diff --git a/vendor/github.com/coreos/etcd/wal/encoder.go b/vendor/github.com/coreos/etcd/wal/encoder.go
new file mode 100644
index 0000000..e8890d8
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/wal/encoder.go
@@ -0,0 +1,124 @@
+// 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 wal
+
+import (
+	"encoding/binary"
+	"hash"
+	"io"
+	"os"
+	"sync"
+
+	"github.com/coreos/etcd/pkg/crc"
+	"github.com/coreos/etcd/pkg/ioutil"
+	"github.com/coreos/etcd/wal/walpb"
+)
+
+// walPageBytes is the alignment for flushing records to the backing Writer.
+// It should be a multiple of the minimum sector size so that WAL can safely
+// distinguish between torn writes and ordinary data corruption.
+const walPageBytes = 8 * minSectorSize
+
+type encoder struct {
+	mu sync.Mutex
+	bw *ioutil.PageWriter
+
+	crc       hash.Hash32
+	buf       []byte
+	uint64buf []byte
+}
+
+func newEncoder(w io.Writer, prevCrc uint32, pageOffset int) *encoder {
+	return &encoder{
+		bw:  ioutil.NewPageWriter(w, walPageBytes, pageOffset),
+		crc: crc.New(prevCrc, crcTable),
+		// 1MB buffer
+		buf:       make([]byte, 1024*1024),
+		uint64buf: make([]byte, 8),
+	}
+}
+
+// newFileEncoder creates a new encoder with current file offset for the page writer.
+func newFileEncoder(f *os.File, prevCrc uint32) (*encoder, error) {
+	offset, err := f.Seek(0, io.SeekCurrent)
+	if err != nil {
+		return nil, err
+	}
+	return newEncoder(f, prevCrc, int(offset)), nil
+}
+
+func (e *encoder) encode(rec *walpb.Record) error {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	e.crc.Write(rec.Data)
+	rec.Crc = e.crc.Sum32()
+	var (
+		data []byte
+		err  error
+		n    int
+	)
+
+	if rec.Size() > len(e.buf) {
+		data, err = rec.Marshal()
+		if err != nil {
+			return err
+		}
+	} else {
+		n, err = rec.MarshalTo(e.buf)
+		if err != nil {
+			return err
+		}
+		data = e.buf[:n]
+	}
+
+	lenField, padBytes := encodeFrameSize(len(data))
+	if err = writeUint64(e.bw, lenField, e.uint64buf); err != nil {
+		return err
+	}
+
+	if padBytes != 0 {
+		data = append(data, make([]byte, padBytes)...)
+	}
+	n, err = e.bw.Write(data)
+	walWriteBytes.Add(float64(n))
+	return err
+}
+
+func encodeFrameSize(dataBytes int) (lenField uint64, padBytes int) {
+	lenField = uint64(dataBytes)
+	// force 8 byte alignment so length never gets a torn write
+	padBytes = (8 - (dataBytes % 8)) % 8
+	if padBytes != 0 {
+		lenField |= uint64(0x80|padBytes) << 56
+	}
+	return lenField, padBytes
+}
+
+func (e *encoder) flush() error {
+	e.mu.Lock()
+	n, err := e.bw.FlushN()
+	e.mu.Unlock()
+	walWriteBytes.Add(float64(n))
+	return err
+}
+
+func writeUint64(w io.Writer, n uint64, buf []byte) error {
+	// http://golang.org/src/encoding/binary/binary.go
+	binary.LittleEndian.PutUint64(buf, n)
+	nv, err := w.Write(buf)
+	walWriteBytes.Add(float64(nv))
+	return err
+}