diff --git a/lib/rhino/rhino_ext.rb b/lib/rhino/rhino_ext.rb
index ed5ce04..51ca2f3 100644
--- a/lib/rhino/rhino_ext.rb
+++ b/lib/rhino/rhino_ext.rb
@@ -173,3 +173,43 @@ class Java::OrgMozillaJavascript::BaseFunction
   end
   
 end
+
+class Java::OrgMozillaJavascript::Context
+  
+  def reset_cache!
+    @cache = java.util.WeakHashMap.new
+  end
+
+  def enable_cache!
+    @cache = nil unless @cache
+  end
+
+  def disable_cache!
+    @cache = false
+  end
+  
+  # Support for caching JS data per context.
+  # e.g. to get === comparison's working ...
+  # 
+  # NOTE: the cache only works correctly for keys following Java identity !
+  #       (implementing #equals & #hashCode e.g. RubyStrings will work ...)
+  #
+  def cache(key)
+    return yield if @cache == false
+    reset_cache! unless @cache
+    fetch(key) || store(key, yield)
+  end
+    
+  private
+
+    def fetch(key)
+      ref = @cache.get(key)
+      ref ? ref.get : nil
+    end
+
+    def store(key, value)
+      @cache.put(key, java.lang.ref.WeakReference.new(value))
+      value
+    end
+    
+end
diff --git a/lib/rhino/ruby.rb b/lib/rhino/ruby.rb
index 560d393..cb78f22 100644
--- a/lib/rhino/ruby.rb
+++ b/lib/rhino/ruby.rb
@@ -207,28 +207,12 @@ module Rhino
       end
 
     end
-
-    def self.cache(key)
-      return yield unless @@cache
-      fetch(key) || store(key, yield)
+    
+    def self.cache(key, &block)
+      context = JS::Context.getCurrentContext
+      context ? context.cache(key, &block) : yield
     end
     
-    private
-    
-      # NOTE: just to get === comparison's working ...
-      # if == is enough might be disabled by setting to nil
-      @@cache = java.util.WeakHashMap.new
-    
-      def self.fetch(key)
-        ref = @@cache.get(key)
-        ref ? ref.get : nil
-      end
-
-      def self.store(key, value)
-        @@cache.put(key, java.lang.ref.WeakReference.new(value))
-        value
-      end
-    
   end
   
   RubyObject = Ruby::Object