xps-server-g5/pkg/utils/type_conv.go

package utils

import (
    "bytes"
    "encoding/binary"
    "fmt"
)

// isSymbol表示有无符号
func BytesToInt(b []byte, isSymbol bool) (int, error) {
    if isSymbol {
        return bytesToIntS(b)
    }
    return bytesToIntU(b)
}

// 字节数(大端)组转成int(无符号的)
func bytesToIntU(b []byte) (int, error) {
    if len(b) == 3 {
        b = append([]byte{0}, b...)
    }
    bytesBuffer := bytes.NewBuffer(b)
    switch len(b) {
    case 1:
        var tmp uint8
        err := binary.Read(bytesBuffer, binary.BigEndian, &tmp)
        return int(tmp), err
    case 2:
        var tmp uint16
        err := binary.Read(bytesBuffer, binary.BigEndian, &tmp)
        return int(tmp), err
    case 4:
        var tmp uint32
        err := binary.Read(bytesBuffer, binary.BigEndian, &tmp)
        return int(tmp), err
    default:
        return 0, fmt.Errorf("%s", "BytesToInt bytes lenth is invaild!")
    }
}

// 字节数(大端)组转成int(有符号)
func bytesToIntS(b []byte) (int, error) {
    if len(b) == 3 {
        b = append([]byte{0}, b...)
    }
    bytesBuffer := bytes.NewBuffer(b)
    switch len(b) {
    case 1:
        var tmp int8
        err := binary.Read(bytesBuffer, binary.BigEndian, &tmp)
        return int(tmp), err
    case 2:
        var tmp int16
        err := binary.Read(bytesBuffer, binary.BigEndian, &tmp)
        return int(tmp), err
    case 4:
        var tmp int32
        err := binary.Read(bytesBuffer, binary.BigEndian, &tmp)
        return int(tmp), err
    default:
        return 0, fmt.Errorf("%s", "BytesToInt bytes lenth is invaild!")
    }
}

// 整形转换成字节
func IntToBytes(n int, b byte) ([]byte, error) {
    switch b {
    case 1:
        tmp := int8(n)
        bytesBuffer := bytes.NewBuffer([]byte{})
        binary.Write(bytesBuffer, binary.BigEndian, &tmp)
        return bytesBuffer.Bytes(), nil
    case 2:
        tmp := int16(n)
        bytesBuffer := bytes.NewBuffer([]byte{})
        binary.Write(bytesBuffer, binary.BigEndian, &tmp)
        return bytesBuffer.Bytes(), nil
    case 3, 4:
        tmp := int32(n)
        bytesBuffer := bytes.NewBuffer([]byte{})
        binary.Write(bytesBuffer, binary.BigEndian, &tmp)
        return bytesBuffer.Bytes(), nil
    }
    return nil, fmt.Errorf("IntToBytes b param is invaild")
}