Match in words instead of byte granularity.
Signed-off-by: Gao Xiang <[email protected]>
---
lib/dedupe.c | 48 ++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 42 insertions(+), 6 deletions(-)
diff --git a/lib/dedupe.c b/lib/dedupe.c
index 7f6e56f..84c323b 100644
--- a/lib/dedupe.c
+++ b/lib/dedupe.c
@@ -8,6 +8,45 @@
#include "rolling_hash.h"
#include "sha256.h"
+inline unsigned long erofs_memcmp2(const u8 *s1, const u8 *s2,
+ unsigned long sz)
+{
+ unsigned int n = sz;
+
+ if (sz >= sizeof(long) && ((long)s1 & (sizeof(long) - 1)) ==
+ ((long)s2 & (sizeof(long) - 1))) {
+ const unsigned long *a1, *a2;
+
+ while ((long)s1 & (sizeof(long) - 1)) {
+ if (*s1 != *s2)
+ break;
+ ++s1;
+ ++s2;
+ --sz;
+ }
+
+ a1 = (const unsigned long *)s1;
+ a2 = (const unsigned long *)s2;
+ while (sz >= sizeof(long)) {
+ if (*a1 != *a2)
+ break;
+ ++a1;
+ ++a2;
+ sz -= sizeof(long);
+ }
+ s1 = (const u8 *)a1;
+ s2 = (const u8 *)a2;
+ }
+ while (sz) {
+ if (*s1 != *s2)
+ break;
+ ++s1;
+ ++s2;
+ --sz;
+ }
+ return n - sz;
+}
+
static unsigned int window_size, rollinghash_rm;
static struct rb_tree *dedupe_tree, *dedupe_subtree;
@@ -72,12 +111,9 @@ int z_erofs_dedupe_match(struct z_erofs_dedupe_ctx *ctx)
if (memcmp(sha256, e->prefix_sha256, sizeof(sha256)))
continue;
- extra = 0;
- while (cur + window_size + extra < ctx->end &&
- window_size + extra < e->original_length &&
- e->extra_data[extra] == cur[window_size + extra])
- ++extra;
-
+ extra = min_t(unsigned int, ctx->end - cur - window_size,
+ e->original_length - window_size);
+ extra = erofs_memcmp2(cur + window_size, e->extra_data, extra);
if (window_size + extra <= ctx->cur - cur)
continue;
ctx->cur = cur;
--
2.24.4
