draft

backend/internal/repository/sequence.go

@@ -0,0 +1,90 @@
+package repository
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"gorm.io/gorm"
+	"pay-bridge/internal/model"
+)
+
+// SequenceRepository 序列数据访问
+type SequenceRepository struct {
+	db *gorm.DB
+}
+
+func NewSequenceRepository(db *gorm.DB) *SequenceRepository {
+	return &SequenceRepository{db: db}
+}
+
+// IncrAndGet 原子自增并返回新值（行级锁）
+func (r *SequenceRepository) IncrAndGet(ctx context.Context, appID string, seqType model.SeqType) (uint64, error) {
+	var seq model.OrderSequence
+
+	err := r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
+		// 加行锁读取
+		if err := tx.Set("gorm:query_option", "FOR UPDATE").
+			Where("app_id = ? AND seq_type = ?", appID, seqType).
+			First(&seq).Error; err != nil {
+			if !errors.Is(err, gorm.ErrRecordNotFound) {
+				return err
+			}
+			// 自动初始化序列
+			prefix := defaultPrefix(seqType)
+			seq = model.OrderSequence{
+				AppID:        appID,
+				SeqType:      seqType,
+				Prefix:       prefix,
+				CurrentValue: 0,
+				Step:         1,
+			}
+			if err := tx.Create(&seq).Error; err != nil {
+				return err
+			}
+			// 重新加锁读
+			return tx.Set("gorm:query_option", "FOR UPDATE").
+				Where("app_id = ? AND seq_type = ?", appID, seqType).
+				First(&seq).Error
+		}
+		return nil
+	})
+	if err != nil {
+		return 0, err
+	}
+
+	// 自增
+	newVal := seq.CurrentValue + uint64(seq.Step)
+	if err := r.db.WithContext(ctx).Model(&model.OrderSequence{}).
+		Where("id = ?", seq.ID).
+		Update("current_value", newVal).Error; err != nil {
+		return 0, err
+	}
+	return newVal, nil
+}
+
+func defaultPrefix(t model.SeqType) string {
+	switch t {
+	case model.SeqTypeTrade:
+		return "PAY"
+	case model.SeqTypeRefund:
+		return "REF"
+	case model.SeqTypeSharing:
+		return "SHA"
+	default:
+		return "ORD"
+	}
+}
+
+// GetPrefix 获取序列前缀
+func (r *SequenceRepository) GetPrefix(ctx context.Context, appID string, seqType model.SeqType) (string, error) {
+	var seq model.OrderSequence
+	err := r.db.WithContext(ctx).Where("app_id = ? AND seq_type = ?", appID, seqType).First(&seq).Error
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		return fmt.Sprintf("%s", defaultPrefix(seqType)), nil
+	}
+	if err != nil {
+		return "", err
+	}
+	return seq.Prefix, nil
+}