Added fixed gateway script [Nicholas Seckar]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1721 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

5 files changed, 197 insertions, 215 deletions

diff --git a/railties/Rakefile b/railties/Rakefile
index dc2b7a80f8..ffe2cee774 100644
--- a/railties/Rakefile
+++ b/railties/Rakefile
@@ -137,7 +137,7 @@ task :copy_dispatches do
   chmod 0755, "#{PKG_DESTINATION}/public/dispatch.fcgi"
 
   copy_with_rewritten_ruby_path("dispatches/gateway.cgi", "#{PKG_DESTINATION}/public/gateway.cgi")
-  chmod 0644, "#{PKG_DESTINATION}/public/gateway.cgi"
+  chmod 0755, "#{PKG_DESTINATION}/public/gateway.cgi"
 end
 
 task :copy_html_files do
diff --git a/railties/bin/listener b/railties/bin/listener
index 493ac9dca4..421c453f23 100644
--- a/railties/bin/listener
+++ b/railties/bin/listener
@@ -1,103 +1,86 @@
-require "drb"
-ENV["RAILS_ENV"] = 'production'
-require "#{File.dirname(__FILE__)}/../config/environment.rb"
+#!/usr/local/bin/ruby
+
+require 'stringio'
+require 'fileutils'
 require 'fcgi_handler'
-require 'rbconfig'
 
-VERBOSE = false
+def message(s)
+  $stderr.puts "listener: #{s}" if ENV && ENV["DEBUG_GATEWAY"]
+end
+
+class RemoteCGI < CGI
+  attr_accessor :stdinput, :stdoutput, :env_table
+  def initialize(env_table, input = nil, output = nil)
+    self.env_table = env_table
+    self.stdinput = input || StringIO.new
+    self.stdoutput = output || StringIO.new
+    super()
+  end
+
+  def out(stream) # Ignore the requested output stream
+    super(stdoutput)
+  end
+end
 
 class Listener
   include DRbUndumped
-  attr_accessor :tracker
-  
-  def initialize(timeout = nil)
-    @timeout = timeout
+
+  def initialize(timeout, socket_path)
+    @socket = File.expand_path(socket_path)
     @mutex = Mutex.new
     @active = false
-    
+    @timeout = timeout
+
     @handler = RailsFCGIHandler.new
     @handler.extend DRbUndumped
-    @output = FakeOut.new
-    $stdout = @output
-  end
-  
-  def inform_up(tracker_uri)
-    return unless tracker_uri
-    tracker = DRbObject.new_with_uri(tracker_uri)
-    tracker.register_listener self
-    @tracker = tracker
-  end
-  def inform_down
-    @tracker.remove_listener(self) if @tracker
-  end
 
-  def run(on_uri, tracker_uri)
-    on_uri ||= "drbunix:"
-    DRb.start_service(on_uri, self) # Start a server for us
-    inform_up tracker_uri
-    @handler.process!(self)
-  end
-  
-  def die!
-    inform_down
-    Kernel.exit 0
-  end 
-  
-  def process(input)
-    $stderr.puts "listener: received request -- obtaining lock" if VERBOSE 
-    @mutex.synchronize do
-      @active = true
-      
-      $stderr.puts "listener: obtained -- swaping stdin" if VERBOSE
-      $stdin = input
-      cgi = CGI.new
-      
-      $stderr.puts "listener: yielding to FCGI handler..." if VERBOSE
-      @cgi_block.call cgi
-      $stderr.puts "listener: handler finished, releasing control" if VERBOSE
-      
-      return @output.read!
-    end
+    message 'opening socket'
+    DRb.start_service("drbunix:#{@socket}", self)
+
+    message 'entering process loop'
+    @handler.process! self
   end
-  
-  def each_cgi(&block)
-    @cgi_block = block
+
+  def each_cgi(&cgi_block)
+    @cgi_block = cgi_block
+    message 'entering idle loop'
     loop do
-      @timeout ? sleep(@timeout) : sleep
+      sleep @timeout rescue nil
       die! unless @active
       @active = false
     end
   end
-end
 
-class FakeOut < Struct.new(:contents)
-  def initialize
-    super("")
-  end
-  def write(str)
-    contents << str
+  def process(env, input)
+    message 'received request'
+    @mutex.synchronize do
+      @active = true
+
+      message 'creating input stream'
+      input_stream = StringIO.new(input)
+      message 'building CGI instance'
+      cgi = RemoteCGI.new(eval(env), input_stream)
+
+      message 'yielding to fcgi handler'
+      @cgi_block.call cgi
+      message 'yield finished -- sending output'
+
+      cgi.stdoutput.seek(0)
+      output = cgi.stdoutput.read
+
+      return output
+    end
   end
-  def read!
-    c = contents
-    self.contents = ''
-    return c
+
+  def die!
+    message 'shutting down'
+    DRb.stop_service
+    FileUtils.rm_f @socket
+    Kernel.exit 0
   end
 end
 
-if ARGV.shift == 'start-listeners'
-  tracker = ARGV.shift
-  number = (ARGV.shift || '1').to_i
-  exit(0) if number.zero?
-  
-  if number > 1
-    fork do
-      exec(
-        File.join(Config::CONFIG['bin_dir'], Config::CONFIG['RUBY_SO_NAME']), 
-        __FILE__, 'start-listeners', tracker, (number - 1).to_s
-      )
-    end
-  end
-  
-  l = Listener.new(90)
-  l.run(nil, tracker)
-end
\ No newline at end of file
+socket_path = ARGV.shift
+timeout = (ARGV.shift || 90).to_i
+
+Listener.new(timeout, socket_path)
\ No newline at end of file
diff --git a/railties/bin/tracker b/railties/bin/tracker
index 17fce67e54..859c9fa0e0 100644
--- a/railties/bin/tracker
+++ b/railties/bin/tracker
@@ -1,110 +1,69 @@
-require "drb"
-require "rbconfig"
+#!/usr/local/bin/ruby
 
-VERBOSE = false
+require 'drb'
+require 'thread'
+
+def message(s)
+  $stderr.puts "tracker: #{s}" if ENV && ENV["DEBUG_GATEWAY"]
+end
 
 class Tracker
   include DRbUndumped
-  
-  def initialize(timeout = 90, uri = nil)
-    @timeout = timeout
-    @waiting = []
-    @working = []
-    
-    @waiting_mutex = Mutex.new
-    
-    DRb.start_service(uri, self)
-    @uri = DRb.uri
-  end
-  def run
-    start_listener 3
-    sleep 3
-    
-    background
-  end
-  
-  def register_listener(listener)
-    @waiting.push listener
-    nil
-  end
-  def remove_listener(listener)
-    @waiting.delete listener
-    @working.delete listener
-    nil
+
+  def initialize(instances, socket_path)
+    @instances = instances
+    @socket = File.expand_path(socket_path)
+    @active = false
+
+    @listeners = []
+    @instances.times { @listeners << Mutex.new }
+
+    message "using #{@listeners.length} listeners"
+    message "opening socket at #{@socket}"
+
+    @service = DRb.start_service("drbunix://#{@socket}", self)
   end
-  
+
   def with_listener
-    listener = @waiting.shift
-    unless listener
-      start_listener(2) unless @waiting.length + @working.length > 6
-      @waiting_mutex.synchronize do
-	10.times do
-          sleep 0.5
-          listener = @waiting.shift
-          break if listener
-        end
-        unless listener
-          ($stderr.puts "Dropping request due to lack of listeners!!!" unless listener) if VERBOSE
-          return
-        end
+    message "listener requested"
+
+    mutex = has_lock = index = nil
+    3.times do 
+      @listeners.each_with_index do |mutex, index|
+        has_lock = mutex.try_lock
+        break if has_lock
       end
+      break if has_lock
+      sleep 0.05
     end
-    
-    @working << listener
-    yield listener
-  ensure
-    if listener
-      @working.delete listener
-      @waiting << listener
-    end
-  end
-  
-  def background
-    loop do
-      @timeout ? sleep(@timeout) : sleep
-      unless @processed
-        $stderr.puts "Idle for #{@timeout} -- shutting down tracker." if VERBOSE
-        Kernel.exit 0 
+
+    if has_lock
+      message "obtained listener #{index}"
+      @active = true
+      begin yield index
+      ensure
+        mutex.unlock
+        message "released listener #{index}"
       end
-      @processed = false
+    else
+      message "dropping request because no listeners are available!"
     end
   end
-    
-  def process(input)
-    output = nil
-    $stderr.puts "tracker: received request.. obtaining listener" if VERBOSE
-    with_listener do |listener|
-      $stderr.puts "tracker: obtained -- forwarding request to listener.." if VERBOSE
-      @processed = true
-      output = listener.process(input)
-      $stderr.puts "tracker: listener released control." if VERBOSE
-    end
-    return output
-  end
-  
-  def start_listener(n = 1)
-    tracker_uri = @uri
-    listener_path = File.join(File.dirname(__FILE__), 'listener')
-    fork do
-      exec(
-        File.join(Config::CONFIG['bin_dir'], Config::CONFIG['RUBY_SO_NAME']), 
-        listener_path, 'start-listeners', tracker_uri, n.to_s
-      )
+
+  def background(check_interval = nil)
+    if check_interval
+      loop do
+        sleep check_interval
+        message "Idle for #{check_interval}, shutting down" unless @active
+        @active = false
+        Kernel.exit 0
+      end
+    else DRb.thread.join
     end
   end
-  
-  def ping
-    true
-  end
 end
 
-if ARGV.first == "start"
-  tracker = Tracker.new(90, ARGV[1])
-  socket = (/druby:([^?]*)\?/ =~ ARGV[1]) ? $1 : nil
-  require 'fileutils' if socket
-
-  begin tracker.run
-  ensure 
-    FileUtils.rm_f(socket) if socket
-  end
-end
+socket_path = ARGV.shift
+instances = ARGV.shift.to_i
+t = Tracker.new(instances, socket_path)
+t.background(ARGV.first ? ARGV.shift.to_i : 90)
\ No newline at end of file
diff --git a/railties/dispatches/gateway.cgi b/railties/dispatches/gateway.cgi
index d9f0c17846..d21bf0991a 100644
--- a/railties/dispatches/gateway.cgi
+++ b/railties/dispatches/gateway.cgi
@@ -1,58 +1,97 @@
-#!/usr/bin/ruby
-
-# This is an experimental feature for getting high-speed CGI by using a long-running, DRb-backed server in the background
+#!/usr/local/bin/ruby
 
 require 'drb'
-require 'cgi'
-require 'rbconfig'
 
-VERBOSE = false
+# This file includes an experimental gateway CGI implementation. It will work
+# only on platforms which support both fork and sockets.
+#
+# To enable it edit public/.htaccess and replace dispatch.cgi with gateway.cgi.
+#
+# Next, create the directory log/drb_gateway and grant the apache user rw access
+# to said directory.
+#
+# On the next request to your server, the gateway tracker should start up, along
+# with a few listener processes. This setup should provide you with much better
+# speeds than dispatch.cgi.
+#
+# Keep in mind that the first request made to the server will be slow, as the
+# tracker and listeners will have to load. Also, the tracker and listeners will
+# shutdown after a period if inactivity. You can set this value below -- the
+# default is 90 seconds.
+
+TrackerSocket = File.expand_path(File.join(File.dirname(__FILE__), '../log/drb_gateway/tracker.sock'))
+DieAfter = 90 # Seconds
+Listeners = 3
 
-AppName = File.split(File.expand_path(File.join(__FILE__, '..'))).last
-SocketPath = File.expand_path(File.join(File.dirname(__FILE__), '../log/drb_gateway.sock'))
-ConnectionUri = "drbunix:#{SocketPath}"
-attempted_start = false
+def message(s)
+  $stderr.puts "gateway.cgi: #{s}" if ENV && ENV["DEBUG_GATEWAY"]
+end
 
-def start_tracker
-  tracker_path = File.join(File.dirname(__FILE__), '../script/tracker')
+def listener_socket(number)
+  File.expand_path(File.join(File.dirname(__FILE__), "../log/drb_gateway/listener_#{number}.sock"))
+end
+
+unless File.exists? TrackerSocket
+  message "Starting tracker and #{Listeners} listeners"
   fork do
     Process.setsid
     STDIN.reopen "/dev/null"
     STDOUT.reopen "/dev/null", "a"
-    
-    exec(File.join(Config::CONFIG['bin_dir'], Config::CONFIG['RUBY_SO_NAME']), tracker_path, 'start', ConnectionUri)
+
+    root = File.expand_path(File.dirname(__FILE__) + '/..')
+
+    message "starting tracker"
+    fork do
+      ARGV.clear
+      ARGV << TrackerSocket << Listeners.to_s << DieAfter.to_s
+      load File.join(root, 'script', 'tracker')
+    end
+
+    message "starting listeners"
+    require File.join(root, 'config/environment.rb')
+    Listeners.times do |number|
+      fork do
+        ARGV.clear
+        ARGV << listener_socket(number) << DieAfter.to_s
+        load File.join(root, 'script', 'listener')
+      end
+    end
   end
-  
-  $stderr.puts "dispatch: waiting for tracker to start..." if VERBOSE
+
+  message "waiting for tracker and listener to arise..."
+  ready = false
   10.times do
     sleep 0.5
-    return if File.exists? SocketPath
+    break if (ready = File.exists?(TrackerSocket) && File.exists?(listener_socket(0)))
   end
-  
-  $stderr.puts "Can't start tracker!!! Dropping request!"
-  Kernel.exit 1
-end
 
-unless File.exists?(SocketPath)
-  $stderr.puts "tracker not running: starting it..." if VERBOSE
-  start_tracker
+  if ready
+    message "tracker and listener are ready"
+  else
+    message "Waited 5 seconds, listener and tracker not ready... dropping request"
+    Kernel.exit 1
+  end
 end
 
-$stderr.puts "dispatch: attempting to contact tracker..." if VERBOSE
-tracker = DRbObject.new_with_uri(ConnectionUri)
-tracker.ping # Test connection
+DRb.start_service
 
-$stdout.extend DRbUndumped
-$stdin.extend DRbUndumped
-  
-DRb.start_service "drbunix:", $stdin
-$stderr.puts "dispatch: publishing stdin..." if VERBOSE
+message "connecting to tracker"
+tracker = DRbObject.new_with_uri("drbunix:#{TrackerSocket}")
 
-$stderr.puts "dispatch: sending request to tracker" if VERBOSE
-puts tracker.process($stdin)
+input = $stdin.read
+$stdin.close
 
-$stdout.flush
-[$stdin, $stdout].each {|io| io.close}
-$stderr.puts "dispatch: finished..." if VERBOSE
+env = ENV.inspect
 
+output = nil
+tracker.with_listener do |number|
+  message "connecting to listener #{number}"
+  socket = listener_socket(number)
+  listener = DRbObject.new_with_uri("drbunix:#{socket}")
+  output = listener.process(env, input)
+  message "listener #{number} has finished, writing output"
+end
 
+$stdout.write output
+$stdout.flush
+$stdout.close
\ No newline at end of file
diff --git a/railties/html/index.html b/railties/html/index.html
index d547e7fa04..d780f8e029 100644
--- a/railties/html/index.html
+++ b/railties/html/index.html
@@ -60,6 +60,7 @@
   <li>See all the tests run by running <code>rake</code>.
   <li>Develop your Rails application!
   <li>Setup Apache with <a href="http://www.fastcgi.com">FastCGI</a> (and <a href="http://raa.ruby-lang.org/list.rhtml?name=fcgi">Ruby bindings</a>), if you need better performance
+  <li>Remove the dispatches you don't use (so if you're on FastCGI, delete/move dispatch.rb, dispatch.cgi and gateway.cgi)</li>
 </ol>
 
 <p>