forked from mirror/ledisdb
92 lines
1.5 KiB
Go
92 lines
1.5 KiB
Go
package wal
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import (
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"bytes"
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"encoding/binary"
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"io"
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)
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type Log struct {
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ID uint64
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CreateTime uint32
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// 0 for no compression
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// 1 for snappy compression
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Compression uint8
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Data []byte
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}
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func (l *Log) Marshal() ([]byte, error) {
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buf := bytes.NewBuffer(make([]byte, 17+len(l.Data)))
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buf.Reset()
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if err := l.Encode(buf); err != nil {
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return nil, err
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}
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return buf.Bytes(), nil
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}
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func (l *Log) Unmarshal(b []byte) error {
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buf := bytes.NewBuffer(b)
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return l.Decode(buf)
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}
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func (l *Log) Encode(w io.Writer) error {
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length := uint32(17)
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buf := make([]byte, length)
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pos := 0
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binary.BigEndian.PutUint64(buf[pos:], l.ID)
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pos += 8
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binary.BigEndian.PutUint32(buf[pos:], l.CreateTime)
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pos += 4
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buf[pos] = l.Compression
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pos++
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binary.BigEndian.PutUint32(buf[pos:], uint32(len(l.Data)))
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if n, err := w.Write(buf); err != nil {
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return err
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} else if n != len(buf) {
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return io.ErrShortWrite
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}
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if n, err := w.Write(l.Data); err != nil {
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return err
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} else if n != len(l.Data) {
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return io.ErrShortWrite
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}
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return nil
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}
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func (l *Log) Decode(r io.Reader) error {
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length := uint32(17)
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buf := make([]byte, length)
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if _, err := io.ReadFull(r, buf); err != nil {
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return err
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}
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pos := 0
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l.ID = binary.BigEndian.Uint64(buf[pos:])
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pos += 8
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l.CreateTime = binary.BigEndian.Uint32(buf[pos:])
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pos += 4
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l.Compression = buf[pos]
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pos++
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length = binary.BigEndian.Uint32(buf[pos:])
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l.Data = make([]byte, length)
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if _, err := io.ReadFull(r, l.Data); err != nil {
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return err
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}
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return nil
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}
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