preliminary reverse proxy Rack application

This can be a starting point for developing Cool.io or
EventMachine-based reverse proxy applications on Rainbows!

Eventually Rainbows! could replace nginx for Unicorn users!
Just don't consider this code production ready, yet, at all,
it doesn't handle any sort of failover and has no automated
tests, yet.

1 files changed, 46 insertions, 0 deletions

diff --git a/lib/rainbows/reverse_proxy/event_machine.rb b/lib/rainbows/reverse_proxy/event_machine.rb
new file mode 100644
index 0000000..8cb382c
--- /dev/null
+++ b/lib/rainbows/reverse_proxy/event_machine.rb
@@ -0,0 +1,46 @@
+# -*- encoding: binary -*-
+# :enddoc:
+# TODO: handle large responses without having it all in memory
+module Rainbows::ReverseProxy::EventMachine
+  class Backend < EM::Connection
+    include Rainbows::ReverseProxy::EvClient # provides receive_data
+
+    # +addr+ is a packed sockaddr, so it can be either a UNIX or TCP socket
+    def initialize(env)
+      @env = env
+      @rbuf = ""
+      @parser = Kcar::Parser.new
+      @response = @body = nil
+      @headers = Rack::Utils::HeaderHash.new
+    end
+
+    # prevents us from sending too much at once and OOM-ing on large uploads
+    def stream_input(input)
+      if buf = input.read(16384)
+        send_data buf
+        EM.next_tick { stream_input(input) }
+      end
+    end
+
+    def on_write_complete
+      if @input
+        buf = @input.read(16384, @junk) and return write(buf)
+        @input = nil
+      end
+    end
+
+    def unbind
+      @env[AsyncCallback].call(@response || Rainbows::ReverseProxy::E502)
+    end
+  end
+
+  UpstreamSocket = Rainbows::ReverseProxy::UpstreamSocket
+  def call(env)
+    input = prepare_input!(env)
+    io = UpstreamSocket.start(pick_upstream(env))
+    sock = EM.attach(io, Backend, env)
+    sock.send_data(build_headers(env, input))
+    sock.stream_input(input) if input
+    throw :async
+  end
+end