event_machine: split out uncommonly used modules

Some applications may not use Response*Pipe and TryDefer at all,
so there's no reason to pollute the runtime with extra nodes to
mark during GC.

1 files changed, 27 insertions, 0 deletions

diff --git a/lib/rainbows/event_machine/try_defer.rb b/lib/rainbows/event_machine/try_defer.rb
new file mode 100644
index 0000000..97e384d
--- /dev/null
+++ b/lib/rainbows/event_machine/try_defer.rb
@@ -0,0 +1,27 @@
+# -*- encoding: binary -*-
+# :enddoc:
+
+# Middleware that will run the app dispatch in a separate thread.
+# This middleware is automatically loaded by Rainbows! when using
+# EventMachine and if the app responds to the +deferred?+ method.
+class Rainbows::EventMachine::TryDefer < Struct.new(:app)
+  # shortcuts
+  ASYNC_CALLBACK = Rainbows::EvCore::ASYNC_CALLBACK
+
+  def initialize(app)
+    # the entire app becomes multithreaded, even the root (non-deferred)
+    # thread since any thread can share processes with others
+    Rainbows::Const::RACK_DEFAULTS['rack.multithread'] = true
+    super
+  end
+
+  def call(env)
+    if app.deferred?(env)
+      EM.defer(proc { catch(:async) { app.call(env) } }, env[ASYNC_CALLBACK])
+      # all of the async/deferred stuff breaks Rack::Lint :<
+      nil
+    else
+      app.call(env)
+    end
+  end
+end