[PATCH v4 03/23] multi-pack-index: add builtin

[Derrick Stolee <stolee@gmail.com>]

This new 'git multi-pack-index' builtin will be the plumbing access
for writing, reading, and checking multi-pack-index files. The
initial implementation is a no-op.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 .gitignore                             |  3 ++-
 Documentation/git-multi-pack-index.txt | 36 ++++++++++++++++++++++++++
 Makefile                               |  1 +
 builtin.h                              |  1 +
 builtin/multi-pack-index.c             | 34 ++++++++++++++++++++++++
 command-list.txt                       |  1 +
 git.c                                  |  1 +
 7 files changed, 76 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/git-multi-pack-index.txt
 create mode 100644 builtin/multi-pack-index.c

diff --git a/.gitignore b/.gitignore
index 388cc4beee..25633bc515 100644
--- a/.gitignore
+++ b/.gitignore
@@ -99,8 +99,9 @@
 /git-mergetool--lib
 /git-mktag
 /git-mktree
-/git-name-rev
+/git-multi-pack-index
 /git-mv
+/git-name-rev
 /git-notes
 /git-p4
 /git-pack-redundant
diff --git a/Documentation/git-multi-pack-index.txt b/Documentation/git-multi-pack-index.txt
new file mode 100644
index 0000000000..ec9982cbfc
--- /dev/null
+++ b/Documentation/git-multi-pack-index.txt
@@ -0,0 +1,36 @@
+git-multi-pack-index(1)
+======================
+
+NAME
+----
+git-multi-pack-index - Write and verify multi-pack-indexes
+
+
+SYNOPSIS
+--------
+[verse]
+'git multi-pack-index' [--object-dir=<dir>]
+
+DESCRIPTION
+-----------
+Write or verify a multi-pack-index (MIDX) file.
+
+OPTIONS
+-------
+
+--object-dir=<dir>::
+	Use given directory for the location of Git objects. We check
+	`<dir>/packs/multi-pack-index` for the current MIDX file, and
+	`<dir>/packs` for the pack-files to index.
+
+
+SEE ALSO
+--------
+See link:technical/multi-pack-index.html[The Multi-Pack-Index Design
+Document] and link:technical/pack-format.html[The Multi-Pack-Index
+Format] for more information on the multi-pack-index feature.
+
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/Makefile b/Makefile
index e4b503d259..54610875ec 100644
--- a/Makefile
+++ b/Makefile
@@ -1047,6 +1047,7 @@ BUILTIN_OBJS += builtin/merge-recursive.o
 BUILTIN_OBJS += builtin/merge-tree.o
 BUILTIN_OBJS += builtin/mktag.o
 BUILTIN_OBJS += builtin/mktree.o
+BUILTIN_OBJS += builtin/multi-pack-index.o
 BUILTIN_OBJS += builtin/mv.o
 BUILTIN_OBJS += builtin/name-rev.o
 BUILTIN_OBJS += builtin/notes.o
diff --git a/builtin.h b/builtin.h
index 4e0f64723e..70997d7ace 100644
--- a/builtin.h
+++ b/builtin.h
@@ -191,6 +191,7 @@ extern int cmd_merge_recursive(int argc, const char **argv, const char *prefix);
 extern int cmd_merge_tree(int argc, const char **argv, const char *prefix);
 extern int cmd_mktag(int argc, const char **argv, const char *prefix);
 extern int cmd_mktree(int argc, const char **argv, const char *prefix);
+extern int cmd_multi_pack_index(int argc, const char **argv, const char *prefix);
 extern int cmd_mv(int argc, const char **argv, const char *prefix);
 extern int cmd_name_rev(int argc, const char **argv, const char *prefix);
 extern int cmd_notes(int argc, const char **argv, const char *prefix);
diff --git a/builtin/multi-pack-index.c b/builtin/multi-pack-index.c
new file mode 100644
index 0000000000..3161ddae86
--- /dev/null
+++ b/builtin/multi-pack-index.c
@@ -0,0 +1,34 @@
+#include "builtin.h"
+#include "cache.h"
+#include "config.h"
+#include "parse-options.h"
+
+static char const * const builtin_multi_pack_index_usage[] = {
+	N_("git multi-pack-index [--object-dir=<dir>]"),
+	NULL
+};
+
+static struct opts_multi_pack_index {
+	const char *object_dir;
+} opts;
+
+int cmd_multi_pack_index(int argc, const char **argv,
+			 const char *prefix)
+{
+	static struct option builtin_multi_pack_index_options[] = {
+		OPT_FILENAME(0, "object-dir", &opts.object_dir,
+		  N_("object directory containing set of packfile and pack-index pairs")),
+		OPT_END(),
+	};
+
+	git_config(git_default_config, NULL);
+
+	argc = parse_options(argc, argv, prefix,
+			     builtin_multi_pack_index_options,
+			     builtin_multi_pack_index_usage, 0);
+
+	if (!opts.object_dir)
+		opts.object_dir = get_object_directory();
+
+	return 0;
+}
diff --git a/command-list.txt b/command-list.txt
index e1c26c1bb7..61071f8fa2 100644
--- a/command-list.txt
+++ b/command-list.txt
@@ -123,6 +123,7 @@ git-merge-index                         plumbingmanipulators
 git-merge-one-file                      purehelpers
 git-mergetool                           ancillarymanipulators           complete
 git-merge-tree                          ancillaryinterrogators
+git-multi-pack-index                    plumbingmanipulators
 git-mktag                               plumbingmanipulators
 git-mktree                              plumbingmanipulators
 git-mv                                  mainporcelain           worktree
diff --git a/git.c b/git.c
index c2f48d53dd..a7509fa5f7 100644
--- a/git.c
+++ b/git.c
@@ -505,6 +505,7 @@ static struct cmd_struct commands[] = {
 	{ "merge-tree", cmd_merge_tree, RUN_SETUP | NO_PARSEOPT },
 	{ "mktag", cmd_mktag, RUN_SETUP | NO_PARSEOPT },
 	{ "mktree", cmd_mktree, RUN_SETUP },
+	{ "multi-pack-index", cmd_multi_pack_index, RUN_SETUP_GENTLY },
 	{ "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
 	{ "name-rev", cmd_name_rev, RUN_SETUP },
 	{ "notes", cmd_notes, RUN_SETUP },
-- 
2.18.0.118.gd4f65b8d14