Re: [PATCH] speed: reuse char instead of recreation in loop

Am Mon, 25 May 2009 22:16:02 +0200 schrieb Björn Steinbrink:

On 2009.05.25 19:44:10 +0000, Thomas Spura wrote:

quoted

Move a char and a char * outside of a for loop for speed improvements

Signed-off-by: Thomas Spura <redacted> ---
Comments?

 transport.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/transport.c b/transport.c index 17891d5..e350937 100644
--- a/transport.c
+++ b/transport.c

@@ -263,11 +263,10 @@ static int write_refs_to_temp_dir(struct strbuf

*temp_dir,
 		int refspec_nr, const char **refspec)
 {
 	int i;
+	unsigned char sha1[20];
+	char *ref;
 
 	for (i = 0; i < refspec_nr; i++) {
-		unsigned char sha1[20];
-		char *ref;
-

I doubt that this makes any difference at all.

With ints, the loop costs about 40% of speed. Without recreation, it 
should be always faster.

quoted

 		if (dwim_ref(refspec[i], strlen(refspec[i]), sha1, &ref) !
= 1)
 			return error("Could not get ref %s", refspec[i]);
 

@@ -275,8 +274,8 @@ static int write_refs_to_temp_dir(struct strbuf

*temp_dir,
 			free(ref);
 			return -1;
 		}
-		free(ref);
 	}
+	free(ref);

And this now leaks memory.

Hmm, I don't see it atm. Where do you mean?