Consistently use size_t for sizes.
Unlike av_fifo_grow(), which addds to the currently used size, this
function adds to the allocated size.
No new function is provided for a generic realloc, since the current code
only supports increasing the FIFO size.
---
doc/APIchanges | 3 ++-
libavutil/fifo.c | 61 +++++++++++++++++++++++++++---------------------
libavutil/fifo.h | 14 +++++++++++
3 files changed, 50 insertions(+), 28 deletions(-)
diff --git a/doc/APIchanges b/doc/APIchanges
index 9400c5147a..98eae55719 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -18,7 +18,8 @@ API changes, most recent first:
Add av_fifo_alloc2(), which allows setting a FIFO element size.
Operations on FIFOs created with this function on these elements
rather than bytes.
- Add av_fifo_elem_size(), av_fifo_can_read(), av_fifo_can_write().
+ Add av_fifo_elem_size(), av_fifo_can_read(), av_fifo_can_write(),
+ av_fifo_grow2().
2022-01-xx - xxxxxxxxxx - lavu fifo.h
Access to all AVFifoBuffer members is deprecated. The struct will
diff --git a/libavutil/fifo.c b/libavutil/fifo.c
index 8cde2c20e1..28d6d1b2e6 100644
--- a/libavutil/fifo.c
+++ b/libavutil/fifo.c
@@ -150,41 +150,48 @@ int av_fifo_space(const AVFifoBuffer *f)
return av_fifo_can_write(f);
}
-int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size)
+int av_fifo_grow2(AVFifoBuffer *f, size_t inc)
{
FifoBuffer *fb = (FifoBuffer*)f;
+ uint8_t *tmp;
- if (new_size > FIFO_SIZE_MAX)
+ if (inc > FIFO_SIZE_MAX - fb->nb_elems)
return AVERROR(EINVAL);
- if (fb->nb_elems < new_size) {
- uint8_t *tmp;
-
- tmp = av_realloc_array(f->buffer, new_size, fb->elem_size);
- if (!tmp)
- return AVERROR(ENOMEM);
-
- // move the data from the beginning of the ring buffer
- // to the newly allocated space
- if (fb->offset_w <= fb->offset_r && !fb->is_empty) {
- const size_t copy = FFMIN(new_size - fb->nb_elems, fb->offset_w);
- memcpy(tmp + fb->nb_elems * fb->elem_size, tmp, copy *
fb->elem_size);
- if (copy < fb->offset_w) {
- memmove(tmp, tmp + copy * fb->elem_size,
- (fb->offset_w - copy) * fb->elem_size);
- fb->offset_w -= copy;
- } else
- fb->offset_w = fb->nb_elems + copy;
- }
+ tmp = av_realloc_array(f->buffer, fb->nb_elems + inc, fb->elem_size);
+ if (!tmp)
+ return AVERROR(ENOMEM);
+
+ // move the data from the beginning of the ring buffer
+ // to the newly allocated space
+ if (fb->offset_w <= fb->offset_r && !fb->is_empty) {
+ const size_t copy = FFMIN(inc, fb->offset_w);
+ memcpy(tmp + fb->nb_elems * fb->elem_size, tmp, copy * fb->elem_size);
+ if (copy < fb->offset_w) {
+ memmove(tmp, tmp + copy * fb->elem_size,
+ (fb->offset_w - copy) * fb->elem_size);
+ fb->offset_w -= copy;
+ } else
+ fb->offset_w = fb->nb_elems + copy;
+ }
+
+ f->buffer = tmp;
+ fb->nb_elems += inc;
- f->buffer = tmp;
#if FF_API_FIFO_PUBLIC
- f->end = f->buffer + new_size;
- f->rptr = f->buffer + fb->offset_r * fb->elem_size;
- f->wptr = f->buffer + fb->offset_w * fb->elem_size;
+ f->end = f->buffer + fb->nb_elems * fb->elem_size;
+ f->rptr = f->buffer + fb->offset_r * fb->elem_size;
+ f->wptr = f->buffer + fb->offset_w * fb->elem_size;
#endif
- fb->nb_elems = new_size;
- }
+
+ return 0;
+}
+
+int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size)
+{
+ FifoBuffer *fb = (FifoBuffer*)f;
+ if (fb->nb_elems < new_size)
+ return av_fifo_grow2(f, new_size - fb->nb_elems);
return 0;
}
diff --git a/libavutil/fifo.h b/libavutil/fifo.h
index 9e78082b3b..375d0d133b 100644
--- a/libavutil/fifo.h
+++ b/libavutil/fifo.h
@@ -129,6 +129,20 @@ size_t av_fifo_can_read(const AVFifoBuffer *f);
*/
size_t av_fifo_can_write(const AVFifoBuffer *f);
+/**
+ * Enlarge an AVFifoBuffer.
+ *
+ * On success, the FIFO will be large enough to hold exactly
+ * inc + av_fifo_can_read() + av_fifo_can_write()
+ * elements. In case of failure, the old FIFO is kept unchanged.
+ *
+ * @param f AVFifoBuffer to resize
+ * @param inc number of elements to allocate for, in addition to the current
+ * allocated size
+ * @return a non-negative number on success, a negative error code on failure
+ */
+int av_fifo_grow2(AVFifoBuffer *f, size_t inc);
+
/**
* Feed data at specific position from an AVFifoBuffer to a user-supplied
callback.
* Similar as av_fifo_gereric_read but without discarding data.
--
2.33.0
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