forked from TrueCloudLab/neoneo-go
68 lines
1.3 KiB
Go
68 lines
1.3 KiB
Go
package util
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"errors"
|
|
"io"
|
|
)
|
|
|
|
type BinWriter struct {
|
|
W io.Writer
|
|
Err error
|
|
}
|
|
|
|
func (w *BinWriter) Write(v interface{}) {
|
|
if w.Err != nil {
|
|
return
|
|
}
|
|
w.Err = binary.Write(w.W, binary.LittleEndian, v)
|
|
}
|
|
|
|
// Only used for IP and PORT. Additional method makes the default LittleEndian case clean
|
|
func (w *BinWriter) WriteBigEnd(v interface{}) {
|
|
if w.Err != nil {
|
|
return
|
|
}
|
|
w.Err = binary.Write(w.W, binary.BigEndian, v)
|
|
}
|
|
|
|
func (w *BinWriter) VarString(s string) {
|
|
w.VarBytes([]byte(s))
|
|
}
|
|
|
|
func (w *BinWriter) VarUint(val uint64) {
|
|
if val < 0 {
|
|
w.Err = errors.New("value out of range")
|
|
return
|
|
}
|
|
|
|
if w.Err != nil {
|
|
return
|
|
}
|
|
|
|
if val < 0xfd {
|
|
w.Err = binary.Write(w.W, binary.LittleEndian, uint8(val))
|
|
return
|
|
}
|
|
if val < 0xFFFF {
|
|
w.Err = binary.Write(w.W, binary.LittleEndian, byte(0xfd))
|
|
w.Err = binary.Write(w.W, binary.LittleEndian, uint16(val))
|
|
return
|
|
}
|
|
if val < 0xFFFFFFFF {
|
|
w.Err = binary.Write(w.W, binary.LittleEndian, byte(0xfe))
|
|
w.Err = binary.Write(w.W, binary.LittleEndian, uint32(val))
|
|
return
|
|
|
|
}
|
|
|
|
w.Err = binary.Write(w.W, binary.LittleEndian, byte(0xff))
|
|
w.Err = binary.Write(w.W, binary.LittleEndian, val)
|
|
|
|
}
|
|
|
|
// WriteVarBytes writes a variable length byte array.
|
|
func (w *BinWriter) VarBytes(b []byte) {
|
|
w.VarUint(uint64(len(b)))
|
|
w.Write(b)
|
|
}
|