text: /*
   * copyright (c) 2009 Michael Niedermayer
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg 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.
   *
   * FFmpeg 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 FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include <string.h>
  
  #include "avstring.h"
  #include "dict.h"
  #include "internal.h"
  #include "mem.h"
  
  struct AVDictionary {
      int count;
      AVDictionaryEntry *elems;
  };
  
  int av_dict_count(const AVDictionary *m)
  {
      return m ? m->count : 0;
  }
  
  AVDictionaryEntry *av_dict_get(FF_CONST_AVUTIL53 AVDictionary *m, const char *key,
                                 const AVDictionaryEntry *prev, int flags)
  {
      unsigned int i, j;
  
      if (!m)
          return NULL;
  
      if (prev)
          i = prev - m->elems + 1;
      else
          i = 0;
  
      for (; i < m->count; i++) {
          const char *s = m->elems[i].key;
          if (flags & AV_DICT_MATCH_CASE)
              for (j = 0; s[j] == key[j] && key[j]; j++)
                  ;
          else
              for (j = 0; av_toupper(s[j]) == av_toupper(key[j]) && key[j]; j++)
                  ;
          if (key[j])
              continue;
          if (s[j] && !(flags & AV_DICT_IGNORE_SUFFIX))
              continue;
          return &m->elems[i];
      }
      return NULL;
  }
  
  int av_dict_set(AVDictionary **pm, const char *key, const char *value,
                  int flags)
  {
      AVDictionary *m = *pm;
      AVDictionaryEntry *tag = av_dict_get(m, key, NULL, flags);
      char *oldval = NULL;
  
      if (!m)
          m = *pm = av_mallocz(sizeof(*m));
  
      if (tag) {
          if (flags & AV_DICT_DONT_OVERWRITE) {
              if (flags & AV_DICT_DONT_STRDUP_KEY) av_free(key);
              if (flags & AV_DICT_DONT_STRDUP_VAL) av_free(value);
              return 0;
          }
          if (flags & AV_DICT_APPEND)
              oldval = tag->value;
          else
              av_free(tag->value);
          av_free(tag->key);
          *tag = m->elems[--m->count];
      } else {
          AVDictionaryEntry *tmp = av_realloc(m->elems,
                                              (m->count + 1) * sizeof(*m->elems));
          if (tmp)
              m->elems = tmp;
          else
              return AVERROR(ENOMEM);
      }
      if (value) {
          if (flags & AV_DICT_DONT_STRDUP_KEY)
              m->elems[m->count].key = (char*)(intptr_t)key;
          else
              m->elems[m->count].key = av_strdup(key);
          if (flags & AV_DICT_DONT_STRDUP_VAL) {
              m->elems[m->count].value = (char*)(intptr_t)value;
          } else if (oldval && flags & AV_DICT_APPEND) {
              int len = strlen(oldval) + strlen(value) + 1;
              char *newval = av_mallocz(len);
              if (!newval)
                  return AVERROR(ENOMEM);
              av_strlcat(newval, oldval, len);
              av_freep(&oldval);
              av_strlcat(newval, value, len);
              m->elems[m->count].value = newval;
          } else
              m->elems[m->count].value = av_strdup(value);
          m->count++;
      }
      if (!m->count) {
          av_free(m->elems);
          av_freep(pm);
      }
  
      return 0;
  }
  
  static int parse_key_value_pair(AVDictionary **pm, const char **buf,
                                  const char *key_val_sep, const char *pairs_sep,
                                  int flags)
  {
      char *key = av_get_token(buf, key_val_sep);
      char *val = NULL;
      int ret;
  
      if (key && *key && strspn(*buf, key_val_sep)) {
          (*buf)++;
          val = av_get_token(buf, pairs_sep);
      }
  
      if (key && *key && val && *val)
          ret = av_dict_set(pm, key, val, flags);
      else
          ret = AVERROR(EINVAL);
  
      av_freep(&key);
      av_freep(&val);
  
      return ret;
  }
  
  int av_dict_parse_string(AVDictionary **pm, const char *str,
                           const char *key_val_sep, const char *pairs_sep,
                           int flags)
  {
      int ret;
  
      if (!str)
          return 0;
  
      /* ignore STRDUP flags */
      flags &= ~(AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
  
      while (*str) {
          if ((ret = parse_key_value_pair(pm, &str, key_val_sep, pairs_sep, flags)) < 0)
              return ret;
  
          if (*str)
              str++;
      }
  
      return 0;
  }
  
  void av_dict_free(AVDictionary **pm)
  {
      AVDictionary *m = *pm;
  
      if (m) {
          while (m->count--) {
              av_free(m->elems[m->count].key);
              av_free(m->elems[m->count].value);
          }
          av_free(m->elems);
      }
      av_freep(pm);
  }
  
  void av_dict_copy(AVDictionary **dst, FF_CONST_AVUTIL53 AVDictionary *src, int flags)
  {
      AVDictionaryEntry *t = NULL;
  
      while ((t = av_dict_get(src, "", t, AV_DICT_IGNORE_SUFFIX)))
          av_dict_set(dst, t->key, t->value, flags);
  }
  