[#142] Fix multipart-objects download

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

internal/service/frostfs/pool_wrapper.go

@@ -0,0 +1,91 @@
+package frostfs
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/tokens"
+	"git.frostfs.info/TrueCloudLab/frostfs-http-gw/tree"
+	treepool "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/pool/tree"
+	grpcService "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/pool/tree/service"
+)
+
+type GetNodeByPathResponseInfoWrapper struct {
+	response *grpcService.GetNodeByPathResponse_Info
+}
+
+func (n GetNodeByPathResponseInfoWrapper) GetNodeID() []uint64 {
+	return []uint64{n.response.GetNodeId()}
+}
+
+func (n GetNodeByPathResponseInfoWrapper) GetParentID() []uint64 {
+	return []uint64{n.response.GetParentId()}
+}
+
+func (n GetNodeByPathResponseInfoWrapper) GetTimestamp() []uint64 {
+	return []uint64{n.response.GetTimestamp()}
+}
+
+func (n GetNodeByPathResponseInfoWrapper) GetMeta() []tree.Meta {
+	res := make([]tree.Meta, len(n.response.Meta))
+	for i, value := range n.response.Meta {
+		res[i] = value
+	}
+	return res
+}
+
+type PoolWrapper struct {
+	p *treepool.Pool
+}
+
+func NewPoolWrapper(p *treepool.Pool) *PoolWrapper {
+	return &PoolWrapper{p: p}
+}
+
+func (w *PoolWrapper) GetNodes(ctx context.Context, prm *tree.GetNodesParams) ([]tree.NodeResponse, error) {
+	poolPrm := treepool.GetNodesParams{
+		CID:           prm.CnrID,
+		TreeID:        prm.TreeID,
+		Path:          prm.Path,
+		Meta:          prm.Meta,
+		PathAttribute: tree.FileNameKey,
+		LatestOnly:    prm.LatestOnly,
+		AllAttrs:      prm.AllAttrs,
+		BearerToken:   getBearer(ctx),
+	}
+
+	nodes, err := w.p.GetNodes(ctx, poolPrm)
+	if err != nil {
+		return nil, handleError(err)
+	}
+
+	res := make([]tree.NodeResponse, len(nodes))
+	for i, info := range nodes {
+		res[i] = GetNodeByPathResponseInfoWrapper{info}
+	}
+
+	return res, nil
+}
+
+func getBearer(ctx context.Context) []byte {
+	token, err := tokens.LoadBearerToken(ctx)
+	if err != nil {
+		return nil
+	}
+	return token.Marshal()
+}
+
+func handleError(err error) error {
+	if err == nil {
+		return nil
+	}
+	if errors.Is(err, treepool.ErrNodeNotFound) {
+		return fmt.Errorf("%w: %s", tree.ErrNodeNotFound, err.Error())
+	}
+	if errors.Is(err, treepool.ErrNodeAccessDenied) {
+		return fmt.Errorf("%w: %s", tree.ErrNodeAccessDenied, err.Error())
+	}
+
+	return err
+}