Merge branch 'jk/pack-bitmap'

Borrow the bitmap index into packfiles from JGit to speed up
enumeration of objects involved in a commit range without having to
fully traverse the history.

* jk/pack-bitmap: (26 commits)
  ewah: unconditionally ntohll ewah data
  ewah: support platforms that require aligned reads
  read-cache: use get_be32 instead of hand-rolled ntoh_l
  block-sha1: factor out get_be and put_be wrappers
  do not discard revindex when re-preparing packfiles
  pack-bitmap: implement optional name_hash cache
  t/perf: add tests for pack bitmaps
  t: add basic bitmap functionality tests
  count-objects: recognize .bitmap in garbage-checking
  repack: consider bitmaps when performing repacks
  repack: handle optional files created by pack-objects
  repack: turn exts array into array-of-struct
  repack: stop using magic number for ARRAY_SIZE(exts)
  pack-objects: implement bitmap writing
  rev-list: add bitmap mode to speed up object lists
  pack-objects: use bitmaps when packing objects
  pack-objects: split add_object_entry
  pack-bitmap: add support for bitmap indexes
  documentation: add documentation for the bitmap format
  ewah: compressed bitmap implementation
  ...

1 files changed, 2 insertions, 4 deletions

diff --git a/sha1_file.c b/sha1_file.c
index 6e8c05d108..019628add5 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -252,8 +252,6 @@ char *sha1_pack_index_name(const unsigned char *sha1)
 struct alternate_object_database *alt_odb_list;
 static struct alternate_object_database **alt_odb_tail;
 
-static int git_open_noatime(const char *name);
-
 /*
  * Prepare alternate object database registry.
  *
@@ -1232,6 +1230,7 @@ static void prepare_packed_git_one(char *objdir, int local)
 
 		if (has_extension(de->d_name, ".idx") ||
 		    has_extension(de->d_name, ".pack") ||
+		    has_extension(de->d_name, ".bitmap") ||
 		    has_extension(de->d_name, ".keep"))
 			string_list_append(&garbage, path);
 		else
@@ -1316,7 +1315,6 @@ void prepare_packed_git(void)
 
 void reprepare_packed_git(void)
 {
-	discard_revindex();
 	prepare_packed_git_run_once = 0;
 	prepare_packed_git();
 }
@@ -1393,7 +1391,7 @@ int check_sha1_signature(const unsigned char *sha1, void *map,
 	return hashcmp(sha1, real_sha1) ? -1 : 0;
 }
 
-static int git_open_noatime(const char *name)
+int git_open_noatime(const char *name)
 {
 	static int sha1_file_open_flag = O_NOATIME;