Body parts: future rendering, threaded future, queued future, open-uri example

7 files changed, 231 insertions, 37 deletions

diff --git a/actionpack/lib/action_view/base.rb b/actionpack/lib/action_view/base.rb
index e19acc5c29..3bbd2ca530 100644
--- a/actionpack/lib/action_view/base.rb
+++ b/actionpack/lib/action_view/base.rb
@@ -288,12 +288,12 @@ module ActionView #:nodoc:
     # Access the current template being rendered.
     # Returns a ActionView::Template object.
     def template
-      @_current_render
+      Thread.current[:_current_render]
     end
 
     def template=(template) #:nodoc:
       @_first_render ||= template
-      @_current_render = template
+      Thread.current[:_current_render] = template
     end
 
     def with_template(current_template)
@@ -303,6 +303,12 @@ module ActionView #:nodoc:
       self.template = last_template
     end
 
+    def punctuate_body!(part)
+      flush_output_buffer
+      response.body_parts << part
+      nil
+    end
+
     private
       # Evaluates the local assigns and controller ivars, pushes them to the view.
       def _evaluate_assigns_and_ivars #:nodoc:
diff --git a/actionpack/lib/action_view/body_parts/future.rb b/actionpack/lib/action_view/body_parts/future.rb
new file mode 100644
index 0000000000..a5291c6e8c
--- /dev/null
+++ b/actionpack/lib/action_view/body_parts/future.rb
@@ -0,0 +1,26 @@
+module ActionView
+  module BodyParts
+    class Future
+      def initialize(&block)
+        @block = block
+        @parts = []
+      end
+
+      def to_s
+        finish
+        body
+      end
+
+      protected
+        def work
+          @block.call(@parts)
+        end
+
+        def body
+          str = ''
+          @parts.each { |part| str << part.to_s }
+          str
+        end
+    end
+  end
+end
diff --git a/actionpack/lib/action_view/body_parts/open_uri.rb b/actionpack/lib/action_view/body_parts/open_uri.rb
new file mode 100644
index 0000000000..8ebd17b4a1
--- /dev/null
+++ b/actionpack/lib/action_view/body_parts/open_uri.rb
@@ -0,0 +1,13 @@
+require 'action_view/body_parts/threaded'
+require 'open-uri'
+
+module ActionView
+  module BodyParts
+    class OpenUri < Threaded
+      def initialize(url)
+        url = URI::Generic === url ? url : URI.parse(url)
+        super(true) { |parts| parts << url.read }
+      end
+    end
+  end
+end
diff --git a/actionpack/lib/action_view/body_parts/queued.rb b/actionpack/lib/action_view/body_parts/queued.rb
new file mode 100644
index 0000000000..f8501f6a85
--- /dev/null
+++ b/actionpack/lib/action_view/body_parts/queued.rb
@@ -0,0 +1,21 @@
+require 'action_view/body_parts/future'
+
+module ActionView
+  module BodyParts
+    class Queued < Future
+      def initialize(job, &block)
+        super(&block)
+        enqueue(job)
+      end
+
+      protected
+        def enqueue(job)
+          @receipt = submit(job)
+        end
+
+        def finish
+          @parts << redeem(@receipt)
+        end
+    end
+  end
+end
diff --git a/actionpack/lib/action_view/body_parts/threaded.rb b/actionpack/lib/action_view/body_parts/threaded.rb
new file mode 100644
index 0000000000..34800bf9c7
--- /dev/null
+++ b/actionpack/lib/action_view/body_parts/threaded.rb
@@ -0,0 +1,21 @@
+require 'action_view/body_parts/future'
+
+module ActionView
+  module BodyParts
+    class Threaded < Future
+      def initialize(concurrent = false, &block)
+        super(&block)
+        concurrent ? start : work
+      end
+
+      protected
+        def start
+          @worker = Thread.new { work }
+        end
+
+        def finish
+          @worker.join if @worker && @worker.alive?
+        end
+    end
+  end
+end
diff --git a/actionpack/test/template/body_parts_test.rb b/actionpack/test/template/body_parts_test.rb
new file mode 100644
index 0000000000..d15c8808d9
--- /dev/null
+++ b/actionpack/test/template/body_parts_test.rb
@@ -0,0 +1,142 @@
+require 'abstract_unit'
+require 'action_view/body_parts/queued'
+require 'action_view/body_parts/open_uri'
+
+class OutputBufferTest < ActionController::TestCase
+  class TestController < ActionController::Base
+    def index
+      render :text => 'foo'
+    end
+  end
+
+  tests TestController
+
+  def test_flush_output_buffer
+    # Start with the default body parts
+    get :index
+    assert_equal ['foo'], @response.body_parts
+    assert_nil @response.template.output_buffer
+
+    # Nil output buffer is skipped
+    @response.template.flush_output_buffer
+    assert_nil @response.template.output_buffer
+    assert_equal ['foo'], @response.body_parts
+
+    # Empty output buffer is skipped
+    @response.template.output_buffer = ''
+    @response.template.flush_output_buffer
+    assert_equal '', @response.template.output_buffer
+    assert_equal ['foo'], @response.body_parts
+
+    # Flushing appends the output buffer to the body parts
+    @response.template.output_buffer = 'bar'
+    @response.template.flush_output_buffer
+    assert_equal '', @response.template.output_buffer
+    assert_equal ['foo', 'bar'], @response.body_parts
+  end
+end
+
+class QueuedPartTest < ActionController::TestCase
+  class SimpleQueued < ActionView::BodyParts::Queued
+    protected
+      def submit(job)
+        job
+      end
+
+      def redeem(receipt)
+        receipt.to_s.reverse
+      end
+  end
+
+  class TestController < ActionController::Base
+    def index
+      queued_render 'foo'
+      queued_render 'bar'
+      queued_render 'baz'
+      @performed_render = true
+    end
+
+    def queued_render(job)
+      response.template.punctuate_body! SimpleQueued.new(job)
+    end
+  end
+
+  tests TestController
+
+  def test_queued_parts
+    get :index
+    assert_equal 'oofrabzab', @response.body
+  end
+end
+
+class ThreadedPartTest < ActionController::TestCase
+  class TestController < ActionController::Base
+    def index
+      append_thread_id = lambda do |parts|
+        parts << Thread.current.object_id
+        parts << '::'
+        parts << Time.now.to_i
+        sleep 1
+      end
+
+      future_render &append_thread_id
+      response.body_parts << '-'
+
+      future_render &append_thread_id
+      response.body_parts << '-'
+
+      future_render do |parts|
+        parts << ActionView::BodyParts::Threaded.new(true, &append_thread_id)
+        parts << '-'
+        parts << ActionView::BodyParts::Threaded.new(true, &append_thread_id)
+      end
+
+      @performed_render = true
+    end
+
+    def future_render(&block)
+      response.template.punctuate_body! ActionView::BodyParts::Threaded.new(true, &block)
+    end
+  end
+
+  tests TestController
+
+  def test_concurrent_threaded_parts
+    get :index
+
+    before = Time.now.to_i
+    thread_ids = @response.body.split('-').map { |part| part.split('::').first.to_i }
+    elapsed = Time.now.to_i - before
+
+    assert_equal thread_ids.size, thread_ids.uniq.size
+    assert elapsed < 1.1
+  end
+end
+
+class OpenUriPartTest < ActionController::TestCase
+  class TestController < ActionController::Base
+    def index
+      render_url 'http://localhost/foo'
+      render_url 'http://localhost/bar'
+      render_url 'http://localhost/baz'
+      @performed_render = true
+    end
+
+    def render_url(url)
+      url = URI.parse(url)
+      def url.read; path end
+      response.template.punctuate_body! ActionView::BodyParts::OpenUri.new(url)
+    end
+  end
+
+  tests TestController
+
+  def test_concurrent_open_uri_parts
+    get :index
+
+    elapsed = Benchmark.ms do
+      assert_equal '/foo/bar/baz', @response.body
+    end
+    assert elapsed < 1.1
+  end
+end
diff --git a/actionpack/test/template/output_buffer_test.rb b/actionpack/test/template/output_buffer_test.rb
deleted file mode 100644
index 6d8eab63dc..0000000000
--- a/actionpack/test/template/output_buffer_test.rb
+++ /dev/null
@@ -1,35 +0,0 @@
-require 'abstract_unit'
-
-class OutputBufferTest < ActionController::TestCase
-  class TestController < ActionController::Base
-    def index
-      render :text => 'foo'
-    end
-  end
-
-  tests TestController
-
-  def test_flush_output_buffer
-    # Start with the default body parts
-    get :index
-    assert_equal ['foo'], @response.body_parts
-    assert_nil @response.template.output_buffer
-
-    # Nil output buffer is skipped
-    @response.template.flush_output_buffer
-    assert_nil @response.template.output_buffer
-    assert_equal ['foo'], @response.body_parts
-
-    # Empty output buffer is skipped
-    @response.template.output_buffer = ''
-    @response.template.flush_output_buffer
-    assert_equal '', @response.template.output_buffer
-    assert_equal ['foo'], @response.body_parts
-
-    # Flushing appends the output buffer to the body parts
-    @response.template.output_buffer = 'bar'
-    @response.template.flush_output_buffer
-    assert_equal '', @response.template.output_buffer
-    assert_equal ['foo', 'bar'], @response.body_parts
-  end
-end