/*
* $Id: json_util.h,v 1.4 2006/01/30 23:07:57 mclark Exp $
*
* Copyright (c) 2004, 2005 Metaparadigm Pte. Ltd.
* Michael Clark <michael@metaparadigm.com>
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the MIT license. See COPYING for details.
*
*/
/**
* @file
* @brief Miscllaneous utility functions and macros.
*/
#ifndef _json_util_h_
#define _json_util_h_
#include "json_object.h"
#ifndef json_min
#define json_min(a, b) ((a) < (b) ? (a) : (b))
#endif
#ifndef json_max
#define json_max(a, b) ((a) > (b) ? (a) : (b))
#endif
#ifdef __cplusplus
extern "C" {
#endif
#define JSON_FILE_BUF_SIZE 4096
/* utility functions */
/**
* Read the full contents of the given file, then convert it to a
* json_object using json_tokener_parse().
*
* Returns NULL on failure. See json_util_get_last_err() for details.
*/
JSON_EXPORT struct json_object *json_object_from_file(const char *filename);
/**
* Create a JSON object from already opened file descriptor.
*
* This function can be helpful, when you opened the file already,
* e.g. when you have a temp file.
* Note, that the fd must be readable at the actual position, i.e.
* use lseek(fd, 0, SEEK_SET) before.
*
* The depth argument specifies the maximum object depth to pass to
* json_tokener_new_ex(). When depth == -1, JSON_TOKENER_DEFAULT_DEPTH
* is used instead.
*
* Returns NULL on failure. See json_util_get_last_err() for details.
*/
JSON_EXPORT struct json_object *json_object_from_fd_ex(int fd, int depth);
/**
* Create a JSON object from an already opened file descriptor, using
* the default maximum object depth. (JSON_TOKENER_DEFAULT_DEPTH)
*
* See json_object_from_fd_ex() for details.
*/
JSON_EXPORT struct json_object *json_object_from_fd(int fd);
/**
* Equivalent to:
* json_object_to_file_ext(filename, obj, JSON_C_TO_STRING_PLAIN);
*
* Returns -1 if something fails. See json_util_get_last_err() for details.
*/
JSON_EXPORT int json_object_to_file(const char *filename, struct json_object *obj);
/**
* Open and truncate the given file, creating it if necessary, then
* convert the json_object to a string and write it to the file.
*
* Returns -1 if something fails. See json_util_get_last_err() for details.
*/
JSON_EXPORT int json_object_to_file_ext(const char *filename, struct json_object *obj, int flags);
/**
* Convert the json_object to a string and write it to the file descriptor.
* Handles partial writes and will keep writing until done, or an error
* occurs.
*
* @param fd an open, writable file descriptor to write to
* @param obj the object to serializer and write
* @param flags flags to pass to json_object_to_json_string_ext()
* @return -1 if something fails. See json_util_get_last_err() for details.
*/
JSON_EXPORT int json_object_to_fd(int fd, struct json_object *obj, int flags);
/**
* Return the last error from various json-c functions, including:
* json_object_to_file{,_ext}, json_object_to_fd() or
* json_object_from_{file,fd}, or NULL if there is none.
*/
JSON_EXPORT const char *json_util_get_last_err(void);
/* these parsing helpers return zero on success */
JSON_EXPORT int json_parse_int64(const char *buf, int64_t *retval);
JSON_EXPORT int json_parse_uint64(const char *buf, uint64_t *retval);
JSON_EXPORT int json_parse_double(const char *buf, double *retval);
/**
* Return a string describing the type of the object.
* e.g. "int", or "object", etc...
*/
JSON_EXPORT const char *json_type_to_name(enum json_type o_type);
#ifdef __cplusplus
}
#endif
#endif
