Initial open source release

internal/app/maintenance/retention.go

@@ -0,0 +1,74 @@
+package maintenance
+
+import (
+	"context"
+	"time"
+
+	"go.uber.org/zap"
+)
+
+// DispatchOutboxRetentionStore 清理彻底失败（已放弃重试）的 outbox 死任务。
+type DispatchOutboxRetentionStore interface {
+	DeleteFailed(ctx context.Context, olderThan time.Duration, limit int) (int, error)
+}
+
+// RetentionWorker 周期性回收存储中的死数据。
+//
+// 注意：本 worker 刻意不清理 user_update_events —— pts log 永久保留。原因：TDesktop 不支持
+// 账号级 updates.differenceTooLong（api_updates.cpp 收到该响应只打一行日志，且漏掉
+// setRequesting(false)，会永久锁死整个 update 引擎），服务端因此无法让"落后超过保留期"的
+// 客户端整库重置；一旦裁剪 events，落后客户端的 getDifference 会拿到不完整的事件链而静默
+// 丢消息。详见 docs/performance-audit.md 与 docs/compatibility-matrix.md。user_update_events
+// 长期膨胀作为已知 todo。
+type RetentionWorker struct {
+	outbox    DispatchOutboxRetentionStore
+	logger    *zap.Logger
+	retention time.Duration
+	interval  time.Duration
+	batch     int
+}
+
+func NewRetentionWorker(outbox DispatchOutboxRetentionStore, logger *zap.Logger, retention, interval time.Duration, batch int) *RetentionWorker {
+	if logger == nil {
+		logger = zap.NewNop()
+	}
+	if retention <= 0 {
+		retention = 168 * time.Hour
+	}
+	if interval <= 0 {
+		interval = time.Hour
+	}
+	if batch <= 0 {
+		batch = 10000
+	}
+	return &RetentionWorker{
+		outbox:    outbox,
+		logger:    logger,
+		retention: retention,
+		interval:  interval,
+		batch:     batch,
+	}
+}
+
+func (w *RetentionWorker) Run(ctx context.Context) {
+	w.runOnce(ctx)
+	ticker := time.NewTicker(w.interval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			w.runOnce(ctx)
+		}
+	}
+}
+
+func (w *RetentionWorker) runOnce(ctx context.Context) {
+	outboxDeleted, err := w.outbox.DeleteFailed(ctx, w.retention, w.batch)
+	if err != nil {
+		w.logger.Warn("清理 failed dispatch_outbox 失败", zap.Error(err))
+	} else if outboxDeleted > 0 {
+		w.logger.Info("清理 failed dispatch_outbox 完成", zap.Int("deleted", outboxDeleted))
+	}
+}