diff options
author | Anton Khirnov <anton@khirnov.net> | 2021-12-30 15:06:15 +0100 |
---|---|---|
committer | Anton Khirnov <anton@khirnov.net> | 2022-01-10 16:05:57 +0100 |
commit | 549ccea54e61e2e35b01a288466476504df03fd8 (patch) | |
tree | 65290cc07000edbc642c77c62c802bf64377bc95 /libavutil | |
parent | 5010c481d1a4bbd52655c43f5d7627d4c0a90f72 (diff) |
lavu/fifo: do not copy the whole fifo when reallocating
av_realloc() the buffer and only move the part of the ring buffer that
needs it. Also avoids allocating a temporary fifo.
Diffstat (limited to 'libavutil')
-rw-r--r-- | libavutil/fifo.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/libavutil/fifo.c b/libavutil/fifo.c index 5eee18a8c8..171c1aa9cd 100644 --- a/libavutil/fifo.c +++ b/libavutil/fifo.c @@ -27,7 +27,7 @@ AVFifoBuffer *av_fifo_alloc_array(size_t nmemb, size_t size) { AVFifoBuffer *f; - void *buffer = av_malloc_array(nmemb, size); + void *buffer = av_realloc_array(NULL, nmemb, size); if (!buffer) return NULL; f = av_mallocz(sizeof(AVFifoBuffer)); @@ -83,17 +83,31 @@ int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size) unsigned int old_size = f->end - f->buffer; if (old_size < new_size) { - int len = av_fifo_size(f); - AVFifoBuffer *f2 = av_fifo_alloc(new_size); + size_t offset_r = f->rptr - f->buffer; + size_t offset_w = f->wptr - f->buffer; + uint8_t *tmp; - if (!f2) + tmp = av_realloc(f->buffer, new_size); + if (!tmp) return AVERROR(ENOMEM); - av_fifo_generic_read(f, f2->buffer, len, NULL); - f2->wptr += len; - f2->wndx += len; - av_free(f->buffer); - *f = *f2; - av_free(f2); + + // move the data from the beginning of the ring buffer + // to the newly allocated space + // the second condition distinguishes full vs empty fifo + if (offset_w <= offset_r && av_fifo_size(f)) { + const size_t copy = FFMIN(new_size - old_size, offset_w); + memcpy(tmp + old_size, tmp, copy); + if (copy < offset_w) { + memmove(tmp, tmp + copy , offset_w - copy); + offset_w -= copy; + } else + offset_w = old_size + copy; + } + + f->buffer = tmp; + f->end = f->buffer + new_size; + f->rptr = f->buffer + offset_r; + f->wptr = f->buffer + offset_w; } return 0; } |