[#1129] policer: Restore EC object

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/services/object/remote_reader.go

@@ -0,0 +1,144 @@
+package object
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	clientcore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/client"
+	netmapCore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/netmap"
+	internalclient "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/internal/client"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/util"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
+	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+)
+
+type ClientConstructor interface {
+	Get(clientcore.NodeInfo) (clientcore.MultiAddressClient, error)
+}
+
+// RemoteReader represents utility for getting
+// the object from a remote host.
+type RemoteReader struct {
+	keyStorage *util.KeyStorage
+
+	clientCache ClientConstructor
+}
+
+// RemoteRequestPrm groups remote operation parameters.
+type RemoteRequestPrm struct {
+	addr oid.Address
+	raw  bool
+	node netmap.NodeInfo
+}
+
+const remoteOpTTL = 1
+
+var ErrNotFound = errors.New("object header not found")
+
+// NewRemoteReader creates, initializes and returns new RemoteHeader instance.
+func NewRemoteReader(keyStorage *util.KeyStorage, cache ClientConstructor) *RemoteReader {
+	return &RemoteReader{
+		keyStorage:  keyStorage,
+		clientCache: cache,
+	}
+}
+
+// WithNodeInfo sets information about the remote node.
+func (p *RemoteRequestPrm) WithNodeInfo(v netmap.NodeInfo) *RemoteRequestPrm {
+	if p != nil {
+		p.node = v
+	}
+
+	return p
+}
+
+// WithObjectAddress sets object address.
+func (p *RemoteRequestPrm) WithObjectAddress(v oid.Address) *RemoteRequestPrm {
+	if p != nil {
+		p.addr = v
+	}
+
+	return p
+}
+
+func (p *RemoteRequestPrm) WithRaw(v bool) *RemoteRequestPrm {
+	if p != nil {
+		p.raw = v
+	}
+	return p
+}
+
+// Head requests object header from the remote node.
+func (h *RemoteReader) Head(ctx context.Context, prm *RemoteRequestPrm) (*objectSDK.Object, error) {
+	key, err := h.keyStorage.GetKey(nil)
+	if err != nil {
+		return nil, fmt.Errorf("(%T) could not receive private key: %w", h, err)
+	}
+
+	var info clientcore.NodeInfo
+
+	err = clientcore.NodeInfoFromRawNetmapElement(&info, netmapCore.Node(prm.node))
+	if err != nil {
+		return nil, fmt.Errorf("parse client node info: %w", err)
+	}
+
+	c, err := h.clientCache.Get(info)
+	if err != nil {
+		return nil, fmt.Errorf("(%T) could not create SDK client %s: %w", h, info.AddressGroup(), err)
+	}
+
+	var headPrm internalclient.HeadObjectPrm
+
+	headPrm.SetClient(c)
+	headPrm.SetPrivateKey(key)
+	headPrm.SetAddress(prm.addr)
+	headPrm.SetTTL(remoteOpTTL)
+	if prm.raw {
+		headPrm.SetRawFlag()
+	}
+
+	res, err := internalclient.HeadObject(ctx, headPrm)
+	if err != nil {
+		return nil, fmt.Errorf("(%T) could not head object in %s: %w", h, info.AddressGroup(), err)
+	}
+
+	return res.Header(), nil
+}
+
+func (h *RemoteReader) Get(ctx context.Context, prm *RemoteRequestPrm) (*objectSDK.Object, error) {
+	key, err := h.keyStorage.GetKey(nil)
+	if err != nil {
+		return nil, fmt.Errorf("(%T) could not receive private key: %w", h, err)
+	}
+
+	var info clientcore.NodeInfo
+
+	err = clientcore.NodeInfoFromRawNetmapElement(&info, netmapCore.Node(prm.node))
+	if err != nil {
+		return nil, fmt.Errorf("parse client node info: %w", err)
+	}
+
+	c, err := h.clientCache.Get(info)
+	if err != nil {
+		return nil, fmt.Errorf("(%T) could not create SDK client %s: %w", h, info.AddressGroup(), err)
+	}
+
+	var getPrm internalclient.GetObjectPrm
+
+	getPrm.SetClient(c)
+	getPrm.SetPrivateKey(key)
+	getPrm.SetAddress(prm.addr)
+	getPrm.SetTTL(remoteOpTTL)
+	if prm.raw {
+		getPrm.SetRawFlag()
+	}
+
+	res, err := internalclient.GetObject(ctx, getPrm)
+	if err != nil {
+		return nil, fmt.Errorf("(%T) could not head object in %s: %w", h, info.AddressGroup(), err)
+	}
+
+	return res.Object(), nil
+}