[VOL-4291] Rw-core updates for gRPC migration
Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
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
+}