Checking stream mode in Event#modified_files.

The mtime mode is the default and is the same as before, checking if any file's mtime is greater than or equal to the last event time.
The cache mode will check the stream's cache to see if any file's mtime or size has changed. (The checks happen explicitly because File::Stat#<=> only compares mtime).

lib/fsevents/event.rb

@@ -13,7 +13,21 @@ def files
     end
 
     def modified_files
-      files.select { |f|  File.mtime(f) >= stream.last_event }
+      case stream.mode
+      when :mtime
+        files.select { |f|  File.mtime(f) >= stream.last_event }
+      when :cache
+        cache = stream.dirs[path]
+
+        files.select do |f|
+          cached = cache[f]
+
+          cached.nil? or
+
+          File.mtime(f) != cached.mtime or
+          File.size(f)  != cached.size
+        end
+      end
     end
   end
 end

spec/event_spec.rb

@@ -56,49 +56,137 @@
   describe 'listing modified files' do
     before :each do
       @now = Time.now
-      @stream.stubs(:last_event).returns(@now)
-      @files = Array.new(5) do |i|
-        file = stub("file #{i+1}")
-        File.stubs(:mtime).with(file).returns(@now + i - 2)
-        file
-      end
+      @files = Array.new(5) { |i|  stub("file #{i+1}") }
       @event.stubs(:files).returns(@files)
     end
-
-    it 'should get the file list' do
-      @event.expects(:files).returns(@files)
-      @event.modified_files
-    end
-
-    it 'should get the last event time from the stream' do
-      @stream.expects(:last_event).returns(@now)
+
+    it 'should check the stream mode' do
+      @stream.expects(:mode)
       @event.modified_files
     end
-
-    it 'should return files modified after the last event time' do
-      expected_files = @files.values_at(3, 4)
-      modified_files = @event.modified_files
-
-      expected_files.each do |file|
-        modified_files.should include(file)
+
+    describe 'when the stream mode is mtime' do
+      before :each do
+        @stream.stubs(:mode).returns(:mtime)
       end
-    end
-
-    it 'should return files modified at the last event time' do
-      expected_files = @files.values_at(2)
-      modified_files = @event.modified_files
-
-      expected_files.each do |file|
-        modified_files.should include(file)
+
+      before :each do
+        @stream.stubs(:last_event).returns(@now)
+        @files.each_with_index do |file, i|
+          File.stubs(:mtime).with(file).returns(@now + i - 2)
+        end
+      end
+
+      it 'should get the file list' do
+        @event.expects(:files).returns(@files)
+        @event.modified_files
+      end
+
+      it 'should get the last event time from the stream' do
+        @stream.expects(:last_event).returns(@now)
+        @event.modified_files
+      end
+
+      it 'should return files modified after the last event time' do
+        expected_files = @files.values_at(3, 4)
+        modified_files = @event.modified_files
+
+        expected_files.each do |file|
+          modified_files.should include(file)
+        end
+      end
+
+      it 'should return files modified at the last event time' do
+        expected_files = @files.values_at(2)
+        modified_files = @event.modified_files
+
+        expected_files.each do |file|
+          modified_files.should include(file)
+        end
+      end
+
+      it 'should not return files not modified after the last event time' do
+        unexpected_files = @files.values_at(0, 1)
+        modified_files = @event.modified_files
+
+        unexpected_files.each do |file|
+          modified_files.should_not include(file)
+        end
       end
     end
-
-    it 'should not return files not modified after the last event time' do
-      unexpected_files = @files.values_at(0, 1)
-      modified_files = @event.modified_files
-
-      unexpected_files.each do |file|
-        modified_files.should_not include(file)
+
+    describe 'when the stream mode is cache' do
+      before :each do
+        @stream.stubs(:mode).returns(:cache)
+      end
+
+      before :each do
+        @dir_cache = { @path => {} }
+        @files.each_with_index do |file, i|
+          size  = 50 * (i + 1)
+          mtime = @now + i - 2
+          File.stubs(:size).with(file).returns(size)
+          File.stubs(:mtime).with(file).returns(mtime)
+          stat = stub("file #{i+1} stat", :mtime => mtime, :size => size)
+          @dir_cache[@path][file] = stat
+        end
+        @stream.stubs(:dirs).returns(@dir_cache)
+      end
+
+      it 'should get the file list' do
+        @event.expects(:files).returns(@files)
+        @event.modified_files
+      end
+
+      it 'should get the stream dir cache' do
+        @stream.expects(:dirs).returns(@dir_cache)
+        @event.modified_files
+      end
+
+      it 'should get the dir cache for the event path' do
+        sub_cache = @dir_cache[@path]
+        @dir_cache.expects(:[]).with(@path).returns(sub_cache)
+        @event.modified_files
+      end
+
+      it 'should return files that do not appear in the cache' do
+        expected_files = Array.new(2) { |i|  stub("new file #{i+1}") }
+        expected_files.each { |file|  @files.push(file) }
+        modified_files = @event.modified_files
+
+        expected_files.each do |file|
+          modified_files.should include(file)
+        end
+      end
+
+      it 'should return files with sizes that differ from the cache' do
+        @dir_cache[@path][@files[3]].stubs(:size).returns(3)
+        @dir_cache[@path][@files[4]].stubs(:size).returns(101)
+        expected_files = @files.values_at(3, 4)
+        modified_files = @event.modified_files
+
+        expected_files.each do |file|
+          modified_files.should include(file)
+        end
+      end
+
+      it 'should return files with mtimes that differ from the cache' do
+        @dir_cache[@path][@files[2]].stubs(:mtime).returns(@now - 234)
+        expected_files = @files.values_at(2)
+        modified_files = @event.modified_files
+
+        expected_files.each do |file|
+          modified_files.should include(file)
+        end
+      end
+
+      it 'should not return files not modified from the cache' do
+        unexpected_files = @files.values_at(0, 1)
+        modified_files = @event.modified_files
+
+        unexpected_files.each do |file|
+          modified_files.should_not include(file)
+        end
       end
     end
   end