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, 39 insertions, 0 deletions

diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index 0745e2d053..9f92905379 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -3,6 +3,8 @@
 #include "diff.h"
 #include "revision.h"
 #include "list-objects.h"
+#include "pack.h"
+#include "pack-bitmap.h"
 #include "builtin.h"
 #include "log-tree.h"
 #include "graph.h"
@@ -257,6 +259,18 @@ static int show_bisect_vars(struct rev_list_info *info, int reaches, int all)
 	return 0;
 }
 
+static int show_object_fast(
+	const unsigned char *sha1,
+	enum object_type type,
+	int exclude,
+	uint32_t name_hash,
+	struct packed_git *found_pack,
+	off_t found_offset)
+{
+	fprintf(stdout, "%s\n", sha1_to_hex(sha1));
+	return 1;
+}
+
 int cmd_rev_list(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info revs;
@@ -265,6 +279,7 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 	int bisect_list = 0;
 	int bisect_show_vars = 0;
 	int bisect_find_all = 0;
+	int use_bitmap_index = 0;
 
 	git_config(git_default_config, NULL);
 	init_revisions(&revs, prefix);
@@ -306,6 +321,14 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 			bisect_show_vars = 1;
 			continue;
 		}
+		if (!strcmp(arg, "--use-bitmap-index")) {
+			use_bitmap_index = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--test-bitmap")) {
+			test_bitmap_walk(&revs);
+			return 0;
+		}
 		usage(rev_list_usage);
 
 	}
@@ -333,6 +356,22 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 	if (bisect_list)
 		revs.limited = 1;
 
+	if (use_bitmap_index) {
+		if (revs.count && !revs.left_right && !revs.cherry_mark) {
+			uint32_t commit_count;
+			if (!prepare_bitmap_walk(&revs)) {
+				count_bitmap_commit_list(&commit_count, NULL, NULL, NULL);
+				printf("%d\n", commit_count);
+				return 0;
+			}
+		} else if (revs.tag_objects && revs.tree_objects && revs.blob_objects) {
+			if (!prepare_bitmap_walk(&revs)) {
+				traverse_bitmap_commit_list(&show_object_fast);
+				return 0;
+			}
+		}
+	}
+
 	if (prepare_revision_walk(&revs))
 		die("revision walk setup failed");
 	if (revs.tree_objects)