1 /* 2 * 3 * This file is part of FFmpeg. 4 * 5 * FFmpeg is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU Lesser General Public 7 * License as published by the Free Software Foundation; either 8 * version 2.1 of the License, or (at your option) any later version. 9 * 10 * FFmpeg is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * Lesser General Public License for more details. 14 * 15 * You should have received a copy of the GNU Lesser General Public 16 * License along with FFmpeg; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 18 */ 19 20 /** 21 * @file 22 * Public dictionary API. 23 * @deprecated 24 * AVDictionary is provided for compatibility with libav. It is both in 25 * implementation as well as API inefficient. It does not scale and is 26 * extremely slow with large dictionaries. 27 * It is recommended that new code uses our tree container from tree.c/h 28 * where applicable, which uses AVL trees to achieve O(log n) performance. 29 */ 30 31 module ffmpeg.libavutil.dict; 32 extern(C): 33 /** 34 * @addtogroup lavu_dict AVDictionary 35 * @ingroup lavu_data 36 * 37 * @brief Simple key:value store 38 * 39 * @{ 40 * Dictionaries are used for storing key:value pairs. To create 41 * an AVDictionary, simply pass an address of a NULL pointer to 42 * av_dict_set(). NULL can be used as an empty dictionary wherever 43 * a pointer to an AVDictionary is required. 44 * Use av_dict_get() to retrieve an entry or iterate over all 45 * entries and finally av_dict_free() to free the dictionary 46 * and all its contents. 47 * 48 @code 49 AVDictionary *d = NULL; // "create" an empty dictionary 50 AVDictionaryEntry *t = NULL; 51 52 av_dict_set(&d, "foo", "bar", 0); // add an entry 53 54 char *k = av_strdup("key"); // if your strings are already allocated, 55 char *v = av_strdup("value"); // you can avoid copying them like this 56 av_dict_set(&d, k, v, AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL); 57 58 while (t = av_dict_get(d, "", t, AV_DICT_IGNORE_SUFFIX)) { 59 <....> // iterate over all entries in d 60 } 61 av_dict_free(&d); 62 @endcode 63 * 64 */ 65 66 enum AV_DICT_MATCH_CASE = 1; /**< Only get an entry with exact-case key match. Only relevant in av_dict_get(). */ 67 enum AV_DICT_IGNORE_SUFFIX = 2;/**< Return first entry in a dictionary whose first part corresponds to the search key, 68 ignoring the suffix of the found key string. Only relevant in av_dict_get(). */ 69 enum AV_DICT_DONT_STRDUP_KEY = 4; /**< Take ownership of a key that's been 70 allocated with av_malloc() and children. */ 71 enum AV_DICT_DONT_STRDUP_VAL = 8; /**< Take ownership of a value that's been 72 allocated with av_malloc() and chilren. */ 73 enum AV_DICT_DONT_OVERWRITE = 16; ///< Don't overwrite existing entries. 74 enum AV_DICT_APPEND = 32; /**< If the entry already exists, append to it. Note that no 75 delimiter is added, the strings are simply concatenated. */ 76 struct AVDictionaryEntry { 77 char *key; 78 char *value; 79 } 80 81 struct AVDictionary; 82 83 /** 84 * Get a dictionary entry with matching key. 85 * 86 * The returned entry key or value must not be changed, or it will 87 * cause undefined behavior. 88 * 89 * To iterate through all the dictionary entries, you can set the matching key 90 * to the null string "" and set the AV_DICT_IGNORE_SUFFIX flag. 91 * 92 * @param prev Set to the previous matching element to find the next. 93 * If set to NULL the first matching element is returned. 94 * @param key matching key 95 * @param flags a collection of AV_DICT_* flags controlling how the entry is retrieved 96 * @return found entry or NULL in case no matching entry was found in the dictionary 97 */ 98 AVDictionaryEntry *av_dict_get(AVDictionary *m, const char *key, 99 const AVDictionaryEntry *prev, int flags); 100 101 /** 102 * Get number of entries in dictionary. 103 * 104 * @param m dictionary 105 * @return number of entries in dictionary 106 */ 107 int av_dict_count(const AVDictionary *m); 108 109 /** 110 * Set the given entry in *pm, overwriting an existing entry. 111 * 112 * Note: If AV_DICT_DONT_STRDUP_KEY or AV_DICT_DONT_STRDUP_VAL is set, 113 * these arguments will be freed on error. 114 * 115 * @param pm pointer to a pointer to a dictionary struct. If *pm is NULL 116 * a dictionary struct is allocated and put in *pm. 117 * @param key entry key to add to *pm (will be av_strduped depending on flags) 118 * @param value entry value to add to *pm (will be av_strduped depending on flags). 119 * Passing a NULL value will cause an existing entry to be deleted. 120 * @return >= 0 on success otherwise an error code <0 121 */ 122 int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags); 123 124 /** 125 * Convenience wrapper for av_dict_set that converts the value to a string 126 * and stores it. 127 * 128 * Note: If AV_DICT_DONT_STRDUP_KEY is set, key will be freed on error. 129 */ 130 int av_dict_set_int(AVDictionary **pm, const char *key, long value, int flags); 131 132 /** 133 * Parse the key/value pairs list and add the parsed entries to a dictionary. 134 * 135 * In case of failure, all the successfully set entries are stored in 136 * *pm. You may need to manually free the created dictionary. 137 * 138 * @param key_val_sep a 0-terminated list of characters used to separate 139 * key from value 140 * @param pairs_sep a 0-terminated list of characters used to separate 141 * two pairs from each other 142 * @param flags flags to use when adding to dictionary. 143 * AV_DICT_DONT_STRDUP_KEY and AV_DICT_DONT_STRDUP_VAL 144 * are ignored since the key/value tokens will always 145 * be duplicated. 146 * @return 0 on success, negative AVERROR code on failure 147 */ 148 int av_dict_parse_string(AVDictionary **pm, const char *str, 149 const char *key_val_sep, const char *pairs_sep, 150 int flags); 151 152 /** 153 * Copy entries from one AVDictionary struct into another. 154 * @param dst pointer to a pointer to a AVDictionary struct. If *dst is NULL, 155 * this function will allocate a struct for you and put it in *dst 156 * @param src pointer to source AVDictionary struct 157 * @param flags flags to use when setting entries in *dst 158 * @note metadata is read using the AV_DICT_IGNORE_SUFFIX flag 159 */ 160 void av_dict_copy(AVDictionary **dst, AVDictionary *src, int flags); 161 162 /** 163 * Free all the memory allocated for an AVDictionary struct 164 * and all keys and values. 165 */ 166 void av_dict_free(AVDictionary **m); 167 168 /** 169 * @} 170 */ 171 172 //#endif /* AVUTIL_DICT_H */