store/tikv: use tikv.error.ErrCannotSetNilValue instead of kv error (#24350)

store/driver/txn/error.go

@@ -156,6 +156,10 @@ func toTiDBErr(err error) error {
 		return kv.ErrNotExist
 	}
 
+	if errors.ErrorEqual(err, tikverr.ErrCannotSetNilValue) {
+		return kv.ErrCannotSetNilValue
+	}
+
 	if e, ok := err.(*tikverr.ErrEntryTooLarge); ok {
 		return kv.ErrEntryTooLarge.GenWithStackByArgs(e.Limit, e.Size)
 	}

store/tikv/error/error.go

@@ -29,6 +29,8 @@ var (
 	ErrTiDBShuttingDown = errors.New("tidb server shutting down")
 	// ErrNotExist means the related data not exist.
 	ErrNotExist = errors.New("not exist")
+	// ErrCannotSetNilValue is the error when sets an empty value.
+	ErrCannotSetNilValue = errors.New("can not set nil value")
 	// ErrInvalidTxn is the error when commits or rollbacks in an invalid transaction.
 	ErrInvalidTxn = errors.New("invalid transaction")
 )

store/tikv/unionstore/memdb.go

@@ -217,7 +217,7 @@ func (db *MemDB) UpdateFlags(key []byte, ops ...kv.FlagsOp) {
 // v must NOT be nil or empty, otherwise it returns ErrCannotSetNilValue.
 func (db *MemDB) Set(key []byte, value []byte) error {
 	if len(value) == 0 {
-		return tidbkv.ErrCannotSetNilValue
+		return tikverr.ErrCannotSetNilValue
 	}
 	return db.set(key, value)
 }
@@ -225,7 +225,7 @@ func (db *MemDB) Set(key []byte, value []byte) error {
 // SetWithFlags put key-value into the last active staging buffer with the given KeyFlags.
 func (db *MemDB) SetWithFlags(key []byte, value []byte, ops ...kv.FlagsOp) error {
 	if len(value) == 0 {
-		return tidbkv.ErrCannotSetNilValue
+		return tikverr.ErrCannotSetNilValue
 	}
 	return db.set(key, value, ops...)
 }