feat(notify): 重构通信内核并补齐 stream/bulk/record/transfer 能力

- 引入 LogicalConn/TransportConn 分层，ClientConn 保留兼容适配层
  - 新增 Stream、Bulk、RecordStream 三条数据面能力及对应控制路径
  - 完成 transfer/file 传输内核与状态快照、诊断能力
  - 补齐 reconnect、inbound dispatcher、modern psk 等基础模块
  - 增加大规模回归、并发与基准测试覆盖
  - 更新依赖库

record_codec.go

@@ -0,0 +1,184 @@
+package notify
+
+import (
+	"encoding/binary"
+	"errors"
+)
+
+const (
+	recordFrameMagic            = "NRS1"
+	recordFrameVersion          = 1
+	recordFrameTypeBatch  uint8 = 1
+	recordFrameTypeAck    uint8 = 2
+	recordFrameTypeError  uint8 = 3
+	recordFrameHeaderSize       = 8
+	recordBatchHeaderSize       = 10
+	recordErrorHeaderSize       = 16
+)
+
+var (
+	errRecordFrameInvalid = errors.New("invalid record frame")
+	errRecordSeqInvalid   = errors.New("invalid record sequence")
+)
+
+type recordOutboundMessage struct {
+	Seq     uint64
+	Payload []byte
+}
+
+type recordFrame struct {
+	Type      uint8
+	Batch     []recordOutboundMessage
+	AckSeq    uint64
+	Failure   RecordFailure
+	Retryable bool
+}
+
+func encodeRecordBatchFrame(batch []recordOutboundMessage) ([]byte, error) {
+	if len(batch) == 0 {
+		return nil, nil
+	}
+	firstSeq := batch[0].Seq
+	if firstSeq == 0 {
+		return nil, errRecordSeqInvalid
+	}
+	size := recordFrameHeaderSize + recordBatchHeaderSize
+	for index, item := range batch {
+		wantSeq := firstSeq + uint64(index)
+		if item.Seq != wantSeq {
+			return nil, errRecordSeqInvalid
+		}
+		size += 4 + len(item.Payload)
+	}
+	frame := make([]byte, size)
+	copy(frame[:4], recordFrameMagic)
+	frame[4] = recordFrameVersion
+	frame[5] = recordFrameTypeBatch
+	binary.BigEndian.PutUint16(frame[8:10], uint16(len(batch)))
+	binary.BigEndian.PutUint64(frame[10:18], firstSeq)
+	offset := recordFrameHeaderSize + recordBatchHeaderSize
+	for _, item := range batch {
+		binary.BigEndian.PutUint32(frame[offset:offset+4], uint32(len(item.Payload)))
+		offset += 4
+		copy(frame[offset:offset+len(item.Payload)], item.Payload)
+		offset += len(item.Payload)
+	}
+	return frame, nil
+}
+
+func encodeRecordAckFrame(ackSeq uint64) ([]byte, error) {
+	frame := make([]byte, recordFrameHeaderSize+8)
+	copy(frame[:4], recordFrameMagic)
+	frame[4] = recordFrameVersion
+	frame[5] = recordFrameTypeAck
+	binary.BigEndian.PutUint64(frame[8:16], ackSeq)
+	return frame, nil
+}
+
+func encodeRecordErrorFrame(failure RecordFailure) ([]byte, error) {
+	if failure.FailedSeq == 0 {
+		return nil, errRecordSeqInvalid
+	}
+	codeBytes := []byte(failure.Code)
+	msgBytes := []byte(failure.Message)
+	frame := make([]byte, recordFrameHeaderSize+recordErrorHeaderSize+len(codeBytes)+len(msgBytes))
+	copy(frame[:4], recordFrameMagic)
+	frame[4] = recordFrameVersion
+	frame[5] = recordFrameTypeError
+	if failure.Retryable {
+		frame[6] = 1
+	}
+	binary.BigEndian.PutUint64(frame[8:16], failure.FailedSeq)
+	binary.BigEndian.PutUint16(frame[16:18], uint16(len(codeBytes)))
+	binary.BigEndian.PutUint32(frame[18:22], uint32(len(msgBytes)))
+	offset := recordFrameHeaderSize + recordErrorHeaderSize
+	copy(frame[offset:offset+len(codeBytes)], codeBytes)
+	offset += len(codeBytes)
+	copy(frame[offset:offset+len(msgBytes)], msgBytes)
+	return frame, nil
+}
+
+func decodeRecordFrame(payload []byte) (recordFrame, error) {
+	if len(payload) < recordFrameHeaderSize || string(payload[:4]) != recordFrameMagic {
+		return recordFrame{}, errRecordFrameInvalid
+	}
+	if payload[4] != recordFrameVersion {
+		return recordFrame{}, errRecordFrameInvalid
+	}
+	frameType := payload[5]
+	switch frameType {
+	case recordFrameTypeBatch:
+		return decodeRecordBatchFrame(payload)
+	case recordFrameTypeAck:
+		if len(payload) != recordFrameHeaderSize+8 {
+			return recordFrame{}, errRecordFrameInvalid
+		}
+		return recordFrame{
+			Type:   recordFrameTypeAck,
+			AckSeq: binary.BigEndian.Uint64(payload[8:16]),
+		}, nil
+	case recordFrameTypeError:
+		return decodeRecordErrorFrame(payload)
+	default:
+		return recordFrame{}, errRecordFrameInvalid
+	}
+}
+
+func decodeRecordBatchFrame(payload []byte) (recordFrame, error) {
+	if len(payload) < recordFrameHeaderSize+recordBatchHeaderSize {
+		return recordFrame{}, errRecordFrameInvalid
+	}
+	count := int(binary.BigEndian.Uint16(payload[8:10]))
+	firstSeq := binary.BigEndian.Uint64(payload[10:18])
+	if count <= 0 || firstSeq == 0 {
+		return recordFrame{}, errRecordFrameInvalid
+	}
+	offset := recordFrameHeaderSize + recordBatchHeaderSize
+	batch := make([]recordOutboundMessage, 0, count)
+	for index := 0; index < count; index++ {
+		if offset+4 > len(payload) {
+			return recordFrame{}, errRecordFrameInvalid
+		}
+		itemLen := int(binary.BigEndian.Uint32(payload[offset : offset+4]))
+		offset += 4
+		if itemLen < 0 || offset+itemLen > len(payload) {
+			return recordFrame{}, errRecordFrameInvalid
+		}
+		item := recordOutboundMessage{
+			Seq:     firstSeq + uint64(index),
+			Payload: append([]byte(nil), payload[offset:offset+itemLen]...),
+		}
+		offset += itemLen
+		batch = append(batch, item)
+	}
+	if offset != len(payload) {
+		return recordFrame{}, errRecordFrameInvalid
+	}
+	return recordFrame{
+		Type:  recordFrameTypeBatch,
+		Batch: batch,
+	}, nil
+}
+
+func decodeRecordErrorFrame(payload []byte) (recordFrame, error) {
+	if len(payload) < recordFrameHeaderSize+recordErrorHeaderSize {
+		return recordFrame{}, errRecordFrameInvalid
+	}
+	failedSeq := binary.BigEndian.Uint64(payload[8:16])
+	codeLen := int(binary.BigEndian.Uint16(payload[16:18]))
+	msgLen := int(binary.BigEndian.Uint32(payload[18:22]))
+	offset := recordFrameHeaderSize + recordErrorHeaderSize
+	if failedSeq == 0 || offset+codeLen+msgLen != len(payload) {
+		return recordFrame{}, errRecordFrameInvalid
+	}
+	failure := RecordFailure{
+		FailedSeq: failedSeq,
+		Retryable: payload[6] == 1,
+		Code:      RecordErrorCode(string(payload[offset : offset+codeLen])),
+		Message:   string(payload[offset+codeLen:]),
+	}
+	return recordFrame{
+		Type:    recordFrameTypeError,
+		Failure: failure,
+	}, nil
+}