X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;ds=sidebyside;f=libavutil%2Fmem.h;h=179e12f32f7734287dc71d571b441543266ab608;hb=c5db8b4d09762f5228eaf3c3a0017657ed27d866;hp=8fdf5b3a4d820c28603b5e2c400728237de50aac;hpb=d912e449b655797407a75527380c566955b71a8e;p=ffmpeg

diff --git a/libavutil/mem.h b/libavutil/mem.h
index 8fdf5b3a4d8..179e12f32f7 100644
--- a/libavutil/mem.h
+++ b/libavutil/mem.h
@@ -27,6 +27,7 @@
 #define AVUTIL_MEM_H
 
 #include "attributes.h"
+#include "error.h"
 #include "avutil.h"
 
 #if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 1110 || defined(__SUNPRO_C)
@@ -86,6 +87,16 @@ void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1);
  */
 void *av_realloc(void *ptr, size_t size) av_alloc_size(2);
 
+/**
+ * Allocate or reallocate a block of memory.
+ * This function does the same thing as av_realloc, except:
+ * - It takes two arguments and checks the result of the multiplication for
+ *   integer overflow.
+ * - It frees the input block in case of failure, thus avoiding the memory
+ *   leak with the classic "buf = realloc(buf); if (!buf) return -1;".
+ */
+void *av_realloc_f(void *ptr, size_t nelem, size_t elsize);
+
 /**
  * Free a memory block which has been allocated with av_malloc(z)() or
  * av_realloc().
@@ -106,6 +117,18 @@ void av_free(void *ptr);
  */
 void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1);
 
+/**
+ * Allocate a block of nmemb * size bytes with alignment suitable for all
+ * memory accesses (including vectors if available on the CPU) and
+ * zero all the bytes of the block.
+ * The allocation will fail if nmemb * size is greater than or equal
+ * to INT_MAX.
+ * @param nmemb
+ * @param size
+ * @return Pointer to the allocated block, NULL if it cannot be allocated.
+ */
+void *av_calloc(size_t nmemb, size_t size) av_malloc_attrib;
+
 /**
  * Duplicate the string s.
  * @param s string to be duplicated
@@ -132,4 +155,19 @@ void av_freep(void *ptr);
  */
 void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem);
 
+/**
+ * Multiply two size_t values checking for overflow.
+ * @return  0 if success, AVERROR(EINVAL) if overflow.
+ */
+static inline int av_size_mult(size_t a, size_t b, size_t *r)
+{
+    size_t t = a * b;
+    /* Hack inspired from glibc: only try the division if nelem and elsize
+     * are both greater than sqrt(SIZE_MAX). */
+    if ((a | b) >= ((size_t)1 << (sizeof(size_t) * 4)) && a && t / a != b)
+        return AVERROR(EINVAL);
+    *r = t;
+    return 0;
+}
+
 #endif /* AVUTIL_MEM_H */