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/*
* $Id: json_object.h,v 1.12 2006/01/30 23:07:57 mclark Exp $
*
* Copyright (c) 2004, 2005 Metaparadigm Pte. Ltd.
* Michael Clark <michael@metaparadigm.com>
* Copyright (c) 2009 Hewlett-Packard Development Company, L.P.
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the MIT license. See COPYING for details.
*
*/
#ifndef _json_object_h_
#define _json_object_h_
#include "json_inttypes.h"
#ifdef __cplusplus
extern "C" {
#endif
#define JSON_OBJECT_DEF_HASH_ENTRIES 16
/**
* A flag for the json_object_to_json_string_ext() and
* json_object_to_file_ext() functions which causes the output
* to have no extra whitespace or formatting applied.
*/
#define JSON_C_TO_STRING_PLAIN 0
/**
* A flag for the json_object_to_json_string_ext() and
* json_object_to_file_ext() functions which causes the output to have
* minimal whitespace inserted to make things slightly more readable.
*/
#define JSON_C_TO_STRING_SPACED (1<<0)
/**
* A flag for the json_object_to_json_string_ext() and
* json_object_to_file_ext() functions which causes
* the output to be formatted.
*
* See the "Two Space Tab" option at http://jsonformatter.curiousconcept.com/
* for an example of the format.
*/
#define JSON_C_TO_STRING_PRETTY (1<<1)
#undef FALSE
#define FALSE ((json_bool)0)
#undef TRUE
#define TRUE ((json_bool)1)
extern const char *json_number_chars;
extern const char *json_hex_chars;
/* CAW: added for ANSI C iteration correctness */
struct json_object_iter
{
char *key;
struct json_object *val;
struct lh_entry *entry;
};
/* forward structure definitions */
typedef int json_bool;
typedef struct printbuf printbuf;
typedef struct lh_table lh_table;
typedef struct array_list array_list;
typedef struct json_object json_object;
typedef struct json_object_iter json_object_iter;
typedef struct json_tokener json_tokener;
/**
* Type of custom user delete functions. See json_object_set_serializer.
*/
typedef void (json_object_delete_fn)(struct json_object *jso, void *userdata);
/**
* Type of a custom serialization function. See json_object_set_serializer.
*/
typedef int (json_object_to_json_string_fn)(struct json_object *jso,
struct printbuf *pb,
int level,
int flags);
/* supported object types */
typedef enum json_type {
/* If you change this, be sure to update json_type_to_name() too */
json_type_null,
json_type_boolean,
json_type_double,
json_type_int,
json_type_object,
json_type_array,
json_type_string,
} json_type;
/* reference counting functions */
/**
* Increment the reference count of json_object, thereby grabbing shared
* ownership of obj.
*
* @param obj the json_object instance
*/
extern struct json_object* json_object_get(struct json_object *obj);
/**
* Decrement the reference count of json_object and free if it reaches zero.
* You must have ownership of obj prior to doing this or you will cause an
* imbalance in the reference count.
*
* @param obj the json_object instance
* @returns 1 if the object was freed.
*/
int json_object_put(struct json_object *obj);
/**
* Check if the json_object is of a given type
* @param obj the json_object instance
* @param type one of:
json_type_null (i.e. obj == NULL),
json_type_boolean,
json_type_double,
json_type_int,
json_type_object,
json_type_array,
json_type_string,
*/
extern int json_object_is_type(struct json_object *obj, enum json_type type);
/**
* Get the type of the json_object. See also json_type_to_name() to turn this
* into a string suitable, for instance, for logging.
*
* @param obj the json_object instance
* @returns type being one of:
json_type_null (i.e. obj == NULL),
json_type_boolean,
json_type_double,
json_type_int,
json_type_object,
json_type_array,
json_type_string,
*/
extern enum json_type json_object_get_type(struct json_object *obj);
/** Stringify object to json format.
* Equivalent to json_object_to_json_string_ext(obj, JSON_C_TO_STRING_SPACED)
* @param obj the json_object instance
* @returns a string in JSON format
*/
extern const char* json_object_to_json_string(struct json_object *obj);
/** Stringify object to json format
* @param obj the json_object instance
* @param flags formatting options, see JSON_C_TO_STRING_PRETTY and other constants
* @returns a string in JSON format
*/
extern const char* json_object_to_json_string_ext(struct json_object *obj, int
flags);
/**
* Set a custom serialization function to be used when this particular object
* is converted to a string by json_object_to_json_string.
*
* If a custom serializer is already set on this object, any existing
* user_delete function is called before the new one is set.
*
* If to_string_func is NULL, the other parameters are ignored
* and the default behaviour is reset.
*
* The userdata parameter is optional and may be passed as NULL. If provided,
* it is passed to to_string_func as-is. This parameter may be NULL even
* if user_delete is non-NULL.
*
* The user_delete parameter is optional and may be passed as NULL, even if
* the userdata parameter is non-NULL. It will be called just before the
* json_object is deleted, after it's reference count goes to zero
* (see json_object_put()).
* If this is not provided, it is up to the caller to free the userdata at
* an appropriate time. (i.e. after the json_object is deleted)
*
* @param jso the object to customize
* @param to_string_func the custom serialization function
* @param userdata an optional opaque cookie
* @param user_delete an optional function from freeing userdata
*/
void json_object_set_serializer(json_object *jso,
json_object_to_json_string_fn to_string_func,
void *userdata,
json_object_delete_fn *user_delete);
/* object type methods */
/** Create a new empty object with a reference count of 1. The caller of
* this object initially has sole ownership. Remember, when using
* json_object_object_add or json_object_array_put_idx, ownership will
* transfer to the object/array. Call json_object_get if you want to maintain
* shared ownership or also add this object as a child of multiple objects or
* arrays. Any ownerships you acquired but did not transfer must be released
* through json_object_put.
*
* @returns a json_object of type json_type_object
*/
extern struct json_object* json_object_new_object(void);
/** Get the hashtable of a json_object of type json_type_object
* @param obj the json_object instance
* @returns a linkhash
*/
extern struct lh_table* json_object_get_object(struct json_object *obj);
/** Add an object field to a json_object of type json_type_object
*
* The reference count will *not* be incremented. This is to make adding
* fields to objects in code more compact. If you want to retain a reference
* to an added object, independent of the lifetime of obj, you must wrap the
* passed object with json_object_get.
*
* Upon calling this, the ownership of val transfers to obj. Thus you must
* make sure that you do in fact have ownership over this object. For instance,
* json_object_new_object will give you ownership until you transfer it,
* whereas json_object_object_get does not.
*
* @param obj the json_object instance
* @param key the object field name (a private copy will be duplicated)
* @param val a json_object or NULL member to associate with the given field
*/
extern void json_object_object_add(struct json_object* obj, const char *key,
struct json_object *val);
/** Get the json_object associate with a given object field
*
* *No* reference counts will be changed. There is no need to manually adjust
* reference counts through the json_object_put/json_object_get methods unless
* you need to have the child (value) reference maintain a different lifetime
* than the owning parent (obj). Ownership of the returned value is retained
* by obj (do not do json_object_put unless you have done a json_object_get).
* If you delete the value from obj (json_object_object_del) and wish to access
* the returned reference afterwards, make sure you have first gotten shared
* ownership through json_object_get (& don't forget to do a json_object_put
* or transfer ownership to prevent a memory leak).
*
* @param obj the json_object instance
* @param key the object field name
* @returns the json_object associated with the given field name
* @deprecated Please use json_object_object_get_ex
*/
extern struct json_object* json_object_object_get(struct json_object* obj,
const char *key);
/** Get the json_object associated with a given object field.
*
* This returns true if the key is found, false in all other cases (including
* if obj isn't a json_type_object).
*
* *No* reference counts will be changed. There is no need to manually adjust
* reference counts through the json_object_put/json_object_get methods unless
* you need to have the child (value) reference maintain a different lifetime
* than the owning parent (obj). Ownership of value is retained by obj.
*
* @param obj the json_object instance
* @param key the object field name
* @param value a pointer where to store a reference to the json_object
* associated with the given field name.
*
* It is safe to pass a NULL value.
* @returns whether or not the key exists
*/
extern json_bool json_object_object_get_ex(struct json_object* obj,
const char *key,
struct json_object **value);
/** Delete the given json_object field
*
* The reference count will be decremented for the deleted object. If there
* are no more owners of the value represented by this key, then the value is
* freed. Otherwise, the reference to the value will remain in memory.
*
* @param obj the json_object instance
* @param key the object field name
*/
extern void json_object_object_del(struct json_object* obj, const char *key);
/**
* Iterate through all keys and values of an object.
*
* Adding keys to the object while iterating is NOT allowed.
*
* Deleting an existing key, or replacing an existing key with a
* new value IS allowed.
*
* @param obj the json_object instance
* @param key the local name for the char* key variable defined in the body
* @param val the local name for the json_object* object variable defined in
* the body
*/
#if defined(__GNUC__) && !defined(__STRICT_ANSI__)
# define json_object_object_foreach(obj,key,val) \
char *key; \
struct json_object *val; \
for(struct lh_entry *entry = json_object_get_object(obj)->head, *entry_next = NULL; \
({ if(entry) { \
key = (char*)entry->k; \
val = (struct json_object*)entry->v; \
entry_next = entry->next; \
} ; entry; }); \
entry = entry_next )
#else /* ANSI C or MSC */
# define json_object_object_foreach(obj,key,val) \
char *key;\
struct json_object *val; \
struct lh_entry *entry; \
struct lh_entry *entry_next = NULL; \
for(entry = json_object_get_object(obj)->head; \
(entry ? ( \
key = (char*)entry->k, \
val = (struct json_object*)entry->v, \
entry_next = entry->next, \
entry) : 0); \
entry = entry_next)
#endif /* defined(__GNUC__) && !defined(__STRICT_ANSI__) */
/** Iterate through all keys and values of an object (ANSI C Safe)
* @param obj the json_object instance
* @param iter the object iterator
*/
#define json_object_object_foreachC(obj,iter) \
for(iter.entry = json_object_get_object(obj)->head; (iter.entry ? (iter.key = (char*)iter.entry->k, iter.val = (struct json_object*)iter.entry->v, iter.entry) : 0); iter.entry = iter.entry->next)
/* Array type methods */
/** Create a new empty json_object of type json_type_array
* @returns a json_object of type json_type_array
*/
extern struct json_object* json_object_new_array(void);
/** Get the arraylist of a json_object of type json_type_array
* @param obj the json_object instance
* @returns an arraylist
*/
extern struct array_list* json_object_get_array(struct json_object *obj);
/** Get the length of a json_object of type json_type_array
* @param obj the json_object instance
* @returns an int
*/
extern int json_object_array_length(struct json_object *obj);
/** Sorts the elements of jso of type json_type_array
*
* Pointers to the json_object pointers will be passed as the two arguments
* to @sort_fn
*
* @param obj the json_object instance
* @param sort_fn a sorting function
*/
extern void json_object_array_sort(struct json_object *jso, int(*sort_fn)(const void *, const void *));
/** Add an element to the end of a json_object of type json_type_array
*
* The reference count will *not* be incremented. This is to make adding
* fields to objects in code more compact. If you want to retain a reference
* to an added object you must wrap the passed object with json_object_get
*
* @param obj the json_object instance
* @param val the json_object to be added
*/
extern int json_object_array_add(struct json_object *obj,
struct json_object *val);
/** Insert or replace an element at a specified index in an array (a json_object of type json_type_array)
*
* The reference count will *not* be incremented. This is to make adding
* fields to objects in code more compact. If you want to retain a reference
* to an added object you must wrap the passed object with json_object_get
*
* The reference count of a replaced object will be decremented.
*
* The array size will be automatically be expanded to the size of the
* index if the index is larger than the current size.
*
* @param obj the json_object instance
* @param idx the index to insert the element at
* @param val the json_object to be added
*/
extern int json_object_array_put_idx(struct json_object *obj, int idx,
struct json_object *val);
/** Get the element at specificed index of the array (a json_object of type json_type_array)
* @param obj the json_object instance
* @param idx the index to get the element at
* @returns the json_object at the specified index (or NULL)
*/
extern struct json_object* json_object_array_get_idx(struct json_object *obj,
int idx);
/* json_bool type methods */
/** Create a new empty json_object of type json_type_boolean
* @param b a json_bool TRUE or FALSE (0 or 1)
* @returns a json_object of type json_type_boolean
*/
extern struct json_object* json_object_new_boolean(json_bool b);
/** Get the json_bool value of a json_object
*
* The type is coerced to a json_bool if the passed object is not a json_bool.
* integer and double objects will return FALSE if there value is zero
* or TRUE otherwise. If the passed object is a string it will return
* TRUE if it has a non zero length. If any other object type is passed
* TRUE will be returned if the object is not NULL.
*
* @param obj the json_object instance
* @returns a json_bool
*/
extern json_bool json_object_get_boolean(struct json_object *obj);
/* int type methods */
/** Create a new empty json_object of type json_type_int
* Note that values are stored as 64-bit values internally.
* To ensure the full range is maintained, use json_object_new_int64 instead.
* @param i the integer
* @returns a json_object of type json_type_int
*/
extern struct json_object* json_object_new_int(int32_t i);
/** Create a new empty json_object of type json_type_int
* @param i the integer
* @returns a json_object of type json_type_int
*/
extern struct json_object* json_object_new_int64(int64_t i);
/** Get the int value of a json_object
*
* The type is coerced to a int if the passed object is not a int.
* double objects will return their integer conversion. Strings will be
* parsed as an integer. If no conversion exists then 0 is returned
* and errno is set to EINVAL. null is equivalent to 0 (no error values set)
*
* Note that integers are stored internally as 64-bit values.
* If the value of too big or too small to fit into 32-bit, INT32_MAX or
* INT32_MIN are returned, respectively.
*
* @param obj the json_object instance
* @returns an int
*/
extern int32_t json_object_get_int(struct json_object *obj);
/** Get the int value of a json_object
*
* The type is coerced to a int64 if the passed object is not a int64.
* double objects will return their int64 conversion. Strings will be
* parsed as an int64. If no conversion exists then 0 is returned.
*
* NOTE: Set errno to 0 directly before a call to this function to determine
* whether or not conversion was successful (it does not clear the value for
* you).
*
* @param obj the json_object instance
* @returns an int64
*/
extern int64_t json_object_get_int64(struct json_object *obj);
/* double type methods */
/** Create a new empty json_object of type json_type_double
* @param d the double
* @returns a json_object of type json_type_double
*/
extern struct json_object* json_object_new_double(double d);
/** Get the double floating point value of a json_object
*
* The type is coerced to a double if the passed object is not a double.
* integer objects will return their double conversion. Strings will be
* parsed as a double. If no conversion exists then 0.0 is returned and
* errno is set to EINVAL. null is equivalent to 0 (no error values set)
*
* If the value is too big to fit in a double, then the value is set to
* the closest infinity with errno set to ERANGE. If strings cannot be
* converted to their double value, then EINVAL is set & NaN is returned.
*
* Arrays of length 0 are interpreted as 0 (with no error flags set).
* Arrays of length 1 are effectively cast to the equivalent object and
* converted using the above rules. All other arrays set the error to
* EINVAL & return NaN.
*
* NOTE: Set errno to 0 directly before a call to this function to
* determine whether or not conversion was successful (it does not clear
* the value for you).
*
* @param obj the json_object instance
* @returns a double floating point number
*/
extern double json_object_get_double(struct json_object *obj);
/* string type methods */
/** Create a new empty json_object of type json_type_string
*
* A copy of the string is made and the memory is managed by the json_object
*
* @param s the string
* @returns a json_object of type json_type_string
*/
extern struct json_object* json_object_new_string(const char *s);
extern struct json_object* json_object_new_string_len(const char *s, int len);
/** Get the string value of a json_object
*
* If the passed object is not of type json_type_string then the JSON
* representation of the object is returned.
*
* The returned string memory is managed by the json_object and will
* be freed when the reference count of the json_object drops to zero.
*
* @param obj the json_object instance
* @returns a string
*/
extern const char* json_object_get_string(struct json_object *obj);
/** Get the string length of a json_object
*
* If the passed object is not of type json_type_string then zero
* will be returned.
*
* @param obj the json_object instance
* @returns int
*/
extern int json_object_get_string_len(struct json_object *obj);
#ifdef __cplusplus
}
#endif
#endif
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