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postgres/src/backend/utils/adt/json.c
Tom Lane 92f57c9ae9 Clean up handling of unknown-type inputs in json_build_object and friends. 
There's actually no need for any special case for unknown-type literals,
since we only need to push the value through its output function and
unknownout() works fine.  The code that was here was completely bizarre
anyway, and would fail outright in cases that should work, not to mention
suffering from some copy-and-paste bugs.
2014-08-09 17:31:13 -04:00

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/*-------------------------------------------------------------------------
*
* json.c
* JSON data type support.
*
* Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/utils/adt/json.c
*
*-------------------------------------------------------------------------
*/
#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 "miscadmin.h"
#include "parser/parse_coerce.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/datetime.h"
#include "utils/lsyscache.h"
#include "utils/json.h"
#include "utils/jsonapi.h"
#include "utils/typcache.h"
#include "utils/syscache.h"
/*
* 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;
typedef enum /* type categories for datum_to_json */
{
JSONTYPE_NULL, /* null, so we didn't bother to identify */
JSONTYPE_BOOL, /* boolean (built-in types only) */
JSONTYPE_NUMERIC, /* numeric (ditto) */
JSONTYPE_TIMESTAMP, /* we use special formatting for timestamp */
JSONTYPE_TIMESTAMPTZ, /* ... and timestamptz */
JSONTYPE_JSON, /* JSON itself (and JSONB) */
JSONTYPE_ARRAY, /* array */
JSONTYPE_COMPOSITE, /* composite */
JSONTYPE_CAST, /* something with an explicit cast to JSON */
JSONTYPE_OTHER /* all else */
} JsonTypeCategory;
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, bool *num_err);
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);
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,
JsonTypeCategory tcategory, Oid outfuncoid,
bool use_line_feeds);
static void array_to_json_internal(Datum array, StringInfo result,
bool use_line_feeds);
static void json_categorize_type(Oid typoid,
JsonTypeCategory *tcategory,
Oid *outfuncoid);
static void datum_to_json(Datum val, bool is_null, StringInfo result,
JsonTypeCategory tcategory, Oid outfuncoid,
bool key_scalar);
static void add_json(Datum val, bool is_null, StringInfo result,
Oid val_type, bool key_scalar);
/* the null action object used for pure validation */
static JsonSemAction nullSemAction =
{
NULL, NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL, NULL
};
/* 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);;
}
/* 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))
/*
* Input.
*/
Datum
json_in(PG_FUNCTION_ARGS)
{
char *json = PG_GETARG_CSTRING(0);
text *result = cstring_to_text(json);
JsonLexContext *lex;
/* validate it */
lex = makeJsonLexContext(result, false);
pg_parse_json(lex, &nullSemAction);
/* Internal representation is the same as text, for now */
PG_RETURN_TEXT_P(result);
}
/*
* Output.
*/
Datum
json_out(PG_FUNCTION_ARGS)
{
/* we needn't detoast because text_to_cstring will handle that */
Datum txt = PG_GETARG_DATUM(0);
PG_RETURN_CSTRING(TextDatumGetCString(txt));
}
/*
* Binary send.
*/
Datum
json_send(PG_FUNCTION_ARGS)
{
text *t = PG_GETARG_TEXT_PP(0);
StringInfoData buf;
pq_begintypsend(&buf);
pq_sendtext(&buf, VARDATA_ANY(t), VARSIZE_ANY_EXHDR(t));
PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
}
/*
* Binary receive.
*/
Datum
json_recv(PG_FUNCTION_ARGS)
{
StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
char *str;
int nbytes;
JsonLexContext *lex;
str = pq_getmsgtext(buf, buf->len - buf->cursor, &nbytes);
/* Validate it. */
lex = makeJsonLexContextCstringLen(str, nbytes, false);
pg_parse_json(lex, &nullSemAction);
PG_RETURN_TEXT_P(cstring_to_text_with_len(str, nbytes));
}
/*
* 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.
*
* If you already have the json as a text* value, use the first of these
* functions, otherwise use makeJsonLexContextCstringLen().
*/
JsonLexContext *
makeJsonLexContext(text *json, bool need_escapes)
{
return makeJsonLexContextCstringLen(VARDATA(json),
VARSIZE(json) - VARHDRSZ,
need_escapes);
}
JsonLexContext *
makeJsonLexContextCstringLen(char *json, int len, bool need_escapes)
{
JsonLexContext *lex = palloc0(sizeof(JsonLexContext));
lex->input = lex->token_terminator = lex->line_start = json;
lex->line_number = 1;
lex->input_length = len;
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. Note: in user-facing docs and error messages, we
* generally call a field name a "key".
*/
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);
}
static void
parse_object(JsonLexContext *lex, JsonSemAction *sem)
{
/*
* an object is a possibly empty sequence of object fields, separated by
* commas and surrounded 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 is 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 is 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, NULL);
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, NULL);
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; p - s < lex->input_length - len && JSON_ALPHANUMERIC_CHAR(*p); 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;
int hi_surrogate = -1;
if (lex->strval != NULL)
resetStringInfo(lex->strval);
Assert(lex->input_length > 0);
s = lex->token_start;
len = lex->token_start - lex->input;
for (;;)
{
s++;
len++;
/* Premature end of the string. */
if (len >= lex->input_length)
{
lex->token_terminator = s;
report_invalid_token(lex);
}
else if (*s == '"')
break;
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;
if (ch >= 0xd800 && ch <= 0xdbff)
{
if (hi_surrogate != -1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("invalid input syntax for type json"),
errdetail("Unicode high surrogate must not follow a high surrogate."),
report_json_context(lex)));
hi_surrogate = (ch & 0x3ff) << 10;
continue;
}
else if (ch >= 0xdc00 && ch <= 0xdfff)
{
if (hi_surrogate == -1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("invalid input syntax for type json"),
errdetail("Unicode low surrogate must follow a high surrogate."),
report_json_context(lex)));
ch = 0x10000 + hi_surrogate + (ch & 0x3ff);
hi_surrogate = -1;
}
if (hi_surrogate != -1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("invalid input syntax for type json"),
errdetail("Unicode low surrogate must follow a high surrogate."),
report_json_context(lex)));
/*
* For UTF8, replace the escape sequence by the actual
* utf8 character in lex->strval. Do this also for other
* encodings if the escape designates an ASCII character,
* otherwise raise an error. We don't ever unescape a
* \u0000, since that would result in an impermissible nul
* byte.
*/
if (ch == 0)
{
appendStringInfoString(lex->strval, "\\u0000");
}
else if (GetDatabaseEncoding() == PG_UTF8)
{
unicode_to_utf8(ch, (unsigned char *) utf8str);
utf8len = pg_utf_mblen((unsigned char *) utf8str);
appendBinaryStringInfo(lex->strval, utf8str, utf8len);
}
else if (ch <= 0x007f)
{
/*
* This is the only way to designate things like a
* form feed character in JSON, so it's useful in all
* encodings.
*/
appendStringInfoChar(lex->strval, (char) ch);
}
else
{
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("invalid input syntax for type json"),
errdetail("Unicode escape values cannot be used for code point values above 007F when the server encoding is not UTF8."),
report_json_context(lex)));
}
}
}
else if (lex->strval != NULL)
{
if (hi_surrogate != -1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("invalid input syntax for type json"),
errdetail("Unicode low surrogate must follow a high surrogate."),
report_json_context(lex)));
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)
{
if (hi_surrogate != -1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("invalid input syntax for type json"),
errdetail("Unicode low surrogate must follow a high surrogate."),
report_json_context(lex)));
appendStringInfoChar(lex->strval, *s);
}
}
if (hi_surrogate != -1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("invalid input syntax for type json"),
errdetail("Unicode low surrogate must follow a high surrogate."),
report_json_context(lex)));
/* 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 *num_err)
{
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 (len < lex->input_length && *s >= '0' && *s <= '9');
}
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 (len < lex->input_length && *s >= '0' && *s <= '9');
}
}
/* 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; len < lex->input_length && JSON_ALPHANUMERIC_CHAR(*p); p++, len++)
error = true;
if (num_err != NULL)
{
/* let the caller handle the error */
*num_err = error;
}
else
{
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 */
if (context_start < context_end && *context_start == '\n')
{
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;
}
/*
* Determine how we want to print values of a given type in datum_to_json.
*
* Given the datatype OID, return its JsonTypeCategory, as well as the type's
* output function OID. If the returned category is JSONTYPE_CAST, we
* return the OID of the type->JSON cast function instead.
*/
static void
json_categorize_type(Oid typoid,
JsonTypeCategory *tcategory,
Oid *outfuncoid)
{
bool typisvarlena;
/* Look through any domain */
typoid = getBaseType(typoid);
/* We'll usually need to return the type output function */
getTypeOutputInfo(typoid, outfuncoid, &typisvarlena);
/* Check for known types */
switch (typoid)
{
case BOOLOID:
*tcategory = JSONTYPE_BOOL;
break;
case INT2OID:
case INT4OID:
case INT8OID:
case FLOAT4OID:
case FLOAT8OID:
case NUMERICOID:
*tcategory = JSONTYPE_NUMERIC;
break;
case TIMESTAMPOID:
*tcategory = JSONTYPE_TIMESTAMP;
break;
case TIMESTAMPTZOID:
*tcategory = JSONTYPE_TIMESTAMPTZ;
break;
case JSONOID:
case JSONBOID:
*tcategory = JSONTYPE_JSON;
break;
default:
/* Check for arrays and composites */
if (OidIsValid(get_element_type(typoid)))
*tcategory = JSONTYPE_ARRAY;
else if (type_is_rowtype(typoid))
*tcategory = JSONTYPE_COMPOSITE;
else
{
/* It's probably the general case ... */
*tcategory = JSONTYPE_OTHER;
/* but let's look for a cast to json, if it's not built-in */
if (typoid >= FirstNormalObjectId)
{
HeapTuple tuple;
tuple = SearchSysCache2(CASTSOURCETARGET,
ObjectIdGetDatum(typoid),
ObjectIdGetDatum(JSONOID));
if (HeapTupleIsValid(tuple))
{
Form_pg_cast castForm = (Form_pg_cast) GETSTRUCT(tuple);
if (castForm->castmethod == COERCION_METHOD_FUNCTION)
{
*tcategory = JSONTYPE_CAST;
*outfuncoid = castForm->castfunc;
}
ReleaseSysCache(tuple);
}
}
}
break;
}
}
/*
* Turn a Datum into JSON text, appending the string to "result".
*
* tcategory and outfuncoid are from a previous call to json_categorize_type,
* except that if is_null is true then they can be invalid.
*
* If key_scalar is true, the value is being printed as a key, so insist
* it's of an acceptable type, and force it to be quoted.
*/
static void
datum_to_json(Datum val, bool is_null, StringInfo result,
JsonTypeCategory tcategory, Oid outfuncoid,
bool key_scalar)
{
char *outputstr;
text *jsontext;
bool numeric_error;
JsonLexContext dummy_lex;
if (is_null)
{
appendStringInfoString(result, "null");
return;
}
if (key_scalar &&
(tcategory == JSONTYPE_ARRAY ||
tcategory == JSONTYPE_COMPOSITE ||
tcategory == JSONTYPE_JSON ||
tcategory == JSONTYPE_CAST))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("key value must be scalar, not array, composite, or json")));
switch (tcategory)
{
case JSONTYPE_ARRAY:
array_to_json_internal(val, result, false);
break;
case JSONTYPE_COMPOSITE:
composite_to_json(val, result, false);
break;
case JSONTYPE_BOOL:
outputstr = DatumGetBool(val) ? "true" : "false";
if (key_scalar)
escape_json(result, outputstr);
else
appendStringInfoString(result, outputstr);
break;
case JSONTYPE_NUMERIC:
outputstr = OidOutputFunctionCall(outfuncoid, val);
if (key_scalar)
{
/* always quote keys */
escape_json(result, outputstr);
}
else
{
/*
* Don't call escape_json for a non-key if it's a valid JSON
* number.
*/
dummy_lex.input = *outputstr == '-' ? outputstr + 1 : outputstr;
dummy_lex.input_length = strlen(dummy_lex.input);
json_lex_number(&dummy_lex, dummy_lex.input, &numeric_error);
if (!numeric_error)
appendStringInfoString(result, outputstr);
else
escape_json(result, outputstr);
}
pfree(outputstr);
break;
case JSONTYPE_TIMESTAMP:
{
Timestamp timestamp;
struct pg_tm tm;
fsec_t fsec;
char buf[MAXDATELEN + 1];
timestamp = DatumGetTimestamp(val);
/* XSD doesn't support infinite values */
if (TIMESTAMP_NOT_FINITE(timestamp))
ereport(ERROR,
(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
errmsg("timestamp out of range"),
errdetail("JSON does not support infinite timestamp values.")));
else if (timestamp2tm(timestamp, NULL, &tm, &fsec, NULL, NULL) == 0)
EncodeDateTime(&tm, fsec, false, 0, NULL, USE_XSD_DATES, buf);
else
ereport(ERROR,
(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
errmsg("timestamp out of range")));
appendStringInfo(result,"\"%s\"",buf);
}
break;
case JSONTYPE_TIMESTAMPTZ:
{
TimestampTz timestamp;
struct pg_tm tm;
int tz;
fsec_t fsec;
const char *tzn = NULL;
char buf[MAXDATELEN + 1];
timestamp = DatumGetTimestamp(val);
/* XSD doesn't support infinite values */
if (TIMESTAMP_NOT_FINITE(timestamp))
ereport(ERROR,
(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
errmsg("timestamp out of range"),
errdetail("JSON does not support infinite timestamp values.")));
else if (timestamp2tm(timestamp, &tz, &tm, &fsec, &tzn, NULL) == 0)
EncodeDateTime(&tm, fsec, true, tz, tzn, USE_XSD_DATES, buf);
else
ereport(ERROR,
(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
errmsg("timestamp out of range")));
appendStringInfo(result,"\"%s\"",buf);
}
break;
case JSONTYPE_JSON:
/* JSON and JSONB output will already be escaped */
outputstr = OidOutputFunctionCall(outfuncoid, val);
appendStringInfoString(result, outputstr);
pfree(outputstr);
break;
case JSONTYPE_CAST:
/* outfuncoid refers to a cast function, not an output function */
jsontext = DatumGetTextP(OidFunctionCall1(outfuncoid, val));
outputstr = text_to_cstring(jsontext);
appendStringInfoString(result, outputstr);
pfree(outputstr);
pfree(jsontext);
break;
default:
outputstr = OidOutputFunctionCall(outfuncoid, val);
if (key_scalar && *outputstr == '\0')
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("key value must not be empty")));
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, JsonTypeCategory tcategory,
Oid outfuncoid, 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,
outfuncoid, false);
(*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, outfuncoid, 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;
JsonTypeCategory tcategory;
Oid outfuncoid;
ndim = ARR_NDIM(v);
dim = ARR_DIMS(v);
nitems = ArrayGetNItems(ndim, dim);
if (nitems <= 0)
{
appendStringInfoString(result, "[]");
return;
}
get_typlenbyvalalign(element_type,
&typlen, &typbyval, &typalign);
json_categorize_type(element_type,
&tcategory, &outfuncoid);
deconstruct_array(v, element_type, typlen, typbyval,
typalign, &elements, &nulls,
&nitems);
array_dim_to_json(result, 0, ndim, dim, elements, nulls, &count, tcategory,
outfuncoid, 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;
bool isnull;
char *attname;
JsonTypeCategory tcategory;
Oid outfuncoid;
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, ':');
val = heap_getattr(tuple, i + 1, tupdesc, &isnull);
if (isnull)
{
tcategory = JSONTYPE_NULL;
outfuncoid = InvalidOid;
}
else
json_categorize_type(tupdesc->attrs[i]->atttypid,
&tcategory, &outfuncoid);
datum_to_json(val, isnull, result, tcategory, outfuncoid, false);
}
appendStringInfoChar(result, '}');
ReleaseTupleDesc(tupdesc);
}
/*
* Append JSON text for "val" to "result".
*
* This is just a thin wrapper around datum_to_json. If the same type will be
* printed many times, avoid using this; better to do the json_categorize_type
* lookups only once.
*/
static void
add_json(Datum val, bool is_null, StringInfo result,
Oid val_type, bool key_scalar)
{
JsonTypeCategory tcategory;
Oid outfuncoid;
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine input data type")));
if (is_null)
{
tcategory = JSONTYPE_NULL;
outfuncoid = InvalidOid;
}
else
json_categorize_type(val_type,
&tcategory, &outfuncoid);
datum_to_json(val, is_null, result, tcategory, outfuncoid, key_scalar);
}
/*
* SQL function array_to_json(row)
*/
extern Datum
array_to_json(PG_FUNCTION_ARGS)
{
Datum array = PG_GETARG_DATUM(0);
StringInfo result;
result = makeStringInfo();
array_to_json_internal(array, result, false);
PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
}
/*
* SQL function array_to_json(row, prettybool)
*/
extern Datum
array_to_json_pretty(PG_FUNCTION_ARGS)
{
Datum array = PG_GETARG_DATUM(0);
bool use_line_feeds = PG_GETARG_BOOL(1);
StringInfo result;
result = makeStringInfo();
array_to_json_internal(array, result, use_line_feeds);
PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
}
/*
* SQL function row_to_json(row)
*/
extern Datum
row_to_json(PG_FUNCTION_ARGS)
{
Datum array = PG_GETARG_DATUM(0);
StringInfo result;
result = makeStringInfo();
composite_to_json(array, result, false);
PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
}
/*
* SQL function row_to_json(row, prettybool)
*/
extern Datum
row_to_json_pretty(PG_FUNCTION_ARGS)
{
Datum array = PG_GETARG_DATUM(0);
bool use_line_feeds = PG_GETARG_BOOL(1);
StringInfo result;
result = makeStringInfo();
composite_to_json(array, result, use_line_feeds);
PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
}
/*
* SQL function to_json(anyvalue)
*/
Datum
to_json(PG_FUNCTION_ARGS)
{
Datum val = PG_GETARG_DATUM(0);
Oid val_type = get_fn_expr_argtype(fcinfo->flinfo, 0);
StringInfo result;
JsonTypeCategory tcategory;
Oid outfuncoid;
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine input data type")));
json_categorize_type(val_type,
&tcategory, &outfuncoid);
result = makeStringInfo();
datum_to_json(val, false, result, tcategory, outfuncoid, false);
PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
}
/*
* json_agg transition function
*/
Datum
json_agg_transfn(PG_FUNCTION_ARGS)
{
Oid val_type = get_fn_expr_argtype(fcinfo->flinfo, 1);
MemoryContext aggcontext,
oldcontext;
StringInfo state;
Datum val;
JsonTypeCategory tcategory;
Oid outfuncoid;
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 of the aggregate call. MemoryContextSwitchTo is only
* needed the first time, 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))
{
datum_to_json((Datum) 0, true, state, JSONTYPE_NULL, InvalidOid, false);
PG_RETURN_POINTER(state);
}
val = PG_GETARG_DATUM(1);
/* XXX we do this every time?? */
json_categorize_type(val_type,
&tcategory, &outfuncoid);
/* add some whitespace if structured type and not first item */
if (!PG_ARGISNULL(0) &&
(tcategory == JSONTYPE_ARRAY || tcategory == JSONTYPE_COMPOSITE))
{
appendStringInfoString(state, "\n ");
}
datum_to_json(val, false, state, tcategory, outfuncoid, false);
/*
* 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
*/
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_with_len(state->data, state->len));
}
/*
* json_object_agg transition function.
*
* aggregate two input columns as a single json value.
*/
Datum
json_object_agg_transfn(PG_FUNCTION_ARGS)
{
Oid val_type;
MemoryContext aggcontext,
oldcontext;
StringInfo state;
Datum arg;
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 the StringInfo in a context where it will persist for the
* duration of the aggregate call. Switching context is only needed
* for this initial step, as the StringInfo routines make sure they
* use the right context to enlarge the object if necessary.
*/
oldcontext = MemoryContextSwitchTo(aggcontext);
state = makeStringInfo();
MemoryContextSwitchTo(oldcontext);
appendStringInfoString(state, "{ ");
}
else
{
state = (StringInfo) PG_GETARG_POINTER(0);
appendStringInfoString(state, ", ");
}
/*
* Note: since json_object_agg() is declared as taking type "any", the
* parser will not do any type conversion on unknown-type literals (that
* is, undecorated strings or NULLs). Such values will arrive here as
* type UNKNOWN, which fortunately does not matter to us, since
* unknownout() works fine.
*/
val_type = get_fn_expr_argtype(fcinfo->flinfo, 1);
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine data type for argument %d", 1)));
if (PG_ARGISNULL(1))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("field name must not be null")));
arg = PG_GETARG_DATUM(1);
add_json(arg, false, state, val_type, true);
appendStringInfoString(state, " : ");
val_type = get_fn_expr_argtype(fcinfo->flinfo, 2);
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine data type for argument %d", 2)));
if (PG_ARGISNULL(2))
arg = (Datum) 0;
else
arg = PG_GETARG_DATUM(2);
add_json(arg, PG_ARGISNULL(2), state, val_type, false);
PG_RETURN_POINTER(state);
}
/*
* json_object_agg final function.
*
*/
Datum
json_object_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_TEXT_P(cstring_to_text("{}"));
appendStringInfoString(state, " }");
PG_RETURN_TEXT_P(cstring_to_text_with_len(state->data, state->len));
}
/*
* SQL function json_build_object(variadic "any")
*/
Datum
json_build_object(PG_FUNCTION_ARGS)
{
int nargs = PG_NARGS();
int i;
Datum arg;
const char *sep = "";
StringInfo result;
Oid val_type;
if (nargs % 2 != 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("argument list must have even number of elements"),
errhint("The arguments of json_build_object() must consist of alternating keys and values.")));
result = makeStringInfo();
appendStringInfoChar(result, '{');
for (i = 0; i < nargs; i += 2)
{
/*
* Note: since json_build_object() is declared as taking type "any",
* the parser will not do any type conversion on unknown-type literals
* (that is, undecorated strings or NULLs). Such values will arrive
* here as type UNKNOWN, which fortunately does not matter to us,
* since unknownout() works fine.
*/
appendStringInfoString(result, sep);
sep = ", ";
/* process key */
val_type = get_fn_expr_argtype(fcinfo->flinfo, i);
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine data type for argument %d",
i + 1)));
if (PG_ARGISNULL(i))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("argument %d cannot be null", i + 1),
errhint("Object keys should be text.")));
arg = PG_GETARG_DATUM(i);
add_json(arg, false, result, val_type, true);
appendStringInfoString(result, " : ");
/* process value */
val_type = get_fn_expr_argtype(fcinfo->flinfo, i + 1);
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine data type for argument %d",
i + 2)));
if (PG_ARGISNULL(i + 1))
arg = (Datum) 0;
else
arg = PG_GETARG_DATUM(i + 1);
add_json(arg, PG_ARGISNULL(i + 1), result, val_type, false);
}
appendStringInfoChar(result, '}');
PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
}
/*
* degenerate case of json_build_object where it gets 0 arguments.
*/
Datum
json_build_object_noargs(PG_FUNCTION_ARGS)
{
PG_RETURN_TEXT_P(cstring_to_text_with_len("{}", 2));
}
/*
* SQL function json_build_array(variadic "any")
*/
Datum
json_build_array(PG_FUNCTION_ARGS)
{
int nargs = PG_NARGS();
int i;
Datum arg;
const char *sep = "";
StringInfo result;
Oid val_type;
result = makeStringInfo();
appendStringInfoChar(result, '[');
for (i = 0; i < nargs; i++)
{
/*
* Note: since json_build_array() is declared as taking type "any",
* the parser will not do any type conversion on unknown-type literals
* (that is, undecorated strings or NULLs). Such values will arrive
* here as type UNKNOWN, which fortunately does not matter to us,
* since unknownout() works fine.
*/
appendStringInfoString(result, sep);
sep = ", ";
val_type = get_fn_expr_argtype(fcinfo->flinfo, i);
if (val_type == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine data type for argument %d",
i + 1)));
if (PG_ARGISNULL(i))
arg = (Datum) 0;
else
arg = PG_GETARG_DATUM(i);
add_json(arg, PG_ARGISNULL(i), result, val_type, false);
}
appendStringInfoChar(result, ']');
PG_RETURN_TEXT_P(cstring_to_text_with_len(result->data, result->len));
}
/*
* degenerate case of json_build_array where it gets 0 arguments.
*/
Datum
json_build_array_noargs(PG_FUNCTION_ARGS)
{
PG_RETURN_TEXT_P(cstring_to_text_with_len("[]", 2));
}
/*
* SQL function json_object(text[])
*
* take a one or two dimensional array of text as key/value pairs
* for a json object.
*/
Datum
json_object(PG_FUNCTION_ARGS)
{
ArrayType *in_array = PG_GETARG_ARRAYTYPE_P(0);
int ndims = ARR_NDIM(in_array);
StringInfoData result;
Datum *in_datums;
bool *in_nulls;
int in_count,
count,
i;
text *rval;
char *v;
switch (ndims)
{
case 0:
PG_RETURN_DATUM(CStringGetTextDatum("{}"));
break;
case 1:
if ((ARR_DIMS(in_array)[0]) % 2)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must have even number of elements")));
break;
case 2:
if ((ARR_DIMS(in_array)[1]) != 2)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must have two columns")));
break;
default:
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("wrong number of array subscripts")));
}
deconstruct_array(in_array,
TEXTOID, -1, false, 'i',
&in_datums, &in_nulls, &in_count);
count = in_count / 2;
initStringInfo(&result);
appendStringInfoChar(&result, '{');
for (i = 0; i < count; ++i)
{
if (in_nulls[i * 2])
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("null value not allowed for object key")));
v = TextDatumGetCString(in_datums[i * 2]);
if (i > 0)
appendStringInfoString(&result, ", ");
escape_json(&result, v);
appendStringInfoString(&result, " : ");
pfree(v);
if (in_nulls[i * 2 + 1])
appendStringInfoString(&result, "null");
else
{
v = TextDatumGetCString(in_datums[i * 2 + 1]);
escape_json(&result, v);
pfree(v);
}
}
appendStringInfoChar(&result, '}');
pfree(in_datums);
pfree(in_nulls);
rval = cstring_to_text_with_len(result.data, result.len);
pfree(result.data);
PG_RETURN_TEXT_P(rval);
}
/*
* SQL function json_object(text[], text[])
*
* take separate key and value arrays of text to construct a json object
* pairwise.
*/
Datum
json_object_two_arg(PG_FUNCTION_ARGS)
{
ArrayType *key_array = PG_GETARG_ARRAYTYPE_P(0);
ArrayType *val_array = PG_GETARG_ARRAYTYPE_P(1);
int nkdims = ARR_NDIM(key_array);
int nvdims = ARR_NDIM(val_array);
StringInfoData result;
Datum *key_datums,
*val_datums;
bool *key_nulls,
*val_nulls;
int key_count,
val_count,
i;
text *rval;
char *v;
if (nkdims > 1 || nkdims != nvdims)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("wrong number of array subscripts")));
if (nkdims == 0)
PG_RETURN_DATUM(CStringGetTextDatum("{}"));
deconstruct_array(key_array,
TEXTOID, -1, false, 'i',
&key_datums, &key_nulls, &key_count);
deconstruct_array(val_array,
TEXTOID, -1, false, 'i',
&val_datums, &val_nulls, &val_count);
if (key_count != val_count)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("mismatched array dimensions")));
initStringInfo(&result);
appendStringInfoChar(&result, '{');
for (i = 0; i < key_count; ++i)
{
if (key_nulls[i])
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("null value not allowed for object key")));
v = TextDatumGetCString(key_datums[i]);
if (i > 0)
appendStringInfoString(&result, ", ");
escape_json(&result, v);
appendStringInfoString(&result, " : ");
pfree(v);
if (val_nulls[i])
appendStringInfoString(&result, "null");
else
{
v = TextDatumGetCString(val_datums[i]);
escape_json(&result, v);
pfree(v);
}
}
appendStringInfoChar(&result, '}');
pfree(key_datums);
pfree(key_nulls);
pfree(val_datums);
pfree(val_nulls);
rval = cstring_to_text_with_len(result.data, result.len);
pfree(result.data);
PG_RETURN_TEXT_P(rval);
}
/*
* Produce a JSON string literal, properly escaping characters in the text.
*/
void
escape_json(StringInfo buf, const char *str)
{
const char *p;
appendStringInfoCharMacro(buf, '\"');
for (p = str; *p; p++)
{
switch (*p)
{
case '\b':
appendStringInfoString(buf, "\\b");
break;
case '\f':
appendStringInfoString(buf, "\\f");
break;
case '\n':
appendStringInfoString(buf, "\\n");
break;
case '\r':
appendStringInfoString(buf, "\\r");
break;
case '\t':
appendStringInfoString(buf, "\\t");
break;
case '"':
appendStringInfoString(buf, "\\\"");
break;
case '\\':
/*
* Unicode escapes are passed through as is. There is no
* requirement that they denote a valid character in the
* server encoding - indeed that is a big part of their
* usefulness.
*
* All we require is that they consist of \uXXXX where
* the Xs are hexadecimal digits. It is the responsibility
* of the caller of, say, to_json() to make sure that the
* unicode escape is valid.
*
* In the case of a jsonb string value being escaped, the
* only unicode escape that should be present is \u0000,
* all the other unicode escapes will have been resolved.
*/
if (p[1] == 'u' &&
isxdigit((unsigned char) p[2]) &&
isxdigit((unsigned char) p[3]) &&
isxdigit((unsigned char) p[4]) &&
isxdigit((unsigned char) p[5]))
appendStringInfoCharMacro(buf, *p);
else
appendStringInfoString(buf, "\\\\");
break;
default:
if ((unsigned char) *p < ' ')
appendStringInfo(buf, "\\u%04x", (int) *p);
else
appendStringInfoCharMacro(buf, *p);
break;
}
}
appendStringInfoCharMacro(buf, '\"');
}
/*
* SQL function json_typeof(json) -> text
*
* Returns the type of the outermost JSON value as TEXT. Possible types are
* "object", "array", "string", "number", "boolean", and "null".
*
* Performs a single call to json_lex() to get the first token of the supplied
* value. This initial token uniquely determines the value's type. As our
* input must already have been validated by json_in() or json_recv(), the
* initial token should never be JSON_TOKEN_OBJECT_END, JSON_TOKEN_ARRAY_END,
* JSON_TOKEN_COLON, JSON_TOKEN_COMMA, or JSON_TOKEN_END.
*/
Datum
json_typeof(PG_FUNCTION_ARGS)
{
text *json;
JsonLexContext *lex;
JsonTokenType tok;
char *type;
json = PG_GETARG_TEXT_P(0);
lex = makeJsonLexContext(json, false);
/* Lex exactly one token from the input and check its type. */
json_lex(lex);
tok = lex_peek(lex);
switch (tok)
{
case JSON_TOKEN_OBJECT_START:
type = "object";
break;
case JSON_TOKEN_ARRAY_START:
type = "array";
break;
case JSON_TOKEN_STRING:
type = "string";
break;
case JSON_TOKEN_NUMBER:
type = "number";
break;
case JSON_TOKEN_TRUE:
case JSON_TOKEN_FALSE:
type = "boolean";
break;
case JSON_TOKEN_NULL:
type = "null";
break;
default:
elog(ERROR, "unexpected json token: %d", tok);
}
PG_RETURN_TEXT_P(cstring_to_text(type));
}
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