1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
/*
*
* 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);
/**
* Parse the key/value pairs list and add to a dictionary.
*
* @param key_val_sep a 0-terminated list of characters used to separate
* key from value
* @param pairs_sep a 0-terminated list of characters used to separate
* two pairs from each other
* @param flags flags to use when adding to dictionary.
* AV_DICT_DONT_STRDUP_KEY and AV_DICT_DONT_STRDUP_VAL
* are ignored since the key/value tokens will always
* be duplicated.
* @return 0 on success, negative AVERROR code on failure
*/
int av_dict_parse_string(AVDictionary **pm, const char *str,
const char *key_val_sep, const char *pairs_sep,
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 */
|
