diff options
Diffstat (limited to 'libavutil/dict.h')
| -rw-r--r-- | libavutil/dict.h | 39 |
1 files changed, 28 insertions, 11 deletions
diff --git a/libavutil/dict.h b/libavutil/dict.h index ab23f26e6f..63c830ae14 100644 --- a/libavutil/dict.h +++ b/libavutil/dict.h @@ -1,25 +1,31 @@ /* * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * 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. * - * Libav is distributed in the hope that it will be useful, + * 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 Libav; if not, write to the Free Software + * 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 @@ -58,12 +64,13 @@ * */ -#define AV_DICT_MATCH_CASE 1 -#define AV_DICT_IGNORE_SUFFIX 2 +#define AV_DICT_MATCH_CASE 1 /**< Only get an entry with exact-case key match. Only relevant in av_dict_get(). */ +#define AV_DICT_IGNORE_SUFFIX 2 /**< Return first entry in a dictionary whose first part corresponds to the search key, + ignoring the suffix of the found key string. Only relevant in av_dict_get(). */ #define AV_DICT_DONT_STRDUP_KEY 4 /**< Take ownership of a key that's been - allocated with av_malloc() and children. */ + allocated with av_malloc() or another memory allocation function. */ #define AV_DICT_DONT_STRDUP_VAL 8 /**< Take ownership of a value that's been - allocated with av_malloc() and chilren. */ + allocated with av_malloc() or another memory allocation function. */ #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. */ @@ -78,10 +85,17 @@ typedef struct AVDictionary AVDictionary; /** * Get a dictionary entry with matching key. * + * The returned entry key or value must not be changed, or it will + * cause undefined behavior. + * + * To iterate through all the dictionary entries, you can set the matching key + * to the null string "" and set the AV_DICT_IGNORE_SUFFIX flag. + * * @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. + * @param key matching key + * @param flags a collection of AV_DICT_* flags controlling how the entry is retrieved + * @return found entry or NULL in case no matching entry was found in the dictionary */ AVDictionaryEntry * av_dict_get(AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags); @@ -107,7 +121,10 @@ int av_dict_count(const AVDictionary *m); 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. + * Parse the key/value pairs list and add the parsed entries to a dictionary. + * + * In case of failure, all the successfully set entries are stored in + * *pm. You may need to manually free the created dictionary. * * @param key_val_sep a 0-terminated list of characters used to separate * key from value |