fix: merge not allowed when using list type (temporary fix) (#457)

* fix: merge not allowed when using list type (temporary fix)

* style: remove useless code

* test: add unit test for merging list

db.go

@@ -180,7 +180,7 @@ func open(opt Options) (*DB, error) {
 		BPTreeKeyEntryPosMap:    make(map[string]int64),
 		bucketMetas:             make(map[string]*BucketMeta),
 		ActiveCommittedTxIdsIdx: NewTree(),
-		Index:                   NewIndex(),
+		Index:                   newIndex(),
 		fm:                      newFileManager(opt.RWMode, opt.MaxFdNumsInCache, opt.CleanFdsCacheThreshold),
 		mergeStartCh:            make(chan struct{}),
 		mergeEndCh:              make(chan error),

db_error.go

@@ -29,4 +29,7 @@ var (
 
 	// ErrIsMerging is returned when merge in progress
 	ErrIsMerging = errors.New("merge in progress")
+
+	// ErrNotSupportMergeWhenUsingList is returned calling 'Merge' when using list
+	ErrNotSupportMergeWhenUsingList = errors.New("not support merge when using list for now")
 )

index.go

@@ -19,7 +19,7 @@ type index struct {
 	list ListIdx
 }
 
-func NewIndex() *index {
+func newIndex() *index {
 	i := new(index)
 	i.list = map[string]*List{}
 	return i

merge.go

@@ -56,6 +56,10 @@ func (db *DB) merge() error {
 		return ErrNotSupportHintBPTSparseIdxMode
 	}
 
+	if len(db.Index.list) != 0 {
+		return ErrNotSupportMergeWhenUsingList
+	}
+
 	// to prevent the initiation of multiple merges simultaneously.
 	db.mu.Lock()
 
@@ -265,24 +269,5 @@ func (db *DB) isPendingMergeEntry(entry *Entry) bool {
 		}
 	}
 
-	//if entry.Meta.Ds == DataStructureList {
-	//	//check the key of list is expired or not
-	//	//if expired, it will clear the items of index
-	//	//so that nutsdb can clear entry of expiring list in the function isPendingMergeEntry
-	//	db.checkListExpired()
-	//
-	//	if listIdx := db.Index.getList(string(entry.Bucket)); listIdx != nil {
-	//		items, _ := listIdx.LRange(string(entry.Key), 0, -1)
-	//		if entry.Meta.Flag == DataRPushFlag || entry.Meta.Flag == DataLPushFlag {
-	//			for _, item := range items {
-	//				v, _ := db.getValueByRecord(item)
-	//				if string(entry.Value) == string(v) {
-	//					return true
-	//				}
-	//			}
-	//		}
-	//	}
-	//}
-
 	return false
 }

merge_test.go

@@ -125,25 +125,14 @@ func TestDB_MergeForZSet(t *testing.T) {
 	})
 }
 
-//func TestDB_MergeForList(t *testing.T) {
-//	opts := DefaultOptions
-//	opts.SegmentSize = 100
-//	opts.EntryIdxMode = HintKeyAndRAMIdxMode
-//	runNutsDBTest(t, &opts, func(t *testing.T, db *DB) {
-//		bucket := "bucket"
-//		key := GetTestBytes(0)
-//
-//		for i := 0; i < 100; i++ {
-//			txPush(t, db, bucket, key, GetTestBytes(i), nil, true)
-//		}
-//		txRange(t, db, bucket, key, 0, 99, 100)
-//
-//		txPop(t, db, bucket, key, GetTestBytes(99), nil, true)
-//		txPop(t, db, bucket, key, GetTestBytes(0), nil, false)
-//
-//		require.NoError(t, db.Merge())
-//	})
-//}
+func TestDB_MergeForList(t *testing.T) {
+	bucket := "bucket"
+	key := GetTestBytes(0)
+	runNutsDBTest(t, nil, func(t *testing.T, db *DB) {
+		txPush(t, db, bucket, key, GetTestBytes(0), nil, true)
+		require.Error(t, ErrNotSupportMergeWhenUsingList, db.Merge())
+	})
+}
 
 func TestDB_MergeAutomatic(t *testing.T) {
 	opts := DefaultOptions