feat: 实现消息分发推送确认撤回与启动恢复

internal/app/message/conn.go

@@ -0,0 +1,144 @@
+package message
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"sync"
+
+	"git.asio.asia/nixevol/NixMsg/internal/app/port"
+)
+
+var (
+	errPayloadTooLarge = errors.New("message: payload too large")
+	errPublishFailed   = errors.New("message: publish failed")
+)
+
+// LiveConn 是端当前连接的快照（含握手中）。
+type LiveConn struct {
+	ConnID          port.ConnID
+	MaxReceiveBytes int
+	MaxPacketSize   uint32
+}
+
+// ConnRegistry 查询端是否有连接（由 N 线或测试假实现注入）。
+// 有连接（含握手中）即视为在线，用于分发时计算 expire_at。
+type ConnRegistry interface {
+	Current(endpointID string) (LiveConn, bool)
+}
+
+// MemoryConns 是测试用的内存连接表。
+type MemoryConns struct {
+	mu sync.RWMutex
+	m  map[string]LiveConn
+}
+
+// NewMemoryConns 创建空连接表。
+func NewMemoryConns() *MemoryConns {
+	return &MemoryConns{m: make(map[string]LiveConn)}
+}
+
+// Set 登记或更新端的当前连接。
+func (c *MemoryConns) Set(endpointID string, conn LiveConn) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.m[endpointID] = conn
+}
+
+// Clear 移除端的当前连接；若代号不匹配则不动。
+func (c *MemoryConns) Clear(endpointID string, connID port.ConnID) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	cur, ok := c.m[endpointID]
+	if !ok {
+		return
+	}
+	if connID != "" && cur.ConnID != connID {
+		return
+	}
+	delete(c.m, endpointID)
+}
+
+// Current 实现 ConnRegistry。
+func (c *MemoryConns) Current(endpointID string) (LiveConn, bool) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	v, ok := c.m[endpointID]
+	return v, ok
+}
+
+// RecordingDownlink 记录下行发布，供测试断言。
+type RecordingDownlink struct {
+	mu        sync.Mutex
+	Published []DownPublish
+	FailNext  int // 接下来 N 次 PublishDown 返回错误
+	MaxSize   int // >0 时超限返回错误
+}
+
+// DownPublish 是一次下行记录。
+type DownPublish struct {
+	EndpointID string
+	ConnID     port.ConnID
+	Payload    []byte
+	QoS        byte
+}
+
+// PublishDown 实现 port.Downlink。
+func (d *RecordingDownlink) PublishDown(_ context.Context, endpointID string, connID port.ConnID, payload []byte, opts port.PublishOpts) error {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if d.MaxSize > 0 && len(payload) > d.MaxSize {
+		return errPayloadTooLarge
+	}
+	if d.FailNext > 0 {
+		d.FailNext--
+		return errPublishFailed
+	}
+	d.Published = append(d.Published, DownPublish{
+		EndpointID: endpointID,
+		ConnID:     connID,
+		Payload:    append([]byte(nil), payload...),
+		QoS:        opts.QoS,
+	})
+	return nil
+}
+
+// Count 返回已发布条数。
+func (d *RecordingDownlink) Count() int {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	return len(d.Published)
+}
+
+// Snapshots 返回发布副本。
+func (d *RecordingDownlink) Snapshots() []DownPublish {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	out := make([]DownPublish, len(d.Published))
+	copy(out, d.Published)
+	return out
+}
+
+// FilterType 统计 type 字段匹配的发布次数。
+func (d *RecordingDownlink) FilterType(typ string) int {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	n := 0
+	for _, p := range d.Published {
+		if payloadType(p.Payload) == typ {
+			n++
+		}
+	}
+	return n
+}
+
+func payloadType(payload []byte) string {
+	var head struct {
+		Type string `json:"type"`
+	}
+	_ = json.Unmarshal(payload, &head)
+	return head.Type
+}
+
+var _ port.Downlink = (*RecordingDownlink)(nil)
+var _ ConnRegistry = (*MemoryConns)(nil)