This json parser was created for the project of C Workflow.
$ make
$ ./parse_json < xxx.json
$ time ./test_speed <repeat times> < xxx.json
/* Parse JSON document and create a JSON value. Returns NULL on parsing
failures (Invalid JSON, nesting too deep, memory allocation failure).
@doc JSON document */
json_value_t *json_value_parse(const char *doc);
/* Destroy the JSON value
@val JSON value. Typically created by the parsing function. */
void json_value_destroy(json_value_t *val);
/* Get JSON value's type
Return values:
JSON_VALUE_STRING: string
JSON_VALUE_NUMBER: number
JSON_VALUE_OBJECT: JSON object
JSON_VALUE_ARRAY: JSON array
JSON_VALUE_TRUE: true
JSON_VALUE_FALSE: false
JSON_VALUE_NULL: null
@val: JSON value */
int json_value_type(const json_value_t *val);
/* Obtain the JSON string. The function returns the string or
returns NULL if the type of @val is not JSON_VALUE_STRING.
@val: JSON value */
const char *json_value_string(const json_value_t *val);
/* Obtain the JSON number. The function returns the number or
returns NAN if the type of @val is not JSON_VALUE_NUMBER.
@val: JSON value */
double json_value_number(const json_value_t *val);
/* Obtain JSON object. The function returns the JSON object or
returns NULL if the type of @val is not JSON_VALUE_OBJECT.
@val: JSON value
Note: The returned pointer to JSON object is not const.
You may extend the object using buiding functions. */
json_object_t *json_value_object(const json_value_t *val);
/* Obtain JSON arary. The function returns the JSON array or
returns NULL if the type of @val is not JSON_VALUE_ARRAY.
@val: JSON value
Note: The returned pointer to the JSON array is not const and
can been extended by using building functions. */
json_array_t *json_value_array(const json_value_t *val);
/* Get the size of the JSON object.
@obj: JSON object */
int json_object_size(const json_object_t *obj);
/* Find the JSON value under the key @name. Returns NULL if @name
can not be found. The time complexity of this function is
O(log(n)), where n is the size of the JSON object.
@name: The key to find
@obj: JSON object
Note: The returned pointer to JSON value is const. */
const json_value_t *json_object_find(const char *name, const json_object_t *obj);
/* Traversing the JSON object forward or backward
@name: Temporary (const char *) pointer for each key
@val: Temporary (const json_value_t *) pointer for each JSON value
@obj: JSON object
NOTE: These are not functions, but macros of looping. */
json_object_for_each(name, val, obj)
json_object_for_each_prev(name, val, obj)
/* Get the size of the JSON array.
@arr:JSON array */
int json_array_size(const json_array_t *arr);
/* Traversing the JSON array forward or backward
@val: Temporary (const json_value_t *) pointer for each JSON value
@arr: JSON array
NOTE: These are not functions, but macros of looping. */
json_array_for_each(val, arr)
json_array_for_each_prev(val, arr)
All the following functions return NULL on failure of allocating memory.
/* Create a JSON value.
@type: JSON value's type.
Note: Variable argument. Example:
v_str = json_value_create(JSON_VALUE_STRING, "hello");
v_num = json_value_create(JSON_VALUE_NUMBER, 3.14);
v_int = json_value_create(JSON_VALUE_NUMBER, (double)100);
v_obj = json_value_create(JSON_VALUE_OBJECT);
v_arr = json_value_create(JSON_VALUE_ARRAY);
v_true = json_value_create(JSON_VALUE_TRUE);
The returned value is not const and has to be destroyed. */
json_value_t *json_value_create(int type, ...);
/* Extend the JSON object. Returns the value that's added.
@obj: JSON object
@name: New member's name
@type: New member's value type or zero which means another JSON value
Note: Variable argument. Example:
v_num = json_object_append(obj, "pi", JSON_VALUE_NUMBER, 3.14);
v_obj = json_object_append(obj, "user", JSON_VALUE_OBJECT);
v_from_doc = json_object_append(obj, "doc", 0, json_value_parse("{\"data\" : [1, 2, 3]}")); */
const json_value_t *json_object_append(json_object_t *obj, const char *name,
int type, ...);
/* Remove a JSON value from a JSON object and return the value.
@val: JSON value to be removed.
@obj: JSON object
Note: The returned value is not const and need to be destroyed,
or appended to another JSON object or JSON array. */
json_value_t *json_object_remove(const json_value_t *val,
json_object_t *obj);
/* Extend the JSON array. Return the value that's added.
@arr: JSON array
@type: New member's value type or zero which means another JSON value
Note: Variable argument. Example:
v_str = json_array_append(arr, JSON_VALUE_STRING, "hello");
equal to:
v_str = json_array_append(arr, 0, json_value_create(JSON_VALUE_STRING, "hello")); */
const json_value_t *json_array_append(json_array_t *arr, int type, ...);
/* Remove a JSON value from a JSON array and return the value.
@val: JSON value to be removed
@arr: JSON array
Note: The returned value is not const and need to be destroyed,
or appended to another JSON object or JSON array. */
json_value_t *json_array_remove(const json_value_t *val,
json_object_t *arr);