General-purpose function to interact with JSMN library, and create objects (potentially with circular references) from the parsed json. More...

#include "jsmn.h"
#include <stdlib.h>
#include <stdio.h>

Classes
struct	json_state
	Structure to hold state while parsing JSON. More...

struct	key_mapping
	Structure to map a key + state to a function. More...

Macros
#define	ASSERT_JSMN_TYPE(tok, toktype, j)
	Asserts that the type of the current token is the provided type, and logs an error if that is not the case. More...

#define	PARSE_FN(fn_name)
	Macro for defining a jsmn_parsing_fn. More...

#define	GET_PARSE_OBJ() (in__->data)
	Within a PARSE_FN, gets the object currently being constructed. More...

#define	GET_STR_TOK() tok_to_str(*tok__, j__)
	Within a PARSE_FN, gets the token being read as a string. More...

#define	GET_INT_TOK() tok_to_int(*tok__, j__)
	Within a PARSE_FN, gets the token being read as an integer. More...

#define	GET_LONG_TOK() tok_to_long(*tok__, j__)
	Within a PARSE_FN, gets the token being read as a long. More...

#define	PARSE_OBJ_LIST_FN(fn_name, init_fn)
	Macro for parsing a list of objects in a json file. More...

#define	INIT_OBJ_FN(fn_name) static struct json_state fn_name(struct json_state *in__, int index__)
	Macro for instantiating a new struct based on the appearance of a new JSON object. More...

#define	GET_OBJ_INDEX() index__
	In an INIT_OBJ_FN, returns the index of the currently parsed object list. More...

#define	RETURN_OBJ(data__, type__)
	Should be the last line in an INIT_OBJ_FN. More...

#define	PARSE_OBJ_FN(fn_name, parent_obj_type, parent_obj_field, new_type)
	Macro to descend into a JSON object and the corresponding C struct for parsing. More...

#define	START_ITER_TOK_LIST(i)
	Macro to iterate over a list of tokens. More...

#define	END_ITER_TOK_LIST(i) tok__ = (tok__) - (tok_size__ - i + 1);
	Macro that should appear at the end of the iteration of a list of tokens. More...

Typedefs
typedef int(*	jsmn_parsing_fn )(jsmntok_t *tok, char j, struct json_state state, struct json_state *saved)
	Typedef for a jsmn parsing function. More...

typedef struct json_state(*	jsmn_initializer )(struct json_state *state, int index)
	Typedef for a json_state initializer, used when iterating over lists of objects. More...

Functions
int	parse_file_into_obj (const char filename, void obj, struct key_mapping *km)
	Using the provided functions, parses the JSON present in 'filename' and stores the resulting object in 'obj'. More...

int	parse_str_into_obj (char contents, void obj, struct key_mapping *km)
	Using the provided functions, parses the JSON present in in the provided string and stores the resulting object in 'obj'. More...

int	jsmn_ignore (jsmntok_t *tok, char j, struct json_state in, struct json_state *saved)
	Can be used as a jsmn_parsing_fn that ignores any value passed into it. More...

int	parse_jsmn_obj (jsmntok_t *tok, char j, struct json_state in, struct json_state *saved)
	SHOULD NOT BE USED DIRECTLY. More...

int	parse_jsmn_obj_list (jsmntok_t *tok, char j, struct json_state in, struct json_state *saved, jsmn_initializer init)
	SHOULD NOT BE USED DIRECTLY. More...

void *	get_root_jsmn_obj ()
	Returns the initial object passed into the JSON parser. More...

char *	tok_to_str (jsmntok_t tok, char j)
	SHOULD NOT BE USED DIRECTLT. More...

int	tok_to_int (jsmntok_t tok, char j)
	SHOULD NOT BE USED DIRECTLY. More...

long	tok_to_long (jsmntok_t tok, char j)
	SHOULD NOT BE USED DIRECTLY. More...

Detailed Description

General-purpose function to interact with JSMN library, and create objects (potentially with circular references) from the parsed json.

Definition in file jsmn_parser.h.

Macro Definition Documentation

#define ASSERT_JSMN_TYPE	(	tok,
		toktype,
		j
	)

Value:

if ((tok)->type != toktype){ \
        log_error("Got type %d, expected %d while parsing %.50s", \
                  (tok)->type, toktype, &j[(tok)->start]); \
        return -1; \
    } \

Asserts that the type of the current token is the provided type, and logs an error if that is not the case.

Definition at line 39 of file jsmn_parser.h.

#define END_ITER_TOK_LIST ( i ) *tok__ = (*tok__) - (tok_size__ - i + 1);

Macro that should appear at the end of the iteration of a list of tokens.

Parameters

i	The same integer which was passed into START_ITER_TOK_LIST

Definition at line 172 of file jsmn_parser.h.

#define GET_INT_TOK ( ) tok_to_int(*tok__, j__)

Within a PARSE_FN, gets the token being read as an integer.

Definition at line 89 of file jsmn_parser.h.

#define GET_LONG_TOK ( ) tok_to_long(*tok__, j__)

Within a PARSE_FN, gets the token being read as a long.

Definition at line 93 of file jsmn_parser.h.

#define GET_OBJ_INDEX ( ) index__

In an INIT_OBJ_FN, returns the index of the currently parsed object list.

Definition at line 120 of file jsmn_parser.h.

#define GET_PARSE_OBJ ( ) (in__->data)

Within a PARSE_FN, gets the object currently being constructed.

Definition at line 81 of file jsmn_parser.h.

#define GET_STR_TOK ( ) tok_to_str(*tok__, j__)

Within a PARSE_FN, gets the token being read as a string.

Definition at line 85 of file jsmn_parser.h.

#define INIT_OBJ_FN ( fn_name ) static struct json_state fn_name(struct json_state *in__, int index__)

Macro for instantiating a new struct based on the appearance of a new JSON object.

Parameters

fn_name Name for the function, which should subsequently be defined to create a new object, which should be returned with RETURN_OBJ

Definition at line 114 of file jsmn_parser.h.

#define PARSE_FN ( fn_name )

Value:

static int fn_name(jsmntok_t **tok__, char *j__, \

struct json_state *in__, struct json_state **saved__)

jsmntok_t

JSON token description.

Definition: jsmn.h:61

json_state

Structure to hold state while parsing JSON.

Definition: jsmn_parser.h:49

Macro for defining a jsmn_parsing_fn.

Each key in the JSON file should have an associated function defined using this macro.

Parameters

fn_name The name of the function to define, which should return 0 on success, -1 on error, 1 to defer (see jsmn_parsing_fn)

Definition at line 76 of file jsmn_parser.h.

#define PARSE_OBJ_FN	(	fn_name,
		parent_obj_type,
		parent_obj_field,
		new_type
	)

Value:

static int fn_name(jsmntok_t **tok__, char *j__, \
                       struct json_state *in__, struct json_state **saved__) { \
        parent_obj_type *type_out__ = in__->data; \
        struct json_state state_out__ = { \
            .data = &type_out__->parent_obj_field, \
            .parent_type = new_type, \
            .tok = *tok__ \
        }; \
        if (parse_jsmn_obj(tok__, j__, &state_out__, saved__) < 0) { \
            return -1; \
        } \
        return 0;  \
    }

Macro to descend into a JSON object and the corresponding C struct for parsing.

Parameters

fn_name	The name of the function to later reference in the key_mapping
parent_obj_type	The typename of the parent C struct already being parsed
parent_obj_field	The field name of the parent C struct which should be descended into
new_type	An identifier (enumerator) for the new type of object being created

Definition at line 143 of file jsmn_parser.h.

#define PARSE_OBJ_LIST_FN	(	fn_name,
		init_fn
	)

Value:

static int fn_name(jsmntok_t **tok__, char *j__, \
                       struct json_state *in__, struct json_state **saved__) { \
        return parse_jsmn_obj_list(tok__, j__, in__, saved__, init_fn); \
    }

Macro for parsing a list of objects in a json file.

For each element that is encountered, init_fn will be called to construct the object which is passed in to each of the keys within that object

Parameters

fn_name	A name for the function to define
init_fn	An INIT_OBJ_FN to create the new object

Definition at line 103 of file jsmn_parser.h.

#define RETURN_OBJ	(	data__,
		type__
	)

Value:

struct json_state out_obj__ = { \
        .data = data__, \
        .parent_type = type__ \
    }; \
    return out_obj__;

Should be the last line in an INIT_OBJ_FN.

Returns the newly-created object.

Parameters

data__	A pointer to the newly-created object which should be parsed into
type__	The enumerator for the type of object which is new being parsed

Definition at line 128 of file jsmn_parser.h.

#define START_ITER_TOK_LIST ( i )

Value:

int tok_size__ = (*tok__)->size; \

for (i = 0, ++(*tok__); i< tok_size__; ++(*tok__), i++)

Macro to iterate over a list of tokens.

Once inside the iteration, can get the current token with GET_*_TOK(). Iteration should be ended with END_ITER_TOK_LIST

Parameters

i	An integer into which to place the current index

Definition at line 164 of file jsmn_parser.h.

Typedef Documentation

typedef struct json_state(* jsmn_initializer)(struct json_state *state, int index)

Typedef for a json_state initializer, used when iterating over lists of objects.

Parameters

state	- current state being parsed
index	- index into the current list

Returns: a new struct with the new data item of interest

Definition at line 223 of file jsmn_parser.h.

typedef int(* jsmn_parsing_fn)(jsmntok_t **tok, char *j, struct json_state *state, struct json_state **saved)

Typedef for a jsmn parsing function.

Each element in the key mapping should have one of these as the third element.

Parameters

tok	- current token to be parsed
j	- entire JSON string
state	- current state being parsed
saved	- items that have been deferred to parse until later are stored here

Returns: 0 on success, -1 on error, 1 to defer parsing until a future pass

Definition at line 66 of file jsmn_parser.h.

Function Documentation

void* get_root_jsmn_obj ( )

Returns the initial object passed into the JSON parser.

Definition at line 92 of file jsmn_parser.c.

int jsmn_ignore	(	jsmntok_t **	tok,
		char *	j,
		struct json_state *	in,
		struct json_state **	saved
	)

Can be used as a jsmn_parsing_fn that ignores any value passed into it.

Definition at line 120 of file jsmn_parser.c.

int parse_file_into_obj	(	const char *	filename,
		void *	obj,
		struct key_mapping *	km
	)

Using the provided functions, parses the JSON present in 'filename' and stores the resulting object in 'obj'.

Can iterate multiple times on tokens which have dependencies.

Parameters

filename	- JSON file to be parsed
obj	- object to be filled with the results of parsing
keymap	- the mapping between the JSON key and the function to be called

Returns: 0 on success, -1 on error

Definition at line 135 of file jsmn_parser.c.

int parse_jsmn_obj	(	jsmntok_t **	tok,
		char *	j,
		struct json_state *	state,
		struct json_state **	saved
	)

SHOULD NOT BE USED DIRECTLY.

Parameters

tok	- pointer to current token to be parsed (advances automatically)
j	- entire json string being parsed
state	- curernt state of parsing, including the data structure being parsed into
saved	- JSON entries on which parsing has been deferred for later

Definition at line 358 of file jsmn_parser.c.

int parse_jsmn_obj_list	(	jsmntok_t **	tok,
		char *	j,
		struct json_state *	state,
		struct json_state **	saved,
		jsmn_initializer	init
	)

SHOULD NOT BE USED DIRECTLY.

Calls init() for each new object, then passes the returned json_state to the next parsed object.

Parameters

tok	- the current jsmn token to parse
j	- the entire json string
state	- the current state of parsing
saved	- list of states to be re-interpreted laster
init	- initialization function, returning a `struct json_state`

Returns: 0 on success, -1 on failure

Definition at line 318 of file jsmn_parser.c.

int parse_str_into_obj	(	char *	contents,
		void *	obj,
		struct key_mapping *	km
	)

Using the provided functions, parses the JSON present in in the provided string and stores the resulting object in 'obj'.

Can iterate multiple times on tokens which have dependencies.

Parameters

contents	- Null-terminated string to be parsed
obj	- object to be filled with the results of parsing
keymap	- the mapping between the JSON key and the function to be called

Returns: 0 on success, -1 on error

Definition at line 171 of file jsmn_parser.c.

int tok_to_int	(	jsmntok_t *	tok,
		char *	j
	)

SHOULD NOT BE USED DIRECTLY.

Sets the "end" char to \0, and converts converts the resulting string to an integer

Parameters

tok	- JSMN token to extract
j	- original json string

Returns: - integer

Definition at line 42 of file jsmn_parser.c.

long tok_to_long	(	jsmntok_t *	tok,
		char *	j
	)

SHOULD NOT BE USED DIRECTLY.

Sets the "end" char to \0, and converts converts the resulting string to a long integer

Parameters

tok	- JSMN token to extract
j	- original json string

Returns: - long

Definition at line 55 of file jsmn_parser.c.

char* tok_to_str	(	jsmntok_t *	tok,
		char *	j
	)

SHOULD NOT BE USED DIRECTLT.

Sets the "end" char to \0, and returns a pointer to the start

Parameters

tok	- JSMN token to extract
j	- original json string

Returns: - null-terminated char *

Definition at line 69 of file jsmn_parser.c.

Classes

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

Typedef Documentation

Function Documentation