Merge branch 'tb/repack-existing-packs-cleanup'

The code to keep track of existing packs in the repository while
repacking has been refactored.

* tb/repack-existing-packs-cleanup:
  builtin/repack.c: extract common cruft pack loop
  builtin/repack.c: avoid directly inspecting "util"
  builtin/repack.c: store existing cruft packs separately
  builtin/repack.c: extract `has_existing_non_kept_packs()`
  builtin/repack.c: extract redundant pack cleanup for existing packs
  builtin/repack.c: extract redundant pack cleanup for --geometric
  builtin/repack.c: extract marking packs for deletion
  builtin/repack.c: extract structure to store existing packs

1 files changed, 180 insertions, 113 deletions

diff --git a/builtin/repack.c b/builtin/repack.c
index 6943c5b..529e131 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -27,7 +27,6 @@
 #define PACK_CRUFT 4
 
 #define DELETE_PACK 1
-#define CRUFT_PACK 2
 
 static int pack_everything;
 static int delta_base_offset = 1;
@@ -95,14 +94,106 @@ static int repack_config(const char *var, const char *value,
 	return git_default_config(var, value, ctx, cb);
 }
 
+struct existing_packs {
+	struct string_list kept_packs;
+	struct string_list non_kept_packs;
+	struct string_list cruft_packs;
+};
+
+#define EXISTING_PACKS_INIT { \
+	.kept_packs = STRING_LIST_INIT_DUP, \
+	.non_kept_packs = STRING_LIST_INIT_DUP, \
+	.cruft_packs = STRING_LIST_INIT_DUP, \
+}
+
+static int has_existing_non_kept_packs(const struct existing_packs *existing)
+{
+	return existing->non_kept_packs.nr || existing->cruft_packs.nr;
+}
+
+static void pack_mark_for_deletion(struct string_list_item *item)
+{
+	item->util = (void*)((uintptr_t)item->util | DELETE_PACK);
+}
+
+static int pack_is_marked_for_deletion(struct string_list_item *item)
+{
+	return (uintptr_t)item->util & DELETE_PACK;
+}
+
+static void mark_packs_for_deletion_1(struct string_list *names,
+				      struct string_list *list)
+{
+	struct string_list_item *item;
+	const int hexsz = the_hash_algo->hexsz;
+
+	for_each_string_list_item(item, list) {
+		char *sha1;
+		size_t len = strlen(item->string);
+		if (len < hexsz)
+			continue;
+		sha1 = item->string + len - hexsz;
+		/*
+		 * Mark this pack for deletion, which ensures that this
+		 * pack won't be included in a MIDX (if `--write-midx`
+		 * was given) and that we will actually delete this pack
+		 * (if `-d` was given).
+		 */
+		if (!string_list_has_string(names, sha1))
+			pack_mark_for_deletion(item);
+	}
+}
+
+static void mark_packs_for_deletion(struct existing_packs *existing,
+				    struct string_list *names)
+
+{
+	mark_packs_for_deletion_1(names, &existing->non_kept_packs);
+	mark_packs_for_deletion_1(names, &existing->cruft_packs);
+}
+
+static void remove_redundant_pack(const char *dir_name, const char *base_name)
+{
+	struct strbuf buf = STRBUF_INIT;
+	struct multi_pack_index *m = get_local_multi_pack_index(the_repository);
+	strbuf_addf(&buf, "%s.pack", base_name);
+	if (m && midx_contains_pack(m, buf.buf))
+		clear_midx_file(the_repository);
+	strbuf_insertf(&buf, 0, "%s/", dir_name);
+	unlink_pack_path(buf.buf, 1);
+	strbuf_release(&buf);
+}
+
+static void remove_redundant_packs_1(struct string_list *packs)
+{
+	struct string_list_item *item;
+	for_each_string_list_item(item, packs) {
+		if (!pack_is_marked_for_deletion(item))
+			continue;
+		remove_redundant_pack(packdir, item->string);
+	}
+}
+
+static void remove_redundant_existing_packs(struct existing_packs *existing)
+{
+	remove_redundant_packs_1(&existing->non_kept_packs);
+	remove_redundant_packs_1(&existing->cruft_packs);
+}
+
+static void existing_packs_release(struct existing_packs *existing)
+{
+	string_list_clear(&existing->kept_packs, 0);
+	string_list_clear(&existing->non_kept_packs, 0);
+	string_list_clear(&existing->cruft_packs, 0);
+}
+
 /*
- * Adds all packs hex strings (pack-$HASH) to either fname_nonkept_list
- * or fname_kept_list based on whether each pack has a corresponding
+ * Adds all packs hex strings (pack-$HASH) to either packs->non_kept
+ * or packs->kept based on whether each pack has a corresponding
  * .keep file or not.  Packs without a .keep file are not to be kept
  * if we are going to pack everything into one file.
  */
-static void collect_pack_filenames(struct string_list *fname_nonkept_list,
-				   struct string_list *fname_kept_list,
+static void collect_pack_filenames(struct existing_packs *existing,
 				   const struct string_list *extra_keep)
 {
 	struct packed_git *p;
@@ -126,28 +217,14 @@ static void collect_pack_filenames(struct string_list *fname_nonkept_list,
 		strbuf_strip_suffix(&buf, ".pack");
 
 		if ((extra_keep->nr > 0 && i < extra_keep->nr) || p->pack_keep)
-			string_list_append(fname_kept_list, buf.buf);
-		else {
-			struct string_list_item *item;
-			item = string_list_append(fname_nonkept_list, buf.buf);
-			if (p->is_cruft)
-				item->util = (void*)(uintptr_t)CRUFT_PACK;
-		}
+			string_list_append(&existing->kept_packs, buf.buf);
+		else if (p->is_cruft)
+			string_list_append(&existing->cruft_packs, buf.buf);
+		else
+			string_list_append(&existing->non_kept_packs, buf.buf);
 	}
 
-	string_list_sort(fname_kept_list);
-	strbuf_release(&buf);
-}
-
-static void remove_redundant_pack(const char *dir_name, const char *base_name)
-{
-	struct strbuf buf = STRBUF_INIT;
-	struct multi_pack_index *m = get_local_multi_pack_index(the_repository);
-	strbuf_addf(&buf, "%s.pack", base_name);
-	if (m && midx_contains_pack(m, buf.buf))
-		clear_midx_file(the_repository);
-	strbuf_insertf(&buf, 0, "%s/", dir_name);
-	unlink_pack_path(buf.buf, 1);
+	string_list_sort(&existing->kept_packs);
 	strbuf_release(&buf);
 }
 
@@ -327,7 +404,7 @@ static int geometry_cmp(const void *va, const void *vb)
 }
 
 static void init_pack_geometry(struct pack_geometry *geometry,
-			       struct string_list *existing_kept_packs,
+			       struct existing_packs *existing,
 			       const struct pack_objects_args *args)
 {
 	struct packed_git *p;
@@ -344,23 +421,24 @@ static void init_pack_geometry(struct pack_geometry *geometry,
 
 		if (!pack_kept_objects) {
 			/*
-			 * Any pack that has its pack_keep bit set will appear
-			 * in existing_kept_packs below, but this saves us from
-			 * doing a more expensive check.
+			 * Any pack that has its pack_keep bit set will
+			 * appear in existing->kept_packs below, but
+			 * this saves us from doing a more expensive
+			 * check.
 			 */
 			if (p->pack_keep)
 				continue;
 
 			/*
-			 * The pack may be kept via the --keep-pack option;
-			 * check 'existing_kept_packs' to determine whether to
-			 * ignore it.
+			 * The pack may be kept via the --keep-pack
+			 * option; check 'existing->kept_packs' to
+			 * determine whether to ignore it.
 			 */
 			strbuf_reset(&buf);
 			strbuf_addstr(&buf, pack_basename(p));
 			strbuf_strip_suffix(&buf, ".pack");
 
-			if (string_list_has_string(existing_kept_packs, buf.buf))
+			if (string_list_has_string(&existing->kept_packs, buf.buf))
 				continue;
 		}
 		if (p->is_cruft)
@@ -494,6 +572,32 @@ static struct packed_git *get_preferred_pack(struct pack_geometry *geometry)
 	return NULL;
 }
 
+static void geometry_remove_redundant_packs(struct pack_geometry *geometry,
+					    struct string_list *names,
+					    struct existing_packs *existing)
+{
+	struct strbuf buf = STRBUF_INIT;
+	uint32_t i;
+
+	for (i = 0; i < geometry->split; i++) {
+		struct packed_git *p = geometry->pack[i];
+		if (string_list_has_string(names, hash_to_hex(p->hash)))
+			continue;
+
+		strbuf_reset(&buf);
+		strbuf_addstr(&buf, pack_basename(p));
+		strbuf_strip_suffix(&buf, ".pack");
+
+		if ((p->pack_keep) ||
+		    (string_list_has_string(&existing->kept_packs, buf.buf)))
+			continue;
+
+		remove_redundant_pack(packdir, buf.buf);
+	}
+
+	strbuf_release(&buf);
+}
+
 static void free_pack_geometry(struct pack_geometry *geometry)
 {
 	if (!geometry)
@@ -565,14 +669,13 @@ static void midx_snapshot_refs(struct tempfile *f)
 }
 
 static void midx_included_packs(struct string_list *include,
-				struct string_list *existing_nonkept_packs,
-				struct string_list *existing_kept_packs,
+				struct existing_packs *existing,
 				struct string_list *names,
 				struct pack_geometry *geometry)
 {
 	struct string_list_item *item;
 
-	for_each_string_list_item(item, existing_kept_packs)
+	for_each_string_list_item(item, &existing->kept_packs)
 		string_list_insert(include, xstrfmt("%s.idx", item->string));
 	for_each_string_list_item(item, names)
 		string_list_insert(include, xstrfmt("pack-%s.idx", item->string));
@@ -599,24 +702,32 @@ static void midx_included_packs(struct string_list *include,
 
 			string_list_insert(include, strbuf_detach(&buf, NULL));
 		}
-
-		for_each_string_list_item(item, existing_nonkept_packs) {
-			if (!((uintptr_t)item->util & CRUFT_PACK)) {
-				/*
-				 * no need to check DELETE_PACK, since we're not
-				 * doing an ALL_INTO_ONE repack
-				 */
-				continue;
-			}
-			string_list_insert(include, xstrfmt("%s.idx", item->string));
-		}
 	} else {
-		for_each_string_list_item(item, existing_nonkept_packs) {
-			if ((uintptr_t)item->util & DELETE_PACK)
+		for_each_string_list_item(item, &existing->non_kept_packs) {
+			if (pack_is_marked_for_deletion(item))
 				continue;
 			string_list_insert(include, xstrfmt("%s.idx", item->string));
 		}
 	}
+
+	for_each_string_list_item(item, &existing->cruft_packs) {
+		/*
+		 * When doing a --geometric repack, there is no need to check
+		 * for deleted packs, since we're by definition not doing an
+		 * ALL_INTO_ONE repack (hence no packs will be deleted).
+		 * Otherwise we must check for and exclude any packs which are
+		 * enqueued for deletion.
+		 *
+		 * So we could omit the conditional below in the --geometric
+		 * case, but doing so is unnecessary since no packs are marked
+		 * as pending deletion (since we only call
+		 * `mark_packs_for_deletion()` when doing an all-into-one
+		 * repack).
+		 */
+		if (pack_is_marked_for_deletion(item))
+			continue;
+		string_list_insert(include, xstrfmt("%s.idx", item->string));
+	}
 }
 
 static int write_midx_included_packs(struct string_list *include,
@@ -700,8 +811,7 @@ static int write_cruft_pack(const struct pack_objects_args *args,
 			    const char *pack_prefix,
 			    const char *cruft_expiration,
 			    struct string_list *names,
-			    struct string_list *existing_packs,
-			    struct string_list *existing_kept_packs)
+			    struct existing_packs *existing)
 {
 	struct child_process cmd = CHILD_PROCESS_INIT;
 	struct strbuf line = STRBUF_INIT;
@@ -743,9 +853,11 @@ static int write_cruft_pack(const struct pack_objects_args *args,
 	in = xfdopen(cmd.in, "w");
 	for_each_string_list_item(item, names)
 		fprintf(in, "%s-%s.pack\n", pack_prefix, item->string);
-	for_each_string_list_item(item, existing_packs)
+	for_each_string_list_item(item, &existing->non_kept_packs)
+		fprintf(in, "-%s.pack\n", item->string);
+	for_each_string_list_item(item, &existing->cruft_packs)
 		fprintf(in, "-%s.pack\n", item->string);
-	for_each_string_list_item(item, existing_kept_packs)
+	for_each_string_list_item(item, &existing->kept_packs)
 		fprintf(in, "%s.pack\n", item->string);
 	fclose(in);
 
@@ -777,8 +889,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	struct child_process cmd = CHILD_PROCESS_INIT;
 	struct string_list_item *item;
 	struct string_list names = STRING_LIST_INIT_DUP;
-	struct string_list existing_nonkept_packs = STRING_LIST_INIT_DUP;
-	struct string_list existing_kept_packs = STRING_LIST_INIT_DUP;
+	struct existing_packs existing = EXISTING_PACKS_INIT;
 	struct pack_geometry geometry = { 0 };
 	struct strbuf line = STRBUF_INIT;
 	struct tempfile *refs_snapshot = NULL;
@@ -914,13 +1025,12 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	packtmp_name = xstrfmt(".tmp-%d-pack", (int)getpid());
 	packtmp = mkpathdup("%s/%s", packdir, packtmp_name);
 
-	collect_pack_filenames(&existing_nonkept_packs, &existing_kept_packs,
-			       &keep_pack_list);
+	collect_pack_filenames(&existing, &keep_pack_list);
 
 	if (geometry.split_factor) {
 		if (pack_everything)
 			die(_("options '%s' and '%s' cannot be used together"), "--geometric", "-A/-a");
-		init_pack_geometry(&geometry, &existing_kept_packs, &po_args);
+		init_pack_geometry(&geometry, &existing, &po_args);
 		split_pack_geometry(&geometry);
 	}
 
@@ -964,7 +1074,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	if (pack_everything & ALL_INTO_ONE) {
 		repack_promisor_objects(&po_args, &names);
 
-		if (existing_nonkept_packs.nr && delete_redundant &&
+		if (has_existing_non_kept_packs(&existing) &&
+		    delete_redundant &&
 		    !(pack_everything & PACK_CRUFT)) {
 			for_each_string_list_item(item, &names) {
 				strvec_pushf(&cmd.args, "--keep-pack=%s-%s.pack",
@@ -1055,8 +1166,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 
 		ret = write_cruft_pack(&cruft_po_args, packtmp, pack_prefix,
 				       cruft_expiration, &names,
-				       &existing_nonkept_packs,
-				       &existing_kept_packs);
+				       &existing);
 		if (ret)
 			goto cleanup;
 
@@ -1087,8 +1197,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 					       pack_prefix,
 					       NULL,
 					       &names,
-					       &existing_nonkept_packs,
-					       &existing_kept_packs);
+					       &existing);
 			if (ret)
 				goto cleanup;
 		}
@@ -1132,29 +1241,12 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	}
 	/* End of pack replacement. */
 
-	if (delete_redundant && pack_everything & ALL_INTO_ONE) {
-		const int hexsz = the_hash_algo->hexsz;
-		for_each_string_list_item(item, &existing_nonkept_packs) {
-			char *sha1;
-			size_t len = strlen(item->string);
-			if (len < hexsz)
-				continue;
-			sha1 = item->string + len - hexsz;
-			/*
-			 * Mark this pack for deletion, which ensures that this
-			 * pack won't be included in a MIDX (if `--write-midx`
-			 * was given) and that we will actually delete this pack
-			 * (if `-d` was given).
-			 */
-			if (!string_list_has_string(&names, sha1))
-				item->util = (void*)(uintptr_t)((size_t)item->util | DELETE_PACK);
-		}
-	}
+	if (delete_redundant && pack_everything & ALL_INTO_ONE)
+		mark_packs_for_deletion(&existing, &names);
 
 	if (write_midx) {
 		struct string_list include = STRING_LIST_INIT_NODUP;
-		midx_included_packs(&include, &existing_nonkept_packs,
-				    &existing_kept_packs, &names, &geometry);
+		midx_included_packs(&include, &existing, &names, &geometry);
 
 		ret = write_midx_included_packs(&include, &geometry,
 						refs_snapshot ? get_tempfile_path(refs_snapshot) : NULL,
@@ -1173,35 +1265,11 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 
 	if (delete_redundant) {
 		int opts = 0;
-		for_each_string_list_item(item, &existing_nonkept_packs) {
-			if (!((uintptr_t)item->util & DELETE_PACK))
-				continue;
-			remove_redundant_pack(packdir, item->string);
-		}
+		remove_redundant_existing_packs(&existing);
 
-		if (geometry.split_factor) {
-			struct strbuf buf = STRBUF_INIT;
-
-			uint32_t i;
-			for (i = 0; i < geometry.split; i++) {
-				struct packed_git *p = geometry.pack[i];
-				if (string_list_has_string(&names,
-							   hash_to_hex(p->hash)))
-					continue;
-
-				strbuf_reset(&buf);
-				strbuf_addstr(&buf, pack_basename(p));
-				strbuf_strip_suffix(&buf, ".pack");
-
-				if ((p->pack_keep) ||
-				    (string_list_has_string(&existing_kept_packs,
-							    buf.buf)))
-					continue;
-
-				remove_redundant_pack(packdir, buf.buf);
-			}
-			strbuf_release(&buf);
-		}
+		if (geometry.split_factor)
+			geometry_remove_redundant_packs(&geometry, &names,
+							&existing);
 		if (show_progress)
 			opts |= PRUNE_PACKED_VERBOSE;
 		prune_packed_objects(opts);
@@ -1225,8 +1293,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 
 cleanup:
 	string_list_clear(&names, 1);
-	string_list_clear(&existing_nonkept_packs, 0);
-	string_list_clear(&existing_kept_packs, 0);
+	existing_packs_release(&existing);
 	free_pack_geometry(&geometry);
 
 	return ret;