[#137] Add index page support

Signed-off-by: Nikita Zinkevich <n.zinkevich@yadro.com>

tree/tree.go

@@ -2,11 +2,13 @@ package tree
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"strings"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/internal/api"
 	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/internal/api/layer"
+	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/internal/data"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
 	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
 )
@@ -20,6 +22,7 @@ type (
 	// Each method must return ErrNodeNotFound or ErrNodeAccessDenied if relevant.
 	ServiceClient interface {
 		GetNodes(ctx context.Context, p *GetNodesParams) ([]NodeResponse, error)
+		GetSubTree(ctx context.Context, bktInfo *data.BucketInfo, treeID string, rootID []uint64, depth uint32, sort bool) ([]NodeResponse, error)
 	}
 
 	treeNode struct {
@@ -29,6 +32,7 @@ type (
 
 	GetNodesParams struct {
 		CnrID      cid.ID
+		BktInfo    *data.BucketInfo
 		TreeID     string
 		Path       []string
 		Meta       []string
@@ -54,6 +58,7 @@ const (
 
 	// keys for delete marker nodes.
 	isDeleteMarkerKV = "IsDeleteMarker"
+	sizeKV           = "Size"
 
 	// versionTree -- ID of a tree with object versions.
 	versionTree = "version"
@@ -73,26 +78,28 @@ type Meta interface {
 
 type NodeResponse interface {
 	GetMeta() []Meta
-	GetTimestamp() uint64
+	GetTimestamp() []uint64
+	GetNodeID() []uint64
+	GetParentID() []uint64
 }
 
 func newTreeNode(nodeInfo NodeResponse) (*treeNode, error) {
-	treeNode := &treeNode{
+	tNode := &treeNode{
 		Meta: make(map[string]string, len(nodeInfo.GetMeta())),
 	}
 
 	for _, kv := range nodeInfo.GetMeta() {
 		switch kv.GetKey() {
 		case oidKV:
-			if err := treeNode.ObjID.DecodeString(string(kv.GetValue())); err != nil {
+			if err := tNode.ObjID.DecodeString(string(kv.GetValue())); err != nil {
 				return nil, err
 			}
 		default:
-			treeNode.Meta[kv.GetKey()] = string(kv.GetValue())
+			tNode.Meta[kv.GetKey()] = string(kv.GetValue())
 		}
 	}
 
-	return treeNode, nil
+	return tNode, nil
 }
 
 func (n *treeNode) Get(key string) (string, bool) {
@@ -106,29 +113,44 @@ func (n *treeNode) FileName() (string, bool) {
 }
 
 func newNodeVersion(node NodeResponse) (*api.NodeVersion, error) {
-	treeNode, err := newTreeNode(node)
+	tNode, err := newTreeNode(node)
 	if err != nil {
 		return nil, fmt.Errorf("invalid tree node: %w", err)
 	}
 
-	return newNodeVersionFromTreeNode(treeNode), nil
+	return newNodeVersionFromTreeNode(tNode), nil
 }
 
 func newNodeVersionFromTreeNode(treeNode *treeNode) *api.NodeVersion {
 	_, isDeleteMarker := treeNode.Get(isDeleteMarkerKV)
-
+	size, _ := treeNode.Get(sizeKV)
 	version := &api.NodeVersion{
 		BaseNodeVersion: api.BaseNodeVersion{
 			OID: treeNode.ObjID,
 		},
 		DeleteMarker: isDeleteMarker,
+		IsPrefixNode: size == "",
 	}
 
 	return version
 }
 
 func (c *Tree) GetLatestVersion(ctx context.Context, cnrID *cid.ID, objectName string) (*api.NodeVersion, error) {
-	meta := []string{oidKV, isDeleteMarkerKV}
+	nodes, err := c.GetVersions(ctx, cnrID, objectName)
+	if err != nil {
+		return nil, err
+	}
+
+	latestNode, err := getLatestVersionNode(nodes)
+	if err != nil {
+		return nil, err
+	}
+
+	return newNodeVersion(latestNode)
+}
+
+func (c *Tree) GetVersions(ctx context.Context, cnrID *cid.ID, objectName string) ([]NodeResponse, error) {
+	meta := []string{oidKV, isDeleteMarkerKV, sizeKV}
 	path := pathFromName(objectName)
 
 	p := &GetNodesParams{
@@ -139,30 +161,24 @@ func (c *Tree) GetLatestVersion(ctx context.Context, cnrID *cid.ID, objectName s
 		LatestOnly: false,
 		AllAttrs:   false,
 	}
-	nodes, err := c.service.GetNodes(ctx, p)
-	if err != nil {
-		return nil, err
-	}
 
-	latestNode, err := getLatestNode(nodes)
-	if err != nil {
-		return nil, err
-	}
-
-	return newNodeVersion(latestNode)
+	return c.service.GetNodes(ctx, p)
 }
 
-func getLatestNode(nodes []NodeResponse) (NodeResponse, error) {
+func getLatestVersionNode(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
+		if !checkExistOID(node.GetMeta()) {
+			continue
+		}
+
+		if currentCreationTime := getMaxTimestamp(node); currentCreationTime > maxCreationTime {
 			targetIndexNode = i
+			maxCreationTime = currentCreationTime
 		}
 	}
 
@@ -187,3 +203,145 @@ func checkExistOID(meta []Meta) bool {
 func pathFromName(objectName string) []string {
 	return strings.Split(objectName, separator)
 }
+
+func (c *Tree) GetSubTreeByPrefix(ctx context.Context, bktInfo *data.BucketInfo, prefix string, latestOnly bool) ([]NodeResponse, string, error) {
+	rootID, tailPrefix, err := c.determinePrefixNode(ctx, bktInfo, versionTree, prefix)
+	if err != nil {
+		return nil, "", err
+	}
+	subTree, err := c.service.GetSubTree(ctx, bktInfo, versionTree, rootID, 2, false)
+	if err != nil {
+		if errors.Is(err, layer.ErrNodeNotFound) {
+			return nil, "", nil
+		}
+		return nil, "", err
+	}
+
+	nodesMap := make(map[string][]NodeResponse, len(subTree))
+	for _, node := range subTree {
+		if MultiID(rootID).Equal(node.GetNodeID()) {
+			continue
+		}
+
+		fileName := GetFilename(node)
+		if !strings.HasPrefix(fileName, tailPrefix) {
+			continue
+		}
+
+		nodes := nodesMap[fileName]
+
+		// Add all nodes if flag latestOnly is false.
+		// Add all intermediate nodes
+		// and only latest leaf (object) nodes. To do this store and replace last leaf (object) node in nodes[0]
+		if len(nodes) == 0 {
+			nodes = []NodeResponse{node}
+		} else if !latestOnly || isIntermediate(node) {
+			nodes = append(nodes, node)
+		} else if isIntermediate(nodes[0]) {
+			nodes = append([]NodeResponse{node}, nodes...)
+		} else if getMaxTimestamp(node) > getMaxTimestamp(nodes[0]) {
+			nodes[0] = node
+		}
+
+		nodesMap[fileName] = nodes
+	}
+
+	result := make([]NodeResponse, 0, len(subTree))
+	for _, nodes := range nodesMap {
+		result = append(result, nodes...)
+	}
+
+	return result, strings.TrimSuffix(prefix, tailPrefix), nil
+}
+
+func (c *Tree) determinePrefixNode(ctx context.Context, bktInfo *data.BucketInfo, treeID, prefix string) ([]uint64, string, error) {
+	rootID := []uint64{0}
+	path := strings.Split(prefix, separator)
+	tailPrefix := path[len(path)-1]
+
+	if len(path) > 1 {
+		var err error
+		rootID, err = c.getPrefixNodeID(ctx, bktInfo, treeID, path[:len(path)-1])
+		if err != nil {
+			return nil, "", err
+		}
+	}
+
+	return rootID, tailPrefix, nil
+}
+
+func (c *Tree) getPrefixNodeID(ctx context.Context, bktInfo *data.BucketInfo, treeID string, prefixPath []string) ([]uint64, error) {
+	p := &GetNodesParams{
+		CnrID:      bktInfo.CID,
+		BktInfo:    bktInfo,
+		TreeID:     treeID,
+		Path:       prefixPath,
+		LatestOnly: false,
+		AllAttrs:   true,
+	}
+	nodes, err := c.service.GetNodes(ctx, p)
+	if err != nil {
+		return nil, err
+	}
+
+	var intermediateNodes []uint64
+	for _, node := range nodes {
+		if isIntermediate(node) {
+			intermediateNodes = append(intermediateNodes, node.GetNodeID()...)
+		}
+	}
+
+	if len(intermediateNodes) == 0 {
+		return nil, layer.ErrNodeNotFound
+	}
+
+	return intermediateNodes, nil
+}
+
+func GetFilename(node NodeResponse) string {
+	for _, kv := range node.GetMeta() {
+		if kv.GetKey() == FileNameKey {
+			return string(kv.GetValue())
+		}
+	}
+
+	return ""
+}
+
+func isIntermediate(node NodeResponse) bool {
+	if len(node.GetMeta()) != 1 {
+		return false
+	}
+
+	return node.GetMeta()[0].GetKey() == FileNameKey
+}
+
+func getMaxTimestamp(node NodeResponse) uint64 {
+	var maxTimestamp uint64
+
+	for _, timestamp := range node.GetTimestamp() {
+		if timestamp > maxTimestamp {
+			maxTimestamp = timestamp
+		}
+	}
+
+	return maxTimestamp
+}
+
+type MultiID []uint64
+
+func (m MultiID) Equal(id MultiID) bool {
+	seen := make(map[uint64]struct{}, len(m))
+
+	for i := range m {
+		seen[m[i]] = struct{}{}
+	}
+
+	for i := range id {
+		if _, ok := seen[id[i]]; !ok {
+			return false
+		}
+	}
+
+	return true
+}