mirror of
https://github.com/astaxie/beego.git
synced 2024-06-28 20:44:13 +00:00
131 lines
2.8 KiB
Go
131 lines
2.8 KiB
Go
package rdb
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"fmt"
|
|
"hash"
|
|
"io"
|
|
"math"
|
|
"strconv"
|
|
|
|
"github.com/cupcake/rdb/crc64"
|
|
)
|
|
|
|
const Version = 6
|
|
|
|
type Encoder struct {
|
|
w io.Writer
|
|
crc hash.Hash
|
|
}
|
|
|
|
func NewEncoder(w io.Writer) *Encoder {
|
|
e := &Encoder{crc: crc64.New()}
|
|
e.w = io.MultiWriter(w, e.crc)
|
|
return e
|
|
}
|
|
|
|
func (e *Encoder) EncodeHeader() error {
|
|
_, err := fmt.Fprintf(e.w, "REDIS%04d", Version)
|
|
return err
|
|
}
|
|
|
|
func (e *Encoder) EncodeFooter() error {
|
|
e.w.Write([]byte{rdbFlagEOF})
|
|
_, err := e.w.Write(e.crc.Sum(nil))
|
|
return err
|
|
}
|
|
|
|
func (e *Encoder) EncodeDumpFooter() error {
|
|
binary.Write(e.w, binary.LittleEndian, uint16(Version))
|
|
_, err := e.w.Write(e.crc.Sum(nil))
|
|
return err
|
|
}
|
|
|
|
func (e *Encoder) EncodeDatabase(n int) error {
|
|
e.w.Write([]byte{rdbFlagSelectDB})
|
|
return e.EncodeLength(uint32(n))
|
|
}
|
|
|
|
func (e *Encoder) EncodeExpiry(expiry uint64) error {
|
|
b := make([]byte, 9)
|
|
b[0] = rdbFlagExpiryMS
|
|
binary.LittleEndian.PutUint64(b[1:], expiry)
|
|
_, err := e.w.Write(b)
|
|
return err
|
|
}
|
|
|
|
func (e *Encoder) EncodeType(v ValueType) error {
|
|
_, err := e.w.Write([]byte{byte(v)})
|
|
return err
|
|
}
|
|
|
|
func (e *Encoder) EncodeString(s []byte) error {
|
|
written, err := e.encodeIntString(s)
|
|
if written {
|
|
return err
|
|
}
|
|
e.EncodeLength(uint32(len(s)))
|
|
_, err = e.w.Write(s)
|
|
return err
|
|
}
|
|
|
|
func (e *Encoder) EncodeLength(l uint32) (err error) {
|
|
switch {
|
|
case l < 1<<6:
|
|
_, err = e.w.Write([]byte{byte(l)})
|
|
case l < 1<<14:
|
|
_, err = e.w.Write([]byte{byte(l>>8) | rdb14bitLen<<6, byte(l)})
|
|
default:
|
|
b := make([]byte, 5)
|
|
b[0] = rdb32bitLen << 6
|
|
binary.BigEndian.PutUint32(b[1:], l)
|
|
_, err = e.w.Write(b)
|
|
}
|
|
return
|
|
}
|
|
|
|
func (e *Encoder) EncodeFloat(f float64) (err error) {
|
|
switch {
|
|
case math.IsNaN(f):
|
|
_, err = e.w.Write([]byte{253})
|
|
case math.IsInf(f, 1):
|
|
_, err = e.w.Write([]byte{254})
|
|
case math.IsInf(f, -1):
|
|
_, err = e.w.Write([]byte{255})
|
|
default:
|
|
b := []byte(strconv.FormatFloat(f, 'g', 17, 64))
|
|
e.w.Write([]byte{byte(len(b))})
|
|
_, err = e.w.Write(b)
|
|
}
|
|
return
|
|
}
|
|
|
|
func (e *Encoder) encodeIntString(b []byte) (written bool, err error) {
|
|
s := string(b)
|
|
i, err := strconv.ParseInt(s, 10, 32)
|
|
if err != nil {
|
|
return
|
|
}
|
|
// if the stringified parsed int isn't exactly the same, we can't encode it as an int
|
|
if s != strconv.FormatInt(i, 10) {
|
|
return
|
|
}
|
|
switch {
|
|
case i >= math.MinInt8 && i <= math.MaxInt8:
|
|
_, err = e.w.Write([]byte{rdbEncVal << 6, byte(int8(i))})
|
|
case i >= math.MinInt16 && i <= math.MaxInt16:
|
|
b := make([]byte, 3)
|
|
b[0] = rdbEncVal<<6 | rdbEncInt16
|
|
binary.LittleEndian.PutUint16(b[1:], uint16(int16(i)))
|
|
_, err = e.w.Write(b)
|
|
case i >= math.MinInt32 && i <= math.MaxInt32:
|
|
b := make([]byte, 5)
|
|
b[0] = rdbEncVal<<6 | rdbEncInt32
|
|
binary.LittleEndian.PutUint32(b[1:], uint32(int32(i)))
|
|
_, err = e.w.Write(b)
|
|
default:
|
|
return
|
|
}
|
|
return true, err
|
|
}
|