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[PATCH 2/4] diffcore-pickaxe: micro-optimize has_match() function

From
Junio C Hamano <gitster@pobox.com>
Date
Feb 26, 2009, 06:52 UTC
Message-ID
<2dbd5fcdfd9da5f8fbbab5b0928b361d8119c97b.1235629933.git.gitster@pobox.com>
In-Reply-To
<cover.1235629933.git.gitster@pobox.com>

When we are looking at an event that creates (or removes) a path, we only need to see if the created (or removed) blob has an instance of the needle we are looking for. There is no need to count, once we know there is one.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 diffcore-pickaxe.c |   13 +++++++++----
 1 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
index d27e725..007b39c 100644
--- a/diffcore-pickaxe.c
+++ b/diffcore-pickaxe.c
@@ -5,7 +5,8 @@
 #include "diff.h"
 #include "diffcore.h"
 
-static unsigned int count_match(struct diff_filespec *one,
+static unsigned int count_match(int one_or_more,
+				struct diff_filespec *one,
 				const char *needle, unsigned long len,
 				regex_t *regexp)
 {
@@ -30,6 +31,8 @@ static unsigned int count_match(struct diff_filespec *one,
 			data += regmatch.rm_so;
 			if (*data) data++;
 			cnt++;
+			if (one_or_more)
+				break;
 		}
 
 	} else { /* Classic exact string match */
@@ -41,6 +44,8 @@ static unsigned int count_match(struct diff_filespec *one,
 			if (!memcmp(needle, data + offset, len)) {
 				offset += len - 1;
 				cnt++;
+				if (one_or_more)
+					break;
 			}
 		}
 	}
@@ -52,15 +57,15 @@ static int has_match(struct diff_filespec *one,
 		     const char *needle, unsigned long len,
 		     regex_t *regexp)
 {
-	return !!count_match(one, needle, len, regexp);
+	return count_match(1, one, needle, len, regexp);
 }
 
 static int has_different_matches(struct diff_filepair *p,
 				 const char *needle, unsigned long len,
 				 regex_t *regexp)
 {
-	return (count_match(p->one, needle, len, regexp)
-		!= count_match(p->two, needle, len, regexp));
+	return (count_match(0, p->one, needle, len, regexp)
+		!= count_match(0, p->two, needle, len, regexp));
 
 }
 
-- 
1.6.2.rc2.91.gf9a36
Previous: René ScharfeNext: Junio C Hamano
Message 4 of 23 in “Pickaxe search clean-up and optimization”
  1. 0/4 Pickaxe search clean-up and optimizationJunio C Hamano, Feb 26, 2009
  2. 1/4 diffcore-pickaxe: refactor diffcore_pickaxe()Junio C Hamano, Feb 26, 2009
  3. René ScharfeFeb 27, 2009
  4. 2/4 diffcore-pickaxe: micro-optimize has_match() functionJunio C Hamano, Feb 26, 2009
  5. 3/4 diffcore-pickaxe: further refactor count_match()Junio C Hamano, Feb 26, 2009
  6. Kjetil BarvikFeb 26, 2009
  7. René ScharfeFeb 28, 2009
  8. Junio C HamanoFeb 28, 2009
  9. Junio C HamanoFeb 28, 2009
  10. René ScharfeFeb 28, 2009
  11. Junio C HamanoFeb 28, 2009
  12. René ScharfeFeb 28, 2009
  13. import memmem() with linear complexity from GnulibRené Scharfe, Feb 28, 2009
  14. Mike HommeyFeb 28, 2009
  15. Jeff KingMar 1, 2009
  16. René ScharfeMar 1, 2009
  17. René ScharfeMar 1, 2009
  18. Junio C HamanoMar 1, 2009
  19. René ScharfeMar 1, 2009
  20. 4/4 diffcore-pickaxe: optimize by trimming common initial and trailing partsJunio C Hamano, Feb 26, 2009
  21. Junio C HamanoFeb 26, 2009
  22. 1/2 diffcore-pickaxe: use memmem()René Scharfe, Mar 2, 2009
  23. 2/2 optimize compat/ memmem()René Scharfe, Mar 2, 2009

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