[Qemu-devel] [v3 04/13] qemu-file: Add tow function will be used in migration

[Liang Li <liang.z.li@intel.com>]

migrate_qemu_add_compression_data() compress the data
and put it to QEMUFile. migrate_qemu_flush() put the
data in the source QEMUFile to destination QEMUFile.

The two function can help to do live migration.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
---
 include/migration/qemu-file.h |  3 +++
 qemu-file.c                   | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
index 401676b..d70fb8d 100644
--- a/include/migration/qemu-file.h
+++ b/include/migration/qemu-file.h
@@ -150,6 +150,9 @@ 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 migrate_qemu_add_compression_data(QEMUFile *f,
+        const uint8_t *p, size_t size, int level);
+int migrate_qemu_flush(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/qemu-file.c b/qemu-file.c
index f938e36..2668ad0 100644
--- a/qemu-file.c
+++ b/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"
@@ -993,3 +994,34 @@ QEMUFile *qemu_bufopen(const char *mode, QEMUSizedBuffer *input)
     }
     return s->file;
 }
+
+/* compress size bytes of data start at p with specific compression
+ * leve and store the compressed data to the buffer of f.
+ */
+
+size_t migrate_qemu_add_compression_data(QEMUFile *f,
+        const uint8_t *p, size_t size, int level)
+{
+    size_t blen = IO_BUF_SIZE - f->buf_index - sizeof(int);
+
+    if (compress2(f->buf + f->buf_index + sizeof(int), &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(int);
+}
+
+int migrate_qemu_flush(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;
+}
-- 
1.8.3.1