display */ context_start = lex->input; context_end = lex->token_terminator; line_start = context_start; line_number = 1; for (;;) { /* Always advance over newlines (context_end test is just paranoia) */ if (*context_start == '\n' && context_start < context_end) { context_start++; line_start = context_start; line_number++; continue; } /* Otherwise, done as soon as we are close enough to context_end */ if (context_end - context_start < 50) break; /* Advance to next multibyte character */ if (IS_HIGHBIT_SET(*context_start)) context_start += pg_mblen(context_start); else context_start++; } /* * We add "..." to indicate that the excerpt doesn't start at the * beginning of the line ... but if we're within 3 characters of the * beginning of the line, we might as well just show the whole line. */ if (context_start - line_start <= 3) context_start = line_start; /* Get a null-terminated copy of the data to present */ ctxtlen = context_end - context_start; ctxt = palloc(ctxtlen + 1); memcpy(ctxt, context_start, ctxtlen); ctxt[ctxtlen] = '\0'; /* * Show the context, prefixing "..." if not starting at start of line, and * suffixing "..." if not ending at end of line. */ prefix = (context_start > line_start) ? "..." : ""; suffix = (lex->token_type != JSON_TOKEN_END && context_end - lex->input < lex->input_length && *context_end != '\n' && *context_end != '\r') ? "..." : ""; return errcontext("JSON data, line %d: %s%s%s", line_number, prefix, ctxt, suffix); } /* * Extract a single, possibly multi-byte char from the input string. */ static char * extract_mb_char(char *s) { char *res; int len; len = pg_mblen(s); res = palloc(len + 1); memcpy(res, s, len); res[len] = '\0'; return res; } /* * Turn a scalar Datum into JSON, appending the string to "result". * * Hand off a non-scalar datum to composite_to_json or array_to_json_internal * as appropriate. */ static void datum_to_json(Datum val, bool is_null, StringInfo result, TYPCATEGORY tcategory, Oid typoutputfunc) { char *outputstr; text *jsontext; if (is_null) { appendStringInfoString(result, "null"); return; } switch (tcategory) { case TYPCATEGORY_ARRAY: array_to_json_internal(val, result, false); break; case TYPCATEGORY_COMPOSITE: composite_to_json(val, result, false); break; case TYPCATEGORY_BOOLEAN: if (DatumGetBool(val)) appendStringInfoString(result, "true"); else appendStringInfoString(result, "false"); break; case TYPCATEGORY_NUMERIC: outputstr = OidOutputFunctionCall(typoutputfunc, val); /* * Don't call escape_json here if it's a valid JSON number. * Numeric output should usually be a valid JSON number and JSON * numbers shouldn't be quoted. Quote cases like "Nan" and * "Infinity", however. */ if (strpbrk(outputstr, NON_NUMERIC_LETTER) == NULL) appendStringInfoString(result, outputstr); else escape_json(result, outputstr); pfree(outputstr); break; case TYPCATEGORY_JSON: /* JSON will already be escaped */ outputstr = OidOutputFunctionCall(typoutputfunc, val); appendStringInfoString(result, outputstr); pfree(outputstr); break; case TYPCATEGORY_JSON_CAST: jsontext = DatumGetTextP(OidFunctionCall1(typoutputfunc, val)); outputstr = text_to_cstring(jsontext); appendStringInfoString(result, outputstr); pfree(outputstr); pfree(jsontext); break; default: outputstr = OidOutputFunctionCall(typoutputfunc, val); escape_json(result, outputstr); pfree(outputstr); break; } } /* * Process a single dimension of an array. * If it's the innermost dimension, output the values, otherwise call * ourselves recursively to process the next dimension. */ static void array_dim_to_json(StringInfo result, int dim, int ndims, int *dims, Datum *vals, bool *nulls, int *valcount, TYPCATEGORY tcategory, Oid typoutputfunc, bool use_line_feeds) { int i; const char *sep; Assert(dim < ndims); sep = use_line_feeds ? ",\n " : ","; appendStringInfoChar(result, '['); for (i = 1; i <= dims[dim]; i++) { if (i > 1) appendStringInfoString(result, sep); if (dim + 1 == ndims) { datum_to_json(vals[*valcount], nulls[*valcount], result, tcategory, typoutputfunc); (*valcount)++; } else { /* * Do we want line feeds on inner dimensions of arrays? For now * we'll say no. */ array_dim_to_json(result, dim + 1, ndims, dims, vals, nulls, valcount, tcategory, typoutputfunc, false); } } appendStringInfoChar(result, ']'); } /* * Turn an array into JSON. */ static void array_to_json_internal(Datum array, StringInfo result, bool use_line_feeds) { ArrayType *v = DatumGetArrayTypeP(array); Oid element_type = ARR_ELEMTYPE(v); int *dim; int ndim; int nitems; int count = 0; Datum *elements; bool *nulls; int16 typlen; bool typbyval; char typalign, typdelim; Oid typioparam; Oid typoutputfunc; TYPCATEGORY tcategory; Oid castfunc = InvalidOid; ndim = ARR_NDIM(v); dim = ARR_DIMS(v); nitems = ArrayGetNItems(ndim, dim); if (nitems <= 0) { appendStringInfoString(result, "[]"); return; } get_type_io_data(element_type, IOFunc_output, &typlen, &typbyval, &typalign, &typdelim, &typioparam, &typoutputfunc); if (element_type > FirstNormalObjectId) { HeapTuple tuple; Form_pg_cast castForm; tuple = SearchSysCache2(CASTSOURCETARGET, ObjectIdGetDatum(element_type), ObjectIdGetDatum(JSONOID)); if (HeapTupleIsValid(tuple)) { castForm = (Form_pg_cast) GETSTRUCT(tuple); if (castForm->castmethod == COERCION_METHOD_FUNCTION) castfunc = typoutputfunc = castForm->castfunc; ReleaseSysCache(tuple); } } deconstruct_array(v, element_type, typlen, typbyval, typalign, &elements, &nulls, &nitems); if (castfunc != InvalidOid) tcategory = TYPCATEGORY_JSON_CAST; else if (element_type == RECORDOID) tcategory = TYPCATEGORY_COMPOSITE; else if (element_type == JSONOID) tcategory = TYPCATEGORY_JSON; else tcategory = TypeCategory(element_type); array_dim_to_json(result, 0, ndim, dim, elements, nulls, &count, tcategory, typoutputfunc, use_line_feeds); pfree(elements); pfree(nulls); } /* * Turn a composite / record into JSON. */ static void composite_to_json(Datum composite, StringInfo result, bool use_line_feeds) { HeapTupleHeader td; Oid tupType; int32 tupTypmod; TupleDesc tupdesc; HeapTupleData tmptup, *tuple; int i; bool needsep = false; const char *sep; sep = use_line_feeds ? ",\n " : ","; td = DatumGetHeapTupleHeader(composite); /* Extract rowtype info and find a tupdesc */ tupType = HeapTupleHeaderGetTypeId(td); tupTypmod = HeapTupleHeaderGetTypMod(td); tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod); /* Build a temporary HeapTuple control structure */ tmptup.t_len = HeapTupleHeaderGetDatumLength(td); tmptup.t_data = td; tuple = &tmptup; appendStringInfoChar(result, '{'); for (i = 0; i < tupdesc->natts; i++) { Datum val, origval; bool isnull; char *attname; TYPCATEGORY tcategory; Oid typoutput; bool typisvarlena; Oid castfunc = InvalidOid; if (tupdesc->attrs[i]->attisdropped) continue; if (needsep) appendStringInfoString(result, sep); needsep = true; attname = NameStr(tupdesc->attrs[i]->attname); escape_json(result, attname); appendStringInfoChar(result, ':'); origval = heap_getattr(tuple, i + 1, tupdesc, &isnull); getTypeOutputInfo(tupdesc->attrs[i]->atttypid, &typoutput, &typisvarlena); if (tupdesc->attrs[i]->atttypid > FirstNormalObjectId) { HeapTuple cast_tuple; Form_pg_cast castForm; cast_tuple = SearchSysCache2(CASTSOURCETARGET, ObjectIdGetDatum(tupdesc->attrs[i]->atttypid), ObjectIdGetDatum(JSONOID)); if (HeapTupleIsValid(cast_tuple)) { castForm = (Form_pg_cast) GETSTRUCT(cast_tuple); if (castForm->castmethod == COERCION_METHOD_FUNCTION) castfunc = typoutput = castForm->castfunc; ReleaseSysCache(cast_tuple); } } if (castfunc != InvalidOid) tcategory = TYPCATEGORY_JSON_CAST; else if (tupdesc->attrs[i]->atttypid == RECORDARRAYOID) tcategory = TYPCATEGORY_ARRAY; else if (tupdesc->attrs[i]->atttypid == RECORDOID) tcategory = TYPCATEGORY_COMPOSITE; else if (tupdesc->attrs[i]->atttypid == JSONOID) tcategory = TYPCATEGORY_JSON; else tcategory = TypeCategory(tupdesc->attrs[i]->atttypid); /* * If we have a toasted datum, forcibly detoast it here to avoid * memory leakage inside the type's output routine. */ if (typisvarlena && !isnull) val = PointerGetDatum(PG_DETOAST_DATUM(origval)); else val = origval; datum_to_json(val, isnull, result, tcategory, typoutput); /* Clean up detoasted copy, if any */ if (val != origval) pfree(DatumGetPointer(val)); } appendStringInfoChar(result, '}'); ReleaseTupleDesc(tupdesc); } /* * SQL function to_json(anyvalue) */ PG_FUNCTION_INFO_V1(to_json); Datum to_json(PG_FUNCTION_ARGS) { Oid val_type = get_fn_expr_argtype(fcinfo->flinfo, 0); StringInfo result; Datum orig_val, val; TYPCATEGORY tcategory; Oid typoutput; bool typisvarlena; Oid castfunc = InvalidOid; if (val_type == InvalidOid) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("could not determine input data type"))); result = makeStringInfo(); orig_val = PG_ARGISNULL(0) ? (Datum) 0 : PG_GETARG_DATUM(0); getTypeOutputInfo(val_type, &typoutput, &typisvarlena); if (val_type > FirstNormalObjectId) { HeapTuple tuple; Form_pg_cast castForm; tuple = SearchSysCache2(CASTSOURCETARGET, ObjectIdGetDatum(val_type), ObjectIdGetDatum(JSONOID)); if (HeapTupleIsValid(tuple)) { castForm = (Form_pg_cast) GETSTRUCT(tuple); if (castForm->castmethod == COERCION_METHOD_FUNCTION) castfunc = typoutput = castForm->castfunc; ReleaseSysCache(tuple); } } if (castfunc != InvalidOid) tcategory = TYPCATEGORY_JSON_CAST; else if (val_type == RECORDARRAYOID) tcategory = TYPCATEGORY_ARRAY; else if (val_type == RECORDOID) tcategory = TYPCATEGORY_COMPOSITE; else if (val_type == JSONOID) tcategory = TYPCATEGORY_JSON; else tcategory = TypeCategory(val_type); /* * If we have a toasted datum, forcibly detoast it here to avoid * memory leakage inside the type's output routine. */ if (typisvarlena && orig_val != (Datum) 0) val = PointerGetDatum(PG_DETOAST_DATUM(orig_val)); else val = orig_val; datum_to_json(val, false, result, tcategory, typoutput); /* Clean up detoasted copy, if any */ if (val != orig_val) pfree(DatumGetPointer(val)); PG_RETURN_TEXT_P(cstring_to_text(result->data)); } /* * json_agg transition function */ PG_FUNCTION_INFO_V1(json_agg_transfn); Datum json_agg_transfn(PG_FUNCTION_ARGS) { Oid val_type = get_fn_expr_argtype(fcinfo->flinfo, 1); MemoryContext aggcontext, oldcontext; StringInfo state; Datum orig_val, val; TYPCATEGORY tcategory; Oid typoutput; bool typisvarlena; Oid castfunc = InvalidOid; if (val_type == InvalidOid) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("could not determine input data type"))); if (!AggCheckCallContext(fcinfo, &aggcontext)) { /* cannot be called directly because of internal-type argument */ elog(ERROR, "json_agg_transfn called in non-aggregate context"); } if (PG_ARGISNULL(0)) { /* * Make this StringInfo in a context where it will persist * for the duration off the aggregate call. It's only needed * for this initial piece, as the StringInfo routines make sure * they use the right context to enlarge the object if necessary. */ oldcontext = MemoryContextSwitchTo(aggcontext); state = makeStringInfo(); MemoryContextSwitchTo(oldcontext); appendStringInfoChar(state,'['); } else { state = (StringInfo) PG_GETARG_POINTER(0); appendStringInfoString(state, ", "); } /* fast path for NULLs */ if (PG_ARGISNULL(1)) { orig_val = (Datum) 0; datum_to_json(orig_val, true, state, 0, InvalidOid); PG_RETURN_POINTER(state); } orig_val = PG_GETARG_DATUM(1); getTypeOutputInfo(val_type, &typoutput, &typisvarlena); if (val_type > FirstNormalObjectId) { HeapTuple tuple; Form_pg_cast castForm; tuple = SearchSysCache2(CASTSOURCETARGET, ObjectIdGetDatum(val_type), ObjectIdGetDatum(JSONOID)); if (HeapTupleIsValid(tuple)) { castForm = (Form_pg_cast) GETSTRUCT(tuple); if (castForm->castmethod == COERCION_METHOD_FUNCTION) castfunc = typoutput = castForm->castfunc; ReleaseSysCache(tuple); } } if (castfunc != InvalidOid) tcategory = TYPCATEGORY_JSON_CAST; else if (val_type == RECORDARRAYOID) tcategory = TYPCATEGORY_ARRAY; else if (val_type == RECORDOID) tcategory = TYPCATEGORY_COMPOSITE; else if (val_type == JSONOID) tcategory = TYPCATEGORY_JSON; else tcategory = TypeCategory(val_type); /* * If we have a toasted datum, forcibly detoast it here to avoid * memory leakage inside the type's output routine. */ if (typisvarlena) val = PointerGetDatum(PG_DETOAST_DATUM(orig_val)); else val = orig_val; if (! PG_ARGISNULL(0) && (tcategory == TYPCATEGORY_ARRAY || tcategory == TYPCATEGORY_COMPOSITE)) { appendStringInfoString(state,"\n "); } datum_to_json(val, false, state, tcategory, typoutput); /* Clean up detoasted copy, if any */ if (val != orig_val) pfree(DatumGetPointer(val)); /* * The transition type for array_agg() is declared to be "internal", which * is a pass-by-value type the same size as a pointer. So we can safely * pass the ArrayBuildState pointer through nodeAgg.c's machinations. */ PG_RETURN_POINTER(state); } /* * json_agg final function */ PG_FUNCTION_INFO_V1(json_agg_finalfn); Datum json_agg_finalfn(PG_FUNCTION_ARGS) { StringInfo state; /* cannot be called directly because of internal-type argument */ Assert(AggCheckCallContext(fcinfo, NULL)); state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0); if (state == NULL) PG_RETURN_NULL(); appendStringInfoChar(state,']'); PG_RETURN_TEXT_P(cstring_to_text(state->data)); }