libavutil/dict.c

   1 /*
   2  * copyright (c) 2009 Michael Niedermayer
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * Libav is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with Libav; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <string.h>
  22
  23 #include "avstring.h"
  24 #include "dict.h"
  25 #include "internal.h"
  26 #include "mem.h"
  27
  28 struct AVDictionary {
  29     int count;
  30     AVDictionaryEntry *elems;
  31 };
  32
  33 int av_dict_count(const AVDictionary *m)
  34 {
  35     return m ? m->count : 0;
  36 }
  37
  38 AVDictionaryEntry *av_dict_get(const AVDictionary *m, const char *key,
  39                                const AVDictionaryEntry *prev, int flags)
  40 {
  41     unsigned int i, j;
  42
  43     if (!m)
  44         return NULL;
  45
  46     if (prev)
  47         i = prev - m->elems + 1;
  48     else
  49         i = 0;
  50
  51     for (; i < m->count; i++) {
  52         const char *s = m->elems[i].key;
  53         if (flags & AV_DICT_MATCH_CASE)
  54             for (j = 0; s[j] == key[j] && key[j]; j++)
  55                 ;
  56         else
  57             for (j = 0; av_toupper(s[j]) == av_toupper(key[j]) && key[j]; j++)
  58                 ;
  59         if (key[j])
  60             continue;
  61         if (s[j] && !(flags & AV_DICT_IGNORE_SUFFIX))
  62             continue;
  63         return &m->elems[i];
  64     }
  65     return NULL;
  66 }
  67
  68 int av_dict_set(AVDictionary **pm, const char *key, const char *value,
  69                 int flags)
  70 {
  71     AVDictionary *m = *pm;
  72     AVDictionaryEntry *tag = av_dict_get(m, key, NULL, flags);
  73     char *oldval = NULL;
  74     int allocated = !!m;
  75
  76     if (!m)
  77         m = *pm = av_mallocz(sizeof(*m));
  78     if (!m)
  79         return AVERROR(ENOMEM);
  80
  81     if (tag) {
  82         if (flags & AV_DICT_DONT_OVERWRITE) {
  83             if (flags & AV_DICT_DONT_STRDUP_KEY) av_free(key);
  84             if (flags & AV_DICT_DONT_STRDUP_VAL) av_free(value);
  85             return 0;
  86         }
  87         if (flags & AV_DICT_APPEND)
  88             oldval = tag->value;
  89         else
  90             av_free(tag->value);
  91         av_free(tag->key);
  92         *tag = m->elems[--m->count];
  93     } else {
  94         int ret = av_reallocp_array(&m->elems,
  95                                     m->count + 1, sizeof(*m->elems));
  96         if (ret < 0) {
  97             if (allocated)
  98                 av_freep(pm);
  99
 100             return ret;
 101         }
 102     }
 103     if (value) {
 104         if (flags & AV_DICT_DONT_STRDUP_KEY)
 105             m->elems[m->count].key = key;
 106         else
 107             m->elems[m->count].key = av_strdup(key);
 108         if (flags & AV_DICT_DONT_STRDUP_VAL) {
 109             m->elems[m->count].value = value;
 110         } else if (oldval && flags & AV_DICT_APPEND) {
 111             int len = strlen(oldval) + strlen(value) + 1;
 112             if (!(oldval = av_realloc(oldval, len)))
 113                 return AVERROR(ENOMEM);
 114             av_strlcat(oldval, value, len);
 115             m->elems[m->count].value = oldval;
 116         } else
 117             m->elems[m->count].value = av_strdup(value);
 118         m->count++;
 119     }
 120     if (!m->count) {
 121         av_free(m->elems);
 122         av_freep(pm);
 123     }
 124
 125     return 0;
 126 }
 127
 128 static int parse_key_value_pair(AVDictionary **pm, const char **buf,
 129                                 const char *key_val_sep, const char *pairs_sep,
 130                                 int flags)
 131 {
 132     char *key = av_get_token(buf, key_val_sep);
 133     char *val = NULL;
 134     int ret;
 135
 136     if (key && *key && strspn(*buf, key_val_sep)) {
 137         (*buf)++;
 138         val = av_get_token(buf, pairs_sep);
 139     }
 140
 141     if (key && *key && val && *val)
 142         ret = av_dict_set(pm, key, val, flags);
 143     else
 144         ret = AVERROR(EINVAL);
 145
 146     av_freep(&key);
 147     av_freep(&val);
 148
 149     return ret;
 150 }
 151
 152 int av_dict_parse_string(AVDictionary **pm, const char *str,
 153                          const char *key_val_sep, const char *pairs_sep,
 154                          int flags)
 155 {
 156     int ret;
 157
 158     if (!str)
 159         return 0;
 160
 161     /* ignore STRDUP flags */
 162     flags &= ~(AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
 163
 164     while (*str) {
 165         if ((ret = parse_key_value_pair(pm, &str, key_val_sep, pairs_sep, flags)) < 0)
 166             return ret;
 167
 168         if (*str)
 169             str++;
 170     }
 171
 172     return 0;
 173 }
 174
 175 void av_dict_free(AVDictionary **pm)
 176 {
 177     AVDictionary *m = *pm;
 178
 179     if (m) {
 180         while (m->count--) {
 181             av_free(m->elems[m->count].key);
 182             av_free(m->elems[m->count].value);
 183         }
 184         av_free(m->elems);
 185     }
 186     av_freep(pm);
 187 }
 188
 189 int av_dict_copy(AVDictionary **dst, const AVDictionary *src, int flags)
 190 {
 191     AVDictionaryEntry *t = NULL;
 192
 193     while ((t = av_dict_get(src, "", t, AV_DICT_IGNORE_SUFFIX))) {
 194         int ret = av_dict_set(dst, t->key, t->value, flags);
 195         if (ret < 0)
 196             return ret;
 197     }
 198
 199     return 0;
 200 }