basic type mechanism working

1 files changed, 142 insertions, 14 deletions

diff --git a/ffmpeg/libavutil/mem.h b/ffmpeg/libavutil/mem.h
index ced9453..703ce81 100644
--- a/ffmpeg/libavutil/mem.h
+++ b/ffmpeg/libavutil/mem.h
@@ -83,8 +83,7 @@
 void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1);
 
 /**
- * Helper function to allocate a block of size * nmemb bytes with
- * using av_malloc()
+ * Allocate a block of size * nmemb bytes with av_malloc().
  * @param nmemb Number of elements
  * @param size Size of the single element
  * @return Pointer to the allocated block, NULL if the block cannot
@@ -93,7 +92,7 @@ void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1);
  */
 av_alloc_size(1, 2) static inline void *av_malloc_array(size_t nmemb, size_t size)
 {
-    if (size <= 0 || nmemb >= INT_MAX / size)
+    if (!size || nmemb >= INT_MAX / size)
         return NULL;
     return av_malloc(nmemb * size);
 }
@@ -103,11 +102,17 @@ av_alloc_size(1, 2) static inline void *av_malloc_array(size_t nmemb, size_t siz
  * If ptr is NULL and size > 0, allocate a new block. If
  * size is zero, free the memory block pointed to by ptr.
  * @param ptr Pointer to a memory block already allocated with
- * av_malloc(z)() or av_realloc() or NULL.
- * @param size Size in bytes for the memory block to be allocated or
+ * av_realloc() or NULL.
+ * @param size Size in bytes of the memory block to be allocated or
  * reallocated.
- * @return Pointer to a newly reallocated block or NULL if the block
+ * @return Pointer to a newly-reallocated block or NULL if the block
  * cannot be reallocated or the function is used to free the memory block.
+ * @warning Pointers originating from the av_malloc() family of functions must
+ *          not be passed to av_realloc(). The former can be implemented using
+ *          memalign() (or other functions), and there is no guarantee that
+ *          pointers from such functions can be passed to realloc() at all.
+ *          The situation is undefined according to POSIX and may crash with
+ *          some libc implementations.
  * @see av_fast_realloc()
  */
 void *av_realloc(void *ptr, size_t size) av_alloc_size(2);
@@ -123,6 +128,63 @@ void *av_realloc(void *ptr, size_t size) av_alloc_size(2);
 void *av_realloc_f(void *ptr, size_t nelem, size_t elsize);
 
 /**
+ * Allocate or reallocate a block of memory.
+ * If *ptr is NULL and size > 0, allocate a new block. If
+ * size is zero, free the memory block pointed to by ptr.
+ * @param   ptr Pointer to a pointer to a memory block already allocated
+ *          with av_realloc(), or pointer to a pointer to NULL.
+ *          The pointer is updated on success, or freed on failure.
+ * @param   size Size in bytes for the memory block to be allocated or
+ *          reallocated
+ * @return  Zero on success, an AVERROR error code on failure.
+ * @warning Pointers originating from the av_malloc() family of functions must
+ *          not be passed to av_reallocp(). The former can be implemented using
+ *          memalign() (or other functions), and there is no guarantee that
+ *          pointers from such functions can be passed to realloc() at all.
+ *          The situation is undefined according to POSIX and may crash with
+ *          some libc implementations.
+ */
+int av_reallocp(void *ptr, size_t size);
+
+/**
+ * Allocate or reallocate an array.
+ * If ptr is NULL and nmemb > 0, allocate a new block. If
+ * nmemb is zero, free the memory block pointed to by ptr.
+ * @param ptr Pointer to a memory block already allocated with
+ * av_realloc() or NULL.
+ * @param nmemb Number of elements
+ * @param size Size of the single element
+ * @return Pointer to a newly-reallocated block or NULL if the block
+ * cannot be reallocated or the function is used to free the memory block.
+ * @warning Pointers originating from the av_malloc() family of functions must
+ *          not be passed to av_realloc(). The former can be implemented using
+ *          memalign() (or other functions), and there is no guarantee that
+ *          pointers from such functions can be passed to realloc() at all.
+ *          The situation is undefined according to POSIX and may crash with
+ *          some libc implementations.
+ */
+av_alloc_size(2, 3) void *av_realloc_array(void *ptr, size_t nmemb, size_t size);
+
+/**
+ * Allocate or reallocate an array through a pointer to a pointer.
+ * If *ptr is NULL and nmemb > 0, allocate a new block. If
+ * nmemb is zero, free the memory block pointed to by ptr.
+ * @param ptr Pointer to a pointer to a memory block already allocated
+ * with av_realloc(), or pointer to a pointer to NULL.
+ * The pointer is updated on success, or freed on failure.
+ * @param nmemb Number of elements
+ * @param size Size of the single element
+ * @return Zero on success, an AVERROR error code on failure.
+ * @warning Pointers originating from the av_malloc() family of functions must
+ *          not be passed to av_realloc(). The former can be implemented using
+ *          memalign() (or other functions), and there is no guarantee that
+ *          pointers from such functions can be passed to realloc() at all.
+ *          The situation is undefined according to POSIX and may crash with
+ *          some libc implementations.
+ */
+av_alloc_size(2, 3) int av_reallocp_array(void *ptr, size_t nmemb, size_t size);
+
+/**
  * Free a memory block which has been allocated with av_malloc(z)() or
  * av_realloc().
  * @param ptr Pointer to the memory block which should be freed.
@@ -155,8 +217,7 @@ void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1);
 void *av_calloc(size_t nmemb, size_t size) av_malloc_attrib;
 
 /**
- * Helper function to allocate a block of size * nmemb bytes with
- * using av_mallocz()
+ * Allocate a block of size * nmemb bytes with av_mallocz().
  * @param nmemb Number of elements
  * @param size Size of the single element
  * @return Pointer to the allocated block, NULL if the block cannot
@@ -166,7 +227,7 @@ void *av_calloc(size_t nmemb, size_t size) av_malloc_attrib;
  */
 av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t size)
 {
-    if (size <= 0 || nmemb >= INT_MAX / size)
+    if (!size || nmemb >= INT_MAX / size)
         return NULL;
     return av_mallocz(nmemb * size);
 }
@@ -174,12 +235,20 @@ av_alloc_size(1, 2) static inline void *av_mallocz_array(size_t nmemb, size_t si
 /**
  * Duplicate the string s.
  * @param s string to be duplicated
- * @return Pointer to a newly allocated string containing a
+ * @return Pointer to a newly-allocated string containing a
  * copy of s or NULL if the string cannot be allocated.
  */
 char *av_strdup(const char *s) av_malloc_attrib;
 
 /**
+ * Duplicate the buffer p.
+ * @param p buffer to be duplicated
+ * @return Pointer to a newly allocated buffer containing a
+ * copy of p or NULL if the buffer cannot be allocated.
+ */
+void *av_memdup(const void *p, size_t size);
+
+/**
  * Free a memory block which has been allocated with av_malloc(z)() or
  * av_realloc() and set the pointer pointing to it to NULL.
  * @param ptr Pointer to the pointer to the memory block which should
@@ -191,13 +260,51 @@ void av_freep(void *ptr);
 /**
  * Add an element to a dynamic array.
  *
- * @param tab_ptr Pointer to the array.
- * @param nb_ptr  Pointer to the number of elements in the array.
- * @param elem    Element to be added.
+ * The array to grow is supposed to be an array of pointers to
+ * structures, and the element to add must be a pointer to an already
+ * allocated structure.
+ *
+ * The array is reallocated when its size reaches powers of 2.
+ * Therefore, the amortized cost of adding an element is constant.
+ *
+ * In case of success, the pointer to the array is updated in order to
+ * point to the new grown array, and the number pointed to by nb_ptr
+ * is incremented.
+ * In case of failure, the array is freed, *tab_ptr is set to NULL and
+ * *nb_ptr is set to 0.
+ *
+ * @param tab_ptr pointer to the array to grow
+ * @param nb_ptr  pointer to the number of elements in the array
+ * @param elem    element to add
+ * @see av_dynarray2_add()
  */
 void av_dynarray_add(void *tab_ptr, int *nb_ptr, void *elem);
 
 /**
+ * Add an element of size elem_size to a dynamic array.
+ *
+ * The array is reallocated when its number of elements reaches powers of 2.
+ * Therefore, the amortized cost of adding an element is constant.
+ *
+ * In case of success, the pointer to the array is updated in order to
+ * point to the new grown array, and the number pointed to by nb_ptr
+ * is incremented.
+ * In case of failure, the array is freed, *tab_ptr is set to NULL and
+ * *nb_ptr is set to 0.
+ *
+ * @param tab_ptr   pointer to the array to grow
+ * @param nb_ptr    pointer to the number of elements in the array
+ * @param elem_size size in bytes of the elements in the array
+ * @param elem_data pointer to the data of the element to add. If NULL, the space of
+ *                  the new added element is not filled.
+ * @return          pointer to the data of the element to copy in the new allocated space.
+ *                  If NULL, the new allocated space is left uninitialized."
+ * @see av_dynarray_add()
+ */
+void *av_dynarray2_add(void **tab_ptr, int *nb_ptr, size_t elem_size,
+                       const uint8_t *elem_data);
+
+/**
  * Multiply two size_t values checking for overflow.
  * @return  0 if success, AVERROR(EINVAL) if overflow.
  */
@@ -218,7 +325,7 @@ static inline int av_size_mult(size_t a, size_t b, size_t *r)
 void av_max_alloc(size_t max);
 
 /**
- * @brief deliberately overlapping memcpy implementation
+ * deliberately overlapping memcpy implementation
  * @param dst destination buffer
  * @param back how many bytes back we start (the initial size of the overlapping window), must be > 0
  * @param cnt number of bytes to copy, must be >= 0
@@ -229,6 +336,27 @@ void av_max_alloc(size_t max);
 void av_memcpy_backptr(uint8_t *dst, int back, int cnt);
 
 /**
+ * Reallocate the given block if it is not large enough, otherwise do nothing.
+ *
+ * @see av_realloc
+ */
+void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size);
+
+/**
+ * Allocate a buffer, reusing the given one if large enough.
+ *
+ * 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_malloc(void *ptr, unsigned int *size, size_t min_size);
+
+/**
  * @}
  */