Began on a file system to help test flush/fsync support.

samples/flushfs/flush_fs.go

+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package flushfs
+
+import "github.com/jacobsa/fuse"
+
+// Create a file system containing a single file named "foo".
+//
+// The file may be opened for reading and/or writing. Its initial contents are
+// empty. Whenever a flush or fsync is received, the supplied function will be
+// called with the current contents of the file.
+func NewFileSystem(
+	reportFlush func([]byte),
+	reportFsync func([]byte)) (fs fuse.FileSystem, err error)