packet

type Message struct {
	Seq    int32  // 序列号
	Route  int32  // 路由ID
	Buffer []byte // 消息内容
}

type NocopyReader interface {
	// Next returns a slice containing the next n bytes from the buffer,
	// advancing the buffer as if the bytes had been returned by Read.
	Next(n int) (p []byte, err error)

	// Peek returns the next n bytes without advancing the reader.
	Peek(n int) (buf []byte, err error)

	// Release the memory space occupied by all read slices.
	Release() (err error)

	Slice(n int) (r NocopyReader, err error)
}

type Option func(o *options)

type Packer interface {
	// ReadBuffer 以buffer的形式读取消息
	ReadBuffer(reader io.Reader) (buffer.Buffer, error)
	// PackBuffer 以buffer的形式打包消息
	PackBuffer(message *Message) (*buffer.NocopyBuffer, error)
	// ReadMessage 读取消息
	ReadMessage(reader io.Reader) ([]byte, error)
	// PackMessage 打包消息
	PackMessage(message *Message) ([]byte, error)
	// UnpackMessage 解包消息
	UnpackMessage(data []byte) (*Message, error)
	// PackHeartbeat 打包心跳
	PackHeartbeat() ([]byte, error)
	// CheckHeartbeat 检测心跳包
	CheckHeartbeat(data []byte) (bool, error)
}

type RouteCodec interface {
	// EncodeToWriter 将路由编码写入 buffer.Writer
	EncodeToWriter(writer *buffer.Writer, route int32)
	// EncodeToBuf 将路由编码写入 bytes.Buffer
	EncodeToBuf(buf *bytes.Buffer, route int32) error
	// Decode 从 reader 中解码路由
	Decode(reader *bytes.Reader) (int32, error)
	// Size 返回路由占用的字节数
	Size() int
}

type SeqCodec interface {
	// EncodeToWriter 将序列号编码写入 buffer.Writer
	EncodeToWriter(writer *buffer.Writer, seq int32)
	// EncodeToBuf 将序列号编码写入 bytes.Buffer
	EncodeToBuf(buf *bytes.Buffer, seq int32) error
	// Decode 从 reader 中解码序列号
	Decode(reader *bytes.Reader) (int32, error)
	// Size 返回序列号占用的字节数
	Size() int
}