xC: reorganize relay code, improve logging

Even with one forward function declaration down,
it was possible to move most code to a more convenient location.

Most logging has thus been fixed to go to buffers.

xC.c

@@ -1756,7 +1756,6 @@ client_destroy (struct client *self)
 }
 
 static void client_kill (struct client *c);
-static bool client_process_buffer (struct client *c);
 
 // ~~~ Server ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -2808,7 +2807,7 @@ serialize_configuration (struct config_item *root, struct str *output)
 	config_item_write (root, true, output);
 }
 
-// --- Relay plumbing ----------------------------------------------------------
+// --- Relay output ------------------------------------------------------------
 
 static void
 client_kill (struct client *c)
@@ -2822,59 +2821,6 @@ client_kill (struct client *c)
 	client_destroy (c);
 }
 
-static bool
-client_try_read (struct client *c)
-{
-	struct str *buf = &c->read_buffer;
-	ssize_t n_read;
-
-	while ((n_read = read (c->socket_fd, buf->str + buf->len,
-		buf->alloc - buf->len - 1 /* null byte */)) > 0)
-	{
-		buf->len += n_read;
-		if (!client_process_buffer (c))
-			break;
-		str_reserve (buf, 512);
-	}
-
-	if (n_read < 0)
-	{
-		if (errno == EAGAIN || errno == EINTR)
-			return true;
-
-		print_debug ("%s: %s: %s", __func__, "read", strerror (errno));
-	}
-
-	client_kill (c);
-	return false;
-}
-
-static bool
-client_try_write (struct client *c)
-{
-	struct str *buf = &c->write_buffer;
-	ssize_t n_written;
-
-	while (buf->len)
-	{
-		n_written = write (c->socket_fd, buf->str, buf->len);
-		if (n_written >= 0)
-		{
-			str_remove_slice (buf, 0, n_written);
-			continue;
-		}
-		if (errno == EAGAIN || errno == EINTR)
-			return true;
-
-		print_debug ("%s: %s: %s", __func__, "write", strerror (errno));
-		client_kill (c);
-		return false;
-	}
-	return true;
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
 static void
 client_update_poller (struct client *c, const struct pollfd *pfd)
 {
@@ -2887,173 +2833,8 @@ client_update_poller (struct client *c, const struct pollfd *pfd)
 		poller_fd_set (&c->socket_event, new_events);
 }
 
-static void
-on_client_ready (const struct pollfd *pfd, void *user_data)
-{
-	struct client *c = user_data;
-	if (client_try_read (c) && client_try_write (c))
-		client_update_poller (c, pfd);
-}
-
-static bool
-relay_try_fetch_client (struct app_context *ctx, int listen_fd)
-{
-	// XXX: `struct sockaddr_storage' is not the most portable thing
-	struct sockaddr_storage peer;
-	socklen_t peer_len = sizeof peer;
-
-	int fd = accept (listen_fd, (struct sockaddr *) &peer, &peer_len);
-	if (fd == -1)
-	{
-		if (errno == EAGAIN || errno == EWOULDBLOCK)
-			return false;
-		if (errno == EINTR)
-			return true;
-
-		if (accept_error_is_transient (errno))
-			print_warning ("%s: %s", "accept", strerror (errno));
-		else
-			// TODO: Rather dispose of the listening socket.
-			print_fatal ("%s: %s", "accept", strerror (errno));
-		return true;
-	}
-
-	hard_assert (peer_len <= sizeof peer);
-	set_blocking (fd, false);
-	set_cloexec (fd);
-
-	// We already buffer our output, so reduce latencies.
-	int yes = 1;
-	soft_assert (setsockopt (fd, IPPROTO_TCP, TCP_NODELAY,
-		&yes, sizeof yes) != -1);
-
-	struct client *c = client_new ();
-	c->ctx = ctx;
-	c->socket_fd = fd;
-	LIST_PREPEND (ctx->clients, c);
-
-	c->socket_event = poller_fd_make (&c->ctx->poller, c->socket_fd);
-	c->socket_event.dispatcher = (poller_fd_fn) on_client_ready;
-	c->socket_event.user_data = c;
-
-	client_update_poller (c, NULL);
-	return true;
-}
-
-static void
-on_relay_client_available (const struct pollfd *pfd, void *user_data)
-{
-	struct app_context *ctx = user_data;
-	while (relay_try_fetch_client (ctx, pfd->fd))
-		;
-}
-
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-static int
-relay_listen (struct addrinfo *ai, struct error **e)
-{
-	int fd = socket (ai->ai_family, ai->ai_socktype, ai->ai_protocol);
-	if (fd == -1)
-	{
-		error_set (e, "socket: %s", strerror (errno));
-		return -1;
-	}
-
-	set_cloexec (fd);
-
-	int yes = 1;
-	soft_assert (setsockopt (fd, SOL_SOCKET, SO_KEEPALIVE,
-		&yes, sizeof yes) != -1);
-	soft_assert (setsockopt (fd, SOL_SOCKET, SO_REUSEADDR,
-		&yes, sizeof yes) != -1);
-
-	if (bind (fd, ai->ai_addr, ai->ai_addrlen))
-		error_set (e, "bind: %s", strerror (errno));
-	else if (listen (fd, 16 /* arbitrary number */))
-		error_set (e, "listen: %s", strerror (errno));
-	else
-		return fd;
-
-	xclose (fd);
-	return -1;
-}
-
-static int
-relay_listen_with_context (struct addrinfo *ai, struct error **e)
-{
-	char *address = gai_reconstruct_address (ai);
-	print_debug ("binding to `%s'", address);
-
-	struct error *error = NULL;
-	int fd = relay_listen (ai, &error);
-	if (fd == -1)
-	{
-		error_set (e, "binding to `%s' failed: %s", address, error->message);
-		error_free (error);
-	}
-	free (address);
-	return fd;
-}
-
-static bool
-relay_start (struct app_context *ctx, char *address, struct error **e)
-{
-	const char *port = NULL, *host = tokenize_host_port (address, &port);
-	if (!port || !*port)
-		return error_set (e, "missing port");
-
-	struct addrinfo hints = {}, *result = NULL;
-	hints.ai_socktype = SOCK_STREAM;
-	hints.ai_flags = AI_PASSIVE;
-
-	int err = getaddrinfo (*host ? host : NULL, port, &hints, &result);
-	if (err)
-	{
-		return error_set (e, "failed to resolve `%s', port `%s': %s: %s",
-			host, port, "getaddrinfo", gai_strerror (err));
-	}
-
-	// Just try the first one, disregarding IPv4/IPv6 ordering.
-	int fd = relay_listen_with_context (result, e);
-	freeaddrinfo (result);
-	if (fd == -1)
-		return false;
-
-	set_blocking (fd, false);
-
-	struct poller_fd *event = &ctx->relay_event;
-	*event = poller_fd_make (&ctx->poller, fd);
-	event->dispatcher = (poller_fd_fn) on_relay_client_available;
-	event->user_data = ctx;
-
-	ctx->relay_fd = fd;
-	poller_fd_set (event, POLLIN);
-	return true;
-}
-
-static void
-on_config_relay_bind_change (struct config_item *item)
-{
-	struct app_context *ctx = item->user_data;
-	char *value = item->value.string.str;
-	app_context_relay_stop (ctx);
-	if (!value)
-		return;
-
-	struct error *e = NULL;
-	char *address = xstrdup (value);
-	if (!relay_start (ctx, address, &e))
-	{
-		// TODO: Try to make sure this finds its way to the global buffer.
-		print_error ("%s: %s", item->schema->name, e->message);
-		error_free (e);
-	}
-	free (address);
-}
-
-// --- Relay output ------------------------------------------------------------
-
 static void
 relay_send (struct client *c)
 {
@@ -11399,8 +11180,9 @@ lua_ctx_gc (lua_State *L)
 
 static luaL_Reg lua_plugin_library[] =
 {
-	// These are global functions:
+	// These are pseudo-global functions:
 
+	{ "measure",         lua_plugin_measure         },
 	{ "parse",           lua_plugin_parse           },
 	{ "hook_input",      lua_plugin_hook_input      },
 	{ "hook_irc",        lua_plugin_hook_irc        },
@@ -11410,8 +11192,8 @@ static luaL_Reg lua_plugin_library[] =
 
 	// And these are methods:
 
+	// Note that this only returns the height when used through an accessor.
 	{ "get_screen_size", lua_plugin_get_screen_size },
-	{ "measure",         lua_plugin_measure         },
 	{ "__gc",            lua_ctx_gc                 },
 	{ NULL,              NULL                       },
 };
@@ -15632,6 +15414,233 @@ client_process_buffer (struct client *c)
 	return true;
 }
 
+// --- Relay plumbing ----------------------------------------------------------
+
+static bool
+client_try_read (struct client *c)
+{
+	struct str *buf = &c->read_buffer;
+	ssize_t n_read;
+
+	while ((n_read = read (c->socket_fd, buf->str + buf->len,
+		buf->alloc - buf->len - 1 /* null byte */)) > 0)
+	{
+		buf->len += n_read;
+		if (!client_process_buffer (c))
+			break;
+		str_reserve (buf, 512);
+	}
+
+	if (n_read < 0)
+	{
+		if (errno == EAGAIN || errno == EINTR)
+			return true;
+
+		log_global_debug (c->ctx,
+			"#s: #s: #l", __func__, "read", strerror (errno));
+	}
+
+	client_kill (c);
+	return false;
+}
+
+static bool
+client_try_write (struct client *c)
+{
+	struct str *buf = &c->write_buffer;
+	ssize_t n_written;
+
+	while (buf->len)
+	{
+		n_written = write (c->socket_fd, buf->str, buf->len);
+		if (n_written >= 0)
+		{
+			str_remove_slice (buf, 0, n_written);
+			continue;
+		}
+		if (errno == EAGAIN || errno == EINTR)
+			return true;
+
+		log_global_debug (c->ctx,
+			"#s: #s: #l", __func__, "write", strerror (errno));
+		client_kill (c);
+		return false;
+	}
+	return true;
+}
+
+static void
+on_client_ready (const struct pollfd *pfd, void *user_data)
+{
+	struct client *c = user_data;
+	if (client_try_read (c) && client_try_write (c))
+		client_update_poller (c, pfd);
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static bool
+relay_try_fetch_client (struct app_context *ctx, int listen_fd)
+{
+	// XXX: `struct sockaddr_storage' is not the most portable thing
+	struct sockaddr_storage peer;
+	socklen_t peer_len = sizeof peer;
+
+	int fd = accept (listen_fd, (struct sockaddr *) &peer, &peer_len);
+	if (fd == -1)
+	{
+		if (errno == EAGAIN || errno == EWOULDBLOCK)
+			return false;
+		if (errno == EINTR)
+			return true;
+
+		if (accept_error_is_transient (errno))
+		{
+			log_global_debug (ctx, "#s: #l", "accept", strerror (errno));
+			return true;
+		}
+
+		log_global_error (ctx, "#s: #l", "accept", strerror (errno));
+		app_context_relay_stop (ctx);
+		return false;
+	}
+
+	hard_assert (peer_len <= sizeof peer);
+	set_blocking (fd, false);
+	set_cloexec (fd);
+
+	// We already buffer our output, so reduce latencies.
+	int yes = 1;
+	soft_assert (setsockopt (fd, IPPROTO_TCP, TCP_NODELAY,
+		&yes, sizeof yes) != -1);
+
+	struct client *c = client_new ();
+	c->ctx = ctx;
+	c->socket_fd = fd;
+	LIST_PREPEND (ctx->clients, c);
+
+	c->socket_event = poller_fd_make (&c->ctx->poller, c->socket_fd);
+	c->socket_event.dispatcher = (poller_fd_fn) on_client_ready;
+	c->socket_event.user_data = c;
+
+	client_update_poller (c, NULL);
+	return true;
+}
+
+static void
+on_relay_client_available (const struct pollfd *pfd, void *user_data)
+{
+	struct app_context *ctx = user_data;
+	while (relay_try_fetch_client (ctx, pfd->fd))
+		;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static int
+relay_listen (struct addrinfo *ai, struct error **e)
+{
+	int fd = socket (ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+	if (fd == -1)
+	{
+		error_set (e, "socket: %s", strerror (errno));
+		return -1;
+	}
+
+	set_cloexec (fd);
+
+	int yes = 1;
+	soft_assert (setsockopt (fd, SOL_SOCKET, SO_KEEPALIVE,
+		&yes, sizeof yes) != -1);
+	soft_assert (setsockopt (fd, SOL_SOCKET, SO_REUSEADDR,
+		&yes, sizeof yes) != -1);
+
+	if (bind (fd, ai->ai_addr, ai->ai_addrlen))
+		error_set (e, "bind: %s", strerror (errno));
+	else if (listen (fd, 16 /* arbitrary number */))
+		error_set (e, "listen: %s", strerror (errno));
+	else
+		return fd;
+
+	xclose (fd);
+	return -1;
+}
+
+static int
+relay_listen_with_context (struct app_context *ctx, struct addrinfo *ai,
+	struct error **e)
+{
+	char *address = gai_reconstruct_address (ai);
+	log_global_debug (ctx, "binding to `#l'", address);
+
+	struct error *error = NULL;
+	int fd = relay_listen (ai, &error);
+	if (fd == -1)
+	{
+		error_set (e, "binding to `%s' failed: %s", address, error->message);
+		error_free (error);
+	}
+	free (address);
+	return fd;
+}
+
+static bool
+relay_start (struct app_context *ctx, char *address, struct error **e)
+{
+	const char *port = NULL, *host = tokenize_host_port (address, &port);
+	if (!port || !*port)
+		return error_set (e, "missing port");
+
+	struct addrinfo hints = {}, *result = NULL;
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags = AI_PASSIVE;
+
+	int err = getaddrinfo (*host ? host : NULL, port, &hints, &result);
+	if (err)
+	{
+		return error_set (e, "failed to resolve `%s', port `%s': %s: %s",
+			host, port, "getaddrinfo", gai_strerror (err));
+	}
+
+	// Just try the first one, disregarding IPv4/IPv6 ordering.
+	int fd = relay_listen_with_context (ctx, result, e);
+	freeaddrinfo (result);
+	if (fd == -1)
+		return false;
+
+	set_blocking (fd, false);
+
+	struct poller_fd *event = &ctx->relay_event;
+	*event = poller_fd_make (&ctx->poller, fd);
+	event->dispatcher = (poller_fd_fn) on_relay_client_available;
+	event->user_data = ctx;
+
+	ctx->relay_fd = fd;
+	poller_fd_set (event, POLLIN);
+	return true;
+}
+
+static void
+on_config_relay_bind_change (struct config_item *item)
+{
+	struct app_context *ctx = item->user_data;
+	char *value = item->value.string.str;
+	app_context_relay_stop (ctx);
+	if (!value)
+		return;
+
+	// XXX: This should perhaps be reencoded as the locale encoding.
+	char *address = xstrdup (value);
+
+	struct error *e = NULL;
+	if (!relay_start (ctx, address, &e))
+	{
+		log_global_error (ctx, "#s: #l", item->schema->name, e->message);
+		error_free (e);
+	}
+	free (address);
+}
+
 // --- Tests -------------------------------------------------------------------
 
 // The application is quite monolithic and can only be partially unit-tested.