struct to buf
package main
import (
"bytes"
"encoding/binary"
"reflect"
"io"
"errors"
"fmt"
)
func writeBuf(w io.Writer,v reflect.Value) (n int, err error){
newBuf := bytes.NewBuffer(nil)
for i := 0; i < v.NumField(); i++ {
switch v.Field(i).Type().Kind() {
case reflect.Struct:
n,err := writeBuf(newBuf,v.Field(i))
if err != nil {
return n,err
}
case reflect.Bool:
boolByte := []byte{0}
if v.Field(i).Bool() {
boolByte = []byte{1}
}
newBuf.Write(boolByte)
case reflect.String:
newBuf.WriteString(v.Field(i).String())
case reflect.Slice:
newBuf.Write(v.Field(i).Bytes())
case reflect.Int:
binary.Write(newBuf, binary.LittleEndian,int32(v.Field(i).Int()))
case reflect.Uint:
binary.Write(newBuf, binary.LittleEndian, uint32(v.Field(i).Uint()))
case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
reflect.Float32, reflect.Float64, reflect.Complex64, reflect.Complex128:
binary.Write(newBuf, binary.LittleEndian, v.Field(i).Interface())
}
}
return w.Write(newBuf.Bytes())
}
func WriteStructToBuffer(w io.Writer ,data interface{}) ( error ) {
v := reflect.Indirect(reflect.ValueOf(data))
if v.Kind() == reflect.Struct {
fmt.Println("test")
_,err := writeBuf(w,v)
return err
}
return errors.New("invalid type Not a struct")
}
func StringFixedLength(s string, length int) []byte {
sLength := len(s)
if sLength >= length {
return []byte(s[:length])
} else {
b := make([]byte, length-sLength)
return append([]byte(s), b...)
}
return nil
}
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