Merge branch 'mh/simplify-repack-without-refs'

"git remote update --prune" to drop many refs has been optimized.

* mh/simplify-repack-without-refs:
  sort_string_list(): rename to string_list_sort()
  prune_remote(): iterate using for_each_string_list_item()
  prune_remote(): rename local variable
  repack_without_refs(): make the refnames argument a string_list
  prune_remote(): sort delete_refs_list references en masse
  prune_remote(): initialize both delete_refs lists in a single loop
  prune_remote(): exit early if there are no stale references

Documentation/technical/api-string-list.txt

@@ -29,7 +29,7 @@ member (you need this if you add things later) and you should set the
   `unsorted_string_list_has_string` and get it from the list using
   `string_list_lookup` for sorted lists.
 
-. Can sort an unsorted list using `sort_string_list`.
+. Can sort an unsorted list using `string_list_sort`.
 
 . Can remove duplicate items from a sorted list using
   `string_list_remove_duplicates`.
@@ -146,7 +146,7 @@ write `string_list_insert(...)->util = ...;`.
 	ownership of a malloc()ed string to a `string_list` that has
 	`strdup_string` set.
 
-`sort_string_list`::
+`string_list_sort`::
 
 	Sort the list's entries by string value in `strcmp()` order.
 

builtin/apply.c

@@ -4180,7 +4180,7 @@ static int write_out_results(struct patch *list)
 	if (cpath.nr) {
 		struct string_list_item *item;
 
-		sort_string_list(&cpath);
+		string_list_sort(&cpath);
 		for_each_string_list_item(item, &cpath)
 			fprintf(stderr, "U %s\n", item->string);
 		string_list_clear(&cpath, 0);

builtin/receive-pack.c

@@ -964,7 +964,7 @@ static void check_aliased_updates(struct command *commands)
 			string_list_append(&ref_list, cmd->ref_name);
 		item->util = (void *)cmd;
 	}
-	sort_string_list(&ref_list);
+	string_list_sort(&ref_list);
 
 	for (cmd = commands; cmd; cmd = cmd->next) {
 		if (!cmd->error_string)

builtin/remote.c

@@ -352,9 +352,9 @@ static int get_ref_states(const struct ref *remote_refs, struct ref_states *stat
 	free_refs(stale_refs);
 	free_refs(fetch_map);
 
-	sort_string_list(&states->new);
-	sort_string_list(&states->tracked);
-	sort_string_list(&states->stale);
+	string_list_sort(&states->new);
+	string_list_sort(&states->tracked);
+	string_list_sort(&states->stale);
 
 	return 0;
 }
@@ -750,16 +750,11 @@ static int mv(int argc, const char **argv)
 static int remove_branches(struct string_list *branches)
 {
 	struct strbuf err = STRBUF_INIT;
-	const char **branch_names;
 	int i, result = 0;
 
-	branch_names = xmalloc(branches->nr * sizeof(*branch_names));
-	for (i = 0; i < branches->nr; i++)
-		branch_names[i] = branches->items[i].string;
-	if (repack_without_refs(branch_names, branches->nr, &err))
+	if (repack_without_refs(branches, &err))
 		result |= error("%s", err.buf);
 	strbuf_release(&err);
-	free(branch_names);
 
 	for (i = 0; i < branches->nr; i++) {
 		struct string_list_item *item = branches->items + i;
@@ -914,7 +909,7 @@ static int get_remote_ref_states(const char *name,
 			get_push_ref_states(remote_refs, states);
 	} else {
 		for_each_ref(append_ref_to_tracked_list, states);
-		sort_string_list(&states->tracked);
+		string_list_sort(&states->tracked);
 		get_push_ref_states_noquery(states);
 	}
 
@@ -1133,7 +1128,7 @@ static int show_all(void)
 	if (!result) {
 		int i;
 
-		sort_string_list(&list);
+		string_list_sort(&list);
 		for (i = 0; i < list.nr; i++) {
 			struct string_list_item *item = list.items + i;
 			if (verbose)
@@ -1314,10 +1309,10 @@ static int set_head(int argc, const char **argv)
 
 static int prune_remote(const char *remote, int dry_run)
 {
-	int result = 0, i;
+	int result = 0;
 	struct ref_states states;
-	struct string_list delete_refs_list = STRING_LIST_INIT_NODUP;
-	const char **delete_refs;
+	struct string_list refs_to_prune = STRING_LIST_INIT_NODUP;
+	struct string_list_item *item;
 	const char *dangling_msg = dry_run
 		? _(" %s will become dangling!")
 		: _(" %s has become dangling!");
@@ -1325,30 +1320,30 @@ static int prune_remote(const char *remote, int dry_run)
 	memset(&states, 0, sizeof(states));
 	get_remote_ref_states(remote, &states, GET_REF_STATES);
 
-	if (states.stale.nr) {
-		printf_ln(_("Pruning %s"), remote);
-		printf_ln(_("URL: %s"),
-		       states.remote->url_nr
-		       ? states.remote->url[0]
-		       : _("(no URL)"));
-
-		delete_refs = xmalloc(states.stale.nr * sizeof(*delete_refs));
-		for (i = 0; i < states.stale.nr; i++)
-			delete_refs[i] = states.stale.items[i].util;
-		if (!dry_run) {
-			struct strbuf err = STRBUF_INIT;
-			if (repack_without_refs(delete_refs, states.stale.nr,
-						&err))
-				result |= error("%s", err.buf);
-			strbuf_release(&err);
-		}
-		free(delete_refs);
+	if (!states.stale.nr) {
+		free_remote_ref_states(&states);
+		return 0;
 	}
 
-	for (i = 0; i < states.stale.nr; i++) {
-		const char *refname = states.stale.items[i].util;
+	printf_ln(_("Pruning %s"), remote);
+	printf_ln(_("URL: %s"),
+		  states.remote->url_nr
+		  ? states.remote->url[0]
+		  : _("(no URL)"));
+
+	for_each_string_list_item(item, &states.stale)
+		string_list_append(&refs_to_prune, item->util);
+	string_list_sort(&refs_to_prune);
+
+	if (!dry_run) {
+		struct strbuf err = STRBUF_INIT;
+		if (repack_without_refs(&refs_to_prune, &err))
+			result |= error("%s", err.buf);
+		strbuf_release(&err);
+	}
 
-		string_list_insert(&delete_refs_list, refname);
+	for_each_string_list_item(item, &states.stale) {
+		const char *refname = item->util;
 
 		if (!dry_run)
 			result |= delete_ref(refname, NULL, 0);
@@ -1361,9 +1356,9 @@ static int prune_remote(const char *remote, int dry_run)
 			       abbrev_ref(refname, "refs/remotes/"));
 	}
 
-	warn_dangling_symrefs(stdout, dangling_msg, &delete_refs_list);
-	string_list_clear(&delete_refs_list, 0);
+	warn_dangling_symrefs(stdout, dangling_msg, &refs_to_prune);
 
+	string_list_clear(&refs_to_prune, 0);
 	free_remote_ref_states(&states);
 	return result;
 }

builtin/repack.c

@@ -376,7 +376,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 
 	if (delete_redundant) {
 		int opts = 0;
-		sort_string_list(&names);
+		string_list_sort(&names);
 		for_each_string_list_item(item, &existing_packs) {
 			char *sha1;
 			size_t len = strlen(item->string);

connect.c

@@ -93,7 +93,7 @@ static void annotate_refs_with_symref_info(struct ref *ref)
 		parse_one_symref_info(&symref, val, len);
 		feature_list = val + 1;
 	}
-	sort_string_list(&symref);
+	string_list_sort(&symref);
 
 	for (; ref; ref = ref->next) {
 		struct string_list_item *item;

notes.c

@@ -902,7 +902,7 @@ int combine_notes_cat_sort_uniq(unsigned char *cur_sha1,
 	if (string_list_add_note_lines(&sort_uniq_list, new_sha1))
 		goto out;
 	string_list_remove_empty_items(&sort_uniq_list, 0);
-	sort_string_list(&sort_uniq_list);
+	string_list_sort(&sort_uniq_list);
 	string_list_remove_duplicates(&sort_uniq_list, 0);
 
 	/* create a new blob object from sort_uniq_list */

refs.c

@@ -2645,22 +2645,25 @@ static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
 	return 0;
 }
 
-int repack_without_refs(const char **refnames, int n, struct strbuf *err)
+int repack_without_refs(struct string_list *refnames, struct strbuf *err)
 {
 	struct ref_dir *packed;
 	struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
-	struct string_list_item *ref_to_delete;
-	int i, ret, removed = 0;
+	struct string_list_item *refname, *ref_to_delete;
+	int ret, needs_repacking = 0, removed = 0;
 
 	assert(err);
 
 	/* Look for a packed ref */
-	for (i = 0; i < n; i++)
-		if (get_packed_ref(refnames[i]))
+	for_each_string_list_item(refname, refnames) {
+		if (get_packed_ref(refname->string)) {
+			needs_repacking = 1;
 			break;
+		}
+	}
 
 	/* Avoid locking if we have nothing to do */
-	if (i == n)
+	if (!needs_repacking)
 		return 0; /* no refname exists in packed refs */
 
 	if (lock_packed_refs(0)) {
@@ -2670,8 +2673,8 @@ int repack_without_refs(const char **refnames, int n, struct strbuf *err)
 	packed = get_packed_refs(&ref_cache);
 
 	/* Remove refnames from the cache */
-	for (i = 0; i < n; i++)
-		if (remove_entry(packed, refnames[i]) != -1)
+	for_each_string_list_item(refname, refnames)
+		if (remove_entry(packed, refname->string) != -1)
 			removed = 1;
 	if (!removed) {
 		/*
@@ -3744,10 +3747,11 @@ static int ref_update_reject_duplicates(struct ref_update **updates, int n,
 int ref_transaction_commit(struct ref_transaction *transaction,
 			   struct strbuf *err)
 {
-	int ret = 0, delnum = 0, i;
-	const char **delnames;
+	int ret = 0, i;
 	int n = transaction->nr;
 	struct ref_update **updates = transaction->updates;
+	struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;
+	struct string_list_item *ref_to_delete;
 
 	assert(err);
 
@@ -3759,9 +3763,6 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 		return 0;
 	}
 
-	/* Allocate work space */
-	delnames = xmalloc(sizeof(*delnames) * n);
-
 	/* Copy, sort, and reject duplicate refs */
 	qsort(updates, n, sizeof(*updates), ref_update_compare);
 	if (ref_update_reject_duplicates(updates, n, err)) {
@@ -3821,16 +3822,17 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 			}
 
 			if (!(update->flags & REF_ISPRUNING))
-				delnames[delnum++] = update->lock->ref_name;
+				string_list_append(&refs_to_delete,
+						   update->lock->ref_name);
 		}
 	}
 
-	if (repack_without_refs(delnames, delnum, err)) {
+	if (repack_without_refs(&refs_to_delete, err)) {
 		ret = TRANSACTION_GENERIC_ERROR;
 		goto cleanup;
 	}
-	for (i = 0; i < delnum; i++)
-		unlink_or_warn(git_path("logs/%s", delnames[i]));
+	for_each_string_list_item(ref_to_delete, &refs_to_delete)
+		unlink_or_warn(git_path("logs/%s", ref_to_delete->string));
 	clear_loose_ref_cache(&ref_cache);
 
 cleanup:
@@ -3839,7 +3841,7 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 	for (i = 0; i < n; i++)
 		if (updates[i]->lock)
 			unlock_ref(updates[i]->lock);
-	free(delnames);
+	string_list_clear(&refs_to_delete, 0);
 	return ret;
 }
 

refs.h

@@ -163,7 +163,15 @@ extern void rollback_packed_refs(void);
  */
 int pack_refs(unsigned int flags);
 
-extern int repack_without_refs(const char **refnames, int n,
+/*
+ * Rewrite the packed-refs file, omitting any refs listed in
+ * 'refnames'. On error, packed-refs will be unchanged, the return
+ * value is nonzero, and a message about the error is written to the
+ * 'err' strbuf.
+ *
+ * The refs in 'refnames' needn't be sorted. `err` must not be NULL.
+ */
+extern int repack_without_refs(struct string_list *refnames,
 			       struct strbuf *err);
 
 extern int ref_exists(const char *);

remote.c

@@ -1356,7 +1356,7 @@ static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***ds
 	}
 	clear_commit_marks_many(sent_tips.nr, sent_tips.tip, TMP_MARK);
 
-	sort_string_list(&dst_tag);
+	string_list_sort(&dst_tag);
 
 	/* Collect tags they do not have. */
 	for (ref = src; ref; ref = ref->next) {
@@ -1421,7 +1421,7 @@ static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
 	for ( ; ref; ref = ref->next)
 		string_list_append_nodup(ref_index, ref->name)->util = ref;
 
-	sort_string_list(ref_index);
+	string_list_sort(ref_index);
 }
 
 /*
@@ -2135,7 +2135,7 @@ struct ref *get_stale_heads(struct refspec *refs, int ref_count, struct ref *fet
 	info.ref_count = ref_count;
 	for (ref = fetch_map; ref; ref = ref->next)
 		string_list_append(&ref_names, ref->name);
-	sort_string_list(&ref_names);
+	string_list_sort(&ref_names);
 	for_each_ref(get_stale_heads_cb, &info);
 	string_list_clear(&ref_names, 0);
 	return stale_refs;

sha1_file.c

@@ -1198,7 +1198,7 @@ static void report_pack_garbage(struct string_list *list)
 	if (!report_garbage)
 		return;
 
-	sort_string_list(list);
+	string_list_sort(list);
 
 	for (i = 0; i < list->nr; i++) {
 		const char *path = list->items[i].string;

string-list.c

@@ -220,7 +220,7 @@ struct string_list_item *string_list_append(struct string_list *list,
 /* Yuck */
 static compare_strings_fn compare_for_qsort;
 
-/* Only call this from inside sort_string_list! */
+/* Only call this from inside string_list_sort! */
 static int cmp_items(const void *a, const void *b)
 {
 	const struct string_list_item *one = a;
@@ -228,7 +228,7 @@ static int cmp_items(const void *a, const void *b)
 	return compare_for_qsort(one->string, two->string);
 }
 
-void sort_string_list(struct string_list *list)
+void string_list_sort(struct string_list *list)
 {
 	compare_for_qsort = list->cmp ? list->cmp : strcmp;
 	qsort(list->items, list->nr, sizeof(*list->items), cmp_items);

string-list.h

@@ -85,7 +85,7 @@ struct string_list_item *string_list_append(struct string_list *list, const char
  */
 struct string_list_item *string_list_append_nodup(struct string_list *list, char *string);
 
-void sort_string_list(struct string_list *list);
+void string_list_sort(struct string_list *list);
 int unsorted_string_list_has_string(struct string_list *list, const char *string);
 struct string_list_item *unsorted_string_list_lookup(struct string_list *list,
 						     const char *string);