/*
  *

  * This file is part of FFmpeg.

  *

  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**

  * @file
  * Public dictionary API.

  * @deprecated
  *  AVDictionary is provided for compatibility with libav. It is both in

  *  implementation as well as API inefficient. It does not scale and is
  *  extremely slow with large dictionaries.
  *  It is recommended that new code uses our tree container from tree.c/h

  *  where applicable, which uses AVL trees to achieve O(log n) performance.

  */
 
 #ifndef AVUTIL_DICT_H
 #define AVUTIL_DICT_H
 

 /**

  * @addtogroup lavu_dict AVDictionary
  * @ingroup lavu_data
  *
  * @brief Simple key:value store
  *

  * @{
  * Dictionaries are used for storing key:value pairs. To create
  * an AVDictionary, simply pass an address of a NULL pointer to
  * av_dict_set(). NULL can be used as an empty dictionary wherever
  * a pointer to an AVDictionary is required.
  * Use av_dict_get() to retrieve an entry or iterate over all
  * entries and finally av_dict_free() to free the dictionary
  * and all its contents.
  *
  * @code
  * AVDictionary *d = NULL;                // "create" an empty dictionary
  * av_dict_set(&d, "foo", "bar", 0);      // add an entry
  *
  * char *k = av_strdup("key");            // if your strings are already allocated,
  * char *v = av_strdup("value");          // you can avoid copying them like this
  * av_dict_set(&d, k, v, AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
  *
  * AVDictionaryEntry *t = NULL;
  * while (t = av_dict_get(d, "", t, AV_DICT_IGNORE_SUFFIX)) {
  *     <....>                             // iterate over all entries in d
  * }
  *
  * av_dict_free(&d);
  * @endcode
  *
  */
 

 #define AV_DICT_MATCH_CASE      1
 #define AV_DICT_IGNORE_SUFFIX   2

 #define AV_DICT_DONT_STRDUP_KEY 4   /**< Take ownership of a key that's been
                                          allocated with av_malloc() and children. */
 #define AV_DICT_DONT_STRDUP_VAL 8   /**< Take ownership of a value that's been
                                          allocated with av_malloc() and chilren. */

 #define AV_DICT_DONT_OVERWRITE 16   ///< Don't overwrite existing entries.

 #define AV_DICT_APPEND         32   /**< If the entry already exists, append to it.  Note that no
                                       delimiter is added, the strings are simply concatenated. */

 typedef struct AVDictionaryEntry {

     char *key;
     char *value;
 } AVDictionaryEntry;
 
 typedef struct AVDictionary AVDictionary;
 
 /**
  * Get a dictionary entry with matching key.
  *
  * @param prev Set to the previous matching element to find the next.
  *             If set to NULL the first matching element is returned.
  * @param flags Allows case as well as suffix-insensitive comparisons.
  * @return Found entry or NULL, changing key or value leads to undefined behavior.
  */
 AVDictionaryEntry *
 av_dict_get(AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags);
 
 /**

  * Get number of entries in dictionary.
  *
  * @param m dictionary
  * @return  number of entries in dictionary
  */
 int av_dict_count(const AVDictionary *m);
 
 /**

  * Set the given entry in *pm, overwriting an existing entry.
  *
  * @param pm pointer to a pointer to a dictionary struct. If *pm is NULL
  * a dictionary struct is allocated and put in *pm.
  * @param key entry key to add to *pm (will be av_strduped depending on flags)
  * @param value entry value to add to *pm (will be av_strduped depending on flags).

  *        Passing a NULL value will cause an existing entry to be deleted.

  * @return >= 0 on success otherwise an error code <0
  */
 int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags);
 
 /**

  * Parse the key/value pairs list and add to a dictionary.
  *
  * @param key_val_sep  a 0-terminated list of characters used to separate
  *                     key from value
  * @param pairs_sep    a 0-terminated list of characters used to separate
  *                     two pairs from each other
  * @param flags        flags to use when adding to dictionary.
  *                     AV_DICT_DONT_STRDUP_KEY and AV_DICT_DONT_STRDUP_VAL
  *                     are ignored since the key/value tokens will always
  *                     be duplicated.
  * @return             0 on success, negative AVERROR code on failure
  */
 int av_dict_parse_string(AVDictionary **pm, const char *str,
                          const char *key_val_sep, const char *pairs_sep,
                          int flags);
 
 /**

  * Copy entries from one AVDictionary struct into another.
  * @param dst pointer to a pointer to a AVDictionary struct. If *dst is NULL,
  *            this function will allocate a struct for you and put it in *dst
  * @param src pointer to source AVDictionary struct
  * @param flags flags to use when setting entries in *dst
  * @note metadata is read using the AV_DICT_IGNORE_SUFFIX flag
  */
 void av_dict_copy(AVDictionary **dst, AVDictionary *src, int flags);
 
 /**

  * Free all the memory allocated for an AVDictionary struct
  * and all keys and values.

  */
 void av_dict_free(AVDictionary **m);
 

 /**
  * @}
  */
 

 #endif /* AVUTIL_DICT_H */