397ce3852f29f059bc3b5f3f4c339d4bcb244c15
[libav.git] / libavutil / dict.h
1 /*
2 *
3 * This file is part of Libav.
4 *
5 * Libav 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 * Libav 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 Libav; 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 */
24
25 #ifndef AVUTIL_DICT_H
26 #define AVUTIL_DICT_H
27
28 #define AV_DICT_MATCH_CASE 1
29 #define AV_DICT_IGNORE_SUFFIX 2
30 #define AV_DICT_DONT_STRDUP_KEY 4
31 #define AV_DICT_DONT_STRDUP_VAL 8
32 #define AV_DICT_DONT_OVERWRITE 16 ///< Don't overwrite existing entries.
33 #define AV_DICT_APPEND 32 /**< If the entry already exists, append to it. Note that no
34 delimiter is added, the strings are simply concatenated. */
35
36 typedef struct {
37 char *key;
38 char *value;
39 } AVDictionaryEntry;
40
41 typedef struct AVDictionary AVDictionary;
42
43 /**
44 * Get a dictionary entry with matching key.
45 *
46 * @param prev Set to the previous matching element to find the next.
47 * If set to NULL the first matching element is returned.
48 * @param flags Allows case as well as suffix-insensitive comparisons.
49 * @return Found entry or NULL, changing key or value leads to undefined behavior.
50 */
51 AVDictionaryEntry *
52 av_dict_get(AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags);
53
54 /**
55 * Set the given entry in *pm, overwriting an existing entry.
56 *
57 * @param pm pointer to a pointer to a dictionary struct. If *pm is NULL
58 * a dictionary struct is allocated and put in *pm.
59 * @param key entry key to add to *pm (will be av_strduped depending on flags)
60 * @param value entry value to add to *pm (will be av_strduped depending on flags).
61 * Passing a NULL value will cause an existing tag to be deleted.
62 * @return >= 0 on success otherwise an error code <0
63 */
64 int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags);
65
66 /**
67 * Copy entries from one AVDictionary struct into another.
68 * @param dst pointer to a pointer to a AVDictionary struct. If *dst is NULL,
69 * this function will allocate a struct for you and put it in *dst
70 * @param src pointer to source AVDictionary struct
71 * @param flags flags to use when setting entries in *dst
72 * @note metadata is read using the AV_DICT_IGNORE_SUFFIX flag
73 */
74 void av_dict_copy(AVDictionary **dst, AVDictionary *src, int flags);
75
76 /**
77 * Free all the memory allocated for an AVDictionary struct.
78 */
79 void av_dict_free(AVDictionary **m);
80
81 #endif // AVUTIL_DICT_H