static ssize_t read_cb(struct archive *arch, void *priv, const void **buffer)
{
struct mp_archive_volume *vol = priv;
if (!volume_seek(vol))
return -1;
int res = stream_read_partial(vol->src, vol->mpa->buffer,
sizeof(vol->mpa->buffer));
*buffer = vol->mpa->buffer;
return MPMAX(res, 0);
}
// Runs in the cache thread.
// Returns true if reading was attempted, and the mutex was shortly unlocked.
static bool cache_fill(struct priv *s)
{
int64_t read = s->read_filepos;
int len = 0;
// drop cache contents only if seeking backward or too much fwd.
// This is also done for on-disk files, since it loses the backseek cache.
// That in turn can cause major bandwidth increase and performance
// issues with e.g. mov or badly interleaved files
if (read < s->min_filepos || read > s->max_filepos + s->seek_limit) {
MP_VERBOSE(s, "Dropping cache at pos %"PRId64", "
"cached range: %"PRId64"-%"PRId64".\n", read,
s->min_filepos, s->max_filepos);
cache_drop_contents(s);
}
if (stream_tell(s->stream) != s->max_filepos && s->seekable) {
MP_VERBOSE(s, "Seeking underlying stream: %"PRId64" -> %"PRId64"\n",
stream_tell(s->stream), s->max_filepos);
stream_seek(s->stream, s->max_filepos);
if (stream_tell(s->stream) != s->max_filepos)
goto done;
}
if (mp_cancel_test(s->cache->cancel))
goto done;
// number of buffer bytes which should be preserved in backwards direction
int64_t back = MPCLAMP(read - s->min_filepos, 0, s->back_size);
// limit maximum readahead so that the backbuffer space is reserved, even
// if the backbuffer is not used. limit it to ensure that we don't stall the
// network when starting a file, or we wouldn't download new data until we
// get new free space again. (unless everything fits in the cache.)
if (s->stream_size > s->buffer_size)
back = MPMAX(back, s->back_size);
// number of buffer bytes that are valid and can be read
int64_t newb = FFMAX(s->max_filepos - read, 0);
// max. number of bytes that can be written (starting from max_filepos)
int64_t space = s->buffer_size - (newb + back);
// offset into the buffer that maps to max_filepos
int64_t pos = s->max_filepos - s->offset;
if (pos >= s->buffer_size)
pos -= s->buffer_size; // wrap-around
if (space < FILL_LIMIT) {
s->idle = true;
s->reads++; // don't stuck main thread
return false;
}
// limit to end of buffer (without wrapping)
if (pos + space >= s->buffer_size)
space = s->buffer_size - pos;
// limit read size (or else would block and read the entire buffer in 1 call)
space = FFMIN(space, s->stream->read_chunk);
// back+newb+space <= buffer_size
int64_t back2 = s->buffer_size - (space + newb); // max back size
if (s->min_filepos < (read - back2))
s->min_filepos = read - back2;
// The read call might take a long time and block, so drop the lock.
pthread_mutex_unlock(&s->mutex);
len = stream_read_partial(s->stream, &s->buffer[pos], space);
pthread_mutex_lock(&s->mutex);
// Do this after reading a block, because at least libdvdnav updates the
// stream position only after actually reading something after a seek.
if (s->start_pts == MP_NOPTS_VALUE) {
double pts;
if (stream_control(s->stream, STREAM_CTRL_GET_CURRENT_TIME, &pts) > 0)
s->start_pts = pts;
}
s->max_filepos += len;
if (pos + len == s->buffer_size)
s->offset += s->buffer_size; // wrap...
done:
s->eof = len <= 0;
s->idle = s->eof;
s->reads++;
if (s->eof) {
s->eof_pos = stream_tell(s->stream);
MP_TRACE(s, "EOF reached.\n");
}
pthread_cond_signal(&s->wakeup);
return true;
}
// Runs in the cache thread.
// Returns true if reading was attempted, and the mutex was shortly unlocked.
static bool cache_fill(struct priv *s)
{
int64_t read = s->read_filepos;
int len;
if (read < s->min_filepos || read > s->max_filepos) {
// seek...
mp_msg(MSGT_CACHE, MSGL_DBG2,
"Out of boundaries... seeking to 0x%" PRIX64 " \n", read);
// drop cache contents only if seeking backward or too much fwd.
// This is also done for on-disk files, since it loses the backseek cache.
// That in turn can cause major bandwidth increase and performance
// issues with e.g. mov or badly interleaved files
if (read < s->min_filepos || read >= s->max_filepos + s->seek_limit) {
mp_msg(MSGT_CACHE, MSGL_V, "Dropping cache at pos %"PRId64", "
"cached range: %"PRId64"-%"PRId64".\n", read,
s->min_filepos, s->max_filepos);
cache_drop_contents(s);
stream_seek(s->stream, read);
}
}
// number of buffer bytes which should be preserved in backwards direction
int64_t back = mp_clipi64(read - s->min_filepos, 0, s->back_size);
// number of buffer bytes that are valid and can be read
int64_t newb = FFMAX(s->max_filepos - read, 0);
// max. number of bytes that can be written (starting from max_filepos)
int64_t space = s->buffer_size - (newb + back);
// offset into the buffer that maps to max_filepos
int pos = s->max_filepos - s->offset;
if (pos >= s->buffer_size)
pos -= s->buffer_size; // wrap-around
if (space < s->fill_limit) {
s->idle = true;
return false;
}
// limit to end of buffer (without wrapping)
if (pos + space >= s->buffer_size)
space = s->buffer_size - pos;
// limit read size (or else would block and read the entire buffer in 1 call)
space = FFMIN(space, s->stream->read_chunk);
// back+newb+space <= buffer_size
int64_t back2 = s->buffer_size - (space + newb); // max back size
if (s->min_filepos < (read - back2))
s->min_filepos = read - back2;
// The read call might take a long time and block, so drop the lock.
pthread_mutex_unlock(&s->mutex);
len = stream_read_partial(s->stream, &s->buffer[pos], space);
pthread_mutex_lock(&s->mutex);
double pts;
if (stream_control(s->stream, STREAM_CTRL_GET_CURRENT_TIME, &pts) <= 0)
pts = MP_NOPTS_VALUE;
for (int64_t b_pos = pos; b_pos < pos + len + BYTE_META_CHUNK_SIZE;
b_pos += BYTE_META_CHUNK_SIZE)
{
s->bm[b_pos / BYTE_META_CHUNK_SIZE] = (struct byte_meta){.stream_pts = pts};
}
s->max_filepos += len;
if (pos + len == s->buffer_size)
s->offset += s->buffer_size; // wrap...
s->eof = len > 0 ? 0 : 1;
s->idle = s->eof;
pthread_cond_signal(&s->wakeup);
return true;
}
