92 lines
1.6 KiB
Go
92 lines
1.6 KiB
Go
package wal
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import (
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"bufio"
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"encoding/binary"
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"hash"
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"io"
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"github.com/coreos/etcd/crc"
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"github.com/coreos/etcd/raft/raftpb"
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"github.com/coreos/etcd/wal/walpb"
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)
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type decoder struct {
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br *bufio.Reader
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c io.Closer
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crc hash.Hash32
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}
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func newDecoder(rc io.ReadCloser) *decoder {
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return &decoder{
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br: bufio.NewReader(rc),
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c: rc,
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crc: crc.New(0, crcTable),
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}
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}
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func (d *decoder) decode(rec *walpb.Record) error {
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rec.Reset()
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l, err := readInt64(d.br)
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if err != nil {
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return err
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}
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data := make([]byte, l)
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if _, err = io.ReadFull(d.br, data); err != nil {
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return err
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}
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if err := rec.Unmarshal(data); err != nil {
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return err
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}
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// skip crc checking if the record type is crcType
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if rec.Type == crcType {
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return nil
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}
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d.crc.Write(rec.Data)
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return rec.Validate(d.crc.Sum32())
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}
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func (d *decoder) updateCRC(prevCrc uint32) {
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d.crc = crc.New(prevCrc, crcTable)
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}
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func (d *decoder) lastCRC() uint32 {
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return d.crc.Sum32()
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}
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func (d *decoder) close() error {
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return d.c.Close()
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}
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func mustUnmarshalInfo(d []byte) raftpb.Info {
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var i raftpb.Info
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if err := i.Unmarshal(d); err != nil {
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// crc matched, but we cannot unmarshal the struct?!
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// we must be the next winner of the $1B lottery.
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panic(err)
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}
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return i
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}
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func mustUnmarshalEntry(d []byte) raftpb.Entry {
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var e raftpb.Entry
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if err := e.Unmarshal(d); err != nil {
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panic(err)
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}
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return e
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}
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func mustUnmarshalState(d []byte) raftpb.HardState {
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var s raftpb.HardState
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if err := s.Unmarshal(d); err != nil {
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panic(err)
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}
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return s
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}
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func readInt64(r io.Reader) (int64, error) {
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var n int64
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err := binary.Read(r, binary.LittleEndian, &n)
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return n, err
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}
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