utils/network/data_reader.go

package network

import (
	"bytes"
	"encoding/binary"
)

type DataReader struct {
	buffer *bytes.Buffer
}

func NewDataReader(data []byte) *DataReader {
	return &DataReader{buffer: bytes.NewBuffer(data)}
}

func (reader *DataReader) Byte() (byte, error) {
	var b byte

	err := binary.Read(reader.buffer, binary.BigEndian, &b)
	if err != nil {
		return 0, err
	}

	return b, nil
}

func (reader *DataReader) Bytes(bytesLen int) ([]byte, error) {
	bs := make([]byte, bytesLen)
	err := binary.Read(reader.buffer, binary.BigEndian, bs)
	if err != nil {
		return nil, err
	}

	return bs, nil
}

func (reader *DataReader) Uint8() (uint8, error) {
	var u uint8

	err := binary.Read(reader.buffer, binary.BigEndian, &u)
	if err != nil {
		return 0, err
	}

	return u, nil
}

func (reader *DataReader) Uint16() (uint16, error) {
	var u uint16

	err := binary.Read(reader.buffer, binary.BigEndian, &u)
	if err != nil {
		return 0, err
	}

	return u, nil
}

func (reader *DataReader) Uint32() (uint32, error) {
	var u uint32

	err := binary.Read(reader.buffer, binary.BigEndian, &u)
	if err != nil {
		return 0, err
	}

	return u, nil
}

func (reader *DataReader) Uint64() (uint64, error) {
	var u uint64

	err := binary.Read(reader.buffer, binary.BigEndian, &u)
	if err != nil {
		return 0, err
	}

	return u, nil
}

func (reader *DataReader) String(bytesLen int) (string, error) {
	retBytes := make([]byte, bytesLen)
	err := binary.Read(reader.buffer, binary.BigEndian, retBytes)
	if err != nil {
		return "", err
	}

	return string(retBytes), nil
}

func (reader *DataReader) Len() int {
	return reader.buffer.Len()
}

func (reader *DataReader) Cap() int {
	return reader.buffer.Cap()
}

func (reader *DataReader) GetBytes() []byte {
	return reader.buffer.Bytes()
}

func (reader *DataReader) ToWriter() (*DataWriter, error) {
	writer := NewDataWriter()
	err := writer.Bytes(writer.buffer.Bytes())
	if err != nil {
		return nil, err
	}

	return writer, nil
}