ledisdb/rpl/log.go

106 lines
1.7 KiB
Go

package rpl
import (
"bytes"
"encoding/binary"
"io"
"time"
)
type Log struct {
ID uint64
CreateTime uint32
Data []byte
}
func NewLog(id uint64, data []byte) *Log {
l := new(Log)
l.ID = id
l.CreateTime = uint32(time.Now().Unix())
l.Data = data
return l
}
func (l *Log) HeadSize() int {
return 16
}
func (l *Log) Size() int {
return l.HeadSize() + len(l.Data)
}
func (l *Log) Marshal() ([]byte, error) {
buf := bytes.NewBuffer(make([]byte, l.HeadSize()+len(l.Data)))
buf.Reset()
if err := l.Encode(buf); err != nil {
return nil, err
}
return buf.Bytes(), nil
}
func (l *Log) Unmarshal(b []byte) error {
buf := bytes.NewBuffer(b)
return l.Decode(buf)
}
func (l *Log) Encode(w io.Writer) error {
buf := make([]byte, l.HeadSize())
pos := 0
binary.BigEndian.PutUint64(buf[pos:], l.ID)
pos += 8
binary.BigEndian.PutUint32(buf[pos:], l.CreateTime)
pos += 4
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 {
buf := make([]byte, l.HeadSize())
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
length := binary.BigEndian.Uint32(buf[pos:])
l.Data = l.Data[0:0]
if cap(l.Data) >= int(length) {
l.Data = l.Data[0:length]
} else {
l.Data = make([]byte, length)
}
if _, err := io.ReadFull(r, l.Data); err != nil {
return err
}
return nil
}