avutil/mem: Add av_fast_mallocz()

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

doc/APIchanges

@@ -15,6 +15,9 @@ libavutil:     2015-08-28
 
 API changes, most recent first:
 
+2015-11-18 - lavu 55.7.100 - mem.h
+  Add av_fast_mallocz()
+
 2015-10-29 - lavc 57.12.100 / 57.8.0 - avcodec.h
   xxxxxx - Deprecate av_free_packet(). Use av_packet_unref() as replacement,
            it resets the packet in a more consistent way.

libavutil/mem.c

@@ -501,3 +501,7 @@ void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size)
     ff_fast_malloc(ptr, size, min_size, 0);
 }
 
+void av_fast_mallocz(void *ptr, unsigned int *size, size_t min_size)
+{
+    ff_fast_malloc(ptr, size, min_size, 1);
+}

libavutil/mem.h

@@ -384,6 +384,21 @@ void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size);
  */
 void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size);
 
+/**
+ * Allocate a buffer, reusing the given one if large enough.
+ *
+ * All newly allocated space is initially cleared
+ * Contrary to av_fast_realloc the current buffer contents might not be
+ * preserved and on error the old buffer is freed, thus no special
+ * handling to avoid memleaks is necessary.
+ *
+ * @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer
+ * @param size size of the buffer *ptr points to
+ * @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and
+ *                 *size 0 if an error occurred.
+ */
+void av_fast_mallocz(void *ptr, unsigned int *size, size_t min_size);
+
 /**
  * @}
  */

libavutil/version.h

@@ -56,7 +56,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  55
-#define LIBAVUTIL_VERSION_MINOR   6
+#define LIBAVUTIL_VERSION_MINOR   7
 #define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \