net/connect.lua

   1 local server = require "net.server";
   2 local log = require "util.logger".init("net.connect");
   3 local new_id = require "util.id".short;
   4
   5 local pending_connection_methods = {};
   6 local pending_connection_mt = {
   7         __name = "pending_connection";
   8         __index = pending_connection_methods;
   9         __tostring = function (p)
  10                 return "<pending connection "..p.id.." to "..tostring(p.target_resolver.hostname)..">";
  11         end;
  12 };
  13
  14 function pending_connection_methods:log(level, message, ...)
  15         log(level, "[pending connection %s] "..message, self.id, ...);
  16 end
  17
  18 -- pending_connections_map[conn] = pending_connection
  19 local pending_connections_map = {};
  20
  21 local pending_connection_listeners = {};
  22
  23 local function attempt_connection(p)
  24         p:log("debug", "Checking for targets...");
  25         if p.conn then
  26                 pending_connections_map[p.conn] = nil;
  27                 p.conn = nil;
  28         end
  29         p.target_resolver:next(function (conn_type, ip, port, extra)
  30                 if not conn_type then
  31                         -- No more targets to try
  32                         p:log("debug", "No more connection targets to try");
  33                         if p.listeners.onfail then
  34                                 p.listeners.onfail(p.data, p.last_error or "unable to resolve service");
  35                         end
  36                         return;
  37                 end
  38                 p:log("debug", "Next target to try is %s:%d", ip, port);
  39                 local conn, err = server.addclient(ip, port, pending_connection_listeners, p.options.pattern or "*a", p.options.sslctx, conn_type, extra);
  40                 if not conn then
  41                         log("debug", "Connection attempt failed immediately: %s", err);
  42                         p.last_error = err or "unknown reason";
  43                         return attempt_connection(p);
  44                 end
  45                 p.conn = conn;
  46                 pending_connections_map[conn] = p;
  47         end);
  48 end
  49
  50 function pending_connection_listeners.onconnect(conn)
  51         local p = pending_connections_map[conn];
  52         if not p then
  53                 log("warn", "Successful connection, but unexpected! Closing.");
  54                 conn:close();
  55                 return;
  56         end
  57         pending_connections_map[conn] = nil;
  58         p:log("debug", "Successfully connected");
  59         conn:setlistener(p.listeners, p.data);
  60         return p.listeners.onconnect(conn);
  61 end
  62
  63 function pending_connection_listeners.ondisconnect(conn, reason)
  64         local p = pending_connections_map[conn];
  65         if not p then
  66                 log("warn", "Failed connection, but unexpected!");
  67                 return;
  68         end
  69         p.last_error = reason or "unknown reason";
  70         p:log("debug", "Connection attempt failed: %s", p.last_error);
  71         attempt_connection(p);
  72 end
  73
  74 local function connect(target_resolver, listeners, options, data)
  75         local p = setmetatable({
  76                 id = new_id();
  77                 target_resolver = target_resolver;
  78                 listeners = assert(listeners);
  79                 options = options or {};
  80                 data = data;
  81         }, pending_connection_mt);
  82
  83         p:log("debug", "Starting connection process");
  84         attempt_connection(p);
  85 end
  86
  87 return {
  88         connect = connect;
  89 };