[testing] Execjs runtime benchmarks

benchmarks/server_rendering_benchmark.rb

@@ -0,0 +1,68 @@
+# - `gem install duktape`
+# - Remove `JavaScriptCore` from RUNTIMES if you're not on mac
+# - `ruby -I lib  benchmarks/server_rendering_benchmark.rb`
+
+require 'react-rails'
+require 'duktape'
+require 'benchmark'
+
+SLOW_COMPONENT = "
+var SlowComponent = React.createClass({
+  render: function() {
+    var rand = 0
+    for (var i = 0; i < 10000; i++) {
+      rand = rand + (Math.random() * i)
+    }
+    return React.createElement('h1', rand + ' :)')
+  }
+})
+"
+
+REACT_JS_PATH = File.expand_path("../../vendor/react/react.js", __FILE__)
+JS_CODE = File.read(REACT_JS_PATH) + SLOW_COMPONENT
+
+React::ServerRendering.renderer = React::ServerRendering::ExecJSRenderer
+React::ServerRendering.renderer_options = {code: JS_CODE}
+React::ServerRendering.pool_timeout = 1000
+
+def test_runtime(runtime, renders:, pool_size:, threaded:, thread_size:)
+  ExecJS.runtime = runtime
+  React::ServerRendering.pool_size = pool_size
+  React::ServerRendering.reset_pool
+  if threaded
+    threads = thread_size.times.map do
+      Thread.new do
+        renders.times do
+          React::ServerRendering.render("SlowComponent", {}, {})
+          Thread.pass
+        end
+      end
+    end
+    threads.map(&:join)
+  else
+    renders.times.map do
+      React::ServerRendering.render("SlowComponent", {}, {})
+    end
+  end
+end
+
+RUNTIMES = [
+  ExecJS::Runtimes::RubyRacer,
+  ExecJS::Runtimes::Duktape,
+  ExecJS::Runtimes::JavaScriptCore,
+  ExecJS::Runtimes::Node,
+]
+
+Benchmark.bm(45) do |x|
+  [true, false].each do |threaded|
+    [1, 10, 25].each do |pool_size|
+      [1, 2, 4, 8].each do |thread_size|
+        RUNTIMES.each do |runtime|
+          x.report("#{threaded ? "threaded, " : ""}#{pool_size} conn, #{thread_size} threads, #{runtime.name}") do
+            test_runtime(runtime, renders: 100, pool_size: pool_size, threaded: true, thread_size: thread_size)
+          end
+        end
+      end
+    end
+  end
+end

lib/react/server_rendering.rb

@@ -1,5 +1,6 @@
 require 'connection_pool'
 require 'react/server_rendering/sprockets_renderer'
+require 'react/server_rendering/exec_js_renderer'
 
 module React
   module ServerRendering

lib/react/server_rendering/exec_js_renderer.rb

@@ -0,0 +1,31 @@
+module React
+  module ServerRendering
+    class ExecJSRenderer
+      def initialize(options={})
+        js_code = options.fetch(:code) || raise("Pass `code:` option to instantiate a JS context!")
+        @context = ExecJS.compile(js_code)
+      end
+
+      def render(component_name, props, prerender_options)
+        js_code = <<-JS
+          (function () {
+            var result = React.renderToString(React.createElement(#{component_name}, #{props}));
+            return result;
+          })()
+        JS
+
+        @context.eval(js_code)
+      rescue ExecJS::ProgramError => err
+        raise PrerenderError.new(component_name, props, err)
+      end
+
+      class PrerenderError < RuntimeError
+        def initialize(component_name, props, js_message)
+          message = ["Encountered error \"#{js_message}\" when prerendering #{component_name} with #{props}",
+                      js_message.backtrace.join("\n")].join("\n")
+          super(message)
+        end
+      end
+    end
+  end
+end

lib/react/server_rendering/sprockets_renderer.rb

@@ -8,12 +8,21 @@ def initialize(options={})
         js_code = GLOBAL_WRAPPER + CONSOLE_POLYFILL
 
         filenames.each do |filename|
-          js_code << ::Rails.application.assets[filename].to_s
+          js_code << load_asset(filename)
         end
 
         @context = ExecJS.compile(js_code)
       end
 
+      def load_asset(file)
+        if ::Rails.application.config.assets.compile
+          ::Rails.application.assets[file].to_s
+        else
+          asset_path = ActionView::Base.new.asset_path(file)
+          File.read(File.join(::Rails.public_path, asset_path))
+        end
+      end
+
       def render(component_name, props, prerender_options)
         # pass prerender: :static to use renderToStaticMarkup
         react_render_method = if prerender_options == :static