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[Qemu-devel] [PATCH v3 2/2] xbzrle: check 8 bytes at a time after an con
From: |
arei.gonglei |
Subject: |
[Qemu-devel] [PATCH v3 2/2] xbzrle: check 8 bytes at a time after an concurrency scene |
Date: |
Tue, 1 Apr 2014 20:45:26 +0800 |
From: ChenLiang <address@hidden>
The logic of old code is correct. But Checking byte by byte will
consume time after an concurrency scene.
Reported-by: Dr. David Alan Gilbert <address@hidden>
Signed-off-by: ChenLiang <address@hidden>
Signed-off-by: Gonglei <address@hidden>
---
xbzrle.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/xbzrle.c b/xbzrle.c
index 92cccd7..9d67309 100644
--- a/xbzrle.c
+++ b/xbzrle.c
@@ -51,16 +51,24 @@ int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t
*new_buf, int slen,
/* word at a time for speed */
if (!res) {
- while (i < slen &&
- (*(long *)(old_buf + i)) == (*(long *)(new_buf + i))) {
- i += sizeof(long);
- zrun_len += sizeof(long);
- }
-
- /* go over the rest */
- while (i < slen && old_buf[i] == new_buf[i]) {
- zrun_len++;
- i++;
+ while (i < slen) {
+ if ((*(long *)(old_buf + i)) == (*(long *)(new_buf + i))) {
+ i += sizeof(long);
+ zrun_len += sizeof(long);
+ } else {
+ /* go over the rest */
+ for (j = 0; j < sizeof(long); j++) {
+ if (old_buf[i] == new_buf[i]) {
+ i++;
+ zrun_len++;
+ } else {
+ break;
+ }
+ }
+ if (j != sizeof(long)) {
+ break;
+ }
+ }
}
}
--
1.7.12.4