ledisdb/wal/log.go

74 lines
1.2 KiB
Go

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