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, 61 insertions, 0 deletions

diff --git a/lib/rainbows/reverse_proxy/coolio.rb b/lib/rainbows/reverse_proxy/coolio.rb
new file mode 100644
index 0000000..2197958
--- /dev/null
+++ b/lib/rainbows/reverse_proxy/coolio.rb
@@ -0,0 +1,61 @@
+# -*- encoding: binary -*-
+# :enddoc:
+# TODO: handle large responses without having it all in memory
+module Rainbows::ReverseProxy::Coolio
+  LOOP = Cool.io::Loop.default
+
+  class Backend < Cool.io::IO
+    include Rainbows::ReverseProxy::EvClient
+
+    def initialize(env, addr, input)
+      @env = env
+      @input = input
+      @junk, @rbuf = "", ""
+      @parser = Kcar::Parser.new
+      @response = @body = nil
+      @headers = Rack::Utils::HeaderHash.new
+      super(UpstreamSocket.start(addr)) # kgio-enabled socket
+    end
+
+    def on_write_complete
+      if @input
+        buf = @input.read(16384, @junk) and return write(buf)
+        @input = nil
+      end
+    end
+
+    def on_readable
+      # avoiding IO#read_nonblock since that's expensive in 1.9.2
+      case buf = @_io.kgio_tryread(16384, @junk)
+      when String
+        receive_data(buf)
+      when :wait_readable
+        return
+      when nil
+        @env[AsyncCallback].call(@response)
+        return close
+      end while true # we always read until EAGAIN or EOF
+
+      rescue => e
+        case e
+        when Errno::ECONNRESET
+          @env[AsyncCallback].call(@response)
+          return close
+        when SystemCallError
+        else
+          logger = @env["rack.logger"]
+          logger.error "#{e} #{e.message}"
+          e.backtrace.each { |m| logger.error m }
+        end
+        @env[AsyncCallback].call(Rainbows::ReverseProxy::E502)
+        close
+    end
+  end
+
+  def call(env)
+    input = prepare_input!(env)
+    sock = Backend.new(env, pick_upstream(env), input).attach(LOOP)
+    sock.write(build_headers(env, input))
+    throw :async
+  end
+end