net.connect: New API for outgoing connections, based on 'service resolvers'

1 files changed, 78 insertions, 0 deletions

diff --git a/net/connect.lua b/net/connect.lua
new file mode 100644
index 00000000..dbd09694
--- /dev/null
+++ b/net/connect.lua
@@ -0,0 +1,78 @@
+local server = require "net.server";
+local log = require "util.logger".init("net.connect");
+local new_id = require "util.id".short;
+
+local pending_connection_methods = {};
+local pending_connection_mt = {
+	__name = "pending_connection";
+	__index = pending_connection_methods;
+	__tostring = function (p)
+		return "<pending connection "..p.id.." to "..tostring(p.target_resolver.hostname)..">";
+	end;
+};
+
+function pending_connection_methods:log(level, message, ...)
+	log(level, "[pending connection %s] "..message, self.id, ...);
+end
+
+-- pending_connections_map[conn] = pending_connection
+local pending_connections_map = {};
+
+local pending_connection_listeners = {};
+
+local function attempt_connection(p)
+	p:log("debug", "Checking for targets...");
+	if p.conn then
+		pending_connections_map[p.conn] = nil;
+		p.conn = nil;
+	end
+	p.target_resolver:next(function (conn_type, ip, port, extra)
+		p:log("debug", "Next target to try is %s:%d", ip, port);
+		local conn = assert(server.addclient(ip, port, pending_connection_listeners, p.options.pattern, p.options.sslctx, conn_type, extra));
+		p.conn = conn;
+		pending_connections_map[conn] = p;
+	end);
+end
+
+function pending_connection_listeners.onconnect(conn)
+	local p = pending_connections_map[conn];
+	if not p then
+		log("warn", "Successful connection, but unexpected! Closing.");
+		conn:close();
+		return;
+	end
+	pending_connections_map[conn] = nil;
+	p:log("debug", "Successfully connected");
+	if p.listeners.onattach then
+		p.listeners.onattach(conn, p.data);
+	end
+	conn:setlistener(p.listeners);
+	return p.listeners.onconnect(conn);
+end
+
+function pending_connection_listeners.ondisconnect(conn, reason)
+	local p = pending_connections_map[conn];
+	if not p then
+		log("warn", "Failed connection, but unexpected!");
+		return;
+	end
+	p:log("debug", "Connection attempt failed");
+	attempt_connection(p);
+end
+
+local function connect(target_resolver, listeners, options, data)
+	local p = setmetatable({
+		id = new_id();
+		target_resolver = target_resolver;
+		listeners = assert(listeners);
+		options = options or {};
+		cb = cb;
+	}, pending_connection_mt);
+
+	p:log("debug", "Starting connection process");
+	attempt_connection(p);
+end
+
+return {
+	connect = connect;
+};