pkg/local_object_storage/pilorama/forest.go

@@ -12,7 +12,7 @@ import (
 // memoryForest represents multiple replicating trees sharing a single storage.
 type memoryForest struct {
 	// treeMap maps tree identifier (container ID + name) to the replicated log.
-	treeMap map[string]*state
+	treeMap map[string]*memoryTree
 }
 
 var _ Forest = (*memoryForest)(nil)
@@ -21,7 +21,7 @@ var _ Forest = (*memoryForest)(nil)
 // TODO: this function will eventually be removed and is here for debugging.
 func NewMemoryForest() ForestStorage {
 	return &memoryForest{
-		treeMap: make(map[string]*state),
+		treeMap: make(map[string]*memoryTree),
 	}
 }
 
@@ -34,7 +34,7 @@ func (f *memoryForest) TreeMove(_ context.Context, d CIDDescriptor, treeID strin
 	fullID := d.CID.String() + "/" + treeID
 	s, ok := f.treeMap[fullID]
 	if !ok {
-		s = newState()
+		s = newMemoryTree()
 		f.treeMap[fullID] = s
 	}
 
@@ -60,7 +60,7 @@ func (f *memoryForest) TreeAddByPath(_ context.Context, d CIDDescriptor, treeID
 	fullID := d.CID.String() + "/" + treeID
 	s, ok := f.treeMap[fullID]
 	if !ok {
-		s = newState()
+		s = newMemoryTree()
 		f.treeMap[fullID] = s
 	}
 
@@ -89,6 +89,7 @@ func (f *memoryForest) TreeAddByPath(_ context.Context, d CIDDescriptor, treeID
 		},
 		Child: s.findSpareID(),
 	})
+	s.operations = append(s.operations, op)
 	lm[len(lm)-1] = op.Move
 	return lm, nil
 }
@@ -98,7 +99,7 @@ func (f *memoryForest) TreeApply(_ context.Context, cnr cid.ID, treeID string, o
 	fullID := cnr.String() + "/" + treeID
 	s, ok := f.treeMap[fullID]
 	if !ok {
-		s = newState()
+		s = newMemoryTree()
 		f.treeMap[fullID] = s
 	}
 
@@ -131,7 +132,7 @@ func (f *memoryForest) TreeGetByPath(_ context.Context, cid cid.ID, treeID strin
 		return nil, ErrTreeNotFound
 	}
 
-	return s.get(attr, path, latest), nil
+	return s.getByPath(attr, path, latest), nil
 }
 
 // TreeGetMeta implements the Forest interface.
@@ -142,7 +143,7 @@ func (f *memoryForest) TreeGetMeta(_ context.Context, cid cid.ID, treeID string,
 		return Meta{}, 0, ErrTreeNotFound
 	}
 
-	return s.getMeta(nodeID), s.infoMap[nodeID].Parent, nil
+	return s.infoMap[nodeID].Meta, s.infoMap[nodeID].Parent, nil
 }
 
 // TreeGetChildren implements the Forest interface.
@@ -153,11 +154,7 @@ func (f *memoryForest) TreeGetChildren(_ context.Context, cid cid.ID, treeID str
 		return nil, ErrTreeNotFound
 	}
 
-	children, ok := s.childMap[nodeID]
+	children := s.tree.getChildren(nodeID)
-	if !ok {
-		return nil, nil
-	}
-
 	res := make([]Node, len(children))
 	copy(res, children)
 	return res, nil

pkg/local_object_storage/pilorama/forest_test.go

@@ -322,6 +322,10 @@ func testForestTreeAddByPath(t *testing.T, s Forest) {
 	firstID := lm[2].Child
 	testMeta(t, s, cid, treeID, firstID, lm[2].Parent, Meta{Time: lm[2].Time, Items: meta})
 
+	// TreeAddByPath must return operations in increasing time order.
+	require.True(t, lm[0].Time < lm[1].Time)
+	require.True(t, lm[1].Time < lm[2].Time)
+
 	meta[0].Value = []byte("YYY")
 	lm, err = s.TreeAddByPath(context.Background(), d, treeID, AttributeFilename, []string{"path", "to"}, meta)
 	require.NoError(t, err)
@@ -714,13 +718,6 @@ func compareForests(t *testing.T, expected, actual Forest, cid cidSDK.ID, treeID
 				require.True(t, ok)
 				require.Equal(t, se.operations, sa.operations)
 				require.Equal(t, se.infoMap, sa.infoMap)
-
-				require.Equal(t, len(se.childMap), len(sa.childMap))
-				for ck, la := range sa.childMap {
-					le, ok := se.childMap[ck]
-					require.True(t, ok)
-					require.ElementsMatch(t, le, la)
-				}
 			}
 			require.Equal(t, expected, actual, i)
 		}

pkg/local_object_storage/pilorama/inmemory.go

@@ -1,5 +1,7 @@
 package pilorama
 
+import "sort"
+
 // nodeInfo couples parent and metadata.
 type nodeInfo struct {
 	Parent Node
@@ -12,42 +14,25 @@ type move struct {
 	Old    nodeInfo
 }
 
-// state represents state being replicated.
+// memoryTree represents memoryTree being replicated.
-type state struct {
+type memoryTree struct {
 	operations []move
 	tree
 }
 
-// newState constructs new empty tree.
+// newMemoryTree constructs new empty tree.
-func newState() *state {
+func newMemoryTree() *memoryTree {
-	return &state{
+	return &memoryTree{
-		tree: *newTree(),
+		tree: tree{
+			infoMap: make(map[Node]nodeInfo),
+		},
 	}
 }
 
 // undo un-does op and changes s in-place.
-func (s *state) undo(op *move) {
+func (s *memoryTree) undo(op *move) {
-	children := s.tree.childMap[op.Parent]
-	for i := range children {
-		if children[i] == op.Child {
-			if len(children) > 1 {
-				s.tree.childMap[op.Parent] = append(children[:i], children[i+1:]...)
-			} else {
-				delete(s.tree.childMap, op.Parent)
-			}
-			break
-		}
-	}
-
 	if op.HasOld {
 		s.tree.infoMap[op.Child] = op.Old
-		oldChildren := s.tree.childMap[op.Old.Parent]
-		for i := range oldChildren {
-			if oldChildren[i] == op.Child {
-				return
-			}
-		}
-		s.tree.childMap[op.Old.Parent] = append(oldChildren, op.Child)
 	} else {
 		delete(s.tree.infoMap, op.Child)
 	}
@@ -55,7 +40,7 @@ func (s *state) undo(op *move) {
 
 // Apply puts op in log at a proper position, re-applies all subsequent operations
 // from log and changes s in-place.
-func (s *state) Apply(op *Move) error {
+func (s *memoryTree) Apply(op *Move) error {
 	var index int
 	for index = len(s.operations); index > 0; index-- {
 		if s.operations[index-1].Time <= op.Time {
@@ -82,7 +67,7 @@ func (s *state) Apply(op *Move) error {
 }
 
 // do performs a single move operation on a tree.
-func (s *state) do(op *Move) move {
+func (s *memoryTree) do(op *Move) move {
 	lm := move{
 		Move: Move{
 			Parent: op.Parent,
@@ -104,36 +89,23 @@ func (s *state) do(op *Move) move {
 
 	if !ok {
 		p.Meta.Time = op.Time
-	} else {
-		s.removeChild(op.Child, p.Parent)
 	}
 
 	p.Meta = op.Meta
 	p.Parent = op.Parent
 	s.tree.infoMap[op.Child] = p
-	s.tree.childMap[op.Parent] = append(s.tree.childMap[op.Parent], op.Child)
 
 	return lm
 }
 
-func (s *state) removeChild(child, parent Node) {
+func (s *memoryTree) timestamp(pos, size int) Timestamp {
-	oldChildren := s.tree.childMap[parent]
-	for i := range oldChildren {
-		if oldChildren[i] == child {
-			s.tree.childMap[parent] = append(oldChildren[:i], oldChildren[i+1:]...)
-			break
-		}
-	}
-}
-
-func (s *state) timestamp(pos, size int) Timestamp {
 	if len(s.operations) == 0 {
 		return nextTimestamp(0, uint64(pos), uint64(size))
 	}
 	return nextTimestamp(s.operations[len(s.operations)-1].Time, uint64(pos), uint64(size))
 }
 
-func (s *state) findSpareID() Node {
+func (s *memoryTree) findSpareID() Node {
 	id := uint64(1)
 	for _, ok := s.infoMap[id]; ok; _, ok = s.infoMap[id] {
 		id++
@@ -145,14 +117,22 @@ func (s *state) findSpareID() Node {
 type tree struct {
 	syncHeight uint64
 	infoMap    map[Node]nodeInfo
-	childMap   map[Node][]Node
 }
 
-func newTree() *tree {
+func (t tree) getChildren(parent Node) []Node {
-	return &tree{
+	var children []Node
-		childMap: make(map[Node][]Node),
+	for c, info := range t.infoMap {
-		infoMap:  make(map[Node]nodeInfo),
+		if info.Parent == parent {
+			children = append(children, c)
+		}
 	}
+
+	sort.Slice(children, func(i, j int) bool {
+		a := t.infoMap[children[i]]
+		b := t.infoMap[children[j]]
+		return a.Meta.Time < b.Meta.Time
+	})
+	return children
 }
 
 // isAncestor returns true if parent is an ancestor of a child.
@@ -176,7 +156,7 @@ func (t tree) getPathPrefix(attr string, path []string) (int, Node) {
 
 loop:
 	for i := range path {
-		children := t.childMap[curNode]
+		children := t.getChildren(curNode)
 		for j := range children {
 			meta := t.infoMap[children[j]].Meta
 			f := meta.GetAttr(attr)
@@ -191,9 +171,10 @@ loop:
 	return len(path), curNode
 }
 
-// get returns list of nodes which have the specified path from root
+// getByPath returns list of nodes which have the specified path from root
 // descending by values of attr from meta.
-func (t tree) get(attr string, path []string, latest bool) []Node {
+// If latest is true, only the latest node is returned.
+func (t tree) getByPath(attr string, path []string, latest bool) []Node {
 	if len(path) == 0 {
 		return nil
 	}
@@ -206,7 +187,7 @@ func (t tree) get(attr string, path []string, latest bool) []Node {
 	var nodes []Node
 	var lastTs Timestamp
 
-	children := t.childMap[curNode]
+	children := t.getChildren(curNode)
 	for i := range children {
 		info := t.infoMap[children[i]]
 		fileName := string(info.Meta.GetAttr(attr))
@@ -223,8 +204,3 @@ func (t tree) get(attr string, path []string, latest bool) []Node {
 
 	return nodes
 }
-
-// getMeta returns meta information of node n.
-func (t tree) getMeta(n Node) Meta {
-	return t.infoMap[n].Meta
-}