d313449c5c
- 将所有trustlog-sdk文件移动到trustlog/go-trustlog/目录 - 更新README中所有import路径从trustlog-sdk改为go-trustlog - 更新cookiecutter配置文件中的项目名称 - 更新根目录.lefthook.yml以引用新位置的配置 - 添加go.sum文件到版本控制 - 删除过时的示例文件 这次重构与trustlog-server保持一致的目录结构， 为未来支持多语言SDK（Python、Java等）预留空间。
150 lines
3.5 KiB
Go
150 lines
3.5 KiB
Go
package adapter
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import (
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"encoding/binary"
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"errors"
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"io"
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)
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// 协议常量.
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const (
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// MessageTypeData 表示数据消息.
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MessageTypeData byte = 0x01
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// MessageTypeAck 表示 ACK 确认.
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MessageTypeAck byte = 0x02
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// MessageTypeNack 表示 NACK 否定确认.
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MessageTypeNack byte = 0x03
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// 协议限制.
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maxTopicLength = 65535
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maxUUIDLength = 255
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maxPayloadSize = 1 << 30
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topicLengthSize = 2
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uuidLengthSize = 1
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payloadLengthSize = 4
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)
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// 预定义错误.
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var (
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ErrNilMessage = errors.New("message is nil")
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ErrTopicTooLong = errors.New("topic too long")
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ErrUUIDTooLong = errors.New("uuid too long")
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ErrPayloadTooLarge = errors.New("payload too large")
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)
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// TCPMessage 表示 TCP 传输的消息.
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type TCPMessage struct {
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Type byte // 消息类型
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Topic string // 主题
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UUID string // 消息 UUID
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Payload []byte // 消息内容
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}
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// EncodeTCPMessage 将消息编码为字节数组.
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// 格式: [消息类型 1字节][Topic长度 2字节][Topic][UUID长度 1字节][UUID][Payload长度 4字节][Payload].
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func EncodeTCPMessage(msg *TCPMessage) ([]byte, error) {
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if msg == nil {
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return nil, ErrNilMessage
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}
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topicLen := len(msg.Topic)
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if topicLen > maxTopicLength {
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return nil, ErrTopicTooLong
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}
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uuidLen := len(msg.UUID)
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if uuidLen > maxUUIDLength {
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return nil, ErrUUIDTooLong
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}
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payloadLen := len(msg.Payload)
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if payloadLen > maxPayloadSize {
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return nil, ErrPayloadTooLarge
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}
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// 计算总长度
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totalLen := 1 + topicLengthSize + topicLen + uuidLengthSize + uuidLen + payloadLengthSize + payloadLen
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buf := make([]byte, totalLen)
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offset := 0
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// 写入消息类型
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buf[offset] = msg.Type
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offset++
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// 写入 Topic 长度和内容
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binary.BigEndian.PutUint16(buf[offset:], uint16(topicLen))
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offset += topicLengthSize
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copy(buf[offset:], []byte(msg.Topic))
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offset += topicLen
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// 写入 UUID 长度和内容
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buf[offset] = byte(uuidLen)
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offset++
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copy(buf[offset:], []byte(msg.UUID))
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offset += uuidLen
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// 写入 Payload 长度和内容
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binary.BigEndian.PutUint32(buf[offset:], uint32(payloadLen))
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offset += payloadLengthSize
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copy(buf[offset:], msg.Payload)
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return buf, nil
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}
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// DecodeTCPMessage 从字节数组解码消息.
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func DecodeTCPMessage(reader io.Reader) (*TCPMessage, error) {
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msg := &TCPMessage{}
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// 读取消息类型
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msgTypeBuf := make([]byte, 1)
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if _, err := io.ReadFull(reader, msgTypeBuf); err != nil {
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return nil, err
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}
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msg.Type = msgTypeBuf[0]
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// 读取 Topic 长度
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topicLenBuf := make([]byte, topicLengthSize)
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if _, err := io.ReadFull(reader, topicLenBuf); err != nil {
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return nil, err
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}
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topicLen := binary.BigEndian.Uint16(topicLenBuf)
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// 读取 Topic
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topicBuf := make([]byte, topicLen)
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if _, err := io.ReadFull(reader, topicBuf); err != nil {
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return nil, err
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}
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msg.Topic = string(topicBuf)
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// 读取 UUID 长度
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uuidLenBuf := make([]byte, 1)
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if _, err := io.ReadFull(reader, uuidLenBuf); err != nil {
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return nil, err
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}
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uuidLen := uuidLenBuf[0]
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// 读取 UUID
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uuidBuf := make([]byte, uuidLen)
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if _, err := io.ReadFull(reader, uuidBuf); err != nil {
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return nil, err
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}
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msg.UUID = string(uuidBuf)
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// 读取 Payload 长度
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payloadLenBuf := make([]byte, payloadLengthSize)
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if _, err := io.ReadFull(reader, payloadLenBuf); err != nil {
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return nil, err
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}
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payloadLen := binary.BigEndian.Uint32(payloadLenBuf)
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// 读取 Payload
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payloadBuf := make([]byte, payloadLen)
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if _, err := io.ReadFull(reader, payloadBuf); err != nil {
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return nil, err
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}
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msg.Payload = payloadBuf
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return msg, nil
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}
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