feat: remove orphans

CHANGELOG.md

@@ -2,10 +2,12 @@
 
 ### Breaking Changes
 
+- [#646](https://github.com/cosmos/iavl/pull/646) Remove the `orphans` from the storage
 - [#622](https://github.com/cosmos/iavl/pull/622) `export/newExporter()` and `ImmutableTree.Export()` returns error for nil arguements
 
-## Unreleased
+### API Changes
 
+- [#646](https://github.com/cosmos/iavl/pull/646) Remove the `DeleteVersion`, `DeleteVersions`, `DeleteVersionsRange` and introduce a new endpoint of `DeleteVersionsTo` instead
 - [#586](https://github.com/cosmos/iavl/pull/586) Remove the `RangeProof` and refactor the ics23_proof to use the internal methods.
 - [#640](https://github.com/cosmos/iavl/pull/640) commit `NodeDB` batch in `LoadVersionForOverwriting`.
 - [#636](https://github.com/cosmos/iavl/pull/636) Speed up rollback method: `LoadVersionForOverwriting`.

benchmarks/bench_test.go

@@ -51,7 +51,7 @@ func commitTree(b *testing.B, t *iavl.MutableTree) {
 	}
 
 	if version > historySize {
-		err = t.DeleteVersion(version - historySize)
+		err = t.DeleteVersionsTo(version - historySize)
 		if err != nil {
 			b.Errorf("Can't delete: %v", err)
 		}

export_test.go

@@ -296,13 +296,14 @@ func TestExporter_DeleteVersionErrors(t *testing.T) {
 	require.NoError(t, err)
 	defer exporter.Close()
 
-	err = tree.DeleteVersion(2)
-	require.Error(t, err)
-	err = tree.DeleteVersion(1)
+	err = tree.DeleteVersionsTo(1)
 	require.NoError(t, err)
 
+	err = tree.DeleteVersionsTo(2)
+	require.Error(t, err)
+
 	exporter.Close()
-	err = tree.DeleteVersion(2)
+	err = tree.DeleteVersionsTo(2)
 	require.NoError(t, err)
 }
 

iterator.go

@@ -322,16 +322,17 @@ func (iter *NodeIterator) Next(isSkipped bool) {
 		return
 	}
 
-	leftNode, err := iter.ndb.GetNode(node.leftHash)
+	rightNode, err := iter.ndb.GetNode(node.rightHash)
 	if err != nil {
 		iter.err = err
 		return
 	}
-	iter.nodesToVisit = append(iter.nodesToVisit, leftNode)
-	rightNode, err := iter.ndb.GetNode(node.rightHash)
+	iter.nodesToVisit = append(iter.nodesToVisit, rightNode)
+
+	leftNode, err := iter.ndb.GetNode(node.leftHash)
 	if err != nil {
 		iter.err = err
 		return
 	}
-	iter.nodesToVisit = append(iter.nodesToVisit, rightNode)
+	iter.nodesToVisit = append(iter.nodesToVisit, leftNode)
 }

iterator_test.go

@@ -180,7 +180,7 @@ func TestIterator_WithDelete_Full_Ascending_Success(t *testing.T) {
 	_, _, err = tree.SaveVersion()
 	require.NoError(t, err)
 
-	err = tree.DeleteVersion(1)
+	err = tree.DeleteVersionsTo(1)
 	require.NoError(t, err)
 
 	latestVersion, err := tree.ndb.getLatestVersion()
@@ -330,3 +330,45 @@ func setupUnsavedFastIterator(t *testing.T, config *iteratorTestConfig) (dbm.Ite
 	itr := NewUnsavedFastIterator(config.startIterate, config.endIterate, config.ascending, tree.ndb, tree.unsavedFastNodeAdditions, tree.unsavedFastNodeRemovals)
 	return itr, mirror
 }
+
+func TestNodeIterator_Success(t *testing.T) {
+	tree, mirror := getRandomizedTreeAndMirror(t)
+
+	_, _, err := tree.SaveVersion()
+	require.NoError(t, err)
+
+	randomizeTreeAndMirror(t, tree, mirror)
+
+	_, _, err = tree.SaveVersion()
+	require.NoError(t, err)
+
+	// check if the iterating count is same with the entire node count of the tree
+	itr, err := NewNodeIterator(tree.root.hash, tree.ndb)
+	require.NoError(t, err)
+	nodeCount := 0
+	for ; itr.Valid(); itr.Next(false) {
+		nodeCount++
+	}
+	require.Equal(t, int64(nodeCount), tree.Size()*2-1)
+
+	// check if the skipped node count is right
+	itr, err = NewNodeIterator(tree.root.hash, tree.ndb)
+	require.NoError(t, err)
+	updateCount := 0
+	skipCount := 0
+	for itr.Valid() {
+		node := itr.GetNode()
+		updateCount++
+		if node.version < tree.Version() {
+			skipCount += int(node.size*2 - 2) // the size of the subtree without the root
+		}
+		itr.Next(node.version < tree.Version())
+	}
+	require.Equal(t, nodeCount, updateCount+skipCount)
+}
+
+func TestNodeIterator_WithEmptyRoot(t *testing.T) {
+	itr, err := NewNodeIterator([]byte{}, newNodeDB(dbm.NewMemDB(), 0, nil))
+	require.NoError(t, err)
+	require.False(t, itr.Valid())
+}