[Sass] Add support for dumping certain Tree::Node options.

lib/haml/util.rb

@@ -269,6 +269,35 @@ module Haml
       version_gt(v1, v2) || !version_gt(v2, v1)
     end
 
+    # A wrapper for `Marshal.dump` that calls `#_before_dump` on the object
+    # before dumping it, `#_after_dump` afterwards.
+    # It also calls `#_around_dump` and passes it a block in which the object is dumped.
+    #
+    # If any of these methods are undefined, they are not called.
+    #
+    # @param obj [Object] The object to dump.
+    # @return [String] The dumped data.
+    def dump(obj)
+      obj._before_dump if obj.respond_to?(:_before_dump)
+      return Marshal.dump(obj) unless obj.respond_to?(:_around_dump)
+      res = nil
+      obj._around_dump {res = Marshal.dump(obj)}
+      res
+    ensure
+      obj._after_dump if obj.respond_to?(:_after_dump)
+    end
+
+    # A wrapper for `Marshal.load` that calls `#_after_load` on the object
+    # after loading it, if it's defined.
+    #
+    # @param data [String] The data to load.
+    # @return [Object] The loaded object.
+    def load(data)
+      obj = Marshal.load(data)
+      obj._after_load if obj.respond_to?(:_after_load)
+      obj
+    end
+
     # Silence all output to STDERR within a block.
     #
     # @yield A block in which no output will be printed to STDERR

lib/sass/cache_store.rb

@@ -49,8 +49,7 @@ module Sass
     def store(key, sha, root)
       orig_options = root.options
       begin
-        root.options = {}
-        _store_(key, Sass::VERSION, sha, Marshal.dump(root))
+        _store_(key, Sass::VERSION, sha, Haml::Util.dump(root))
       ensure
         root.options = orig_options
       end
@@ -63,7 +62,7 @@ module Sass
     # @return [Sass::Tree::RootNode] The root node.
     def retrieve(key, sha)
       contents = _retrieve_(key, Sass::VERSION, sha)
-      Marshal.load(contents) if contents
+      Haml::Util.load(contents) if contents
     rescue EOFError, TypeError, ArgumentError => e
       raise
       Haml::Util.haml_warn "Warning. Error encountered while reading cache #{path_to(key)}: #{e}"

lib/sass/files.rb

@@ -29,7 +29,8 @@ module Sass
         sha = Digest::SHA1.hexdigest(sass_file.contents)
 
         if root = options[:cache_store].retrieve(key, sha)
-          root.options = options.merge(:filename => sass_file.filename)
+          root.options = root.options.merge(
+            options.merge(:filename => sass_file.filename))
           return root
         end
       end

lib/sass/tree/node.rb

@@ -244,6 +244,23 @@ module Sass
         to_src(tabs, opts, :scss)
       end
 
+      # Names of options that are saved when the node is serialized and cached.
+      #
+      # @type [Array<Symbol>]
+      SAVED_OPTIONS = []
+
+      # Ensures that only {SAVED_OPTIONS} get saved.
+      def _around_dump
+        old_options = @options
+        @options = {}
+        SAVED_OPTIONS.each do |opt|
+          @options[opt] = old_options[opt]
+        end
+        yield
+      ensure
+        options = old_options
+      end
+
       protected
 
       # Computes the CSS corresponding to this particular Sass node.

test/haml/util_test.rb

@@ -5,6 +5,19 @@ require 'pathname'
 class UtilTest < Test::Unit::TestCase
   include Haml::Util
 
+  class Dumpable
+    attr_reader :arr
+    def initialize; @arr = []; end
+    def _before_dump; @arr << :before; end
+    def _after_dump; @arr << :after; end
+    def _around_dump
+      @arr << :around_before
+      yield
+      @arr << :around_after
+    end
+    def _after_load; @arr << :loaded; end
+  end
+
   def test_scope
     assert(File.exist?(scope("Rakefile")))
   end
@@ -240,6 +253,14 @@ class UtilTest < Test::Unit::TestCase
     assert(!version_gt(v2, v1), "Expected #{v2} = #{v1}")
   end
 
+  def test_dump_and_load
+    obj = Dumpable.new
+    data = dump(obj)
+    assert_equal([:before, :around_before, :around_after, :after], obj.arr)
+    obj2 = load(data)
+    assert_equal([:before, :around_before, :loaded], obj2.arr)
+  end
+
   def test_def_static_method
     klass = Class.new
     def_static_method(klass, :static_method, [:arg1, :arg2],