* Liang Li (liang.z...@intel.com) wrote:
> qemu_put_compression_data() compress the data and put it to QEMUFile.
> qemu_put_qemu_file() put the data in the buffer of source QEMUFile to
> destination QEMUFile.
>
> Signed-off-by: Liang Li <liang.z...@intel.com>
> Signed-off-by: Yang Zhang <yang.z.zh...@intel.com>
> ---
> include/migration/qemu-file.h | 3 +++
> migration/qemu-file.c | 39 +++++++++++++++++++++++++++++++++++++++
> 2 files changed, 42 insertions(+)
>
> diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
> index d843c00..2204fb9 100644
> --- a/include/migration/qemu-file.h
> +++ b/include/migration/qemu-file.h
> @@ -159,6 +159,9 @@ void qemu_put_be32(QEMUFile *f, unsigned int v);
> void qemu_put_be64(QEMUFile *f, uint64_t v);
> int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset);
> int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size);
> +size_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
> + int level);
> +int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
> /*
> * Note that you can only peek continuous bytes from where the current
> pointer
> * is; you aren't guaranteed to be able to peak to +n bytes unless you've
> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
> index edc2830..de2da2d 100644
> --- a/migration/qemu-file.c
> +++ b/migration/qemu-file.c
> @@ -21,6 +21,7 @@
> * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> * THE SOFTWARE.
> */
> +#include <zlib.h>
> #include "qemu-common.h"
> #include "qemu/iov.h"
> #include "qemu/sockets.h"
> @@ -529,3 +530,41 @@ uint64_t qemu_get_be64(QEMUFile *f)
> v |= qemu_get_be32(f);
> return v;
> }
> +
> +/* compress size bytes of data start at p with specific compression
> + * leve and store the compressed data to the buffer of f.
Typo: 'leve'
> + */
> +
> +size_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
> + int level)
> +{
> + size_t blen = IO_BUF_SIZE - f->buf_index - sizeof(int32_t);
> +
> + if (blen < compressBound(size)) {
> + return 0;
> + }
Imagine that there were only 3 bytes space in the buffer; so that
IO_BUF_SIZE - f->buf_index = 3
then you subtract sizeof(int32_t) and get -1, but size_t is unsigned
so the calculation works out as a very big number, and that comparison
fails and it carries on to call compress2.
> + if (compress2(f->buf + f->buf_index + sizeof(int32_t), &blen, (Bytef *)p,
> + size, level) != Z_OK) {
> + error_report("Compress Failed!");
> + return 0;
> + }
> + qemu_put_be32(f, blen);
> + f->buf_index += blen;
> + return blen + sizeof(int32_t);
> +}
> +
> +/* Put the data in the buffer of f_src to the buffer of f_des, and
> + * then reset the buf_index of f_src to 0.
> + */
> +
> +int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src)
> +{
> + int len = 0;
> +
> + if (f_src->buf_index > 0) {
> + len = f_src->buf_index;
> + qemu_put_buffer(f_des, f_src->buf, f_src->buf_index);
> + f_src->buf_index = 0;
> + }
> + return len;
> +}
> --
> 1.9.1
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
