ClientInternal: use std::set for subscriptions

src/ClientInternal.hxx

@@ -24,6 +24,9 @@
 #include "ClientMessage.hxx"
 #include "command.h"
 
+#include <set>
+#include <string>
+
 #include <glib.h>
 
 #undef G_LOG_DOMAIN
@@ -82,7 +85,7 @@ public:
 	/**
 	 * A list of channel names this client is subscribed to.
 	 */
-	GSList *subscriptions;
+	std::set<std::string> subscriptions;
 
 	/**
 	 * The number of subscriptions in #subscriptions.  Used to
@@ -100,6 +103,11 @@ public:
 	 * The number of messages in #messages.
 	 */
 	unsigned num_messages;
+
+	gcc_pure
+	bool IsSubscribed(const char *channel_name) const {
+		return subscriptions.find(channel_name) != subscriptions.end();
+	}
 };
 
 extern unsigned int client_max_connections;

src/ClientNew.cxx

@@ -120,7 +120,6 @@ client_new(struct player_control *player_control,
 
 	client->send_buf_used = 0;
 
-	client->subscriptions = NULL;
 	client->messages = NULL;
 	client->num_messages = 0;
 

src/ClientSubscribe.cxx

@@ -27,17 +27,6 @@ extern "C" {
 
 #include <string.h>
 
-G_GNUC_PURE
-static GSList *
-client_find_subscription(const Client *client, const char *channel)
-{
-	for (GSList *i = client->subscriptions; i != NULL; i = g_slist_next(i))
-		if (strcmp((const char *)i->data, channel) == 0)
-			return i;
-
-	return NULL;
-}
-
 enum client_subscribe_result
 client_subscribe(Client *client, const char *channel)
 {
@@ -47,14 +36,13 @@ client_subscribe(Client *client, const char *channel)
 	if (!client_message_valid_channel_name(channel))
 		return CLIENT_SUBSCRIBE_INVALID;
 
-	if (client_find_subscription(client, channel) != NULL)
-		return CLIENT_SUBSCRIBE_ALREADY;
-
 	if (client->num_subscriptions >= CLIENT_MAX_SUBSCRIPTIONS)
 		return CLIENT_SUBSCRIBE_FULL;
 
-	client->subscriptions = g_slist_prepend(client->subscriptions,
-						g_strdup(channel));
+	auto r = client->subscriptions.insert(channel);
+	if (!r.second)
+		return CLIENT_SUBSCRIBE_ALREADY;
+
 	++client->num_subscriptions;
 
 	idle_add(IDLE_SUBSCRIPTION);
@@ -65,19 +53,19 @@ client_subscribe(Client *client, const char *channel)
 bool
 client_unsubscribe(Client *client, const char *channel)
 {
-	GSList *i = client_find_subscription(client, channel);
-	if (i == NULL)
+	const auto i = client->subscriptions.find(channel);
+	if (i == client->subscriptions.end())
 		return false;
 
 	assert(client->num_subscriptions > 0);
 
-	client->subscriptions = g_slist_remove(client->subscriptions, i->data);
+	client->subscriptions.erase(i);
 	--client->num_subscriptions;
 
 	idle_add(IDLE_SUBSCRIPTION);
 
 	assert((client->num_subscriptions == 0) ==
-	       (client->subscriptions == NULL));
+	       client->subscriptions.empty());
 
 	return true;
 }
@@ -85,11 +73,7 @@ client_unsubscribe(Client *client, const char *channel)
 void
 client_unsubscribe_all(Client *client)
 {
-	for (GSList *i = client->subscriptions; i != NULL; i = g_slist_next(i))
-		g_free(i->data);
-
-	g_slist_free(client->subscriptions);
-	client->subscriptions = NULL;
+	client->subscriptions.clear();
 	client->num_subscriptions = 0;
 }
 
@@ -101,7 +85,7 @@ client_push_message(Client *client, const struct client_message *msg)
 	assert(client_message_defined(msg));
 
 	if (client->num_messages >= CLIENT_MAX_MESSAGES ||
-	    client_find_subscription(client, msg->channel) == NULL)
+	    !client->IsSubscribed(msg->channel))
 		return false;
 
 	if (client->messages == NULL)

src/MessageCommands.cxx

@@ -83,12 +83,8 @@ collect_channels(gpointer data, gpointer user_data)
 		(struct channels_context *)user_data;
 	const Client *client = (const Client *)data;
 
-	for (GSList *i = client->subscriptions; i != NULL;
-	     i = g_slist_next(i)) {
-		const char *channel = (const char *)i->data;
-
-		context->channels.insert(channel);
-	}
+	context->channels.insert(client->subscriptions.begin(),
+				 client->subscriptions.end());
 }
 
 enum command_return