Iterate over clients instead of listing

This model avoids memory allocations and allows for re-use of
the info function for client events.

include/ctl-server.h

@@ -21,7 +21,9 @@
 struct ctl;
 struct cmd_response;
 
-struct ctl_server_vnc_client {
+struct ctl_server_client;
+
+struct ctl_server_client_info {
 	char id[64];
 	char hostname[256];
 	char username[256];
@@ -47,11 +49,10 @@ struct ctl_server_actions {
 			const char* id);
 	struct cmd_response* (*on_wayvnc_exit)(struct ctl*);
 
-	// Return number of elements created
-	// Allocate 'clients' array or set ton ULL if none
-	// Receiver will free(clients) when done.
-	int (*get_client_list)(struct ctl*,
-			struct ctl_server_vnc_client** clients);
+	struct ctl_server_client *(*client_next)(struct ctl*,
+			struct ctl_server_client* prev);
+	void (*client_info)(const struct ctl_server_client*,
+			struct ctl_server_client_info* info);
 
 	// Return number of elements created
 	// Allocate 'outputs' array or set to NULL if none

src/ctl-server.c

@@ -328,26 +328,49 @@ static struct cmd_response* generate_version_object()
 	return response;
 }
 
+static struct ctl_server_client* ctl_server_client_first(struct ctl* self)
+{
+	return self->actions.client_next(self, NULL);
+}
+
+static struct ctl_server_client* ctl_server_client_next(struct ctl* self,
+		struct ctl_server_client* prev)
+{
+	return self->actions.client_next(self, prev);
+}
+
+static void ctl_server_client_get_info(struct ctl* self,
+		const struct ctl_server_client* client,
+		struct ctl_server_client_info* info)
+{
+	return self->actions.client_info(client, info);
+}
+
 static struct cmd_response* generate_vnc_client_list(struct ctl* self)
 {
-	struct ctl_server_vnc_client* clients;
-	size_t num_clients = self->actions.get_client_list(self, &clients);
 	struct cmd_response* response = cmd_ok();
-
 	response->data = json_array();
-	for (size_t i = 0; i < num_clients; ++i) {
-		json_t* packed = json_pack("{s:s}", "id", clients[i].id);
-		if (clients[i].hostname[0] != '\0')
+
+	struct ctl_server_client* client;
+	for (client = ctl_server_client_first(self); client;
+			client = ctl_server_client_next(self, client)) {
+		struct ctl_server_client_info info = {};
+		ctl_server_client_get_info(self, client, &info);
+
+		json_t* packed = json_pack("{s:s}", "id", info.id);
+
+		if (info.hostname[0] != '\0')
 			json_object_set_new(packed, "hostname",
-					json_string(clients[i].hostname));
-		if (clients[i].username[0] != '\0')
+					json_string(info.hostname));
+
+		if (info.username[0] != '\0')
 			json_object_set_new(packed, "username",
-					json_string(clients[i].username));
-		json_object_set_new(packed, "seat",
-				json_string(clients[i].seat));
+					json_string(info.username));
+
+		json_object_set_new(packed, "seat", json_string(info.seat));
 		json_array_append_new(response->data, packed);
 	}
-	free(clients);
+
 	return response;
 }
 

src/main.c

@@ -507,42 +507,34 @@ struct cmd_response* on_output_switch(struct ctl* ctl,
 	return cmd_ok();
 }
 
-static int get_client_list(struct ctl* ctl,
-		struct ctl_server_vnc_client** clients)
+static struct ctl_server_client *client_next(struct ctl* ctl,
+		struct ctl_server_client *prev)
 {
 	struct wayvnc* self = ctl_server_userdata(ctl);
-	if (self->nr_clients == 0) {
-		*clients = NULL;
-		return 0;
+	struct nvnc_client* vnc_prev = (struct nvnc_client*)prev;
+
+	return prev ? (struct ctl_server_client*)nvnc_client_next(vnc_prev) :
+		(struct ctl_server_client*)nvnc_client_first(self->nvnc);
 }
 
-	*clients = calloc(self->nr_clients, sizeof(**clients));
-	struct nvnc_client* nvnc_client = nvnc_client_first(self->nvnc);
+static void client_info(const struct ctl_server_client* client_handle,
+		struct ctl_server_client_info* info)
+{
+	const struct nvnc_client *vnc_client =
+		(const struct nvnc_client*)client_handle;
+	const struct wayvnc_client *client = nvnc_get_userdata(vnc_client);
 
-	for (int i = 0; i < self->nr_clients && nvnc_client; ++i) {
-		struct wayvnc_client* client = nvnc_get_userdata(nvnc_client);
-		struct ctl_server_vnc_client* ctl_client =&(*clients)[i];
+	snprintf(info->id, sizeof(info->id), "%u", client->id);
 
-		snprintf(ctl_client->id, sizeof(ctl_client->id), "%u",
-				client->id);
-
-		const char* hostname = nvnc_client_get_hostname(nvnc_client);
+	const char* hostname = nvnc_client_get_hostname(vnc_client);
 	if (hostname)
-			strlcpy(ctl_client->hostname, hostname,
-					sizeof(ctl_client->hostname));
+		strlcpy(info->hostname, hostname, sizeof(info->hostname));
 
-		const char* username = nvnc_client_get_auth_username(nvnc_client);
+	const char* username = nvnc_client_get_auth_username(vnc_client);
 	if (username)
-			strlcpy(ctl_client->username, username,
-					sizeof(ctl_client->username));
+		strlcpy(info->username, username, sizeof(info->username));
 
-		strlcpy(ctl_client->seat, client->seat->name,
-				sizeof(ctl_client->seat));
-
-		nvnc_client = nvnc_client_next(nvnc_client);
-	}
-
-	return self->nr_clients;
+	strlcpy(info->seat, client->seat->name, sizeof(info->seat));
 }
 
 static int get_output_list(struct ctl* ctl,
@@ -1569,7 +1561,8 @@ int main(int argc, char* argv[])
 		.userdata = &self,
 		.on_output_cycle = on_output_cycle,
 		.on_output_switch = on_output_switch,
-		.get_client_list = get_client_list,
+		.client_next = client_next,
+		.client_info = client_info,
 		.get_output_list = get_output_list,
 		.on_disconnect_client = on_disconnect_client,
 		.on_wayvnc_exit = on_wayvnc_exit,