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 module ffmpeg.libavutil.dict; 31 32 @nogc nothrow extern(C): 33 34 /** 35 * @addtogroup lavu_dict AVDictionary 36 * @ingroup lavu_data 37 * 38 * @brief Simple key:value store 39 * 40 * @{ 41 * Dictionaries are used for storing key:value pairs. To create 42 * an AVDictionary, simply pass an address of a NULL pointer to 43 * av_dict_set(). NULL can be used as an empty dictionary wherever 44 * a pointer to an AVDictionary is required. 45 * Use av_dict_get() to retrieve an entry or iterate over all 46 * entries and finally av_dict_free() to free the dictionary 47 * and all its contents. 48 * 49 @code 50 AVDictionary *d = NULL; // "create" an empty dictionary 51 AVDictionaryEntry *t = NULL; 52 53 av_dict_set(&d, "foo", "bar", 0); // add an entry 54 55 char *k = av_strdup("key"); // if your strings are already allocated, 56 char *v = av_strdup("value"); // you can avoid copying them like this 57 av_dict_set(&d, k, v, AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL); 58 59 while (t = av_dict_get(d, "", t, AV_DICT_IGNORE_SUFFIX)) { 60 <....> // iterate over all entries in d 61 } 62 av_dict_free(&d); 63 @endcode 64 * 65 */ 66 67 enum AV_DICT_MATCH_CASE = 1; /**< Only get an entry with exact-case key match. Only relevant in av_dict_get(). */ 68 enum AV_DICT_IGNORE_SUFFIX = 2;/**< Return first entry in a dictionary whose first part corresponds to the search key, 69 ignoring the suffix of the found key string. Only relevant in av_dict_get(). */ 70 enum AV_DICT_DONT_STRDUP_KEY = 4; /**< Take ownership of a key that's been 71 allocated with av_malloc() and children. */ 72 enum AV_DICT_DONT_STRDUP_VAL = 8; /**< Take ownership of a value that's been 73 allocated with av_malloc() and chilren. */ 74 enum AV_DICT_DONT_OVERWRITE = 16; ///< Don't overwrite existing entries. 75 enum AV_DICT_APPEND = 32; /**< If the entry already exists, append to it. Note that no 76 delimiter is added, the strings are simply concatenated. */ 77 78 struct AVDictionaryEntry { 79 char *key; 80 char *value; 81 } 82 83 struct AVDictionary; 84 85 /** 86 * Get a dictionary entry with matching key. 87 * 88 * The returned entry key or value must not be changed, or it will 89 * cause undefined behavior. 90 * 91 * To iterate through all the dictionary entries, you can set the matching key 92 * to the null string "" and set the AV_DICT_IGNORE_SUFFIX flag. 93 * 94 * @param prev Set to the previous matching element to find the next. 95 * If set to NULL the first matching element is returned. 96 * @param key matching key 97 * @param flags a collection of AV_DICT_* flags controlling how the entry is retrieved 98 * @return found entry or NULL in case no matching entry was found in the dictionary 99 */ 100 AVDictionaryEntry *av_dict_get(AVDictionary *m, const char *key, 101 const AVDictionaryEntry *prev, int flags); 102 103 /** 104 * Get number of entries in dictionary. 105 * 106 * @param m dictionary 107 * @return number of entries in dictionary 108 */ 109 int av_dict_count(const AVDictionary *m); 110 111 /** 112 * Set the given entry in *pm, overwriting an existing entry. 113 * 114 * Note: If AV_DICT_DONT_STRDUP_KEY or AV_DICT_DONT_STRDUP_VAL is set, 115 * these arguments will be freed on error. 116 * 117 * @param pm pointer to a pointer to a dictionary struct. If *pm is NULL 118 * a dictionary struct is allocated and put in *pm. 119 * @param key entry key to add to *pm (will be av_strduped depending on flags) 120 * @param value entry value to add to *pm (will be av_strduped depending on flags). 121 * Passing a NULL value will cause an existing entry to be deleted. 122 * @return >= 0 on success otherwise an error code <0 123 */ 124 int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags); 125 126 /** 127 * Convenience wrapper for av_dict_set that converts the value to a string 128 * and stores it. 129 * 130 * Note: If AV_DICT_DONT_STRDUP_KEY is set, key will be freed on error. 131 */ 132 int av_dict_set_int(AVDictionary **pm, const char *key, long value, int flags); 133 134 /** 135 * Parse the key/value pairs list and add the parsed entries to a dictionary. 136 * 137 * In case of failure, all the successfully set entries are stored in 138 * *pm. You may need to manually free the created dictionary. 139 * 140 * @param key_val_sep a 0-terminated list of characters used to separate 141 * key from value 142 * @param pairs_sep a 0-terminated list of characters used to separate 143 * two pairs from each other 144 * @param flags flags to use when adding to dictionary. 145 * AV_DICT_DONT_STRDUP_KEY and AV_DICT_DONT_STRDUP_VAL 146 * are ignored since the key/value tokens will always 147 * be duplicated. 148 * @return 0 on success, negative AVERROR code on failure 149 */ 150 int av_dict_parse_string(AVDictionary **pm, const char *str, 151 const char *key_val_sep, const char *pairs_sep, 152 int flags); 153 154 /** 155 * Copy entries from one AVDictionary struct into another. 156 * @param dst pointer to a pointer to a AVDictionary struct. If *dst is NULL, 157 * this function will allocate a struct for you and put it in *dst 158 * @param src pointer to source AVDictionary struct 159 * @param flags flags to use when setting entries in *dst 160 * @note metadata is read using the AV_DICT_IGNORE_SUFFIX flag 161 * @return 0 on success, negative AVERROR code on failure. If dst was allocated 162 * by this function, callers should free the associated memory. 163 */ 164 void av_dict_copy(AVDictionary **dst, AVDictionary *src, int flags); 165 166 /** 167 * Free all the memory allocated for an AVDictionary struct 168 * and all keys and values. 169 */ 170 void av_dict_free(AVDictionary **m); 171 172 /** 173 * Get dictionary entries as a string. 174 * 175 * Create a string containing dictionary's entries. 176 * Such string may be passed back to av_dict_parse_string(). 177 * @note String is escaped with backslashes ('\'). 178 * 179 * @param[in] m dictionary 180 * @param[out] buffer Pointer to buffer that will be allocated with string containg entries. 181 * Buffer must be freed by the caller when is no longer needed. 182 * @param[in] key_val_sep character used to separate key from value 183 * @param[in] pairs_sep character used to separate two pairs from each other 184 * @return >= 0 on success, negative on error 185 * @warning Separators cannot be neither '\\' nor '\0'. They also cannot be the same. 186 */ 187 int av_dict_get_string(AVDictionary *m, char **buffer, 188 const char key_val_sep, const char pairs_sep); 189 190 /** 191 * @} 192 */ 193 194 //#endif /* AVUTIL_DICT_H */