Fix option caching issues

fix #123
fix #125

Author: rwz

lib/multi_json.rb

@@ -5,6 +5,16 @@ module MultiJson
   include Options
   extend self
 
+  class << self
+    def cached_options
+      @cached_options || reset_cached_options!
+    end
+
+    def reset_cached_options!
+      @cached_options = {}
+    end
+  end
+
   class LoadError < StandardError
     attr_reader :data
     def initialize(message='', backtrace=[], data='')
@@ -27,17 +37,7 @@ def default_options=(value)
     self.load_options = self.dump_options = value
   end
 
-  # cache busting
-  %w(load_options= dump_options=).each do |method|
-    define_method method do |*args|
-      use current_adapter
-      super(*args)
-    end
-  end
-
-  ALIASES = {
-    'jrjackson' => :jr_jackson
-  }
+  ALIASES = { 'jrjackson' => :jr_jackson }
 
   REQUIREMENT_MAP = [
     ['oj',           :oj],
@@ -95,9 +95,7 @@ def adapter
   # * <tt>:gson</tt> (JRuby only)
   # * <tt>:jr_jackson</tt> (JRuby only)
   def use(new_adapter)
-    adapter = load_adapter(new_adapter)
-    adapter.activate! if adapter.respond_to?(:activate!)
-    @adapter = adapter
+    @adapter = load_adapter(new_adapter)
   end
   alias adapter= use
   alias engine= use

lib/multi_json/adapter.rb

@@ -15,35 +15,34 @@ def defaults(action, value)
         end
       end
 
-      def activate!
-        @load_options_cache = {}
-        @dump_options_cache = {}
-        instance.activate if instance.respond_to?(:activate)
-      end
-
       def load(string, options={})
-        instance.load(string, collect_load_options(string, options).clone)
+        instance.load(string, collect_load_options(options).clone)
       end
 
       def dump(object, options={})
-        instance.dump(object, collect_dump_options(object, options).clone)
+        instance.dump(object, collect_dump_options(options).clone)
       end
 
     protected
 
-      def collect_load_options(string, options)
-        @load_options_cache[options] ||= collect_options(:load_options, options).merge(options)
+      def collect_load_options(options)
+        cache('load', options){ collect_options(:load_options, options).merge(options) }
       end
 
-      def collect_dump_options(object, options)
-        @dump_options_cache[options] ||= collect_options(:dump_options, options).merge(options)
+      def collect_dump_options(options)
+        cache('dump', options){ collect_options(:dump_options, options).merge(options) }
       end
 
       def collect_options(method, *args)
         global, local = *[MultiJson, self].map{ |r| r.send(method, *args) }
         local.merge(global)
       end
 
+      def cache(method, options)
+        cache_key = [self, options].map(&:hash).join + method
+        MultiJson.cached_options[cache_key] ||= yield
+      end
+
     end
   end
 end

lib/multi_json/options.rb

@@ -1,6 +1,15 @@
 module MultiJson
   module Options
-    attr_writer :load_options, :dump_options
+
+    def load_options=(options)
+      MultiJson.reset_cached_options!
+      @load_options = options
+    end
+
+    def dump_options=(options)
+      MultiJson.reset_cached_options!
+      @dump_options = options
+    end
 
     def load_options(*args)
       get_options :load_options, *args

spec/multi_json_spec.rb

@@ -51,15 +51,24 @@
     end
 
     context 'caching' do
-      before{ MultiJson.use :json_gem }
+      before{ MultiJson.use adapter }
+      let(:adapter){ MultiJson::Adapters::JsonGem }
       let(:json_string){ '{"abc":"def"}' }
 
-      it 'busts options caches on change' do
+      it 'busts caches on global options change' do
         MultiJson.load_options = { :symbolize_keys => true }
         expect(MultiJson.load(json_string)).to eq(:abc => 'def')
         MultiJson.load_options = nil
         expect(MultiJson.load(json_string)).to eq('abc' => 'def')
       end
+
+      it 'busts caches on per-adapter options change' do
+        adapter.load_options = { :symbolize_keys => true }
+        expect(MultiJson.load(json_string)).to eq(:abc => 'def')
+        adapter.load_options = nil
+        expect(MultiJson.load(json_string)).to eq('abc' => 'def')
+      end
+
     end
 
     it 'defaults to the best available gem' do