Make zlib compression level configurable, and change default.

With the change in default, "git add ." on kernel dir is about
twice as fast as before, with only minimal (0.5%) change in
object size. The speed difference is even more noticeable
when committing large files, which is now up to 8 times faster.

The configurability is through setting core.compression = [-1..9]
which maps to the zlib constants; -1 is the default, 0 is no
compression, and 1..9 are various speed/size tradeoffs, 9
being slowest.

Signed-off-by: Joachim B Haga (cjhaga@fys.uio.no)
Acked-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/cache.h b/cache.h
index 87199396a..84770bf67 100644
--- a/cache.h
+++ b/cache.h
@@ -183,6 +183,7 @@ extern int log_all_ref_updates;
 extern int warn_ambiguous_refs;
 extern int shared_repository;
 extern const char *apply_default_whitespace;
+extern int zlib_compression_level;
 
 #define GIT_REPO_VERSION 0
 extern int repository_format_version;