Tl/ls remote filter

connect.c

@@ -483,6 +483,8 @@ struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 	const char *hash_name;
 	struct strvec *ref_prefixes = transport_options ?
 		&transport_options->ref_prefixes : NULL;
+	struct strvec *ref_suffixes = transport_options ?
+		&transport_options->ref_suffixes : NULL;
 	const char **unborn_head_target = transport_options ?
 		&transport_options->unborn_head_target : NULL;
 	*list = NULL;
@@ -520,6 +522,10 @@ struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 		packet_write_fmt(fd_out, "ref-prefix %s\n",
 				 ref_prefixes->v[i]);
 	}
+	for (i = 0; ref_suffixes && i < ref_suffixes->nr; i++) {
+		packet_write_fmt(fd_out, "ref-suffix %s\n",
+				 ref_suffixes->v[i]);
+	}
 	packet_flush(fd_out);
 
 	/* Process response from server */

ls-refs.c

@@ -42,10 +42,12 @@ static void ensure_config_read(void)
 }
 
 /*
- * If we see this many or more "ref-prefix" lines from the client, we consider
- * it "too many" and will avoid using the prefix feature entirely.
+ * If we see this many or more "ref-prefix" or "ref-suffix" lines from the
+ * client, we consider it "too many" and will avoid using the prefix or
+ * suffix feature entirely.
  */
 #define TOO_MANY_PREFIXES 65536
+#define TOO_MANY_SUFFIXES 65536
 
 /*
  * Check if one of the prefixes is a prefix of the ref.
@@ -72,6 +74,7 @@ struct ls_refs_data {
 	unsigned peel;
 	unsigned symrefs;
 	struct strvec prefixes;
+	struct strvec suffixes;
 	struct strbuf buf;
 	unsigned unborn : 1;
 };
@@ -152,6 +155,7 @@ int ls_refs(struct repository *r, struct packet_reader *request)
 
 	memset(&data, 0, sizeof(data));
 	strvec_init(&data.prefixes);
+	strvec_init(&data.suffixes);
 	strbuf_init(&data.buf, 0);
 
 	ensure_config_read();
@@ -168,6 +172,9 @@ int ls_refs(struct repository *r, struct packet_reader *request)
 		else if (skip_prefix(arg, "ref-prefix ", &out)) {
 			if (data.prefixes.nr < TOO_MANY_PREFIXES)
 				strvec_push(&data.prefixes, out);
+		}else if (skip_prefix(arg, "ref-suffix ", &out)) {
+			if (data.prefixes.nr < TOO_MANY_SUFFIXES)
+				strvec_push(&data.suffixes, out);
 		}
 		else if (!strcmp("unborn", arg))
 			data.unborn = allow_unborn;
@@ -186,13 +193,19 @@ int ls_refs(struct repository *r, struct packet_reader *request)
 	if (data.prefixes.nr >= TOO_MANY_PREFIXES)
 		strvec_clear(&data.prefixes);
 
+	if (data.suffixes.nr >= TOO_MANY_SUFFIXES)
+		strvec_clear(&data.suffixes);
+
 	send_possibly_unborn_head(&data);
 	if (!data.prefixes.nr)
 		strvec_push(&data.prefixes, "");
+	if (!data.suffixes.nr)
+		strvec_push(&data.suffixes, "");
 	for_each_fullref_in_prefixes(get_git_namespace(), data.prefixes.v,
 				     send_ref, &data);
 	packet_fflush(stdout);
 	strvec_clear(&data.prefixes);
+	strvec_clear(&data.suffixes);
 	strbuf_release(&data.buf);
 	return 0;
 }

refs.h

@@ -63,6 +63,16 @@ struct worktree;
 #define RESOLVE_REF_NO_RECURSE 0x02
 #define RESOLVE_REF_ALLOW_BAD_NAME 0x04
 
+struct ref_patterns {
+	char **ref_prefixes;
+	char **ref_suffixes;
+};
+
+#define REF_PATTERNS_INIT { \
+	.ref_prefixes = empty_strvec, \
+	.ref_suffixes = empty_strvec, \
+}
+
 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
 				    const char *refname,
 				    int resolve_flags,

transport.h

@@ -254,6 +254,14 @@ struct transport_ls_refs_options {
 	 */
 	struct strvec ref_prefixes;
 
+	/*
+	 * Similar with 'ref_prefixes', list of ref suffixes can be sent to
+	 * the server (when communicating using protocol v2) to limit the
+	 * ref advetisement too. This also will speed up some tail-matching
+	 * operations like `git ls-remote`.
+	*/
+	struct strvec ref_suffixes;
+
 	/*
 	 * If unborn_head_target is not NULL, and the remote reports HEAD as
 	 * pointing to an unborn branch, transport_get_remote_refs() stores the