degesch: replace degesch.connect with async.dial

Halfway there, looks much saner.

degesch.c

@@ -9580,149 +9580,6 @@ lua_plugin_push_connection (struct lua_plugin *plugin, int socket_fd)
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-/// Identifier for the Lua metatable
-#define XLUA_CONNECTOR_METATABLE "connector"
-
-struct lua_connector
-{
-	struct lua_plugin *plugin;          ///< The plugin we belong to
-	struct connector connector;         ///< Connector object
-	bool active;                        ///< Whether the connector is alive
-
-	int ref_on_success;                 ///< Reference to "on_success" callback
-	int ref_on_error;                   ///< Reference to "on_error" callback
-
-	char *last_error;                   ///< Connecting error, if any
-};
-
-static void
-lua_connector_discard (struct lua_connector *self)
-{
-	if (self->active)
-	{
-		connector_free (&self->connector);
-		self->active = false;
-
-		luaL_unref (self->plugin->L, LUA_REGISTRYINDEX, self->ref_on_success);
-		luaL_unref (self->plugin->L, LUA_REGISTRYINDEX, self->ref_on_error);
-		self->ref_on_success = LUA_REFNIL;
-		self->ref_on_error   = LUA_REFNIL;
-	}
-
-	free (self->last_error);
-	self->last_error = NULL;
-
-	lua_cache_invalidate (self->plugin->L, self);
-}
-
-static int
-lua_connector_abort (lua_State *L)
-{
-	lua_connector_discard (luaL_checkudata (L, 1, XLUA_CONNECTOR_METATABLE));
-	return 0;
-}
-
-static luaL_Reg lua_connector_table[] =
-{
-	{ "abort", lua_connector_abort },
-	{ "__gc",  lua_connector_abort },
-	{ NULL,    NULL                }
-};
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
-static void
-lua_connector_on_connected (void *user_data, int socket, const char *hostname)
-{
-	struct lua_connector *self = user_data;
-
-	// TODO: use the hostname for SNI once TLS is implemented
-
-	if (self->ref_on_success != LUA_REFNIL)
-	{
-		lua_State *L = self->plugin->L;
-		lua_rawgeti (L, LUA_REGISTRYINDEX, self->ref_on_success);
-		struct lua_connection *connection =
-			lua_plugin_push_connection (self->plugin, socket);  // 1: connection
-		lua_pushstring (L, hostname);                           // 2: hostname
-
-		struct error *e = NULL;
-		if (!lua_plugin_call (self->plugin, 2, 0, &e))
-		{
-			lua_plugin_log_error (self->plugin, "connector on_success", e);
-			// The connection has placed itself in the cache
-			lua_connection_discard (connection);
-		}
-	}
-
-	lua_connector_discard (self);
-}
-
-static void
-lua_connector_on_failure (void *user_data)
-{
-	struct lua_connector *self = user_data;
-	if (self->ref_on_error != LUA_REFNIL)
-	{
-		lua_State *L = self->plugin->L;
-		lua_rawgeti (L, LUA_REGISTRYINDEX, self->ref_on_error);
-		lua_pushstring (L, self->last_error);  // 1: error string
-
-		struct error *e = NULL;
-		if (!lua_plugin_call (self->plugin, 1, 0, &e))
-			lua_plugin_log_error (self->plugin, "connector on_error", e);
-	}
-
-	lua_connector_discard (self);
-}
-
-static void
-lua_connector_on_error (void *user_data, const char *error)
-{
-	struct lua_connector *self = user_data;
-	free (self->last_error);
-	self->last_error = xstrdup (error);
-}
-
-static int
-lua_plugin_connect (lua_State *L)
-{
-	struct lua_plugin *plugin = lua_touserdata (L, lua_upvalueindex (1));
-	const char *host = luaL_checkstring (L, 1);
-	const char *service = luaL_checkstring (L, 2);
-	luaL_checktype (L, 3, LUA_TTABLE);
-
-	struct lua_connector *self = lua_newuserdata (L, sizeof *self);
-	luaL_setmetatable (L, XLUA_CONNECTOR_METATABLE);
-	memset (self, 0, sizeof *self);
-
-	self->plugin         = plugin;
-	self->ref_on_success = LUA_REFNIL;
-	self->ref_on_error   = LUA_REFNIL;
-
-	(void) lua_plugin_check_field (L, 3, "on_success", LUA_TFUNCTION, true);
-	self->ref_on_success = luaL_ref (L, LUA_REGISTRYINDEX);
-	(void) lua_plugin_check_field (L, 3, "on_error",   LUA_TFUNCTION, true);
-	self->ref_on_error   = luaL_ref (L, LUA_REGISTRYINDEX);
-
-	struct app_context *ctx = plugin->ctx;
-	struct connector *connector = &self->connector;
-	connector_init (connector, &ctx->poller);
-	connector_add_target (connector, host, service);
-
-	connector->on_connected  = lua_connector_on_connected;
-	connector->on_connecting = NULL;
-	connector->on_error      = lua_connector_on_error;
-	connector->on_failure    = lua_connector_on_failure;
-	connector->user_data     = self;
-
-	self->active = true;
-	lua_cache_store (L, self, -1);
-	return 1;
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
 // The script can create as many wait channels as wanted.  They only actually
 // do anything once they get yielded to the main lua_resume() call.
 
@@ -9978,6 +9835,127 @@ lua_plugin_push_wait_timer (struct lua_plugin *plugin, lua_State *L,
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
+struct lua_wait_dial
+{
+	struct lua_wait_channel super;      ///< The structure we're deriving
+
+	struct lua_plugin *plugin;          ///< The plugin we belong to
+	struct connector connector;         ///< Connector object
+	bool active;                        ///< Whether the connector is alive
+
+	struct lua_connection *connection;  ///< Established connection
+	char *hostname;                     ///< Target hostname
+	char *last_error;                   ///< Connecting error, if any
+};
+
+static bool
+lua_wait_dial_check (struct lua_wait_channel *wchannel)
+{
+	struct lua_wait_dial *self =
+		CONTAINER_OF (wchannel, struct lua_wait_dial, super);
+
+	lua_State *L = self->super.task->thread;
+	if (self->connection)
+	{
+		// FIXME: this way the connection can leak, it shouldn't stay in cache
+		//   automatically all the time but clean itself up on GC
+		lua_cache_get (L, self->connection);
+		lua_pushstring (L, self->hostname);
+		self->connection = NULL;
+	}
+	else if (self->last_error)
+	{
+		lua_pushnil (L);
+		lua_pushnil (L);
+		lua_pushstring (L, self->last_error);
+	}
+	else
+		return false;
+	return true;
+}
+
+static void
+lua_wait_dial_cancel (struct lua_wait_dial *self)
+{
+	if (self->active)
+	{
+		connector_free (&self->connector);
+		self->active = false;
+	}
+}
+
+static void
+lua_wait_dial_cleanup (struct lua_wait_channel *wchannel)
+{
+	struct lua_wait_dial *self =
+		CONTAINER_OF (wchannel, struct lua_wait_dial, super);
+
+	lua_wait_dial_cancel (self);
+	if (self->connection)
+		lua_connection_discard (self->connection);
+
+	free (self->hostname);
+	free (self->last_error);
+}
+
+static void
+lua_wait_dial_on_connected (void *user_data, int socket, const char *hostname)
+{
+	struct lua_wait_dial *self = user_data;
+	if (self->super.task)
+		lua_task_wakeup (self->super.task);
+
+	self->connection = lua_plugin_push_connection (self->plugin, socket);
+	// TODO: use the hostname for SNI once TLS is implemented
+	self->hostname = xstrdup (hostname);
+	lua_wait_dial_cancel (self);
+}
+
+static void
+lua_wait_dial_on_failure (void *user_data)
+{
+	struct lua_wait_dial *self = user_data;
+	if (self->super.task)
+		lua_task_wakeup (self->super.task);
+	lua_wait_dial_cancel (self);
+}
+
+static void
+lua_wait_dial_on_error (void *user_data, const char *error)
+{
+	struct lua_wait_dial *self = user_data;
+	free (self->last_error);
+	self->last_error = xstrdup (error);
+}
+
+static int
+lua_plugin_push_wait_dial (struct lua_plugin *plugin, lua_State *L,
+	const char *host, const char *service)
+{
+	struct lua_wait_dial *self = lua_newuserdata (L, sizeof *self);
+	luaL_setmetatable (L, XLUA_WCHANNEL_METATABLE);
+	memset (self, 0, sizeof *self);
+
+	self->super.check = lua_wait_dial_check;
+	self->super.cleanup = lua_wait_dial_cleanup;
+
+	struct connector *connector = &self->connector;
+	connector_init (connector, &plugin->ctx->poller);
+	connector_add_target (connector, host, service);
+
+	connector->on_connected  = lua_wait_dial_on_connected;
+	connector->on_connecting = NULL;
+	connector->on_error      = lua_wait_dial_on_error;
+	connector->on_failure    = lua_wait_dial_on_failure;
+	connector->user_data     = self;
+
+	self->plugin = plugin;
+	self->active = true;
+	return 1;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
 static int
 lua_async_go (lua_State *L)
 {
@@ -10017,10 +9995,19 @@ lua_async_timer_ms (lua_State *L)
 	return lua_plugin_push_wait_timer (plugin, L, timeout);
 }
 
+static int
+lua_async_dial (lua_State *L)
+{
+	struct lua_plugin *plugin = lua_touserdata (L, lua_upvalueindex (1));
+	return lua_plugin_push_wait_dial (plugin, L,
+		luaL_checkstring (L, 1), luaL_checkstring (L, 2));
+}
+
 static luaL_Reg lua_async_library[] =
 {
 	{ "go",       lua_async_go       },
 	{ "timer_ms", lua_async_timer_ms },
+	{ "dial",     lua_async_dial     },
 	{ NULL,       NULL               },
 };
 
@@ -10050,7 +10037,6 @@ static luaL_Reg lua_plugin_library[] =
 	{ "hook_prompt",     lua_plugin_hook_prompt     },
 	{ "hook_completion", lua_plugin_hook_completion },
 	{ "setup_config",    lua_plugin_setup_config    },
-	{ "connect",         lua_plugin_connect         },
 
 	// And these are methods:
 
@@ -10332,7 +10318,6 @@ lua_plugin_load (struct app_context *ctx, const char *filename,
 	lua_plugin_reg_weak (L, &lua_server_info,          lua_server_table);
 	lua_plugin_reg_meta (L, XLUA_SCHEMA_METATABLE,     lua_schema_table);
 	lua_plugin_reg_meta (L, XLUA_CONNECTION_METATABLE, lua_connection_table);
-	lua_plugin_reg_meta (L, XLUA_CONNECTOR_METATABLE,  lua_connector_table);
 
 	lua_plugin_reg_meta (L, XLUA_TASK_METATABLE,       lua_task_table);
 	lua_plugin_reg_meta (L, XLUA_WCHANNEL_METATABLE,   lua_wchannel_table);

plugins/degesch/last-fm.lua

@@ -118,24 +118,23 @@ end
 local running
 
 -- Initiate a connection to last.fm servers
+async, await = degesch.async, coroutine.yield
 local make_request = function (buffer, action)
 	if not user or not api_key then
 		report_error (buffer, "configuration is incomplete")
 		return
 	end
 
-	if running then running.abort () end
+	if running then running:cancel () end
-
+	running = async.go (function ()
-	running = degesch.connect ("ws.audioscrobbler.com", 80, {
+		local c, host, e = await (async.dial ("ws.audioscrobbler.com", 80))
-		on_success = function (c, host)
+		if e then
-			on_connected (buffer, c, host, action)
-			running = nil
-		end,
-		on_error   = function (e)
 			report_error (buffer, e)
-			running = nil
+		else
+			on_connected (buffer, c, host, action)
 		end
-	})
+		running = nil
+	end)
 end
 
 -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -