Improve view rendering performance in development mode and reinstate template recompiling in production [#1909 state:resolved]

Signed-off-by: Joshua Peek <josh@joshpeek.com>

10 files changed, 84 insertions, 102 deletions

diff --git a/actionpack/lib/action_controller/rescue.rb b/actionpack/lib/action_controller/rescue.rb
index ec61715b57..40aa7cdd57 100644
--- a/actionpack/lib/action_controller/rescue.rb
+++ b/actionpack/lib/action_controller/rescue.rb
@@ -38,7 +38,7 @@ module ActionController #:nodoc:
       'ActionView::TemplateError'         => 'template_error'
     }
 
-    RESCUES_TEMPLATE_PATH = ActionView::Template::EagerPath.new(
+    RESCUES_TEMPLATE_PATH = ActionView::Template::Path.new(
       File.join(File.dirname(__FILE__), "templates"))
 
     def self.included(base) #:nodoc:
diff --git a/actionpack/lib/action_view/base.rb b/actionpack/lib/action_view/base.rb
index 70a0ba91a7..3134807a08 100644
--- a/actionpack/lib/action_view/base.rb
+++ b/actionpack/lib/action_view/base.rb
@@ -182,6 +182,10 @@ module ActionView #:nodoc:
     # that alert()s the caught exception (and then re-raises it).
     cattr_accessor :debug_rjs
 
+    # Specify whether to check whether modified templates are recompiled without a restart
+    @@cache_template_loading = false
+    cattr_accessor :cache_template_loading
+
     attr_internal :request
 
     delegate :request_forgery_protection_token, :template, :params, :session, :cookies, :response, :headers,
@@ -243,8 +247,8 @@ module ActionView #:nodoc:
         if options[:layout]
           _render_with_layout(options, local_assigns, &block)
         elsif options[:file]
-          tempalte = self.view_paths.find_template(options[:file], template_format)
-          tempalte.render_template(self, options[:locals])
+          template = self.view_paths.find_template(options[:file], template_format)
+          template.render_template(self, options[:locals])
         elsif options[:partial]
           render_partial(options)
         elsif options[:inline]
diff --git a/actionpack/lib/action_view/partials.rb b/actionpack/lib/action_view/partials.rb
index 9e5e0f786e..6fe4dbf375 100644
--- a/actionpack/lib/action_view/partials.rb
+++ b/actionpack/lib/action_view/partials.rb
@@ -235,6 +235,5 @@ module ActionView
 
         self.view_paths.find_template(path, self.template_format)
       end
-      memoize :_pick_partial_template
   end
 end
diff --git a/actionpack/lib/action_view/paths.rb b/actionpack/lib/action_view/paths.rb
index b487bd1aa7..e14b21221c 100644
--- a/actionpack/lib/action_view/paths.rb
+++ b/actionpack/lib/action_view/paths.rb
@@ -2,11 +2,7 @@ module ActionView #:nodoc:
   class PathSet < Array #:nodoc:
     def self.type_cast(obj)
       if obj.is_a?(String)
-        if !Object.const_defined?(:Rails) || Rails.configuration.cache_classes
-          Template::EagerPath.new(obj)
-        else
-          Template::Path.new(obj)
-        end
+        Template::Path.new(obj)
       else
         obj
       end
@@ -36,9 +32,8 @@ module ActionView #:nodoc:
       super(*objs.map { |obj| self.class.type_cast(obj) })
     end
 
-    def find_template(original_template_path, format = nil)
-      return original_template_path if original_template_path.respond_to?(:render)
-      template_path = original_template_path.sub(/^\//, '')
+    def find_template(template_path, format = nil)
+      return template_path if template_path.respond_to?(:render)
 
       each do |load_path|
         if format && (template = load_path["#{template_path}.#{I18n.locale}.#{format}"])
@@ -57,7 +52,11 @@ module ActionView #:nodoc:
         end
       end
 
-      Template.new(original_template_path, self)
+      if File.exist?(template_path)
+        return Template.new(template_path, template_path[0] == 47 ? "" : ".")
+      end
+
+      raise MissingTemplate.new(self, template_path, format)
     end
   end
 end
diff --git a/actionpack/lib/action_view/renderable.rb b/actionpack/lib/action_view/renderable.rb
index cb774d8248..c127bb25d6 100644
--- a/actionpack/lib/action_view/renderable.rb
+++ b/actionpack/lib/action_view/renderable.rb
@@ -18,7 +18,6 @@ module ActionView
     def compiled_source
       handler.call(self)
     end
-    memoize :compiled_source
 
     def method_name_without_locals
       ['_run', extension, method_segment].compact.join('_')
@@ -80,6 +79,8 @@ module ActionView
 
         begin
           ActionView::Base::CompiledTemplates.module_eval(source, filename, 0)
+        rescue Errno::ENOENT => e
+          raise e # Missing template file, re-raise for Base to rescue
         rescue Exception => e # errors from template code
           if logger = defined?(ActionController) && Base.logger
             logger.debug "ERROR: compiling #{render_symbol} RAISED #{e}"
@@ -90,9 +91,5 @@ module ActionView
           raise ActionView::TemplateError.new(self, {}, e)
         end
       end
-
-      def recompile?
-        false
-      end
   end
 end
diff --git a/actionpack/lib/action_view/template.rb b/actionpack/lib/action_view/template.rb
index 575ec7ce1c..ee1b9f2886 100644
--- a/actionpack/lib/action_view/template.rb
+++ b/actionpack/lib/action_view/template.rb
@@ -7,6 +7,11 @@ module ActionView #:nodoc:
       def initialize(path)
         raise ArgumentError, "path already is a Path class" if path.is_a?(Path)
         @path = path.freeze
+
+        @paths = {}
+        templates_in_path do |template|
+          load_template(template)
+        end
       end
 
       def to_s
@@ -39,12 +44,7 @@ module ActionView #:nodoc:
       # etc. A format must be supplied to match a formated file. +hello/index+
       # will never match +hello/index.html.erb+.
       def [](path)
-        templates_in_path do |template|
-          if template.accessible_paths.include?(path)
-            return template
-          end
-        end
-        nil
+        @paths[path] || find_template(path)
       end
 
       private
@@ -57,25 +57,30 @@ module ActionView #:nodoc:
         def create_template(file)
           Template.new(file.split("#{self}/").last, self)
         end
-    end
 
-    class EagerPath < Path
-      def initialize(path)
-        super
-
-        @paths = {}
-        templates_in_path do |template|
+        def load_template(template)
           template.load!
           template.accessible_paths.each do |path|
             @paths[path] = template
           end
         end
-        @paths.freeze
-      end
 
-      def [](path)
-        @paths[path]
-      end
+        def matching_templates(template_path)
+          Dir.glob("#{@path}/#{template_path}.*").each do |file|
+            yield create_template(file) unless File.directory?(file)
+          end
+        end
+
+        def find_template(path)
+          return nil if Base.cache_template_loading || ActionController::Base.allow_concurrency
+          matching_templates(path) do |template|
+            if template.accessible_paths.include?(path)
+              load_template(template)
+              return template
+            end
+          end
+          nil
+        end
     end
 
     extend TemplateHandlers
@@ -97,9 +102,9 @@ module ActionView #:nodoc:
     attr_accessor :locale, :name, :format, :extension
     delegate :to_s, :to => :path
 
-    def initialize(template_path, load_paths = [])
+    def initialize(template_path, load_path)
       template_path = template_path.dup
-      @load_path, @filename = find_full_path(template_path, load_paths)
+      @load_path, @filename = load_path, File.join(load_path, template_path)
       @base_path, @name, @locale, @format, @extension = split(template_path)
       @base_path.to_s.gsub!(/\/$/, '') # Push to split method
 
@@ -171,7 +176,6 @@ module ActionView #:nodoc:
     def source
       File.read(filename)
     end
-    memoize :source
 
     def method_segment
       relative_path.to_s.gsub(/([^a-zA-Z0-9_])/) { $1.ord }
@@ -185,25 +189,34 @@ module ActionView #:nodoc:
       if TemplateError === e
         e.sub_template_of(self)
         raise e
+      elsif Errno::ENOENT === e
+        raise MissingTemplate.new(view.view_paths, filename.sub("#{RAILS_ROOT}/#{load_path}/", ""))
       else
         raise TemplateError.new(self, view.assigns, e)
       end
     end
 
     def stale?
-      File.mtime(filename) > mtime
-    end
-
-    def recompile?
-      !@cached
+      !frozen? && mtime < mtime(:reload)
     end
 
     def load!
-      @cached = true
-      freeze
+      reloadable? ? memoize_all : freeze
     end
 
     private
+      def cached?
+        Base.cache_template_loading || ActionController::Base.allow_concurrency
+      end
+
+      def reloadable?
+        !cached?
+      end
+
+      def recompile?
+        reloadable? ? stale? : false
+      end
+
       def valid_extension?(extension)
         !Template.registered_template_handler(extension).nil?
       end
@@ -212,15 +225,6 @@ module ActionView #:nodoc:
         I18n.available_locales.include?(locale.to_sym)
       end
 
-      def find_full_path(path, load_paths)
-        load_paths = Array(load_paths) + [nil]
-        load_paths.each do |load_path|
-          file = load_path ? "#{load_path.to_str}/#{path}" : path
-          return load_path, file if File.file?(file)
-        end
-        raise MissingTemplate.new(load_paths, path)
-      end
-
       # Returns file split into an array
       #   [base_path, name, locale, format, extension]
       def split(file)
@@ -259,5 +263,5 @@ module ActionView #:nodoc:
 
         [base_path, name, locale, format, extension]
       end
-  end
+ end
 end
diff --git a/actionpack/test/template/compiled_templates_test.rb b/actionpack/test/template/compiled_templates_test.rb
index a7ed13cf57..2c32fdee0b 100644
--- a/actionpack/test/template/compiled_templates_test.rb
+++ b/actionpack/test/template/compiled_templates_test.rb
@@ -39,35 +39,29 @@ class CompiledTemplatesTest < Test::Unit::TestCase
   end
 
   def test_template_changes_are_not_reflected_with_cached_templates
-    assert_equal "Hello world!", render(:file => "test/hello_world.erb")
-    modify_template "test/hello_world.erb", "Goodbye world!" do
+    with_caching(true) do
+      assert_equal "Hello world!", render(:file => "test/hello_world.erb")
+      modify_template "test/hello_world.erb", "Goodbye world!" do
+        assert_equal "Hello world!", render(:file => "test/hello_world.erb")
+      end
       assert_equal "Hello world!", render(:file => "test/hello_world.erb")
     end
-    assert_equal "Hello world!", render(:file => "test/hello_world.erb")
   end
 
-  def test_template_changes_are_reflected_with_uncached_templates
-    assert_equal "Hello world!", render_without_cache(:file => "test/hello_world.erb")
-    modify_template "test/hello_world.erb", "Goodbye world!" do
-      assert_equal "Goodbye world!", render_without_cache(:file => "test/hello_world.erb")
+  def test_template_changes_are_reflected_without_cached_templates
+    with_caching(false) do
+      assert_equal "Hello world!", render(:file => "test/hello_world.erb")
+      modify_template "test/hello_world.erb", "Goodbye world!" do
+        assert_equal "Goodbye world!", render(:file => "test/hello_world.erb")
+        sleep(1) # Need to sleep so that the timestamp actually changes
+      end
+      assert_equal "Hello world!", render(:file => "test/hello_world.erb")
     end
-    assert_equal "Hello world!", render_without_cache(:file => "test/hello_world.erb")
   end
 
   private
     def render(*args)
-      render_with_cache(*args)
-    end
-
-    def render_with_cache(*args)
       view_paths = ActionController::Base.view_paths
-      assert_equal ActionView::Template::EagerPath, view_paths.first.class
-      ActionView::Base.new(view_paths, {}).render(*args)
-    end
-
-    def render_without_cache(*args)
-      path = ActionView::Template::Path.new(FIXTURE_LOAD_PATH)
-      view_paths = ActionView::Base.process_view_paths(path)
       assert_equal ActionView::Template::Path, view_paths.first.class
       ActionView::Base.new(view_paths, {}).render(*args)
     end
@@ -82,4 +76,14 @@ class CompiledTemplatesTest < Test::Unit::TestCase
         File.open(filename, "wb+") { |f| f.write(old_content) }
       end
     end
+
+    def with_caching(caching_enabled)
+      old_caching_enabled = ActionView::Base.cache_template_loading
+      begin
+        ActionView::Base.cache_template_loading = caching_enabled
+        yield
+      ensure
+        ActionView::Base.cache_template_loading = old_caching_enabled
+      end
+    end
 end
diff --git a/actionpack/test/template/render_test.rb b/actionpack/test/template/render_test.rb
index 9db62d9c23..34e7e82366 100644
--- a/actionpack/test/template/render_test.rb
+++ b/actionpack/test/template/render_test.rb
@@ -243,25 +243,12 @@ module RenderTestCases
   end
 end
 
-class CachedViewRenderTest < Test::Unit::TestCase
+class CachedRenderTest < Test::Unit::TestCase
   include RenderTestCases
 
   # Ensure view path cache is primed
   def setup
     view_paths = ActionController::Base.view_paths
-    assert_equal ActionView::Template::EagerPath, view_paths.first.class
-    setup_view(view_paths)
-  end
-end
-
-class LazyViewRenderTest < Test::Unit::TestCase
-  include RenderTestCases
-
-  # Test the same thing as above, but make sure the view path
-  # is not eager loaded
-  def setup
-    path = ActionView::Template::Path.new(FIXTURE_LOAD_PATH)
-    view_paths = ActionView::Base.process_view_paths(path)
     assert_equal ActionView::Template::Path, view_paths.first.class
     setup_view(view_paths)
   end
diff --git a/railties/environments/production.rb b/railties/environments/production.rb
index 1fc9f6b923..27119d2d18 100644
--- a/railties/environments/production.rb
+++ b/railties/environments/production.rb
@@ -7,6 +7,7 @@ config.cache_classes = true
 # Full error reports are disabled and caching is turned on
 config.action_controller.consider_all_requests_local = false
 config.action_controller.perform_caching             = true
+config.action_view.cache_template_loading            = true
 
 # See everything in the log (default is :info)
 # config.log_level = :debug
diff --git a/railties/lib/initializer.rb b/railties/lib/initializer.rb
index e3811dd8be..2cc0943b78 100644
--- a/railties/lib/initializer.rb
+++ b/railties/lib/initializer.rb
@@ -181,9 +181,6 @@ module Rails
       # Observers are loaded after plugins in case Observers or observed models are modified by plugins.
       load_observers
 
-      # Load view path cache
-      load_view_paths
-
       # Load application classes
       load_application_classes
 
@@ -367,16 +364,6 @@ Run `rake gems:install` to install the missing gems.
       end
     end
 
-    def load_view_paths
-      if configuration.frameworks.include?(:action_view)
-        if configuration.cache_classes
-          view_path = ActionView::Template::EagerPath.new(configuration.view_path)
-          ActionController::Base.view_paths = view_path if configuration.frameworks.include?(:action_controller)
-          ActionMailer::Base.template_root = view_path if configuration.frameworks.include?(:action_mailer)
-        end
-      end
-    end
-
     # Eager load application classes
     def load_application_classes
       return if $rails_rake_task