avutil/dict: Add av_dict_iterate

This is a more explicit iteration API rather than using the "magic"
av_dict_get(d, "", t, AV_DICT_IGNORE_SUFFIX) which is not really
trivial to grasp what it does when casually reading through code.

Signed-off-by: Anton Khirnov <anton@khirnov.net>

1 files changed, 19 insertions, 0 deletions

diff --git a/libavutil/dict.c b/libavutil/dict.c
index 14ad780a79..ee059d712c 100644
--- a/libavutil/dict.c
+++ b/libavutil/dict.c
@@ -20,6 +20,7 @@
 
 #include <string.h>
 
+#include "avassert.h"
 #include "avstring.h"
 #include "dict.h"
 #include "dict_internal.h"
@@ -38,6 +39,24 @@ int av_dict_count(const AVDictionary *m)
     return m ? m->count : 0;
 }
 
+const AVDictionaryEntry *av_dict_iterate(const AVDictionary *m,
+                                         const AVDictionaryEntry *prev)
+{
+    int i = 0;
+
+    if (!m)
+        return NULL;
+
+    if (prev)
+        i = prev - m->elems + 1;
+
+    av_assert2(i >= 0);
+    if (i >= m->count)
+        return NULL;
+
+    return &m->elems[i];
+}
+
 AVDictionaryEntry *av_dict_get(const AVDictionary *m, const char *key,
                                const AVDictionaryEntry *prev, int flags)
 {