From 356787fce80ba545e288f464450483d52782871a Mon Sep 17 00:00:00 2001
From: Aaron Patterson <aaron.patterson@gmail.com>
Date: Sun, 29 Jul 2012 15:51:21 -0700
Subject: [PATCH] adding a buffered stream to the response object

---
 actionpack/lib/action_controller/metal.rb     |  2 +-
 .../lib/action_dispatch/http/response.rb      | 44 ++++++++++++++++++-
 actionpack/test/controller/streaming_test.rb  | 30 +++++++++++++
 actionpack/test/dispatch/response_test.rb     | 20 +++++++++
 4 files changed, 93 insertions(+), 3 deletions(-)
 create mode 100644 actionpack/test/controller/streaming_test.rb

diff --git a/actionpack/lib/action_controller/metal.rb b/actionpack/lib/action_controller/metal.rb
index 92433ab462..0a0f5393ce 100644
--- a/actionpack/lib/action_controller/metal.rb
+++ b/actionpack/lib/action_controller/metal.rb
@@ -187,7 +187,7 @@ module ActionController
     end
 
     def performed?
-      !!response_body
+      response_body || (response && response.committed?)
     end
 
     def dispatch(name, request) #:nodoc:
diff --git a/actionpack/lib/action_dispatch/http/response.rb b/actionpack/lib/action_dispatch/http/response.rb
index 5ef1c86967..912463bc0e 100644
--- a/actionpack/lib/action_dispatch/http/response.rb
+++ b/actionpack/lib/action_dispatch/http/response.rb
@@ -65,6 +65,36 @@ module ActionDispatch # :nodoc:
     include ActionDispatch::Http::Cache::Response
     include MonitorMixin
 
+    class Buffer # :nodoc:
+      def initialize(response, buf)
+        @response = response
+        @buf      = buf
+        @closed   = false
+      end
+
+      def write(string)
+        raise IOError, "closed stream" if closed?
+
+        @response.commit!
+        @buf.push string
+      end
+
+      def each(&block)
+        @buf.each(&block)
+      end
+
+      def close
+        @response.commit!
+        @closed = true
+      end
+
+      def closed?
+        @closed
+      end
+    end
+
+    attr_reader :stream
+
     def initialize(status = 200, header = {}, body = [])
       super()
 
@@ -76,6 +106,8 @@ module ActionDispatch # :nodoc:
       @committed    = false
       @content_type = nil
       @charset      = nil
+      @stream       = build_buffer self, @body
+
 
       if content_type = self[CONTENT_TYPE]
         type, charset = content_type.split(/;\s*charset=/)
@@ -102,7 +134,7 @@ module ActionDispatch # :nodoc:
     end
 
     def committed?
-      synchronize { @committed }
+      @committed
     end
 
     def status=(status)
@@ -151,7 +183,7 @@ module ActionDispatch # :nodoc:
     def body=(body)
       @blank = true if body == EMPTY
 
-      @body = body.respond_to?(:each) ? body : [body]
+      @body = munge_body_object(body)
     end
 
     def body_parts
@@ -214,6 +246,14 @@ module ActionDispatch # :nodoc:
 
   private
 
+    def build_buffer(response, body)
+      Buffer.new response, body
+    end
+
+    def munge_body_object(body)
+      body.respond_to?(:each) ? body : [body]
+    end
+
     def assign_default_content_type_and_charset!
       return if headers[CONTENT_TYPE].present?
 
diff --git a/actionpack/test/controller/streaming_test.rb b/actionpack/test/controller/streaming_test.rb
new file mode 100644
index 0000000000..50c98f220a
--- /dev/null
+++ b/actionpack/test/controller/streaming_test.rb
@@ -0,0 +1,30 @@
+require 'abstract_unit'
+
+module ActionController
+  class StreamingResponseTest < ActionController::TestCase
+    class TestController < ActionController::Base
+      def self.controller_path
+        'test'
+      end
+
+      def basic_stream
+        %w{ hello world }.each do |word|
+          response.stream.write word
+          response.stream.write "\n"
+        end
+        response.stream.close
+      end
+    end
+
+    tests TestController
+
+    def test_write_to_stream
+      get :basic_stream
+      assert_equal "hello\nworld\n", @response.body
+    end
+
+    def test_write_after_close
+      @response.stream
+    end
+  end
+end
diff --git a/actionpack/test/dispatch/response_test.rb b/actionpack/test/dispatch/response_test.rb
index 51948a623c..e2903d4b36 100644
--- a/actionpack/test/dispatch/response_test.rb
+++ b/actionpack/test/dispatch/response_test.rb
@@ -14,6 +14,26 @@ class ResponseTest < ActiveSupport::TestCase
     assert t.join(0.5)
   end
 
+  def test_stream_close
+    @response.stream.close
+    assert @response.stream.closed?
+  end
+
+  def test_stream_write
+    @response.stream.write "foo"
+    @response.stream.close
+    assert_equal "foo", @response.body
+  end
+
+  def test_write_after_close
+    @response.stream.close
+
+    e = assert_raises(IOError) do
+      @response.stream.write "omg"
+    end
+    assert_equal "closed stream", e.message
+  end
+
   def test_response_body_encoding
     body = ["hello".encode('utf-8')]
     response = ActionDispatch::Response.new 200, {}, body