promisor-remote: refactor how we parse advertised fields

In a follow up commit we are going to parse more fields, like a filter
and a token, coming from the server when it advertises promisor remotes
using the "promisor-remote" capability.

To prepare for this, let's refactor the code that parses the advertised
fields coming from the server into a new parse_one_advertised_remote()
function that will populate a `struct promisor_info` with the content
of the fields it parsed.

While at it, let's also pass this `struct promisor_info` to the
should_accept_remote() function, instead of passing it the parsed name
and url.

These changes will make it simpler to both parse more fields and access
the content of these parsed fields in follow up commits.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

promisor-remote.c

@@ -405,16 +405,20 @@ struct promisor_info {
 	const char *token;
 };
 
+static void promisor_info_free(struct promisor_info *p)
+{
+	free((char *)p->name);
+	free((char *)p->url);
+	free((char *)p->filter);
+	free((char *)p->token);
+	free(p);
+}
+
 static void promisor_info_list_clear(struct string_list *list)
 {
-	for (size_t i = 0; i < list->nr; i++) {
+	for (size_t i = 0; i < list->nr; i++)
-		struct promisor_info *p = list->items[i].util;
+		promisor_info_free(list->items[i].util);
-		free((char *)p->name);
+	string_list_clear(list, 0);
-		free((char *)p->url);
-		free((char *)p->filter);
-		free((char *)p->token);
-	}
-	string_list_clear(list, 1);
 }
 
 static void set_one_field(struct promisor_info *p,
@@ -531,11 +535,13 @@ enum accept_promisor {
 };
 
 static int should_accept_remote(enum accept_promisor accept,
-				const char *remote_name, const char *remote_url,
+				struct promisor_info *advertised,
 				struct string_list *config_info)
 {
 	struct promisor_info *p;
 	struct string_list_item *item;
+	const char *remote_name = advertised->name;
+	const char *remote_url = advertised->url;
 
 	if (accept == ACCEPT_ALL)
 		return 1;
@@ -578,6 +584,41 @@ static int skip_field_name_prefix(const char *elem, const char *field_name, cons
 	return 1;
 }
 
+static struct promisor_info *parse_one_advertised_remote(const char *remote_info)
+{
+	struct promisor_info *info = xcalloc(1, sizeof(*info));
+	struct string_list elem_list = STRING_LIST_INIT_DUP;
+	struct string_list_item *item;
+
+	string_list_split(&elem_list, remote_info, ",", -1);
+
+	for_each_string_list_item(item, &elem_list) {
+		const char *elem = item->string;
+		const char *p = strchr(elem, '=');
+
+		if (!p) {
+			warning(_("invalid element '%s' from remote info"), elem);
+			continue;
+		}
+
+		if (skip_field_name_prefix(elem, promisor_field_name, &p))
+			info->name = url_percent_decode(p);
+		else if (skip_field_name_prefix(elem, promisor_field_url, &p))
+			info->url = url_percent_decode(p);
+	}
+
+	string_list_clear(&elem_list, 0);
+
+	if (!info->name || !info->url) {
+		warning(_("server advertised a promisor remote without a name or URL: %s"),
+			remote_info);
+		promisor_info_free(info);
+		return NULL;
+	}
+
+	return info;
+}
+
 static void filter_promisor_remote(struct repository *repo,
 				   struct strvec *accepted,
 				   const char *info)
@@ -614,32 +655,19 @@ static void filter_promisor_remote(struct repository *repo,
 	remotes = strbuf_split_str(info, ';', 0);
 
 	for (size_t i = 0; remotes[i]; i++) {
-		struct strbuf **elems;
+		struct promisor_info *advertised;
-		const char *remote_name = NULL;
-		const char *remote_url = NULL;
-		char *decoded_name = NULL;
-		char *decoded_url = NULL;
 
 		strbuf_strip_suffix(remotes[i], ";");
-		elems = strbuf_split(remotes[i], ',');
 
-		for (size_t j = 0; elems[j]; j++) {
+		advertised = parse_one_advertised_remote(remotes[i]->buf);
-			strbuf_strip_suffix(elems[j], ",");
-			if (!skip_field_name_prefix(elems[j]->buf, promisor_field_name, &remote_name))
-				skip_field_name_prefix(elems[j]->buf, promisor_field_url, &remote_url);
-		}
 
-		if (remote_name)
+		if (!advertised)
-			decoded_name = url_percent_decode(remote_name);
+			continue;
-		if (remote_url)
-			decoded_url = url_percent_decode(remote_url);
 
-		if (decoded_name && should_accept_remote(accept, decoded_name, decoded_url, &config_info))
+		if (should_accept_remote(accept, advertised, &config_info))
-			strvec_push(accepted, decoded_name);
+			strvec_push(accepted, advertised->name);
 
-		strbuf_list_free(elems);
+		promisor_info_free(advertised);
-		free(decoded_name);
-		free(decoded_url);
 	}
 
 	promisor_info_list_clear(&config_info);