JSON encoding/decoding. More...

#include <yaz/json.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <assert.h>
#include <stdio.h>
#include <yaz/xmalloc.h>

Data Structures
struct	json_subst_info
struct	json_parser_s

Functions
json_parser_t	json_parser_create (void)
	create JSON parser
void	json_parser_subst (json_parser_t p, int idx, struct json_node *n)
	configure subst rule
void	json_parser_destroy (json_parser_t p)
	destroys JSON parser
static int	look_ch (json_parser_t p)
static void	move_ch (json_parser_t p)
static struct json_node *	json_new_node (json_parser_t p, enum json_node_type type)
void	json_remove_node (struct json_node *n)
	destroys JSON tree node and its children
struct json_node *	json_clone_node (const struct json_node *n)
	clones JSON tree node and its children
static struct json_node *	json_parse_object (json_parser_t p)
static struct json_node *	json_parse_array (json_parser_t p)
static int	json_one_char (const char *p, char out)
static struct json_node *	json_parse_string (json_parser_t p)
static struct json_node *	json_parse_number (json_parser_t p)
static struct json_node *	json_parse_value (json_parser_t p)
static struct json_node *	json_parse_elements (json_parser_t p)
static struct json_node *	json_parse_pair (json_parser_t p)
static struct json_node *	json_parse_members (json_parser_t p)
struct json_node *	json_parser_parse (json_parser_t p, const char *json_str)
	parses JSON string
struct json_node *	json_parse2 (const char json_str, const char errmsg, size_t pos)
	parses JSON string
struct json_node *	json_parse (const char json_str, const char *errmsg)
	parses JSON string
static void	json_indent (WRBUF result, int indent)
static void	json_write_wrbuf_r (struct json_node *node, WRBUF result, int indent)
void	json_write_wrbuf_pretty (struct json_node *node, WRBUF result)
	writes JSON tree with indentation (pretty print)
void	json_write_wrbuf (struct json_node *node, WRBUF result)
	converts JSON tree to JSON string
static struct json_node **	json_get_objectp (struct json_node n, const char name)
struct json_node *	json_get_object (struct json_node n, const char name)
	gets object pair value for some name
struct json_node *	json_detach_object (struct json_node n, const char name)
	gets object value and detaches from existing tree
struct json_node *	json_get_elem (struct json_node *n, int idx)
	gets array element
int	json_count_children (struct json_node *n)
	returns number of children (array or object)
int	json_append_array (struct json_node dst, struct json_node src)
	appends array to another
const char *	json_parser_get_errmsg (json_parser_t p)
	returns parser error
size_t	json_parser_get_position (json_parser_t p)
	returns parser position

Detailed Description

JSON encoding/decoding.

Definition in file json.c.

Function Documentation

◆ json_append_array()

int json_append_array	(	struct json_node *	dst,
		struct json_node *	src )

appends array to another

Parameters

dst	original array and resulting array
src	array to be appended to dst

Return values

-1	not arrays
0	array appended OK

Definition at line 793 of file json.c.

References json_append_array(), json_node_array, json_remove_node(), json_node::type, and json_node::u.

Referenced by json_append_array().

◆ json_clone_node()

struct json_node * json_clone_node ( const struct json_node * n )

clones JSON tree node and its children

Parameters

n JSON node

Returns: cloned JSON tree or NULL if n is NULL

The resulting tree should be removed with a call to json_remove_node.

Definition at line 132 of file json.c.

References json_clone_node(), json_new_node(), json_node_array, json_node_false, json_node_list, json_node_null, json_node_number, json_node_object, json_node_pair, json_node_string, json_node_true, json_node::type, json_node::u, and xstrdup.

Referenced by json_clone_node(), and json_parse_value().

◆ json_count_children()

int json_count_children ( struct json_node * n )

returns number of children (array or object)

Parameters

n	JSON node (presumably array node or object node)

Returns: number of children

Definition at line 781 of file json.c.

References json_count_children(), json_node_array, json_node_object, json_node::type, and json_node::u.

Referenced by json_count_children().

◆ json_detach_object()

struct json_node * json_detach_object	(	struct json_node *	n,
		const char *	name )

gets object value and detaches from existing tree

Parameters

n	JSON node (presumably object node)
name	name to match

Returns: node or NULL if not found

Definition at line 755 of file json.c.

References json_detach_object(), and json_get_objectp().

Referenced by json_detach_object().

◆ json_get_elem()

struct json_node * json_get_elem	(	struct json_node *	n,
		int	idx )

gets array element

Parameters

n	JSON node (presumably array node)
idx	(0=first, 1=second, ..)

Returns: node or NULL if not found

Definition at line 768 of file json.c.

References json_get_elem(), json_node_array, json_node::type, and json_node::u.

Referenced by json_get_elem().

◆ json_get_object()

struct json_node * json_get_object	(	struct json_node *	n,
		const char *	name )

gets object pair value for some name

Parameters

n	JSON node (presumably object node)
name	name to match

Returns: node or NULL if not found

Definition at line 746 of file json.c.

References json_get_object(), and json_get_objectp().

Referenced by json_get_object().

◆ json_get_objectp()

struct json_node ** json_get_objectp	(	struct json_node *	n,
		const char *	name )

static

Definition at line 729 of file json.c.

References json_get_objectp(), json_node_object, json_node_pair, json_node_string, json_node::type, and json_node::u.

Referenced by json_detach_object(), json_get_object(), and json_get_objectp().

◆ json_indent()

void json_indent	(	WRBUF	result,
		int	indent )

static

Definition at line 622 of file json.c.

References json_indent(), wrbuf_buf, wrbuf_len, and wrbuf_putc.

Referenced by json_indent(), and json_write_wrbuf_r().

◆ json_new_node()

struct json_node * json_new_node	(	json_parser_t	p,
		enum json_node_type	type )

static

Definition at line 91 of file json.c.

References json_new_node(), json_node::type, json_node::u, and xmalloc.

Referenced by json_clone_node(), json_new_node(), json_parse_array(), json_parse_elements(), json_parse_members(), json_parse_number(), json_parse_object(), json_parse_pair(), json_parse_string(), and json_parse_value().

◆ json_one_char()

int json_one_char	(	const char **	p,
		char *	out )

static

Definition at line 179 of file json.c.

References json_one_char(), and yaz_write_UTF8_char().

Referenced by json_one_char(), and json_parse_string().

◆ json_parse()

struct json_node * json_parse	(	const char *	json_str,
		const char **	errmsg )

parses JSON string

Parameters

json_str	JSON string
errmsg	pointer to error message string

Returns: JSON tree or NULL if parse error occurred.

The resulting tree should be removed with a call to json_remove_node. The errmsg may be NULL in which case the error message is not returned.

Definition at line 617 of file json.c.

References json_parse(), and json_parse2().

Referenced by json_parse().

◆ json_parse2()

struct json_node * json_parse2	(	const char *	json_str,
		const char **	errmsg,
		size_t *	pos )

parses JSON string

Parameters

json_str	JSON string
errmsg	pointer to error message string
pos	position of parser stop (probably error)

Returns: JSON tree or NULL if parse error occurred.

The resulting tree should be removed with a call to json_remove_node. The errmsg may be NULL in which case the error message is not returned.

Definition at line 595 of file json.c.

References json_parse2(), json_parser_create(), json_parser_destroy(), json_parser_get_errmsg(), json_parser_get_position(), and json_parser_parse().

Referenced by json_parse(), and json_parse2().

◆ json_parse_array()

struct json_node * json_parse_array ( json_parser_t p )

static

Definition at line 444 of file json.c.

References json_parser_s::err_msg, json_new_node(), json_node_array, json_parse_array(), json_parse_elements(), json_remove_node(), look_ch(), json_parser_s::max_level, move_ch(), json_parser_s::parse_level, and json_node::u.

Referenced by json_parse_array(), and json_parse_value().

◆ json_parse_elements()

struct json_node * json_parse_elements ( json_parser_t p )

static

Definition at line 417 of file json.c.

References json_new_node(), json_node_list, json_parse_elements(), json_parse_value(), json_remove_node(), look_ch(), move_ch(), and json_node::u.

Referenced by json_parse_array(), and json_parse_elements().

◆ json_parse_members()

struct json_node * json_parse_members ( json_parser_t p )

static

Definition at line 500 of file json.c.

References json_new_node(), json_node_list, json_parse_members(), json_parse_pair(), json_remove_node(), look_ch(), move_ch(), and json_node::u.

Referenced by json_parse_members(), and json_parse_object().

◆ json_parse_number()

struct json_node * json_parse_number ( json_parser_t p )

static

Definition at line 284 of file json.c.

References json_parser_s::cp, json_parser_s::err_msg, json_new_node(), json_node_number, json_parse_number(), and json_node::u.

Referenced by json_parse_number(), and json_parse_value().

◆ json_parse_object()

struct json_node * json_parse_object ( json_parser_t p )

static

Definition at line 527 of file json.c.

References json_parser_s::err_msg, json_new_node(), json_node_object, json_parse_members(), json_parse_object(), json_remove_node(), look_ch(), json_parser_s::max_level, move_ch(), json_parser_s::parse_level, and json_node::u.

Referenced by json_parse_object(), and json_parse_value().

◆ json_parse_pair()

struct json_node * json_parse_pair ( json_parser_t p )

static

Definition at line 475 of file json.c.

References json_parser_s::err_msg, json_new_node(), json_node_pair, json_parse_pair(), json_parse_string(), json_parse_value(), json_remove_node(), look_ch(), move_ch(), and json_node::u.

Referenced by json_parse_members(), and json_parse_pair().

◆ json_parse_string()

struct json_node * json_parse_string ( json_parser_t p )

static

Definition at line 237 of file json.c.

References json_parser_s::cp, json_parser_s::err_msg, json_new_node(), json_node_string, json_one_char(), json_parse_string(), look_ch(), move_ch(), json_node::u, and xmalloc.

Referenced by json_parse_pair(), json_parse_string(), and json_parse_value().

◆ json_parse_value()

struct json_node * json_parse_value ( json_parser_t p )

static

Definition at line 355 of file json.c.

References json_parser_s::cp, json_parser_s::err_msg, json_subst_info::idx, json_clone_node(), json_new_node(), json_node_false, json_node_null, json_node_true, json_parse_array(), json_parse_number(), json_parse_object(), json_parse_string(), json_parse_value(), look_ch(), json_subst_info::next, json_subst_info::node, json_parser_s::subst, and yaz_islower.

Referenced by json_parse_elements(), json_parse_pair(), json_parse_value(), and json_parser_parse().

◆ json_parser_create()

json_parser_t json_parser_create ( void )

create JSON parser

Returns: JSON parser handle

Definition at line 38 of file json.c.

References json_parser_s::buf, json_parser_s::cp, json_parser_create(), json_parser_s::subst, and xmalloc.

Referenced by json_parse2(), and json_parser_create().

◆ json_parser_destroy()

void json_parser_destroy ( json_parser_t p )

destroys JSON parser

Parameters

p	JSON parser handle

Definition at line 65 of file json.c.

References json_parser_destroy(), json_remove_node(), json_subst_info::next, json_subst_info::node, json_parser_s::subst, and xfree.

Referenced by json_parse2(), and json_parser_destroy().

◆ json_parser_get_errmsg()

const char * json_parser_get_errmsg ( json_parser_t p )

returns parser error

Parameters

p	JSON parser handle

Returns: parse error msg

This function should be called if json_parser_parse returns NULL .

Definition at line 809 of file json.c.

References json_parser_s::err_msg, and json_parser_get_errmsg().

Referenced by json_parse2(), and json_parser_get_errmsg().

◆ json_parser_get_position()

size_t json_parser_get_position ( json_parser_t p )

returns parser position

Parameters

p	JSON parser handle

Returns: number of bytes read from parser

This function should be called if json_parser_parse returns NULL .

Definition at line 814 of file json.c.

References json_parser_s::buf, json_parser_s::cp, and json_parser_get_position().

Referenced by json_parse2(), and json_parser_get_position().

◆ json_parser_parse()

struct json_node * json_parser_parse	(	json_parser_t	p,
		const char *	json_str )

parses JSON string

Parameters

p	JSON parser handle
json_str	JSON string

Returns: JSON tree or NULL if parse error occurred.

The resulting tree should be removed with a call to json_remove_node.

Definition at line 567 of file json.c.

References json_parser_s::buf, json_parser_s::cp, json_parser_s::err_msg, json_parse_value(), json_parser_parse(), json_remove_node(), look_ch(), json_parser_s::max_level, and json_parser_s::parse_level.

Referenced by json_parse2(), and json_parser_parse().

◆ json_parser_subst()

void json_parser_subst	(	json_parser_t	p,
		int	idx,
		struct json_node *	n )

configure subst rule

Parameters

p	JSON parser
idx	(idx)
n	node to be substituted for idx (idx)

Ownership of n is transferred to the parser. The parser releases it when the rule is replaced or the parser is destroyed. Each occurrence of idx in the JSON input is replaced by a clone of n.

Definition at line 48 of file json.c.

References json_subst_info::idx, json_parser_subst(), json_remove_node(), json_subst_info::next, json_parser_s::subst, and xmalloc.

Referenced by json_parser_subst().