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[Qemu-devel] [PULL 10/41] qcow2: refactor decompress_buffer
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 10/41] qcow2: refactor decompress_buffer |
Date: |
Wed, 12 Dec 2018 14:27:04 +0100 |
From: Vladimir Sementsov-Ogievskiy <address@hidden>
- make it look more like a pair of qcow2_compress - rename the function
and its parameters
- drop extra out_len variable, check filling of output buffer by strm
structure itself
- fix code style
- add some documentation
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
Reviewed-by: Alberto Garcia <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
block/qcow2.c | 56 ++++++++++++++++++++++++++++++++-------------------
1 file changed, 35 insertions(+), 21 deletions(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index d4d141c495..ac9bb3a225 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3762,32 +3762,46 @@ static ssize_t qcow2_compress(void *dest, size_t
dest_size,
return ret;
}
-static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
- const uint8_t *buf, int buf_size)
+/*
+ * qcow2_decompress()
+ *
+ * Decompress some data (not more than @src_size bytes) to produce exactly
+ * @dest_size bytes.
+ *
+ * @dest - destination buffer, @dest_size bytes
+ * @src - source buffer, @src_size bytes
+ *
+ * Returns: 0 on success
+ * -1 on fail
+ */
+static ssize_t qcow2_decompress(void *dest, size_t dest_size,
+ const void *src, size_t src_size)
{
- z_stream strm1, *strm = &strm1;
- int ret, out_len;
-
- memset(strm, 0, sizeof(*strm));
+ int ret = 0;
+ z_stream strm;
- strm->next_in = (uint8_t *)buf;
- strm->avail_in = buf_size;
- strm->next_out = out_buf;
- strm->avail_out = out_buf_size;
+ memset(&strm, 0, sizeof(strm));
+ strm.avail_in = src_size;
+ strm.next_in = (void *) src;
+ strm.avail_out = dest_size;
+ strm.next_out = dest;
- ret = inflateInit2(strm, -12);
+ ret = inflateInit2(&strm, -12);
if (ret != Z_OK) {
return -1;
}
- ret = inflate(strm, Z_FINISH);
- out_len = strm->next_out - out_buf;
- if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
- out_len != out_buf_size) {
- inflateEnd(strm);
- return -1;
+
+ ret = inflate(&strm, Z_FINISH);
+ if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) || strm.avail_out != 0) {
+ /* We approve Z_BUF_ERROR because we need @dest buffer to be filled,
but
+ * @src buffer may be processed partly (because in qcow2 we know size
of
+ * compressed data with precision of one sector) */
+ ret = -1;
}
- inflateEnd(strm);
- return 0;
+
+ inflateEnd(&strm);
+
+ return ret;
}
#define MAX_COMPRESS_THREADS 4
@@ -3977,8 +3991,8 @@ int qcow2_decompress_cluster(BlockDriverState *bs,
uint64_t cluster_offset)
if (ret < 0) {
return ret;
}
- if (decompress_buffer(s->cluster_cache, s->cluster_size,
- s->cluster_data + sector_offset, csize) < 0) {
+ if (qcow2_decompress(s->cluster_cache, s->cluster_size,
+ s->cluster_data + sector_offset, csize) < 0) {
return -EIO;
}
s->cluster_cache_offset = coffset;
--
2.19.2
- [Qemu-devel] [PULL 00/41] Block layer patches, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 01/41] block: adding lzfse decompressing support as a module., Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 02/41] configure: adding support to lzfse library., Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 03/41] dmg: including dmg-lzfse module inside dmg block driver., Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 05/41] block/replication: drop extra synchronization, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 04/41] dmg: exchanging hardcoded dmg UDIF block types to enum., Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 09/41] qcow2: move decompression from qcow2-cluster.c to qcow2.c, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 06/41] block/backup: drop unused synchronization interface, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 08/41] qcow2: make more generic interface for qcow2_compress, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 10/41] qcow2: refactor decompress_buffer,
Kevin Wolf <=
- [Qemu-devel] [PULL 11/41] qcow2: use byte-based read in qcow2_decompress_cluster, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 07/41] qcow2: use Z_OK instead of 0 for deflateInit2 return code check, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 13/41] qcow2: do decompression in threads, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 12/41] qcow2: aio support for compressed cluster read, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 16/41] file-posix: Avoid aio_worker() for QEMU_AIO_TRUNCATE, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 14/41] file-posix: Reorganise RawPosixAIOData, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 15/41] file-posix: Factor out raw_thread_pool_submit(), Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 18/41] file-posix: Avoid aio_worker() for QEMU_AIO_WRITE_ZEROES, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 17/41] file-posix: Avoid aio_worker() for QEMU_AIO_COPY_RANGE, Kevin Wolf, 2018/12/12
- [Qemu-devel] [PULL 21/41] file-posix: Move read/write operation logic out of aio_worker(), Kevin Wolf, 2018/12/12