add benchmarks

benchmarks/bench_uglify.rb

@@ -0,0 +1,35 @@
+engine = ARGV[0] == "therubyracer" ? "therubyracer" : "MiniRacer"
+
+if ARGV[0] == "rubyracer"
+  require 'therubyracer'
+  puts "Benching with therubyracer"
+else
+  require 'mini_racer'
+  puts "Benching with MiniRacer"
+end
+
+require 'uglifier'
+
+if ARGV[0] == "rubyracer"
+  ExecJS.runtime = ExecJS::RubyRacerRuntime.new
+else
+  ExecJS.runtime = ExecJS::MiniRacerRuntime.new
+end
+
+start = Time.new
+Uglifier.compile(File.read("discourse_app.js"))
+puts "#{engine} minify discourse_app.js #{(Time.new - start)*1000}ms"
+
+start = Time.new
+Uglifier.compile(File.read("discourse_app_minified.js"))
+puts "#{engine} minify discourse_app_minified.js #{(Time.new - start)*1000}ms"
+
+start = Time.new
+(0..1).map do
+  Thread.new do
+    Uglifier.compile(File.read("discourse_app.js"))
+  end
+end.each(&:join)
+
+puts "#{engine} minify discourse_app.js twice (2 threads) #{(Time.new - start)*1000}ms"
+