[FFmpeg-devel] [PATCH 1/2] avutil/dict: Add av_dict_iterate

[Marvin Scholz]

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.
---
 libavutil/dict.c    | 19 +++++++++++++++++++
 libavutil/dict.h    | 27 +++++++++++++++++++++++++++
 libavutil/version.h |  2 +-
 3 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/libavutil/dict.c b/libavutil/dict.c
index 14ad780a79..2f690a5b8e 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;
 }
 
+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)
 {
diff --git a/libavutil/dict.h b/libavutil/dict.h
index 0d1afc6c64..b42b3f07fd 100644
--- a/libavutil/dict.h
+++ b/libavutil/dict.h
@@ -32,6 +32,8 @@
 
 #include <stdint.h>
 
+#include "attributes.h"
+
 /**
  * @addtogroup lavu_dict AVDictionary
  * @ingroup lavu_data
@@ -101,6 +103,31 @@ typedef struct AVDictionary AVDictionary;
 AVDictionaryEntry *av_dict_get(const AVDictionary *m, const char *key,
                                const AVDictionaryEntry *prev, int flags);
 
+/**
+ * Iterate over a dictionary
+ *
+ * Iterates through all entries in the dictionary.
+ * 
+ * @warning The returned AVDictionaryEntry key/value must not be changed.
+ *
+ * @param m     The dictionary to iterate over
+ * @param prev  Pointer to the previous AVDictionaryEntry, NULL initially
+ * 
+ * @retval AVDictionaryEntry* The next element in the dictionary
+ * @retval NULL               No more elements in the dictionary
+ *
+ * Typical usage:
+ * @code
+ * AVDictionaryEntry *e = NULL;
+ * while (e = av_dict_iterate(m, e)) {
+ *     // ...
+ * }
+ * @endcode
+ */
+av_warn_unused_result
+AVDictionaryEntry *av_dict_iterate(const AVDictionary *m,
+                                   const AVDictionaryEntry *prev);
+
 /**
  * Get number of entries in dictionary.
  *
diff --git a/libavutil/version.h b/libavutil/version.h
index 0585fa7b80..6fd07ed2a4 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -80,7 +80,7 @@
 
 #define LIBAVUTIL_VERSION_MAJOR  57
 #define LIBAVUTIL_VERSION_MINOR  36
-#define LIBAVUTIL_VERSION_MICRO 102
+#define LIBAVUTIL_VERSION_MICRO 103
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
                                                LIBAVUTIL_VERSION_MINOR, \
-- 
2.37.0 (Apple Git-136)