1 files changed, 167 insertions, 52 deletions

diff --git a/builtin/repack.c b/builtin/repack.c
index 6c636e159e..45583683ee 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -8,10 +8,14 @@
 #include "strbuf.h"
 #include "string-list.h"
 #include "argv-array.h"
+#include "midx.h"
+#include "packfile.h"
+#include "object-store.h"
 
 static int delta_base_offset = 1;
 static int pack_kept_objects = -1;
 static int write_bitmaps;
+static int use_delta_islands;
 static char *packdir, *packtmp;
 
 static const char *const git_repack_usage[] = {
@@ -40,6 +44,10 @@ static int repack_config(const char *var, const char *value, void *cb)
 		write_bitmaps = git_config_bool(var, value);
 		return 0;
 	}
+	if (!strcmp(var, "repack.usedeltaislands")) {
+		use_delta_islands = git_config_bool(var, value);
+		return 0;
+	}
 	return git_default_config(var, value, cb);
 }
 
@@ -83,7 +91,7 @@ static void remove_pack_on_signal(int signo)
 
 /*
  * Adds all packs hex strings to the fname list, which do not
- * have a corresponding .keep or .promisor file. These packs are not to
+ * have a corresponding .keep file. These packs are not to
  * be kept if we are going to pack everything into one file.
  */
 static void get_non_kept_pack_filenames(struct string_list *fname_list,
@@ -111,8 +119,7 @@ static void get_non_kept_pack_filenames(struct string_list *fname_list,
 
 		fname = xmemdupz(e->d_name, len);
 
-		if (!file_exists(mkpath("%s/%s.keep", packdir, fname)) &&
-		    !file_exists(mkpath("%s/%s.promisor", packdir, fname)))
+		if (!file_exists(mkpath("%s/%s.keep", packdir, fname)))
 			string_list_append_nodup(fname_list, fname);
 		else
 			free(fname);
@@ -122,7 +129,7 @@ static void get_non_kept_pack_filenames(struct string_list *fname_list,
 
 static void remove_redundant_pack(const char *dir_name, const char *base_name)
 {
-	const char *exts[] = {".pack", ".idx", ".keep", ".bitmap"};
+	const char *exts[] = {".pack", ".idx", ".keep", ".bitmap", ".promisor"};
 	int i;
 	struct strbuf buf = STRBUF_INIT;
 	size_t plen;
@@ -138,6 +145,117 @@ static void remove_redundant_pack(const char *dir_name, const char *base_name)
 	strbuf_release(&buf);
 }
 
+struct pack_objects_args {
+	const char *window;
+	const char *window_memory;
+	const char *depth;
+	const char *threads;
+	const char *max_pack_size;
+	int no_reuse_delta;
+	int no_reuse_object;
+	int quiet;
+	int local;
+};
+
+static void prepare_pack_objects(struct child_process *cmd,
+				 const struct pack_objects_args *args)
+{
+	argv_array_push(&cmd->args, "pack-objects");
+	if (args->window)
+		argv_array_pushf(&cmd->args, "--window=%s", args->window);
+	if (args->window_memory)
+		argv_array_pushf(&cmd->args, "--window-memory=%s", args->window_memory);
+	if (args->depth)
+		argv_array_pushf(&cmd->args, "--depth=%s", args->depth);
+	if (args->threads)
+		argv_array_pushf(&cmd->args, "--threads=%s", args->threads);
+	if (args->max_pack_size)
+		argv_array_pushf(&cmd->args, "--max-pack-size=%s", args->max_pack_size);
+	if (args->no_reuse_delta)
+		argv_array_pushf(&cmd->args, "--no-reuse-delta");
+	if (args->no_reuse_object)
+		argv_array_pushf(&cmd->args, "--no-reuse-object");
+	if (args->local)
+		argv_array_push(&cmd->args,  "--local");
+	if (args->quiet)
+		argv_array_push(&cmd->args,  "--quiet");
+	if (delta_base_offset)
+		argv_array_push(&cmd->args,  "--delta-base-offset");
+	argv_array_push(&cmd->args, packtmp);
+	cmd->git_cmd = 1;
+	cmd->out = -1;
+}
+
+/*
+ * Write oid to the given struct child_process's stdin, starting it first if
+ * necessary.
+ */
+static int write_oid(const struct object_id *oid, struct packed_git *pack,
+		     uint32_t pos, void *data)
+{
+	struct child_process *cmd = data;
+
+	if (cmd->in == -1) {
+		if (start_command(cmd))
+			die("Could not start pack-objects to repack promisor objects");
+	}
+
+	xwrite(cmd->in, oid_to_hex(oid), GIT_SHA1_HEXSZ);
+	xwrite(cmd->in, "\n", 1);
+	return 0;
+}
+
+static void repack_promisor_objects(const struct pack_objects_args *args,
+				    struct string_list *names)
+{
+	struct child_process cmd = CHILD_PROCESS_INIT;
+	FILE *out;
+	struct strbuf line = STRBUF_INIT;
+
+	prepare_pack_objects(&cmd, args);
+	cmd.in = -1;
+
+	/*
+	 * NEEDSWORK: Giving pack-objects only the OIDs without any ordering
+	 * hints may result in suboptimal deltas in the resulting pack. See if
+	 * the OIDs can be sent with fake paths such that pack-objects can use a
+	 * {type -> existing pack order} ordering when computing deltas instead
+	 * of a {type -> size} ordering, which may produce better deltas.
+	 */
+	for_each_packed_object(write_oid, &cmd,
+			       FOR_EACH_OBJECT_PROMISOR_ONLY);
+
+	if (cmd.in == -1)
+		/* No packed objects; cmd was never started */
+		return;
+
+	close(cmd.in);
+
+	out = xfdopen(cmd.out, "r");
+	while (strbuf_getline_lf(&line, out) != EOF) {
+		char *promisor_name;
+		int fd;
+		if (line.len != the_hash_algo->hexsz)
+			die("repack: Expecting full hex object ID lines only from pack-objects.");
+		string_list_append(names, line.buf);
+
+		/*
+		 * pack-objects creates the .pack and .idx files, but not the
+		 * .promisor file. Create the .promisor file, which is empty.
+		 */
+		promisor_name = mkpathdup("%s-%s.promisor", packtmp,
+					  line.buf);
+		fd = open(promisor_name, O_CREAT|O_EXCL|O_WRONLY, 0600);
+		if (fd < 0)
+			die_errno("unable to create '%s'", promisor_name);
+		close(fd);
+		free(promisor_name);
+	}
+	fclose(out);
+	if (finish_command(&cmd))
+		die("Could not finish pack-objects to repack promisor objects");
+}
+
 #define ALL_INTO_ONE 1
 #define LOOSEN_UNREACHABLE 2
 
@@ -150,6 +268,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 		{".pack"},
 		{".idx"},
 		{".bitmap", 1},
+		{".promisor", 1},
 	};
 	struct child_process cmd = CHILD_PROCESS_INIT;
 	struct string_list_item *item;
@@ -165,15 +284,10 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	int delete_redundant = 0;
 	const char *unpack_unreachable = NULL;
 	int keep_unreachable = 0;
-	const char *window = NULL, *window_memory = NULL;
-	const char *depth = NULL;
-	const char *threads = NULL;
-	const char *max_pack_size = NULL;
 	struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
-	int no_reuse_delta = 0, no_reuse_object = 0;
 	int no_update_server_info = 0;
-	int quiet = 0;
-	int local = 0;
+	int midx_cleared = 0;
+	struct pack_objects_args po_args = {NULL};
 
 	struct option builtin_repack_options[] = {
 		OPT_BIT('a', NULL, &pack_everything,
@@ -183,30 +297,32 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 				   LOOSEN_UNREACHABLE | ALL_INTO_ONE),
 		OPT_BOOL('d', NULL, &delete_redundant,
 				N_("remove redundant packs, and run git-prune-packed")),
-		OPT_BOOL('f', NULL, &no_reuse_delta,
+		OPT_BOOL('f', NULL, &po_args.no_reuse_delta,
 				N_("pass --no-reuse-delta to git-pack-objects")),
-		OPT_BOOL('F', NULL, &no_reuse_object,
+		OPT_BOOL('F', NULL, &po_args.no_reuse_object,
 				N_("pass --no-reuse-object to git-pack-objects")),
 		OPT_BOOL('n', NULL, &no_update_server_info,
 				N_("do not run git-update-server-info")),
-		OPT__QUIET(&quiet, N_("be quiet")),
-		OPT_BOOL('l', "local", &local,
+		OPT__QUIET(&po_args.quiet, N_("be quiet")),
+		OPT_BOOL('l', "local", &po_args.local,
 				N_("pass --local to git-pack-objects")),
 		OPT_BOOL('b', "write-bitmap-index", &write_bitmaps,
 				N_("write bitmap index")),
+		OPT_BOOL('i', "delta-islands", &use_delta_islands,
+				N_("pass --delta-islands to git-pack-objects")),
 		OPT_STRING(0, "unpack-unreachable", &unpack_unreachable, N_("approxidate"),
 				N_("with -A, do not loosen objects older than this")),
 		OPT_BOOL('k', "keep-unreachable", &keep_unreachable,
 				N_("with -a, repack unreachable objects")),
-		OPT_STRING(0, "window", &window, N_("n"),
+		OPT_STRING(0, "window", &po_args.window, N_("n"),
 				N_("size of the window used for delta compression")),
-		OPT_STRING(0, "window-memory", &window_memory, N_("bytes"),
+		OPT_STRING(0, "window-memory", &po_args.window_memory, N_("bytes"),
 				N_("same as the above, but limit memory size instead of entries count")),
-		OPT_STRING(0, "depth", &depth, N_("n"),
+		OPT_STRING(0, "depth", &po_args.depth, N_("n"),
 				N_("limits the maximum delta depth")),
-		OPT_STRING(0, "threads", &threads, N_("n"),
+		OPT_STRING(0, "threads", &po_args.threads, N_("n"),
 				N_("limits the maximum number of threads")),
-		OPT_STRING(0, "max-pack-size", &max_pack_size, N_("bytes"),
+		OPT_STRING(0, "max-pack-size", &po_args.max_pack_size, N_("bytes"),
 				N_("maximum size of each packfile")),
 		OPT_BOOL(0, "pack-kept-objects", &pack_kept_objects,
 				N_("repack objects in packs marked with .keep")),
@@ -238,7 +354,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 
 	sigchain_push_common(remove_pack_on_signal);
 
-	argv_array_push(&cmd.args, "pack-objects");
+	prepare_pack_objects(&cmd, &po_args);
+
 	argv_array_push(&cmd.args, "--keep-true-parents");
 	if (!pack_kept_objects)
 		argv_array_push(&cmd.args, "--honor-pack-keep");
@@ -251,26 +368,16 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	argv_array_push(&cmd.args, "--indexed-objects");
 	if (repository_format_partial_clone)
 		argv_array_push(&cmd.args, "--exclude-promisor-objects");
-	if (window)
-		argv_array_pushf(&cmd.args, "--window=%s", window);
-	if (window_memory)
-		argv_array_pushf(&cmd.args, "--window-memory=%s", window_memory);
-	if (depth)
-		argv_array_pushf(&cmd.args, "--depth=%s", depth);
-	if (threads)
-		argv_array_pushf(&cmd.args, "--threads=%s", threads);
-	if (max_pack_size)
-		argv_array_pushf(&cmd.args, "--max-pack-size=%s", max_pack_size);
-	if (no_reuse_delta)
-		argv_array_pushf(&cmd.args, "--no-reuse-delta");
-	if (no_reuse_object)
-		argv_array_pushf(&cmd.args, "--no-reuse-object");
 	if (write_bitmaps)
 		argv_array_push(&cmd.args, "--write-bitmap-index");
+	if (use_delta_islands)
+		argv_array_push(&cmd.args, "--delta-islands");
 
 	if (pack_everything & ALL_INTO_ONE) {
 		get_non_kept_pack_filenames(&existing_packs, &keep_pack_list);
 
+		repack_promisor_objects(&po_args, &names);
+
 		if (existing_packs.nr && delete_redundant) {
 			if (unpack_unreachable) {
 				argv_array_pushf(&cmd.args,
@@ -292,17 +399,6 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 		argv_array_push(&cmd.args, "--incremental");
 	}
 
-	if (local)
-		argv_array_push(&cmd.args,  "--local");
-	if (quiet)
-		argv_array_push(&cmd.args,  "--quiet");
-	if (delta_base_offset)
-		argv_array_push(&cmd.args,  "--delta-base-offset");
-
-	argv_array_push(&cmd.args, packtmp);
-
-	cmd.git_cmd = 1;
-	cmd.out = -1;
 	cmd.no_stdin = 1;
 
 	ret = start_command(&cmd);
@@ -311,8 +407,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 
 	out = xfdopen(cmd.out, "r");
 	while (strbuf_getline_lf(&line, out) != EOF) {
-		if (line.len != 40)
-			die("repack: Expecting 40 character sha1 lines only from pack-objects.");
+		if (line.len != the_hash_algo->hexsz)
+			die("repack: Expecting full hex object ID lines only from pack-objects.");
 		string_list_append(&names, line.buf);
 	}
 	fclose(out);
@@ -320,7 +416,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	if (ret)
 		return ret;
 
-	if (!names.nr && !quiet)
+	if (!names.nr && !po_args.quiet)
 		printf("Nothing new to pack.\n");
 
 	/*
@@ -333,6 +429,12 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	for_each_string_list_item(item, &names) {
 		for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
 			char *fname, *fname_old;
+
+			if (!midx_cleared) {
+				clear_midx_file(the_repository);
+				midx_cleared = 1;
+			}
+
 			fname = mkpathdup("%s/pack-%s%s", packdir,
 						item->string, exts[ext].name);
 			if (!file_exists(fname)) {
@@ -429,26 +531,39 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 
 	/* End of pack replacement. */
 
+	reprepare_packed_git(the_repository);
+
 	if (delete_redundant) {
+		const int hexsz = the_hash_algo->hexsz;
 		int opts = 0;
 		string_list_sort(&names);
 		for_each_string_list_item(item, &existing_packs) {
 			char *sha1;
 			size_t len = strlen(item->string);
-			if (len < 40)
+			if (len < hexsz)
 				continue;
-			sha1 = item->string + len - 40;
+			sha1 = item->string + len - hexsz;
 			if (!string_list_has_string(&names, sha1))
 				remove_redundant_pack(packdir, item->string);
 		}
-		if (!quiet && isatty(2))
+		if (!po_args.quiet && isatty(2))
 			opts |= PRUNE_PACKED_VERBOSE;
 		prune_packed_objects(opts);
+
+		if (!keep_unreachable &&
+		    (!(pack_everything & LOOSEN_UNREACHABLE) ||
+		     unpack_unreachable) &&
+		    is_repository_shallow(the_repository))
+			prune_shallow(PRUNE_QUICK);
 	}
 
 	if (!no_update_server_info)
 		update_server_info(0);
 	remove_temporary_files();
+
+	if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0))
+		write_midx_file(get_object_directory());
+
 	string_list_clear(&names, 0);
 	string_list_clear(&rollback, 0);
 	string_list_clear(&existing_packs, 0);