[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/wal/decoder.go b/vendor/go.etcd.io/etcd/wal/decoder.go
new file mode 100644
index 0000000..f2f01fd
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/decoder.go
@@ -0,0 +1,188 @@
+// 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 (
+ "bufio"
+ "encoding/binary"
+ "hash"
+ "io"
+ "sync"
+
+ "go.etcd.io/etcd/pkg/crc"
+ "go.etcd.io/etcd/pkg/pbutil"
+ "go.etcd.io/etcd/raft/raftpb"
+ "go.etcd.io/etcd/wal/walpb"
+)
+
+const minSectorSize = 512
+
+// frameSizeBytes is frame size in bytes, including record size and padding size.
+const frameSizeBytes = 8
+
+type decoder struct {
+ mu sync.Mutex
+ brs []*bufio.Reader
+
+ // lastValidOff file offset following the last valid decoded record
+ lastValidOff int64
+ crc hash.Hash32
+}
+
+func newDecoder(r ...io.Reader) *decoder {
+ readers := make([]*bufio.Reader, len(r))
+ for i := range r {
+ readers[i] = bufio.NewReader(r[i])
+ }
+ return &decoder{
+ brs: readers,
+ crc: crc.New(0, crcTable),
+ }
+}
+
+func (d *decoder) decode(rec *walpb.Record) error {
+ rec.Reset()
+ d.mu.Lock()
+ defer d.mu.Unlock()
+ return d.decodeRecord(rec)
+}
+
+func (d *decoder) decodeRecord(rec *walpb.Record) error {
+ if len(d.brs) == 0 {
+ return io.EOF
+ }
+
+ l, err := readInt64(d.brs[0])
+ if err == io.EOF || (err == nil && l == 0) {
+ // hit end of file or preallocated space
+ d.brs = d.brs[1:]
+ if len(d.brs) == 0 {
+ return io.EOF
+ }
+ d.lastValidOff = 0
+ return d.decodeRecord(rec)
+ }
+ if err != nil {
+ return err
+ }
+
+ recBytes, padBytes := decodeFrameSize(l)
+
+ data := make([]byte, recBytes+padBytes)
+ if _, err = io.ReadFull(d.brs[0], data); err != nil {
+ // ReadFull returns io.EOF only if no bytes were read
+ // the decoder should treat this as an ErrUnexpectedEOF instead.
+ if err == io.EOF {
+ err = io.ErrUnexpectedEOF
+ }
+ return err
+ }
+ if err := rec.Unmarshal(data[:recBytes]); err != nil {
+ if d.isTornEntry(data) {
+ return io.ErrUnexpectedEOF
+ }
+ return err
+ }
+
+ // skip crc checking if the record type is crcType
+ if rec.Type != crcType {
+ d.crc.Write(rec.Data)
+ if err := rec.Validate(d.crc.Sum32()); err != nil {
+ if d.isTornEntry(data) {
+ return io.ErrUnexpectedEOF
+ }
+ return err
+ }
+ }
+ // record decoded as valid; point last valid offset to end of record
+ d.lastValidOff += frameSizeBytes + recBytes + padBytes
+ return nil
+}
+
+func decodeFrameSize(lenField int64) (recBytes int64, padBytes int64) {
+ // the record size is stored in the lower 56 bits of the 64-bit length
+ recBytes = int64(uint64(lenField) & ^(uint64(0xff) << 56))
+ // non-zero padding is indicated by set MSb / a negative length
+ if lenField < 0 {
+ // padding is stored in lower 3 bits of length MSB
+ padBytes = int64((uint64(lenField) >> 56) & 0x7)
+ }
+ return recBytes, padBytes
+}
+
+// isTornEntry determines whether the last entry of the WAL was partially written
+// and corrupted because of a torn write.
+func (d *decoder) isTornEntry(data []byte) bool {
+ if len(d.brs) != 1 {
+ return false
+ }
+
+ fileOff := d.lastValidOff + frameSizeBytes
+ curOff := 0
+ chunks := [][]byte{}
+ // split data on sector boundaries
+ for curOff < len(data) {
+ chunkLen := int(minSectorSize - (fileOff % minSectorSize))
+ if chunkLen > len(data)-curOff {
+ chunkLen = len(data) - curOff
+ }
+ chunks = append(chunks, data[curOff:curOff+chunkLen])
+ fileOff += int64(chunkLen)
+ curOff += chunkLen
+ }
+
+ // if any data for a sector chunk is all 0, it's a torn write
+ for _, sect := range chunks {
+ isZero := true
+ for _, v := range sect {
+ if v != 0 {
+ isZero = false
+ break
+ }
+ }
+ if isZero {
+ return true
+ }
+ }
+ return false
+}
+
+func (d *decoder) updateCRC(prevCrc uint32) {
+ d.crc = crc.New(prevCrc, crcTable)
+}
+
+func (d *decoder) lastCRC() uint32 {
+ return d.crc.Sum32()
+}
+
+func (d *decoder) lastOffset() int64 { return d.lastValidOff }
+
+func mustUnmarshalEntry(d []byte) raftpb.Entry {
+ var e raftpb.Entry
+ pbutil.MustUnmarshal(&e, d)
+ return e
+}
+
+func mustUnmarshalState(d []byte) raftpb.HardState {
+ var s raftpb.HardState
+ pbutil.MustUnmarshal(&s, d)
+ return s
+}
+
+func readInt64(r io.Reader) (int64, error) {
+ var n int64
+ err := binary.Read(r, binary.LittleEndian, &n)
+ return n, err
+}