/* * * This file is part of Libav. * * Libav 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, * 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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA *//** * @file * Public dictionary API. */#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);/** * 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 */