jsonfuncs.h

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/*-------------------------------------------------------------------------
 *
 * jsonfuncs.h
 *    Functions to process JSON data types.
 *
 * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/utils/jsonfuncs.h
 *
 *-------------------------------------------------------------------------
 */
 
#ifndef JSONFUNCS_H
#define JSONFUNCS_H
 
#include "common/jsonapi.h"
#include "nodes/nodes.h"
#include "utils/jsonb.h"
 
/*
 * Flag types for iterate_json(b)_values to specify what elements from a
 * json(b) document we want to iterate.
 */
typedef enum JsonToIndex
{
    jtiKey = 0x01,
    jtiString = 0x02,
    jtiNumeric = 0x04,
    jtiBool = 0x08,
    jtiAll = jtiKey | jtiString | jtiNumeric | jtiBool
} JsonToIndex;
 
/* an action that will be applied to each value in iterate_json(b)_values functions */
typedef void (*JsonIterateStringValuesAction) (void *state, char *elem_value, int elem_len);
 
/* an action that will be applied to each value in transform_json(b)_values functions */
typedef text *(*JsonTransformStringValuesAction) (void *state, char *elem_value, int elem_len);
 
/* build a JsonLexContext from a text datum; see also freeJsonLexContext */
extern JsonLexContext *makeJsonLexContext(JsonLexContext *lex, text *json, bool need_escapes);
 
/* try to parse json, and errsave(escontext) on failure */
extern bool pg_parse_json_or_errsave(JsonLexContext *lex, JsonSemAction *sem,
                                     struct Node *escontext);
 
#define pg_parse_json_or_ereport(lex, sem) \
    (void) pg_parse_json_or_errsave(lex, sem, NULL)
 
/* save an error during json lexing or parsing */
extern void json_errsave_error(JsonParseErrorType error, JsonLexContext *lex,
                               struct Node *escontext);
 
/* get first JSON token */
extern JsonTokenType json_get_first_token(text *json, bool throw_error);
 
extern uint32 parse_jsonb_index_flags(Jsonb *jb);
extern void iterate_jsonb_values(Jsonb *jb, uint32 flags, void *state,
                                 JsonIterateStringValuesAction action);
extern void iterate_json_values(text *json, uint32 flags, void *action_state,
                                JsonIterateStringValuesAction action);
extern Jsonb *transform_jsonb_string_values(Jsonb *jsonb, void *action_state,
                                            JsonTransformStringValuesAction transform_action);
extern text *transform_json_string_values(text *json, void *action_state,
                                          JsonTransformStringValuesAction transform_action);
 
/* Type categories returned by json_categorize_type */
typedef enum
{
    JSONTYPE_NULL,              /* null, so we didn't bother to identify */
    JSONTYPE_BOOL,              /* boolean (built-in types only) */
    JSONTYPE_NUMERIC,           /* numeric (ditto) */
    JSONTYPE_DATE,              /* we use special formatting for datetimes */
    JSONTYPE_TIMESTAMP,
    JSONTYPE_TIMESTAMPTZ,
    JSONTYPE_JSON,              /* JSON (and JSONB, if not is_jsonb) */
    JSONTYPE_JSONB,             /* JSONB (if is_jsonb) */
    JSONTYPE_ARRAY,             /* array */
    JSONTYPE_COMPOSITE,         /* composite */
    JSONTYPE_CAST,              /* something with an explicit cast to JSON */
    JSONTYPE_OTHER,             /* all else */
} JsonTypeCategory;
 
extern void json_categorize_type(Oid typoid, bool is_jsonb,
                                 JsonTypeCategory *tcategory, Oid *outfuncoid);
extern Datum datum_to_json(Datum val, JsonTypeCategory tcategory,
                           Oid outfuncoid);
extern Datum datum_to_jsonb(Datum val, JsonTypeCategory tcategory,
                            Oid outfuncoid);
extern Datum jsonb_from_text(text *js, bool unique_keys);
 
extern Datum json_populate_type(Datum json_val, Oid json_type,
                                Oid typid, int32 typmod,
                                void **cache, MemoryContext mcxt,
                                bool *isnull,
                                Node *escontext);
 
#endif