From dce96489162b05ae3463741f7f0365ff56f0de36 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 28 Oct 2010 11:28:04 -0700 Subject: Make the default abbrev length configurable The default of 7 comes from fairly early in git development, when seven hex digits was a lot (it covers about 250+ million hash values). Back then I thought that 65k revisions was a lot (it was what we were about to hit in BK), and each revision tends to be about 5-10 new objects or so, so a million objects was a big number. These days, the kernel isn't even the largest git project, and even the kernel has about 220k revisions (_much_ bigger than the BK tree ever was) and we are approaching two million objects. At that point, seven hex digits is still unique for a lot of them, but when we're talking about just two orders of magnitude difference between number of objects and the hash size, there _will_ be collisions in truncated hash values. It's no longer even close to unrealistic - it happens all the time. We should both increase the default abbrev that was unrealistically small, _and_ add a way for people to set their own default per-project in the git config file. This is the first step to first make it configurable; the default of 7 is not raised yet. Signed-off-by: Junio C Hamano --- cache.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'cache.h') diff --git a/cache.h b/cache.h index d83d68c859..8d73d88962 100644 --- a/cache.h +++ b/cache.h @@ -540,6 +540,7 @@ extern int trust_executable_bit; extern int trust_ctime; extern int quote_path_fully; extern int has_symlinks; +extern int minimum_abbrev, default_abbrev; extern int ignore_case; extern int assume_unchanged; extern int prefer_symlink_refs; @@ -758,8 +759,8 @@ static inline unsigned int hexval(unsigned char c) } /* Convert to/from hex/sha1 representation */ -#define MINIMUM_ABBREV 4 -#define DEFAULT_ABBREV 7 +#define MINIMUM_ABBREV minimum_abbrev +#define DEFAULT_ABBREV default_abbrev struct object_context { unsigned char tree[20]; -- cgit v1.3