Searched hist:ebf7bba0 (Results 1 – 2 of 2) sorted by relevance
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H A D | qcow.c | ebf7bba0 Thu Jul 14 16:59:25 GMT 2016 Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> qcow2: do not allocate extra memory
There are no needs to allocate more than one cluster, as we set avail_out for deflate to one cluster.
Zlib docs (http://www.zlib.net/manual.html) says: "deflate compresses as much data as possible, and stops when the input buffer becomes empty or the output buffer becomes full."
So, deflate will not write more than avail_out to output buffer. If there is not enough space in output buffer for compressed data (it may be larger than input data) deflate just returns Z_OK. (if all data is compressed and written to output buffer deflate returns Z_STREAM_END).
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 1468515565-81313-1-git-send-email-vsementsov@virtuozzo.com Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
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H A D | qcow2.c | ebf7bba0 Thu Jul 14 16:59:25 GMT 2016 Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> qcow2: do not allocate extra memory
There are no needs to allocate more than one cluster, as we set avail_out for deflate to one cluster.
Zlib docs (http://www.zlib.net/manual.html) says: "deflate compresses as much data as possible, and stops when the input buffer becomes empty or the output buffer becomes full."
So, deflate will not write more than avail_out to output buffer. If there is not enough space in output buffer for compressed data (it may be larger than input data) deflate just returns Z_OK. (if all data is compressed and written to output buffer deflate returns Z_STREAM_END).
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 1468515565-81313-1-git-send-email-vsementsov@virtuozzo.com Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
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