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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 | #ifndef AVUTIL_DICT_H | |
32 | #define AVUTIL_DICT_H | |
33 | ||
34 | #include <stdint.h> | |
35 | ||
36 | #include "version.h" | |
37 | ||
38 | /** | |
39 | * @addtogroup lavu_dict AVDictionary | |
40 | * @ingroup lavu_data | |
41 | * | |
42 | * @brief Simple key:value store | |
43 | * | |
44 | * @{ | |
45 | * Dictionaries are used for storing key:value pairs. To create | |
46 | * an AVDictionary, simply pass an address of a NULL pointer to | |
47 | * av_dict_set(). NULL can be used as an empty dictionary wherever | |
48 | * a pointer to an AVDictionary is required. | |
49 | * Use av_dict_get() to retrieve an entry or iterate over all | |
50 | * entries and finally av_dict_free() to free the dictionary | |
51 | * and all its contents. | |
52 | * | |
53 | @code | |
54 | AVDictionary *d = NULL; // "create" an empty dictionary | |
55 | AVDictionaryEntry *t = NULL; | |
56 | ||
57 | av_dict_set(&d, "foo", "bar", 0); // add an entry | |
58 | ||
59 | char *k = av_strdup("key"); // if your strings are already allocated, | |
60 | char *v = av_strdup("value"); // you can avoid copying them like this | |
61 | av_dict_set(&d, k, v, AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL); | |
62 | ||
63 | while (t = av_dict_get(d, "", t, AV_DICT_IGNORE_SUFFIX)) { | |
64 | <....> // iterate over all entries in d | |
65 | } | |
66 | av_dict_free(&d); | |
67 | @endcode | |
68 | * | |
69 | */ | |
70 | ||
71 | #define AV_DICT_MATCH_CASE 1 /**< Only get an entry with exact-case key match. Only relevant in av_dict_get(). */ | |
72 | #define AV_DICT_IGNORE_SUFFIX 2 /**< Return first entry in a dictionary whose first part corresponds to the search key, | |
73 | ignoring the suffix of the found key string. Only relevant in av_dict_get(). */ | |
74 | #define AV_DICT_DONT_STRDUP_KEY 4 /**< Take ownership of a key that's been | |
75 | allocated with av_malloc() or another memory allocation function. */ | |
76 | #define AV_DICT_DONT_STRDUP_VAL 8 /**< Take ownership of a value that's been | |
77 | allocated with av_malloc() or another memory allocation function. */ | |
78 | #define AV_DICT_DONT_OVERWRITE 16 ///< Don't overwrite existing entries. | |
79 | #define AV_DICT_APPEND 32 /**< If the entry already exists, append to it. Note that no | |
80 | delimiter is added, the strings are simply concatenated. */ | |
81 | ||
82 | typedef struct AVDictionaryEntry { | |
83 | char *key; | |
84 | char *value; | |
85 | } AVDictionaryEntry; | |
86 | ||
87 | typedef struct AVDictionary AVDictionary; | |
88 | ||
89 | /** | |
90 | * Get a dictionary entry with matching key. | |
91 | * | |
92 | * The returned entry key or value must not be changed, or it will | |
93 | * cause undefined behavior. | |
94 | * | |
95 | * To iterate through all the dictionary entries, you can set the matching key | |
96 | * to the null string "" and set the AV_DICT_IGNORE_SUFFIX flag. | |
97 | * | |
98 | * @param prev Set to the previous matching element to find the next. | |
99 | * If set to NULL the first matching element is returned. | |
100 | * @param key matching key | |
101 | * @param flags a collection of AV_DICT_* flags controlling how the entry is retrieved | |
102 | * @return found entry or NULL in case no matching entry was found in the dictionary | |
103 | */ | |
104 | AVDictionaryEntry *av_dict_get(FF_CONST_AVUTIL53 AVDictionary *m, const char *key, | |
105 | const AVDictionaryEntry *prev, int flags); | |
106 | ||
107 | /** | |
108 | * Get number of entries in dictionary. | |
109 | * | |
110 | * @param m dictionary | |
111 | * @return number of entries in dictionary | |
112 | */ | |
113 | int av_dict_count(const AVDictionary *m); | |
114 | ||
115 | /** | |
116 | * Set the given entry in *pm, overwriting an existing entry. | |
117 | * | |
118 | * Note: If AV_DICT_DONT_STRDUP_KEY or AV_DICT_DONT_STRDUP_VAL is set, | |
119 | * these arguments will be freed on error. | |
120 | * | |
121 | * @param pm pointer to a pointer to a dictionary struct. If *pm is NULL | |
122 | * a dictionary struct is allocated and put in *pm. | |
123 | * @param key entry key to add to *pm (will be av_strduped depending on flags) | |
124 | * @param value entry value to add to *pm (will be av_strduped depending on flags). | |
125 | * Passing a NULL value will cause an existing entry to be deleted. | |
126 | * @return >= 0 on success otherwise an error code <0 | |
127 | */ | |
128 | int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags); | |
129 | ||
130 | /** | |
131 | * Convenience wrapper for av_dict_set that converts the value to a string | |
132 | * and stores it. | |
133 | * | |
134 | * Note: If AV_DICT_DONT_STRDUP_KEY is set, key will be freed on error. | |
135 | */ | |
136 | int av_dict_set_int(AVDictionary **pm, const char *key, int64_t value, int flags); | |
137 | ||
138 | /** | |
139 | * Parse the key/value pairs list and add the parsed entries to a dictionary. | |
140 | * | |
141 | * In case of failure, all the successfully set entries are stored in | |
142 | * *pm. You may need to manually free the created dictionary. | |
143 | * | |
144 | * @param key_val_sep a 0-terminated list of characters used to separate | |
145 | * key from value | |
146 | * @param pairs_sep a 0-terminated list of characters used to separate | |
147 | * two pairs from each other | |
148 | * @param flags flags to use when adding to dictionary. | |
149 | * AV_DICT_DONT_STRDUP_KEY and AV_DICT_DONT_STRDUP_VAL | |
150 | * are ignored since the key/value tokens will always | |
151 | * be duplicated. | |
152 | * @return 0 on success, negative AVERROR code on failure | |
153 | */ | |
154 | int av_dict_parse_string(AVDictionary **pm, const char *str, | |
155 | const char *key_val_sep, const char *pairs_sep, | |
156 | int flags); | |
157 | ||
158 | /** | |
159 | * Copy entries from one AVDictionary struct into another. | |
160 | * @param dst pointer to a pointer to a AVDictionary struct. If *dst is NULL, | |
161 | * this function will allocate a struct for you and put it in *dst | |
162 | * @param src pointer to source AVDictionary struct | |
163 | * @param flags flags to use when setting entries in *dst | |
164 | * @note metadata is read using the AV_DICT_IGNORE_SUFFIX flag | |
165 | */ | |
166 | void av_dict_copy(AVDictionary **dst, FF_CONST_AVUTIL53 AVDictionary *src, int flags); | |
167 | ||
168 | /** | |
169 | * Free all the memory allocated for an AVDictionary struct | |
170 | * and all keys and values. | |
171 | */ | |
172 | void av_dict_free(AVDictionary **m); | |
173 | ||
174 | /** | |
175 | * @} | |
176 | */ | |
177 | ||
178 | #endif /* AVUTIL_DICT_H */ |