qcow2: rework the cluster compression routine
The patch enables processing the image compression type defined
for the image and chooses an appropriate method for image clusters
(de)compression.
Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <
20200507082521.29210-3-dplotnikov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>