static void
i_stream_zlib_seek(struct istream_private *stream, uoff_t v_offset, bool mark)
{
struct zlib_istream *zstream = (struct zlib_istream *) stream;
uoff_t start_offset = stream->istream.v_offset - stream->skip;
if (v_offset < start_offset) {
/* have to seek backwards */
i_stream_zlib_reset(zstream);
start_offset = 0;
} else if (zstream->high_pos != 0) {
stream->pos = zstream->high_pos;
zstream->high_pos = 0;
}
if (v_offset <= start_offset + stream->pos) {
/* seeking backwards within what's already cached */
stream->skip = v_offset - start_offset;
stream->istream.v_offset = v_offset;
zstream->high_pos = stream->pos;
stream->pos = stream->skip;
} else {
/* read and cache forward */
ssize_t ret;
do {
size_t avail = stream->pos - stream->skip;
if (stream->istream.v_offset + avail >= v_offset) {
i_stream_skip(&stream->istream,
v_offset -
stream->istream.v_offset);
ret = -1;
break;
}
i_stream_skip(&stream->istream, avail);
} while ((ret = i_stream_read(&stream->istream)) > 0);
i_assert(ret == -1);
if (stream->istream.v_offset != v_offset) {
/* some failure, we've broken it */
if (stream->istream.stream_errno != 0) {
i_error("zlib_istream.seek(%s) failed: %s",
i_stream_get_name(&stream->istream),
strerror(stream->istream.stream_errno));
i_stream_close(&stream->istream);
} else {
/* unexpected EOF. allow it since we may just
want to check if there's anything.. */
i_assert(stream->istream.eof);
}
}
}
if (mark)
zstream->marked = TRUE;
}
static void i_stream_zlib_sync(struct istream_private *stream)
{
struct zlib_istream *zstream = (struct zlib_istream *) stream;
const struct stat *st;
if (i_stream_stat(stream->parent, FALSE, &st) < 0) {
if (memcmp(&zstream->last_parent_statbuf,
st, sizeof(*st)) == 0) {
/* a compressed file doesn't change unexpectedly,
don't clear our caches unnecessarily */
return;
}
zstream->last_parent_statbuf = *st;
}
i_stream_zlib_reset(zstream);
}
