0010-Moving-json-parsing-into-src-common.patch.WIP
application/octet-stream
Filename: 0010-Moving-json-parsing-into-src-common.patch.WIP
Type: application/octet-stream
Part: 9
From caa4056cd113c3488c107ffc5086ded94fde378d Mon Sep 17 00:00:00 2001
From: Mark Dilger <mark.dilger@enterprisedb.com>
Date: Wed, 22 Jan 2020 16:33:04 -0800
Subject: [PATCH 10/11] Moving json parsing into src/common
This commit moves the code for parsing json out of
src/backend/utils and also removes the inherent
dependency on the database encoding.
---
src/backend/utils/adt/json.c | 920 +----------------------------
src/backend/utils/adt/jsonb.c | 2 +-
src/backend/utils/adt/jsonfuncs.c | 9 +-
src/common/jsonapi.c | 938 +++++++++++++++++++++++++++++-
src/include/common/jsonapi.h | 9 +-
5 files changed, 951 insertions(+), 927 deletions(-)
diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c
index 54075d07e3..1e514cb02c 100644
--- a/src/backend/utils/adt/json.c
+++ b/src/backend/utils/adt/json.c
@@ -34,31 +34,6 @@
#include "utils/syscache.h"
#include "utils/typcache.h"
-#define INSIST(x) \
-do { \
- JsonParseErrorType parse_result; \
- if((parse_result = (x)) != JSON_SUCCESS) \
- return parse_result; \
-} while (0)
-
-/*
- * 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 */
@@ -83,17 +58,6 @@ typedef struct JsonAggState
Oid val_output_func;
} JsonAggState;
-static inline JsonTokenType lex_peek(JsonLexContext *lex) __attribute__((warn_unused_result));
-static inline JsonParseErrorType lex_expect(JsonParseContext ctx, JsonLexContext *lex, JsonTokenType token) __attribute__((warn_unused_result));
-static inline JsonParseErrorType json_lex_string(JsonLexContext *lex) __attribute__((warn_unused_result));
-static inline JsonParseErrorType json_lex_number(JsonLexContext *lex, char *s,
- bool *num_err, int *total_len) __attribute__((warn_unused_result));
-static inline JsonParseErrorType parse_scalar(JsonLexContext *lex, const JsonSemAction *sem) __attribute__((warn_unused_result));
-static JsonParseErrorType parse_object_field(JsonLexContext *lex, const JsonSemAction *sem) __attribute__((warn_unused_result));
-static JsonParseErrorType parse_object(JsonLexContext *lex, const JsonSemAction *sem) __attribute__((warn_unused_result));
-static JsonParseErrorType parse_array_element(JsonLexContext *lex, const JsonSemAction *sem) __attribute__((warn_unused_result));
-static JsonParseErrorType parse_array(JsonLexContext *lex, const JsonSemAction *sem) __attribute__((warn_unused_result));
-static JsonParseErrorType report_parse_error(JsonParseContext ctx, JsonLexContext *lex) __attribute__((warn_unused_result));
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,
@@ -112,81 +76,6 @@ static void add_json(Datum val, bool is_null, StringInfo result,
Oid val_type, bool key_scalar);
static text *catenate_stringinfo_string(StringInfo buffer, const char *addon);
-/* 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_except
- *
- * move the lexer to the next token if the current look_ahead token matches
- * the parameter token. Otherwise, report an error.
- */
-static inline JsonParseErrorType
-lex_expect(JsonParseContext ctx, JsonLexContext *lex, JsonTokenType token)
-{
- if (lex_peek(lex) == token)
- INSIST(json_lex(lex));
- else
- return report_parse_error(ctx, lex);
- return JSON_SUCCESS;
-}
-
-/* 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))
-
-/*
- * Utility function to check if a string is a valid JSON number.
- *
- * str is of length len, and need not be null-terminated.
- */
-bool
-IsValidJsonNumber(const char *str, int len)
-{
- bool numeric_error;
- int total_len;
- JsonLexContext dummy_lex;
-
- if (len <= 0)
- return false;
-
- /*
- * json_lex_number expects a leading '-' to have been eaten already.
- *
- * having to cast away the constness of str is ugly, but there's not much
- * easy alternative.
- */
- if (*str == '-')
- {
- dummy_lex.input = unconstify(char *, str) +1;
- dummy_lex.input_length = len - 1;
- }
- else
- {
- dummy_lex.input = unconstify(char *, str);
- dummy_lex.input_length = len;
- }
-
- if (JSON_SUCCESS != json_lex_number(&dummy_lex, dummy_lex.input, &numeric_error, &total_len))
- return false;
-
- return (!numeric_error) && (total_len == dummy_lex.input_length);
-}
-
/*
* Input.
*/
@@ -245,819 +134,12 @@ json_recv(PG_FUNCTION_ARGS)
str = pq_getmsgtext(buf, buf->len - buf->cursor, &nbytes);
/* Validate it. */
- lex = makeJsonLexContextCstringLen(str, nbytes, false);
+ lex = makeJsonLexContextCstringLen(str, nbytes, GetDatabaseEncoding(), false);
pg_parse_json_or_throw(lex, &nullSemAction);
PG_RETURN_TEXT_P(cstring_to_text_with_len(str, nbytes));
}
-/*
- * 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 structure 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.
- */
-JsonParseErrorType
-pg_parse_json(JsonLexContext *lex, const JsonSemAction *sem)
-{
- JsonTokenType tok;
-
- /* get the initial token */
- INSIST(json_lex(lex));
-
- tok = lex_peek(lex);
-
- /* parse by recursive descent */
- switch (tok)
- {
- case JSON_TOKEN_OBJECT_START:
- INSIST(parse_object(lex, sem));
- break;
- case JSON_TOKEN_ARRAY_START:
- INSIST(parse_array(lex, sem));
- break;
- default:
- INSIST(parse_scalar(lex, sem)); /* json can be a bare scalar */
- }
-
- INSIST(lex_expect(JSON_PARSE_END, lex, JSON_TOKEN_END));
- return JSON_SUCCESS;
-}
-
-/*
- * json_count_array_elements
- *
- * Returns number of array elements in lex context at start of array token
- * until end of array token at same nesting level.
- *
- * Designed to be called from array_start routines.
- */
-int
-json_count_array_elements(JsonLexContext *lex)
-{
- JsonLexContext copylex;
- int count;
-
- /*
- * It's safe to do this with a shallow copy because the lexical routines
- * don't scribble on the input. They do scribble on the other pointers
- * etc, so doing this with a copy makes that safe.
- */
- memcpy(©lex, lex, sizeof(JsonLexContext));
- copylex.strval = NULL; /* not interested in values here */
- copylex.lex_level++;
-
- count = 0;
- INSIST(lex_expect(JSON_PARSE_ARRAY_START, ©lex, JSON_TOKEN_ARRAY_START));
- if (lex_peek(©lex) != JSON_TOKEN_ARRAY_END)
- {
- while (1)
- {
- count++;
- if (JSON_SUCCESS != parse_array_element(©lex, &nullSemAction))
- break;
- if (copylex.token_type != JSON_TOKEN_COMMA)
- break;
- INSIST(json_lex(©lex));
- }
- }
- INSIST(lex_expect(JSON_PARSE_ARRAY_NEXT, ©lex, JSON_TOKEN_ARRAY_END));
-
- return count;
-}
-
-/*
- * 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 JsonParseErrorType
-parse_scalar(JsonLexContext *lex, const JsonSemAction *sem)
-{
- char *val = NULL;
- json_scalar_action sfunc = sem->scalar;
- JsonTokenType tok = lex_peek(lex);
-
- /* a scalar must be a string, a number, true, false, or null */
- switch (tok)
- {
- case JSON_TOKEN_STRING:
- case JSON_TOKEN_NUMBER:
- case JSON_TOKEN_TRUE:
- case JSON_TOKEN_FALSE:
- case JSON_TOKEN_NULL:
- break;
- default:
- return report_parse_error(JSON_PARSE_VALUE, lex);
- }
-
- /* if no semantic function, just consume the token */
- if (sfunc == NULL)
- {
- INSIST(json_lex(lex));
- return JSON_SUCCESS;
- }
-
- /* extract the de-escaped string value, or the raw lexeme */
- if (lex_peek(lex) == JSON_TOKEN_STRING)
- {
- if (lex->strval != NULL)
- val = pstrdup(lex->strval->data);
- }
- else
- {
- int len = (lex->token_terminator - lex->token_start);
-
- val = palloc(len + 1);
- memcpy(val, lex->token_start, len);
- val[len] = '\0';
- }
-
- /* consume the token */
- INSIST(json_lex(lex));
-
- /* invoke the callback */
- (*sfunc) (sem->semstate, val, tok);
- return JSON_SUCCESS;
-}
-
-static JsonParseErrorType
-parse_object_field(JsonLexContext *lex, const 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;
- JsonTokenType tok;
-
- if (lex_peek(lex) != JSON_TOKEN_STRING)
- return report_parse_error(JSON_PARSE_STRING, lex);
- if ((ostart != NULL || oend != NULL) && lex->strval != NULL)
- fname = pstrdup(lex->strval->data);
- INSIST(json_lex(lex));
-
- INSIST(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:
- INSIST(parse_object(lex, sem));
- break;
- case JSON_TOKEN_ARRAY_START:
- INSIST(parse_array(lex, sem));
- break;
- default:
- INSIST(parse_scalar(lex, sem));
- }
-
- if (oend != NULL)
- (*oend) (sem->semstate, fname, isnull);
- return JSON_SUCCESS;
-}
-
-static JsonParseErrorType
-parse_object(JsonLexContext *lex, const 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;
-
- check_stack_depth();
-
- 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++;
-
- Assert(lex_peek(lex) == JSON_TOKEN_OBJECT_START);
- INSIST(json_lex(lex));
-
- tok = lex_peek(lex);
- switch (tok)
- {
- case JSON_TOKEN_STRING:
- INSIST(parse_object_field(lex, sem));
- while (lex_peek(lex) == JSON_TOKEN_COMMA)
- {
- INSIST(json_lex(lex));
- INSIST(parse_object_field(lex, sem));
- }
- break;
- case JSON_TOKEN_OBJECT_END:
- break;
- default:
- /* case of an invalid initial token inside the object */
- return report_parse_error(JSON_PARSE_OBJECT_START, lex);
- }
-
- INSIST(lex_expect(JSON_PARSE_OBJECT_NEXT, lex, JSON_TOKEN_OBJECT_END));
-
- lex->lex_level--;
-
- if (oend != NULL)
- (*oend) (sem->semstate);
- return JSON_SUCCESS;
-}
-
-static JsonParseErrorType
-parse_array_element(JsonLexContext *lex, const 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:
- INSIST(parse_object(lex, sem));
- break;
- case JSON_TOKEN_ARRAY_START:
- INSIST(parse_array(lex, sem));
- break;
- default:
- INSIST(parse_scalar(lex, sem));
- }
-
- if (aend != NULL)
- (*aend) (sem->semstate, isnull);
- return JSON_SUCCESS;
-}
-
-static JsonParseErrorType
-parse_array(JsonLexContext *lex, const 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;
-
- check_stack_depth();
-
- 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++;
-
- INSIST(lex_expect(JSON_PARSE_ARRAY_START, lex, JSON_TOKEN_ARRAY_START));
- if (lex_peek(lex) != JSON_TOKEN_ARRAY_END)
- {
-
- INSIST(parse_array_element(lex, sem));
-
- while (lex_peek(lex) == JSON_TOKEN_COMMA)
- {
- INSIST(json_lex(lex));
- INSIST(parse_array_element(lex, sem));
- }
- }
-
- INSIST(lex_expect(JSON_PARSE_ARRAY_NEXT, lex, JSON_TOKEN_ARRAY_END));
-
- lex->lex_level--;
-
- if (aend != NULL)
- (*aend) (sem->semstate);
- return JSON_SUCCESS;
-}
-
-/*
- * Lex one token from the input stream.
- */
-JsonParseErrorType
-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 */
- INSIST(json_lex_string(lex));
- lex->token_type = JSON_TOKEN_STRING;
- break;
- case '-':
- /* Negative number. */
- INSIST(json_lex_number(lex, s + 1, NULL, 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. */
- INSIST(json_lex_number(lex, s, NULL, 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;
- return JSON_INVALID_TOKEN;
- }
-
- /*
- * 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
- return JSON_INVALID_TOKEN;
- }
- else if (p - s == 5 && memcmp(s, "false", 5) == 0)
- lex->token_type = JSON_TOKEN_FALSE;
- else
- return JSON_INVALID_TOKEN;
-
- }
- } /* end of switch */
- return JSON_SUCCESS;
-}
-
-/*
- * The next token in the input stream is known to be a string; lex it.
- */
-static inline JsonParseErrorType
-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;
- return JSON_INVALID_TOKEN;
- }
- 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;
- return JSON_ESCAPING_REQUIRED;
- }
- else if (*s == '\\')
- {
- /* OK, we have an escape character. */
- s++;
- len++;
- if (len >= lex->input_length)
- {
- lex->token_terminator = s;
- return JSON_INVALID_TOKEN;
- }
- 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;
- return JSON_INVALID_TOKEN;
- }
- 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);
- return JSON_UNICODE_ESCAPE_FORMAT;
- }
- }
- if (lex->strval != NULL)
- {
- char utf8str[5];
- int utf8len;
-
- if (ch >= 0xd800 && ch <= 0xdbff)
- {
- if (hi_surrogate != -1)
- return JSON_UNICODE_HIGH_SURROGATE;
- hi_surrogate = (ch & 0x3ff) << 10;
- continue;
- }
- else if (ch >= 0xdc00 && ch <= 0xdfff)
- {
- if (hi_surrogate == -1)
- return JSON_UNICODE_LOW_SURROGATE;
- ch = 0x10000 + hi_surrogate + (ch & 0x3ff);
- hi_surrogate = -1;
- }
-
- if (hi_surrogate != -1)
- return JSON_UNICODE_LOW_SURROGATE;
-
- /*
- * 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.
- */
-
- if (ch == 0)
- {
- /* We can't allow this, since our TEXT type doesn't */
- return JSON_UNICODE_CODE_POINT_ZERO;
- }
- 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
- return JSON_UNICODE_HIGH_ESCAPE;
-
- }
- }
- else if (lex->strval != NULL)
- {
- if (hi_surrogate != -1)
- return JSON_UNICODE_LOW_SURROGATE;
-
- 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);
- return JSON_ESCAPING_INVALID;
- }
- }
- 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);
- return JSON_ESCAPING_INVALID;
- }
-
- }
- else if (lex->strval != NULL)
- {
- if (hi_surrogate != -1)
- return JSON_UNICODE_LOW_SURROGATE;
- appendStringInfoChar(lex->strval, *s);
- }
-
- }
-
- if (hi_surrogate != -1)
- return JSON_UNICODE_LOW_SURROGATE;
-
- /* Hooray, we found the end of the string! */
- lex->prev_token_terminator = lex->token_terminator;
- lex->token_terminator = s + 1;
- return JSON_SUCCESS;
-}
-
-/*
- * 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, or the
- * first character of the string if there is none.
- *
- * If num_err is not NULL, we return an error flag to *num_err rather than
- * raising an error for a badly-formed number. Also, if total_len is not NULL
- * the distance from lex->input to the token end+1 is returned to *total_len.
- */
-static inline JsonParseErrorType
-json_lex_number(JsonLexContext *lex, char *s,
- bool *num_err, int *total_len)
-{
- bool error = false;
- int 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 (len < lex->input_length && *s == '0')
- {
- s++;
- len++;
- }
- else if (len < lex->input_length && *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 (; len < lex->input_length && JSON_ALPHANUMERIC_CHAR(*s); s++, len++)
- error = true;
-
- if (total_len != NULL)
- *total_len = len;
-
- if (num_err != NULL)
- {
- /* let the caller handle any error */
- *num_err = error;
- }
- else
- {
- /* return token endpoint */
- lex->prev_token_terminator = lex->token_terminator;
- lex->token_terminator = s;
- /* handle error if any */
- if (error)
- return JSON_INVALID_TOKEN;
- }
- return JSON_SUCCESS;
-}
-
-/*
- * Report a parse error.
- *
- * lex->token_start and lex->token_terminator must identify the current token.
- */
-static JsonParseErrorType
-report_parse_error(JsonParseContext ctx, JsonLexContext *lex)
-{
- /* Handle case where the input ended prematurely. */
- if (lex->token_start == NULL || lex->token_type == JSON_TOKEN_END)
- return JSON_EXPECTED_MORE;
-
- switch (ctx)
- {
- case JSON_PARSE_END:
- return JSON_EXPECTED_END;
- case JSON_PARSE_VALUE:
- return JSON_EXPECTED_JSON;
- case JSON_PARSE_STRING:
- return JSON_EXPECTED_STRING;
- case JSON_PARSE_ARRAY_START:
- return JSON_EXPECTED_ARRAY_FIRST;
- case JSON_PARSE_ARRAY_NEXT:
- return JSON_EXPECTED_ARRAY_NEXT;
- case JSON_PARSE_OBJECT_START:
- return JSON_EXPECTED_OBJECT_FIRST;
- case JSON_PARSE_OBJECT_LABEL:
- return JSON_EXPECTED_COLON;
- case JSON_PARSE_OBJECT_NEXT:
- return JSON_EXPECTED_OBJECT_NEXT;
- case JSON_PARSE_OBJECT_COMMA:
- return JSON_EXPECTED_STRING;
- default:
- return JSON_BAD_PARSER_STATE;;
- }
-}
-
/*
* Determine how we want to print values of a given type in datum_to_json.
*
diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 63072f616e..a5f2f3eeca 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -261,7 +261,7 @@ jsonb_from_cstring(char *json, int len)
memset(&state, 0, sizeof(state));
memset(&sem, 0, sizeof(sem));
- lex = makeJsonLexContextCstringLen(json, len, true);
+ lex = makeJsonLexContextCstringLen(json, len, GetDatabaseEncoding(), true);
sem.semstate = (void *) &state;
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index be5d30239d..bb22fd23ea 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -521,6 +521,7 @@ makeJsonLexContext(text *json, bool need_escapes)
{
return makeJsonLexContextCstringLen(VARDATA_ANY(json),
VARSIZE_ANY_EXHDR(json),
+ GetDatabaseEncoding(),
need_escapes);
}
@@ -1260,7 +1261,9 @@ get_array_start(void *state)
_state->path_indexes[lex_level] != INT_MIN)
{
/* Negative subscript -- convert to positive-wise subscript */
- int nelements = json_count_array_elements(_state->lex);
+ int nelements;
+
+ PARSE_OR_THROW(json_count_array_elements(_state->lex, &nelements), _state->lex);
if (-_state->path_indexes[lex_level] <= nelements)
_state->path_indexes[lex_level] += nelements;
@@ -2725,7 +2728,7 @@ populate_array_json(PopulateArrayContext *ctx, char *json, int len)
PopulateArrayState state;
JsonSemAction sem;
- state.lex = makeJsonLexContextCstringLen(json, len, true);
+ state.lex = makeJsonLexContextCstringLen(json, len, GetDatabaseEncoding(), true);
state.ctx = ctx;
memset(&sem, 0, sizeof(sem));
@@ -3568,7 +3571,7 @@ get_json_object_as_hash(char *json, int len, const char *funcname)
HASHCTL ctl;
HTAB *tab;
JHashState *state;
- JsonLexContext *lex = makeJsonLexContextCstringLen(json, len, true);
+ JsonLexContext *lex = makeJsonLexContextCstringLen(json, len, GetDatabaseEncoding(), true);
JsonSemAction *sem;
memset(&ctl, 0, sizeof(ctl));
diff --git a/src/common/jsonapi.c b/src/common/jsonapi.c
index c14d6ff4f2..585d4842b2 100644
--- a/src/common/jsonapi.c
+++ b/src/common/jsonapi.c
@@ -10,14 +10,44 @@
*
*-------------------------------------------------------------------------
*/
-#include "c.h"
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+#include "c.h"
#include "common/jsonapi.h"
#ifndef FRONTEND
-#include "utils/palloc.h"
+#include "miscadmin.h"
#endif
+#define INSIST(x) \
+do { \
+ JsonParseErrorType parse_result; \
+ if((parse_result = (x)) != JSON_SUCCESS) \
+ return parse_result; \
+} while (0)
+
+/*
+ * 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;
+
/* the null action object used for pure validation */
const JsonSemAction nullSemAction =
{
@@ -25,8 +55,19 @@ const JsonSemAction nullSemAction =
NULL, NULL, NULL, NULL, NULL
};
+static inline JsonParseErrorType lex_expect(JsonParseContext ctx, JsonLexContext *lex, JsonTokenType token) __attribute__((warn_unused_result));
+static inline JsonParseErrorType json_lex_string(JsonLexContext *lex) __attribute__((warn_unused_result));
+static inline JsonParseErrorType json_lex_number(JsonLexContext *lex, char *s,
+ bool *num_err, int *total_len) __attribute__((warn_unused_result));
+static inline JsonParseErrorType parse_scalar(JsonLexContext *lex, const JsonSemAction *sem) __attribute__((warn_unused_result));
+static JsonParseErrorType parse_object_field(JsonLexContext *lex, const JsonSemAction *sem) __attribute__((warn_unused_result));
+static JsonParseErrorType parse_object(JsonLexContext *lex, const JsonSemAction *sem) __attribute__((warn_unused_result));
+static JsonParseErrorType parse_array_element(JsonLexContext *lex, const JsonSemAction *sem) __attribute__((warn_unused_result));
+static JsonParseErrorType parse_array(JsonLexContext *lex, const JsonSemAction *sem) __attribute__((warn_unused_result));
+static JsonParseErrorType report_parse_error(JsonParseContext ctx, JsonLexContext *lex) __attribute__((warn_unused_result));
+
JsonLexContext *
-makeJsonLexContextCstringLen(char *json, int len, bool need_escapes)
+makeJsonLexContextCstringLen(char *json, int len, pg_enc encoding, bool need_escapes)
{
JsonLexContext *lex;
@@ -40,9 +81,900 @@ makeJsonLexContextCstringLen(char *json, int len, bool need_escapes)
lex->input = lex->token_terminator = lex->line_start = json;
lex->line_number = 1;
lex->input_length = len;
+ lex->input_encoding = encoding;
if (need_escapes)
lex->strval = makeStringInfo();
return lex;
}
+/*
+ * lex_peek
+ *
+ * what is the current look_ahead token?
+*/
+JsonTokenType
+lex_peek(JsonLexContext *lex)
+{
+ return lex->token_type;
+}
+
+/*
+ * lex_except
+ *
+ * move the lexer to the next token if the current look_ahead token matches
+ * the parameter token. Otherwise, report an error.
+ */
+static inline JsonParseErrorType
+lex_expect(JsonParseContext ctx, JsonLexContext *lex, JsonTokenType token)
+{
+ if (lex_peek(lex) == token)
+ INSIST(json_lex(lex));
+ else
+ return report_parse_error(ctx, lex);
+ return JSON_SUCCESS;
+}
+
+/* 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))
+
+/*
+ * Utility function to check if a string is a valid JSON number.
+ *
+ * str is of length len, and need not be null-terminated.
+ */
+bool
+IsValidJsonNumber(const char *str, int len)
+{
+ bool numeric_error;
+ int total_len;
+ JsonLexContext dummy_lex;
+
+ if (len <= 0)
+ return false;
+
+ /*
+ * json_lex_number expects a leading '-' to have been eaten already.
+ *
+ * having to cast away the constness of str is ugly, but there's not much
+ * easy alternative.
+ */
+ if (*str == '-')
+ {
+ dummy_lex.input = unconstify(char *, str) +1;
+ dummy_lex.input_length = len - 1;
+ }
+ else
+ {
+ dummy_lex.input = unconstify(char *, str);
+ dummy_lex.input_length = len;
+ }
+
+ if (JSON_SUCCESS != json_lex_number(&dummy_lex, dummy_lex.input, &numeric_error, &total_len))
+ return false;
+
+ return (!numeric_error) && (total_len == dummy_lex.input_length);
+}
+
+/* Recursive Descent parser support routines */
+
+/*
+ * 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 structure 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.
+ */
+JsonParseErrorType
+pg_parse_json(JsonLexContext *lex, const JsonSemAction *sem)
+{
+ JsonTokenType tok;
+
+ /* get the initial token */
+ INSIST(json_lex(lex));
+
+ tok = lex_peek(lex);
+
+ /* parse by recursive descent */
+ switch (tok)
+ {
+ case JSON_TOKEN_OBJECT_START:
+ INSIST(parse_object(lex, sem));
+ break;
+ case JSON_TOKEN_ARRAY_START:
+ INSIST(parse_array(lex, sem));
+ break;
+ default:
+ INSIST(parse_scalar(lex, sem)); /* json can be a bare scalar */
+ }
+
+ INSIST(lex_expect(JSON_PARSE_END, lex, JSON_TOKEN_END));
+ return JSON_SUCCESS;
+}
+
+/*
+ * json_count_array_elements
+ *
+ * Returns number of array elements in lex context at start of array token
+ * until end of array token at same nesting level.
+ *
+ * Designed to be called from array_start routines.
+ */
+JsonParseErrorType
+json_count_array_elements(JsonLexContext *lex, int *elements)
+{
+ JsonLexContext copylex;
+ int count;
+
+ /*
+ * It's safe to do this with a shallow copy because the lexical routines
+ * don't scribble on the input. They do scribble on the other pointers
+ * etc, so doing this with a copy makes that safe.
+ */
+ memcpy(©lex, lex, sizeof(JsonLexContext));
+ copylex.strval = NULL; /* not interested in values here */
+ copylex.lex_level++;
+
+ count = 0;
+ INSIST(lex_expect(JSON_PARSE_ARRAY_START, ©lex, JSON_TOKEN_ARRAY_START));
+ if (lex_peek(©lex) != JSON_TOKEN_ARRAY_END)
+ {
+ while (1)
+ {
+ count++;
+ if (JSON_SUCCESS != parse_array_element(©lex, &nullSemAction))
+ break;
+ if (copylex.token_type != JSON_TOKEN_COMMA)
+ break;
+ INSIST(json_lex(©lex));
+ }
+ }
+ INSIST(lex_expect(JSON_PARSE_ARRAY_NEXT, ©lex, JSON_TOKEN_ARRAY_END));
+
+ *elements = count;
+ return JSON_SUCCESS;
+}
+
+/*
+ * 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 JsonParseErrorType
+parse_scalar(JsonLexContext *lex, const JsonSemAction *sem)
+{
+ char *val = NULL;
+ json_scalar_action sfunc = sem->scalar;
+ JsonTokenType tok = lex_peek(lex);
+
+ /* a scalar must be a string, a number, true, false, or null */
+ switch (tok)
+ {
+ case JSON_TOKEN_STRING:
+ case JSON_TOKEN_NUMBER:
+ case JSON_TOKEN_TRUE:
+ case JSON_TOKEN_FALSE:
+ case JSON_TOKEN_NULL:
+ break;
+ default:
+ return report_parse_error(JSON_PARSE_VALUE, lex);
+ }
+
+ /* if no semantic function, just consume the token */
+ if (sfunc == NULL)
+ {
+ INSIST(json_lex(lex));
+ return JSON_SUCCESS;
+ }
+
+ /* extract the de-escaped string value, or the raw lexeme */
+ if (lex_peek(lex) == JSON_TOKEN_STRING)
+ {
+ if (lex->strval != NULL)
+ val = pstrdup(lex->strval->data);
+ }
+ else
+ {
+ int len = (lex->token_terminator - lex->token_start);
+
+ val = palloc(len + 1);
+ memcpy(val, lex->token_start, len);
+ val[len] = '\0';
+ }
+
+ /* consume the token */
+ INSIST(json_lex(lex));
+
+ /* invoke the callback */
+ (*sfunc) (sem->semstate, val, tok);
+ return JSON_SUCCESS;
+}
+
+static JsonParseErrorType
+parse_object_field(JsonLexContext *lex, const 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;
+ JsonTokenType tok;
+
+ if (lex_peek(lex) != JSON_TOKEN_STRING)
+ return report_parse_error(JSON_PARSE_STRING, lex);
+ if ((ostart != NULL || oend != NULL) && lex->strval != NULL)
+ fname = pstrdup(lex->strval->data);
+ INSIST(json_lex(lex));
+
+ INSIST(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:
+ INSIST(parse_object(lex, sem));
+ break;
+ case JSON_TOKEN_ARRAY_START:
+ INSIST(parse_array(lex, sem));
+ break;
+ default:
+ INSIST(parse_scalar(lex, sem));
+ }
+
+ if (oend != NULL)
+ (*oend) (sem->semstate, fname, isnull);
+ return JSON_SUCCESS;
+}
+
+static JsonParseErrorType
+parse_object(JsonLexContext *lex, const 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;
+
+#ifndef FRONTEND
+ check_stack_depth();
+#else
+ /* TODO: What do we do in frontend code? */
+#endif
+
+ 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++;
+
+ Assert(lex_peek(lex) == JSON_TOKEN_OBJECT_START);
+ INSIST(json_lex(lex));
+
+ tok = lex_peek(lex);
+ switch (tok)
+ {
+ case JSON_TOKEN_STRING:
+ INSIST(parse_object_field(lex, sem));
+ while (lex_peek(lex) == JSON_TOKEN_COMMA)
+ {
+ INSIST(json_lex(lex));
+ INSIST(parse_object_field(lex, sem));
+ }
+ break;
+ case JSON_TOKEN_OBJECT_END:
+ break;
+ default:
+ /* case of an invalid initial token inside the object */
+ return report_parse_error(JSON_PARSE_OBJECT_START, lex);
+ }
+
+ INSIST(lex_expect(JSON_PARSE_OBJECT_NEXT, lex, JSON_TOKEN_OBJECT_END));
+
+ lex->lex_level--;
+
+ if (oend != NULL)
+ (*oend) (sem->semstate);
+ return JSON_SUCCESS;
+}
+
+static JsonParseErrorType
+parse_array_element(JsonLexContext *lex, const 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:
+ INSIST(parse_object(lex, sem));
+ break;
+ case JSON_TOKEN_ARRAY_START:
+ INSIST(parse_array(lex, sem));
+ break;
+ default:
+ INSIST(parse_scalar(lex, sem));
+ }
+
+ if (aend != NULL)
+ (*aend) (sem->semstate, isnull);
+ return JSON_SUCCESS;
+}
+
+static JsonParseErrorType
+parse_array(JsonLexContext *lex, const 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;
+
+#ifndef FRONTEND
+ check_stack_depth();
+#else
+ /* TODO: What do we do in frontend code? */
+#endif
+
+ 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++;
+
+ INSIST(lex_expect(JSON_PARSE_ARRAY_START, lex, JSON_TOKEN_ARRAY_START));
+ if (lex_peek(lex) != JSON_TOKEN_ARRAY_END)
+ {
+
+ INSIST(parse_array_element(lex, sem));
+
+ while (lex_peek(lex) == JSON_TOKEN_COMMA)
+ {
+ INSIST(json_lex(lex));
+ INSIST(parse_array_element(lex, sem));
+ }
+ }
+
+ INSIST(lex_expect(JSON_PARSE_ARRAY_NEXT, lex, JSON_TOKEN_ARRAY_END));
+
+ lex->lex_level--;
+
+ if (aend != NULL)
+ (*aend) (sem->semstate);
+ return JSON_SUCCESS;
+}
+
+/*
+ * Lex one token from the input stream.
+ */
+JsonParseErrorType
+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 */
+ INSIST(json_lex_string(lex));
+ lex->token_type = JSON_TOKEN_STRING;
+ break;
+ case '-':
+ /* Negative number. */
+ INSIST(json_lex_number(lex, s + 1, NULL, 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. */
+ INSIST(json_lex_number(lex, s, NULL, 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;
+ return JSON_INVALID_TOKEN;
+ }
+
+ /*
+ * 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
+ return JSON_INVALID_TOKEN;
+ }
+ else if (p - s == 5 && memcmp(s, "false", 5) == 0)
+ lex->token_type = JSON_TOKEN_FALSE;
+ else
+ return JSON_INVALID_TOKEN;
+
+ }
+ } /* end of switch */
+ return JSON_SUCCESS;
+}
+
+/*
+ * The next token in the input stream is known to be a string; lex it.
+ */
+static inline JsonParseErrorType
+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;
+ return JSON_INVALID_TOKEN;
+ }
+ 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;
+ return JSON_ESCAPING_REQUIRED;
+ }
+ else if (*s == '\\')
+ {
+ /* OK, we have an escape character. */
+ s++;
+ len++;
+ if (len >= lex->input_length)
+ {
+ lex->token_terminator = s;
+ return JSON_INVALID_TOKEN;
+ }
+ 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;
+ return JSON_INVALID_TOKEN;
+ }
+ 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_wchar_table[lex->input_encoding].mblen((const unsigned char *) s);
+ return JSON_UNICODE_ESCAPE_FORMAT;
+ }
+ }
+ if (lex->strval != NULL)
+ {
+ char utf8str[5];
+ int utf8len;
+
+ if (ch >= 0xd800 && ch <= 0xdbff)
+ {
+ if (hi_surrogate != -1)
+ return JSON_UNICODE_HIGH_SURROGATE;
+ hi_surrogate = (ch & 0x3ff) << 10;
+ continue;
+ }
+ else if (ch >= 0xdc00 && ch <= 0xdfff)
+ {
+ if (hi_surrogate == -1)
+ return JSON_UNICODE_LOW_SURROGATE;
+ ch = 0x10000 + hi_surrogate + (ch & 0x3ff);
+ hi_surrogate = -1;
+ }
+
+ if (hi_surrogate != -1)
+ return JSON_UNICODE_LOW_SURROGATE;
+
+ /*
+ * 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.
+ */
+
+ if (ch == 0)
+ {
+ /* We can't allow this, since our TEXT type doesn't */
+ return JSON_UNICODE_CODE_POINT_ZERO;
+ }
+ else if (lex->input_encoding == 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
+ return JSON_UNICODE_HIGH_ESCAPE;
+
+ }
+ }
+ else if (lex->strval != NULL)
+ {
+ if (hi_surrogate != -1)
+ return JSON_UNICODE_LOW_SURROGATE;
+
+ 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_wchar_table[lex->input_encoding].mblen((const unsigned char *) s);
+ return JSON_ESCAPING_INVALID;
+ }
+ }
+ 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_wchar_table[lex->input_encoding].mblen((const unsigned char *) s);
+ return JSON_ESCAPING_INVALID;
+ }
+
+ }
+ else if (lex->strval != NULL)
+ {
+ if (hi_surrogate != -1)
+ return JSON_UNICODE_LOW_SURROGATE;
+ appendStringInfoChar(lex->strval, *s);
+ }
+
+ }
+
+ if (hi_surrogate != -1)
+ return JSON_UNICODE_LOW_SURROGATE;
+
+ /* Hooray, we found the end of the string! */
+ lex->prev_token_terminator = lex->token_terminator;
+ lex->token_terminator = s + 1;
+ return JSON_SUCCESS;
+}
+
+/*
+ * 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, or the
+ * first character of the string if there is none.
+ *
+ * If num_err is not NULL, we return an error flag to *num_err rather than
+ * raising an error for a badly-formed number. Also, if total_len is not NULL
+ * the distance from lex->input to the token end+1 is returned to *total_len.
+ */
+static inline JsonParseErrorType
+json_lex_number(JsonLexContext *lex, char *s,
+ bool *num_err, int *total_len)
+{
+ bool error = false;
+ int 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 (len < lex->input_length && *s == '0')
+ {
+ s++;
+ len++;
+ }
+ else if (len < lex->input_length && *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 (; len < lex->input_length && JSON_ALPHANUMERIC_CHAR(*s); s++, len++)
+ error = true;
+
+ if (total_len != NULL)
+ *total_len = len;
+
+ if (num_err != NULL)
+ {
+ /* let the caller handle any error */
+ *num_err = error;
+ }
+ else
+ {
+ /* return token endpoint */
+ lex->prev_token_terminator = lex->token_terminator;
+ lex->token_terminator = s;
+ /* handle error if any */
+ if (error)
+ return JSON_INVALID_TOKEN;
+ }
+ return JSON_SUCCESS;
+}
+
+/*
+ * Report a parse error.
+ *
+ * lex->token_start and lex->token_terminator must identify the current token.
+ */
+static JsonParseErrorType
+report_parse_error(JsonParseContext ctx, JsonLexContext *lex)
+{
+ /* Handle case where the input ended prematurely. */
+ if (lex->token_start == NULL || lex->token_type == JSON_TOKEN_END)
+ return JSON_EXPECTED_MORE;
+
+ switch (ctx)
+ {
+ case JSON_PARSE_END:
+ return JSON_EXPECTED_END;
+ case JSON_PARSE_VALUE:
+ return JSON_EXPECTED_JSON;
+ case JSON_PARSE_STRING:
+ return JSON_EXPECTED_STRING;
+ case JSON_PARSE_ARRAY_START:
+ return JSON_EXPECTED_ARRAY_FIRST;
+ case JSON_PARSE_ARRAY_NEXT:
+ return JSON_EXPECTED_ARRAY_NEXT;
+ case JSON_PARSE_OBJECT_START:
+ return JSON_EXPECTED_OBJECT_FIRST;
+ case JSON_PARSE_OBJECT_LABEL:
+ return JSON_EXPECTED_COLON;
+ case JSON_PARSE_OBJECT_NEXT:
+ return JSON_EXPECTED_OBJECT_NEXT;
+ case JSON_PARSE_OBJECT_COMMA:
+ return JSON_EXPECTED_STRING;
+ default:
+ return JSON_BAD_PARSER_STATE;;
+ }
+}
diff --git a/src/include/common/jsonapi.h b/src/include/common/jsonapi.h
index 162437193a..614764bcca 100644
--- a/src/include/common/jsonapi.h
+++ b/src/include/common/jsonapi.h
@@ -14,6 +14,7 @@
#ifndef JSONAPI_H
#define JSONAPI_H
+#include "common/pg_wchar.h"
#include "lib/stringinfo.h"
typedef enum
@@ -73,6 +74,7 @@ typedef struct JsonLexContext
{
char *input;
int input_length;
+ pg_enc input_encoding;
char *token_start;
char *token_terminator;
char *prev_token_terminator;
@@ -133,13 +135,17 @@ extern JsonParseErrorType pg_parse_json(JsonLexContext *lex, const JsonSemAction
*/
extern JsonParseErrorType json_lex(JsonLexContext *lex) __attribute__((warn_unused_result));
+/*
+ * Get the current look_ahead token.
+*/
+extern JsonTokenType lex_peek(JsonLexContext *lex) __attribute__((warn_unused_result));
/*
* json_count_array_elements performs a fast secondary parse to determine the
* number of elements in passed array lex context. It should be called from an
* array_start action.
*/
-extern int json_count_array_elements(JsonLexContext *lex);
+extern JsonParseErrorType json_count_array_elements(JsonLexContext *lex, int *elements);
/*
* constructors for JsonLexContext, with or without strval element.
@@ -152,6 +158,7 @@ extern int json_count_array_elements(JsonLexContext *lex);
*/
extern JsonLexContext *makeJsonLexContextCstringLen(char *json,
int len,
+ pg_enc encoding,
bool need_escapes);
/*
--
2.21.1 (Apple Git-122.3)