[#231] Fix get latest version node

Signed-off-by: Roman Loginov <r.loginov@yadro.com>

CHANGELOG.md

@@ -30,6 +30,7 @@ This document outlines major changes between releases.
 - Implement chunk uploading (#106)
 - Add new `kludge.bypass_content_encoding_check_in_chunks` config param (#146)
 - Add new `frostfs.client_cut` config param (#192)
+- Add selection of the node of the latest version of the object (#231)
 
 ### Changed
 - Update prometheus to v1.15.0 (#94)

pkg/service/tree/tree.go

@@ -586,7 +586,7 @@ func (c *Tree) GetLatestVersion(ctx context.Context, bktInfo *data.BucketInfo, o
 		TreeID:     versionTree,
 		Path:       path,
 		Meta:       meta,
-		LatestOnly: true,
+		LatestOnly: false,
 		AllAttrs:   false,
 	}
 	nodes, err := c.service.GetNodes(ctx, p)
@@ -594,11 +594,43 @@ func (c *Tree) GetLatestVersion(ctx context.Context, bktInfo *data.BucketInfo, o
 		return nil, err
 	}
 
-	if len(nodes) == 0 {
+	latestNode, err := getLatestNode(nodes)
+	if err != nil {
+		return nil, err
+	}
+
+	return newNodeVersion(objectName, latestNode)
+}
+
+func getLatestNode(nodes []NodeResponse) (NodeResponse, error) {
+	var (
+		maxCreationTime uint64
+		targetIndexNode = -1
+	)
+
+	for i, node := range nodes {
+		currentCreationTime := node.GetTimestamp()
+		if checkExistOID(node.GetMeta()) && currentCreationTime > maxCreationTime {
+			maxCreationTime = currentCreationTime
+			targetIndexNode = i
+		}
+	}
+
+	if targetIndexNode == -1 {
 		return nil, layer.ErrNodeNotFound
 	}
 
-	return newNodeVersion(objectName, nodes[0])
+	return nodes[targetIndexNode], nil
+}
+
+func checkExistOID(meta []Meta) bool {
+	for _, kv := range meta {
+		if kv.GetKey() == "OID" {
+			return true
+		}
+	}
+
+	return false
 }
 
 // pathFromName splits name by '/'.

pkg/service/tree/tree_test.go

@@ -168,3 +168,127 @@ func TestTreeServiceAddVersion(t *testing.T) {
 	require.Len(t, versions, 1)
 	require.Equal(t, storedNode, versions[0])
 }
+
+func TestGetLatestNode(t *testing.T) {
+	for _, tc := range []struct {
+		name           string
+		nodes          []NodeResponse
+		exceptedNodeID uint64
+		error          bool
+	}{
+		{
+			name:  "empty",
+			nodes: []NodeResponse{},
+			error: true,
+		},
+		{
+			name: "one node of the object version",
+			nodes: []NodeResponse{
+				nodeResponse{
+					nodeID:    1,
+					parentID:  0,
+					timestamp: 1,
+					meta: []nodeMeta{
+						{
+							key:   oidKV,
+							value: []byte(oidtest.ID().String()),
+						},
+					},
+				},
+			},
+			exceptedNodeID: 1,
+		},
+		{
+			name: "one node of the object version and one node of the secondary object",
+			nodes: []NodeResponse{
+				nodeResponse{
+					nodeID:    2,
+					parentID:  0,
+					timestamp: 3,
+					meta:      []nodeMeta{},
+				},
+				nodeResponse{
+					nodeID:    1,
+					parentID:  0,
+					timestamp: 1,
+					meta: []nodeMeta{
+						{
+							key:   oidKV,
+							value: []byte(oidtest.ID().String()),
+						},
+					},
+				},
+			},
+			exceptedNodeID: 1,
+		},
+		{
+			name: "all nodes represent a secondary object",
+			nodes: []NodeResponse{
+				nodeResponse{
+					nodeID:    2,
+					parentID:  0,
+					timestamp: 3,
+					meta:      []nodeMeta{},
+				},
+				nodeResponse{
+					nodeID:    4,
+					parentID:  0,
+					timestamp: 5,
+					meta:      []nodeMeta{},
+				},
+			},
+			error: true,
+		},
+		{
+			name: "several nodes of different types and with different timestamp",
+			nodes: []NodeResponse{
+				nodeResponse{
+					nodeID:    1,
+					parentID:  0,
+					timestamp: 1,
+					meta: []nodeMeta{
+						{
+							key:   oidKV,
+							value: []byte(oidtest.ID().String()),
+						},
+					},
+				},
+				nodeResponse{
+					nodeID:    3,
+					parentID:  0,
+					timestamp: 3,
+					meta:      []nodeMeta{},
+				},
+				nodeResponse{
+					nodeID:    4,
+					parentID:  0,
+					timestamp: 4,
+					meta: []nodeMeta{
+						{
+							key:   oidKV,
+							value: []byte(oidtest.ID().String()),
+						},
+					},
+				},
+				nodeResponse{
+					nodeID:    6,
+					parentID:  0,
+					timestamp: 6,
+					meta:      []nodeMeta{},
+				},
+			},
+			exceptedNodeID: 4,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			actualNode, err := getLatestNode(tc.nodes)
+			if tc.error {
+				require.Error(t, err)
+				return
+			}
+
+			require.NoError(t, err)
+			require.Equal(t, tc.exceptedNodeID, actualNode.GetNodeID())
+		})
+	}
+}