Use Resolv.getaddresses instead of Socket.getaddrinfo

This is an experiment to see if I can get to the bottom of #50

lib/cql/io/connection.rb

@@ -1,6 +1,7 @@
 # encoding: utf-8
 
 require 'socket'
+require 'resolv'
 
 
 module Cql
@@ -13,13 +14,14 @@ class Connection
       attr_reader :host, :port, :connection_timeout
 
       # @private
-      def initialize(host, port, connection_timeout, unblocker, clock, socket_impl=Socket)
+      def initialize(host, port, connection_timeout, unblocker, clock, socket_impl=Socket, resolv_impl=Resolv)
         @host = host
         @port = port
         @connection_timeout = connection_timeout
         @unblocker = unblocker
         @clock = clock
         @socket_impl = socket_impl
+        @resolv_impl = resolv_impl
         @lock = Mutex.new
         @connected = false
         @write_buffer = ByteBuffer.new
@@ -29,14 +31,24 @@ def initialize(host, port, connection_timeout, unblocker, clock, socket_impl=Soc
       # @private
       def connect
         begin
-          unless @addrinfos
+          unless @addresses
             @connection_started_at = @clock.now
-            @addrinfos = @socket_impl.getaddrinfo(@host, @port, nil, Socket::SOCK_STREAM)
+            @addresses = @resolv_impl.getaddresses(@host)
           end
           unless @io
-            _, port, _, ip, address_family, socket_type = @addrinfos.shift
-            @sockaddr = @socket_impl.sockaddr_in(port, ip)
-            @io = @socket_impl.new(address_family, socket_type, 0)
+            address = nil
+            begin
+              address_str = @addresses.shift
+              address = IPAddr.new(address_str)
+            rescue ArgumentError => e
+              if @addresses.empty?
+                close(ConnectionError.new(%(Could not resolve hostname "#{@host}")))
+              else
+                retry
+              end
+            end
+            @sockaddr = @socket_impl.sockaddr_in(@port, address.to_s)
+            @io = @socket_impl.new(address.family, Socket::SOCK_STREAM)
           end
           unless connected?
             @io.connect_nonblock(@sockaddr)
@@ -51,7 +63,7 @@ def connect
             close(ConnectionTimeoutError.new("Could not connect to #{@host}:#{@port} within #{@connection_timeout}s"))
           end
         rescue Errno::EINVAL => e
-          if @addrinfos.empty?
+          if @addresses.empty?
             close(e)
           else
             @io = nil

spec/cql/io/connection_spec.rb

@@ -7,7 +7,7 @@ module Cql
   module Io
     describe Connection do
       let :handler do
-        described_class.new('example.com', 55555, 5, unblocker, clock, socket_impl)
+        described_class.new('example.com', 55555, 5, unblocker, clock, socket_impl, resolv_impl)
       end
 
       let :unblocker do
@@ -18,6 +18,10 @@ module Io
         double(:socket_impl)
       end
 
+      let :resolv_impl do
+        double(:resolv_impl)
+      end
+
       let :clock do
         double(:clock, now: 0)
       end
@@ -27,14 +31,14 @@ module Io
       end
 
       before do
-        socket_impl.stub(:getaddrinfo)
-          .with('example.com', 55555, nil, Socket::SOCK_STREAM)
-          .and_return([[nil, 'PORT', nil, 'IP1', 'FAMILY1', 'TYPE1'], [nil, 'PORT', nil, 'IP2', 'FAMILY2', 'TYPE2']])
+        resolv_impl.stub(:getaddresses)
+          .with('example.com')
+          .and_return(['1.1.1.1', '2.2.2.2'])
         socket_impl.stub(:sockaddr_in)
-          .with('PORT', 'IP1')
+          .with(55555, '1.1.1.1')
           .and_return('SOCKADDR1')
         socket_impl.stub(:new)
-          .with('FAMILY1', 'TYPE1', 0)
+          .with(Socket::AF_INET, Socket::SOCK_STREAM)
           .and_return(socket)
       end
 
@@ -116,10 +120,10 @@ module Io
         context 'when #connect_nonblock raises EINVAL' do
           before do
             socket_impl.stub(:sockaddr_in)
-              .with('PORT', 'IP2')
+              .with(55555, '2.2.2.2')
               .and_return('SOCKADDR2')
             socket_impl.stub(:new)
-              .with('FAMILY2', 'TYPE2', 0)
+              .with(Socket::AF_INET, Socket::SOCK_STREAM)
               .and_return(socket)
             socket.stub(:close)
           end
@@ -173,9 +177,9 @@ module Io
           end
         end
 
-        context 'when Socket.getaddrinfo raises SocketError' do
+        context 'when Resolv.getaddresses raises SocketError' do
           before do
-            socket_impl.stub(:getaddrinfo).and_raise(SocketError)
+            resolv_impl.stub(:getaddresses).and_raise(SocketError)
           end
 
           it 'fails the returned future with a ConnectionError' do