refactor the encode/decode into it's own class

Author: hone

lib/resque.rb

@@ -13,6 +13,8 @@
 require 'resque/worker'
 require 'resque/plugin'
 require 'resque/queue'
+require 'resque/coder'
+require 'resque/multi_json_coder'
 
 module Resque
   include Helpers
@@ -45,10 +47,17 @@ def redis=(server)
       @redis = Redis::Namespace.new(:resque, :redis => server)
     end
     @queues = Hash.new { |h,name|
-      h[name] = Resque::Queue.new(name, @redis, self)
+      h[name] = Resque::Queue.new(name, @redis, coder)
     }
   end
 
+  # Encapsulation of encode/decode. Overwrite this to use it across Resque.
+  # This defaults to MultiJson for backwards compatibilty.
+  def coder
+    @coder ||= MultiJsonCoder.new
+  end
+  attr_writer :coder
+
   # Returns the current Redis connection. If none has been created, will
   # create a new one.
   def redis

lib/resque/coder.rb

@@ -0,0 +1,27 @@
+module Resque
+  class EncodeException < StandardError; end
+  class DecodeException < StandardError; end
+
+  class Coder
+    # Given a Ruby object, returns a string suitable for storage in a
+    # queue.
+    def encode(object)
+      raise EncodeException
+    end
+
+    # alias for encode
+    def dump(object)
+      encode(object)
+    end
+
+    # Given a string, returns a Ruby object.
+    def decode(object)
+      raise DecodeException
+    end
+
+    # alias for decode
+    def load(object)
+      decode(object)
+    end
+  end
+end

lib/resque/helpers.rb

@@ -1,39 +1,18 @@
-require 'multi_json'
-
-# OkJson won't work because it doesn't serialize symbols
-# in the same way yajl and json do.
-if MultiJson.engine.to_s == 'MultiJson::Engines::OkJson'
-  raise "Please install the yajl-ruby or json gem"
-end
-
 module Resque
   # Methods used by various classes in Resque.
   module Helpers
-    class DecodeException < StandardError; end
-
     # Direct access to the Redis instance.
     def redis
       Resque.redis
     end
 
-    # Given a Ruby object, returns a string suitable for storage in a
-    # queue.
     def encode(object)
-      ::MultiJson.encode(object)
+      Resque.coder.encode(object)
     end
-    alias :dump :encode
 
-    # Given a string, returns a Ruby object.
     def decode(object)
-      return unless object
-
-      begin
-        ::MultiJson.decode(object)
-      rescue ::MultiJson::DecodeError => e
-        raise DecodeException, e.message, e.backtrace
-      end
+      Resque.coder.decode(object)
     end
-    alias :load :decode
 
     # Given a word with dashes, returns a camel cased version of it.
     #

lib/resque/multi_json_coder.rb

@@ -0,0 +1,26 @@
+require 'multi_json'
+require 'resque/coder'
+
+# OkJson won't work because it doesn't serialize symbols
+# in the same way yajl and json do.
+if MultiJson.engine.to_s == 'MultiJson::Engines::OkJson'
+  raise "Please install the yajl-ruby or json gem"
+end
+
+module Resque
+  class MultiJsonCoder < Coder
+    def encode(object)
+      ::MultiJson.encode(object)
+    end
+
+    def decode(object)
+      return unless object
+
+      begin
+        ::MultiJson.decode(object)
+      rescue ::MultiJson::DecodeError => e
+        raise DecodeException, e.message, e.backtrace
+      end
+    end
+  end
+end

test/resque_test.rb

@@ -263,8 +263,8 @@
   end
 
   it "decode bad json" do
-    assert_raises Resque::Helpers::DecodeException do
-      Resque.decode("{\"error\":\"Module not found \\u002\"}")
+    assert_raises Resque::DecodeException do
+      Resque.coder.decode("{\"error\":\"Module not found \\u002\"}")
     end
   end