refactor(*): 数据同步与资源删除 - 收敛服务端真相并保证删除可恢复

backend/internal/repository/resource_deletion.go

@@ -0,0 +1,67 @@
+package repository
+
+import (
+	"time"
+
+	"infinite-canvas/backend/internal/model"
+
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+)
+
+func (r *Repository) ClaimNextResourceDeletionJob(owner string, leaseDuration time.Duration) (*model.ResourceDeletionJob, error) {
+	var job model.ResourceDeletionJob
+	now := time.Now()
+	err := r.db.Transaction(func(tx *gorm.DB) error {
+		available := "(status = ? OR (status = ? AND (lease_expires_at IS NULL OR lease_expires_at <= ?))) AND next_attempt_at <= ?"
+		query := tx.Where(available, model.ResourceDeletionStatusPending, model.ResourceDeletionStatusProcessing, now, now).
+			Order("next_attempt_at asc, created_at asc").Limit(1)
+		if r.Dialect() == "postgres" {
+			query = query.Clauses(clause.Locking{Strength: "UPDATE", Options: "SKIP LOCKED"})
+		}
+		result := query.Find(&job)
+		if result.Error != nil || result.RowsAffected == 0 {
+			return result.Error
+		}
+		claim := tx.Model(&model.ResourceDeletionJob{}).Where("id = ?", job.ID)
+		if r.Dialect() != "postgres" {
+			claim = claim.Where(available, model.ResourceDeletionStatusPending, model.ResourceDeletionStatusProcessing, now, now)
+		}
+		updated := claim.Updates(map[string]any{
+			"status":           model.ResourceDeletionStatusProcessing,
+			"attempts":         gorm.Expr("attempts + ?", 1),
+			"lease_owner":      owner,
+			"lease_expires_at": now.Add(leaseDuration),
+			"updated_at":       now,
+		})
+		if updated.Error != nil {
+			return updated.Error
+		}
+		if updated.RowsAffected == 0 {
+			job = model.ResourceDeletionJob{}
+			return nil
+		}
+		return tx.First(&job, "id = ?", job.ID).Error
+	})
+	if err != nil || job.ID == "" {
+		return nil, err
+	}
+	return &job, nil
+}
+
+func (r *Repository) CompleteResourceDeletionJob(id string, owner string) error {
+	return r.db.Where("id = ? AND lease_owner = ?", id, owner).Delete(&model.ResourceDeletionJob{}).Error
+}
+
+func (r *Repository) RetryResourceDeletionJob(id string, owner string, lastError string, nextAttemptAt time.Time) error {
+	return r.db.Model(&model.ResourceDeletionJob{}).
+		Where("id = ? AND lease_owner = ?", id, owner).
+		Updates(map[string]any{
+			"status":           model.ResourceDeletionStatusPending,
+			"last_error":       lastError,
+			"next_attempt_at":  nextAttemptAt,
+			"lease_owner":      "",
+			"lease_expires_at": nil,
+			"updated_at":       time.Now(),
+		}).Error
+}