From d9bae1a178f0f8b198ea611e874975214ad6f990 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Thu, 1 Apr 2010 20:12:15 -0400 Subject: diff: cache textconv output Running a textconv filter can take a long time. It's particularly bad for a large file which needs to be spooled to disk, but even for small files, the fork+exec overhead can add up for something like "git log -p". This patch uses the notes-cache mechanism to keep a fast cache of textconv output. Caches are stored in refs/notes/textconv/$x, where $x is the userdiff driver defined in gitattributes. Caching is enabled only if diff.$x.cachetextconv is true. In my test repo, on a commit with 45 jpg and avi files changed and a textconv to show their exif tags: [before] $ time git show >/dev/null real 0m13.724s user 0m12.057s sys 0m1.624s [after, first run] $ git config diff.mfo.cachetextconv true $ time git show >/dev/null real 0m14.252s user 0m12.197s sys 0m1.800s [after, subsequent runs] $ time git show >/dev/null real 0m0.352s user 0m0.148s sys 0m0.200s So for a slight (3.8%) cost on the first run, we achieve an almost 40x speed up on subsequent runs. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- userdiff.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'userdiff.h') diff --git a/userdiff.h b/userdiff.h index c3151594f5..942d594950 100644 --- a/userdiff.h +++ b/userdiff.h @@ -1,6 +1,8 @@ #ifndef USERDIFF_H #define USERDIFF_H +#include "notes-cache.h" + struct userdiff_funcname { const char *pattern; int cflags; @@ -13,6 +15,8 @@ struct userdiff_driver { struct userdiff_funcname funcname; const char *word_regex; const char *textconv; + struct notes_cache *textconv_cache; + int textconv_want_cache; }; int userdiff_config(const char *k, const char *v); -- cgit v1.2.3