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); }