[VOL-2235] Mocks and interfaces for rw-core

This update consists of mocks that are used by the rw-core
during unit testing.  It also includes interfaces used for unit
tests.

Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/fileutil.go b/vendor/go.etcd.io/etcd/pkg/fileutil/fileutil.go
new file mode 100644
index 0000000..5d9fb53
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/fileutil.go
@@ -0,0 +1,104 @@
+// Copyright 2015 The etcd Authors
+//
+// 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 fileutil
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/coreos/pkg/capnslog"
+)
+
+const (
+	// PrivateFileMode grants owner to read/write a file.
+	PrivateFileMode = 0600
+	// PrivateDirMode grants owner to make/remove files inside the directory.
+	PrivateDirMode = 0700
+)
+
+var plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "pkg/fileutil")
+
+// IsDirWriteable checks if dir is writable by writing and removing a file
+// to dir. It returns nil if dir is writable.
+func IsDirWriteable(dir string) error {
+	f := filepath.Join(dir, ".touch")
+	if err := ioutil.WriteFile(f, []byte(""), PrivateFileMode); err != nil {
+		return err
+	}
+	return os.Remove(f)
+}
+
+// TouchDirAll is similar to os.MkdirAll. It creates directories with 0700 permission if any directory
+// does not exists. TouchDirAll also ensures the given directory is writable.
+func TouchDirAll(dir string) error {
+	// If path is already a directory, MkdirAll does nothing
+	// and returns nil.
+	err := os.MkdirAll(dir, PrivateDirMode)
+	if err != nil {
+		// if mkdirAll("a/text") and "text" is not
+		// a directory, this will return syscall.ENOTDIR
+		return err
+	}
+	return IsDirWriteable(dir)
+}
+
+// CreateDirAll is similar to TouchDirAll but returns error
+// if the deepest directory was not empty.
+func CreateDirAll(dir string) error {
+	err := TouchDirAll(dir)
+	if err == nil {
+		var ns []string
+		ns, err = ReadDir(dir)
+		if err != nil {
+			return err
+		}
+		if len(ns) != 0 {
+			err = fmt.Errorf("expected %q to be empty, got %q", dir, ns)
+		}
+	}
+	return err
+}
+
+// Exist returns true if a file or directory exists.
+func Exist(name string) bool {
+	_, err := os.Stat(name)
+	return err == nil
+}
+
+// ZeroToEnd zeros a file starting from SEEK_CUR to its SEEK_END. May temporarily
+// shorten the length of the file.
+func ZeroToEnd(f *os.File) error {
+	// TODO: support FALLOC_FL_ZERO_RANGE
+	off, err := f.Seek(0, io.SeekCurrent)
+	if err != nil {
+		return err
+	}
+	lenf, lerr := f.Seek(0, io.SeekEnd)
+	if lerr != nil {
+		return lerr
+	}
+	if err = f.Truncate(off); err != nil {
+		return err
+	}
+	// make sure blocks remain allocated
+	if err = Preallocate(f, lenf, true); err != nil {
+		return err
+	}
+	_, err = f.Seek(off, io.SeekStart)
+	return err
+}