[PATCH 3/4] repack: add --sparse and pass to pack-objects

[Nathaniel Filardo]

The sparse connectivity algorithm saves a whole lot of time when there
are UNINTERESTING trees around.
---
 Documentation/git-repack.txt |  4 ++++
 builtin/repack.c             | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/Documentation/git-repack.txt b/Documentation/git-repack.txt
index aa0cc8bd44..836d81457a 100644
--- a/Documentation/git-repack.txt
+++ b/Documentation/git-repack.txt
@@ -165,6 +165,10 @@ depth is 4095.
        Pass the `--delta-islands` option to `git-pack-objects`, see
        linkgit:git-pack-objects[1].
 
+--sparse::
+       Pass the `--sparse` option to `git-pack-objects`; see
+       linkgit:git-pack-objects[1].
+
 Configuration
 -------------
 
diff --git a/builtin/repack.c b/builtin/repack.c
index 67f8978043..71e715b594 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -17,6 +17,7 @@ static int pack_kept_objects = -1;
 static int write_bitmaps;
 static int use_delta_islands;
 static char *packdir, *packtmp;
+static int sparse;
 
 static const char *const git_repack_usage[] = {
        N_("git repack [<options>]"),
@@ -48,6 +49,10 @@ static int repack_config(const char *var, const char *value, 
void *cb)
                use_delta_islands = git_config_bool(var, value);
                return 0;
        }
+       if (!strcmp(var, "pack.usesparse")) {
+               sparse = git_config_bool(var, value);
+               return 0;
+       }
        return git_default_config(var, value, cb);
 }
 
@@ -326,11 +331,14 @@ int cmd_repack(int argc, const char **argv, const char 
*prefix)
                                N_("maximum size of each packfile")),
                OPT_BOOL(0, "pack-kept-objects", &pack_kept_objects,
                                N_("repack objects in packs marked with 
.keep")),
+               OPT_BOOL(0, "sparse", &sparse,
+                        N_("use the sparse reachability algorithm")),
                OPT_STRING_LIST(0, "keep-pack", &keep_pack_list, N_("name"),
                                N_("do not repack this pack")),
                OPT_END()
        };
 
+       sparse = git_env_bool("GIT_TEST_PACK_SPARSE", 0);
        git_config(repack_config, NULL);
 
        argc = parse_options(argc, argv, prefix, builtin_repack_options,
@@ -366,6 +374,8 @@ int cmd_repack(int argc, const char **argv, const char 
*prefix)
        argv_array_push(&cmd.args, "--all");
        argv_array_push(&cmd.args, "--reflog");
        argv_array_push(&cmd.args, "--indexed-objects");
+       if (sparse)
+               argv_array_push(&cmd.args, "--sparse");
        if (repository_format_partial_clone)
                argv_array_push(&cmd.args, "--exclude-promisor-objects");
        if (write_bitmaps)
-- 
2.17.1