add fibered em connection without activerecord

lib/mysql2/em_fiber.rb

@@ -0,0 +1,25 @@
+# encoding: utf-8
+
+require 'mysql2/em'
+require 'fiber' unless defined? Fiber
+
+module Mysql2
+  module EM
+    module Fiber
+      class Client < ::Mysql2::EM::Client
+        def query(sql, opts={})
+          deferable = super(sql, opts)
+
+          fiber = ::Fiber.current
+          deferable.callback do |result|
+            fiber.resume(result)
+          end
+          deferable.errback do |err|
+            fiber.resume(err)
+          end
+          ::Fiber.yield
+        end
+      end
+    end
+  end
+end

mysql2.gemspec

@@ -46,6 +46,7 @@ Gem::Specification.new do |s|
      "lib/mysql2.rb",
      "lib/mysql2/client.rb",
      "lib/mysql2/em.rb",
+     "lib/mysql2/em_fiber.rb",
      "lib/mysql2/error.rb",
      "lib/mysql2/result.rb",
      "mysql2.gemspec",