diff options
Diffstat (limited to 'stream/stream.c')
| -rw-r--r-- | stream/stream.c | 37 |
1 files changed, 21 insertions, 16 deletions
diff --git a/stream/stream.c b/stream/stream.c index 0a026713f6..0d72aa082f 100644 --- a/stream/stream.c +++ b/stream/stream.c @@ -264,24 +264,28 @@ static int ring_copy(struct stream *s, void *dst, int len, int pos) // Does nothing if the size is adequate. Calling this with 0 ensures it uses the // default buffer size if possible. // The caller must check whether enough data was really allocated. -// Returns false if buffer allocation failed. -static bool stream_resize_buffer(struct stream *s, uint32_t new) +// keep: keep at least [buf_end-keep, buf_end] (used for assert()s only) +// new: new total size of buffer +// returns: false if buffer allocation failed, true if reallocated or size ok +static bool stream_resize_buffer(struct stream *s, int keep, int new) { - // Keep all valid buffer. - int old_used_len = s->buf_end - s->buf_start; - int old_pos = s->buf_cur - s->buf_start; - new = MPMAX(new, old_used_len); + assert(keep >= s->buf_end - s->buf_cur); + assert(keep <= new); - // This much is always required. new = MPMAX(new, s->requested_buffer_size); - new = MPMIN(new, STREAM_MAX_BUFFER_SIZE); new = mp_round_next_power_of_2(new); + assert(keep <= new); // can't fail (if old buffer size was valid) + if (new == s->buffer_mask + 1) return true; - MP_DBG(s, "resize stream to %d bytes\n", new); + int old_pos = s->buf_cur - s->buf_start; + int old_used_len = s->buf_end - s->buf_start; + int skip = old_used_len > new ? old_used_len - new : 0; + + MP_DBG(s, "resize stream to %d bytes, drop %d bytes\n", new, skip); void *nbuf = ta_alloc_size(s, new); if (!nbuf) @@ -289,11 +293,12 @@ static bool stream_resize_buffer(struct stream *s, uint32_t new) int new_len = 0; if (s->buffer) - new_len = ring_copy(s, nbuf, new, s->buf_start); - assert(new_len == old_used_len); - assert(old_pos <= old_used_len); + new_len = ring_copy(s, nbuf, new, s->buf_start + skip); + assert(new_len == old_used_len - skip); + assert(old_pos >= skip); // "keep" too low + assert(old_pos - skip <= new_len); s->buf_start = 0; - s->buf_cur = old_pos; + s->buf_cur = old_pos - skip; s->buf_end = new_len; ta_free(s->buffer); @@ -379,7 +384,7 @@ static int stream_create_instance(const stream_info_t *sinfo, return r; } - if (!stream_resize_buffer(s, 0)) { + if (!stream_resize_buffer(s, 0, 0)) { free_stream(s); return STREAM_ERROR; } @@ -506,7 +511,7 @@ static bool stream_read_more(struct stream *s, int forward) // Keep guaranteed seek-back. int buf_old = MPMIN(s->buf_cur - s->buf_start, s->requested_buffer_size / 2); - if (!stream_resize_buffer(s, buf_old + forward)) + if (!stream_resize_buffer(s, buf_old + forward_avail, buf_old + forward)) return false; int buf_alloc = s->buffer_mask + 1; @@ -648,7 +653,7 @@ void stream_drop_buffers(stream_t *s) s->pos = stream_tell(s); s->buf_start = s->buf_cur = s->buf_end = 0; s->eof = 0; - stream_resize_buffer(s, 0); + stream_resize_buffer(s, 0, 0); } // Seek function bypassing the local stream buffer. |