[#234] services/object: Support netmap epoch and lookup dead in read ops

Support processing of NetmapEpoch and NetmapLookupDepth X-headers when
processing object read operations. Placement for operations
Get/Head/GetRange/GetRangeHash/Search is built for the epoch specified in
NetmapEpoch X-header (by default latest). Also the specified operations are
processed until success is achieved for network maps from the past up to
NetmapLookupDepth value. Behavior for default values (zero or missing) left
unchanged.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

pkg/services/object/util/prm.go

@@ -2,6 +2,7 @@ package util
 
 import (
 	"crypto/ecdsa"
+	"strconv"
 
 	"github.com/nspcc-dev/neofs-api-go/pkg"
 	"github.com/nspcc-dev/neofs-api-go/pkg/client"
@@ -12,6 +13,8 @@ import (
 type CommonPrm struct {
 	local bool
 
+	netmapEpoch, netmapLookupDepth uint64
+
 	token *token.SessionToken
 
 	bearer *token.BearerToken
@@ -21,6 +24,12 @@ type CommonPrm struct {
 	callOpts []client.CallOption
 }
 
+type remoteCallOpts struct {
+	opts []client.CallOption
+}
+
+type DynamicCallOption func(*remoteCallOpts)
+
 func (p *CommonPrm) WithLocalOnly(v bool) *CommonPrm {
 	if p != nil {
 		p.local = v
@@ -81,14 +90,32 @@ func (p *CommonPrm) WithRemoteCallOptions(opts ...client.CallOption) *CommonPrm
 }
 
 // RemoteCallOptions return call options for remote client calls.
-func (p *CommonPrm) RemoteCallOptions() []client.CallOption {
+func (p *CommonPrm) RemoteCallOptions(dynamic ...DynamicCallOption) []client.CallOption {
 	if p != nil {
-		return p.callOpts
+		o := &remoteCallOpts{
+			opts: p.callOpts,
+		}
+
+		for _, applier := range dynamic {
+			applier(o)
+		}
+
+		return o.opts
 	}
 
 	return nil
 }
 
+func WithNetmapEpoch(v uint64) DynamicCallOption {
+	return func(o *remoteCallOpts) {
+		xHdr := pkg.NewXHeader()
+		xHdr.SetKey(session.XHeaderNetmapEpoch)
+		xHdr.SetValue(strconv.FormatUint(v, 10))
+
+		o.opts = append(o.opts, client.WithXHeader(xHdr))
+	}
+}
+
 func (p *CommonPrm) SessionToken() *token.SessionToken {
 	if p != nil {
 		return p.token
@@ -105,9 +132,31 @@ func (p *CommonPrm) BearerToken() *token.BearerToken {
 	return nil
 }
 
+func (p *CommonPrm) NetmapEpoch() uint64 {
+	if p != nil {
+		return p.netmapEpoch
+	}
+
+	return 0
+}
+
+func (p *CommonPrm) NetmapLookupDepth() uint64 {
+	if p != nil {
+		return p.netmapLookupDepth
+	}
+
+	return 0
+}
+
+func (p *CommonPrm) SetNetmapLookupDepth(v uint64) {
+	if p != nil {
+		p.netmapLookupDepth = v
+	}
+}
+
 func CommonPrmFromV2(req interface {
 	GetMetaHeader() *session.RequestMetaHeader
-}) *CommonPrm {
+}) (*CommonPrm, error) {
 	meta := req.GetMetaHeader()
 
 	xHdrs := meta.GetXHeaders()
@@ -134,12 +183,29 @@ func CommonPrmFromV2(req interface {
 	}
 
 	for i := range xHdrs {
-		prm.callOpts = append(prm.callOpts,
-			client.WithXHeader(
-				pkg.NewXHeaderFromV2(xHdrs[i]),
-			),
-		)
+		switch xHdrs[i].GetKey() {
+		case session.XHeaderNetmapEpoch:
+			var err error
+
+			prm.netmapEpoch, err = strconv.ParseUint(xHdrs[i].GetValue(), 10, 64)
+			if err != nil {
+				return nil, err
+			}
+		case session.XHeaderNetmapLookupDepth:
+			var err error
+
+			prm.netmapLookupDepth, err = strconv.ParseUint(xHdrs[i].GetValue(), 10, 64)
+			if err != nil {
+				return nil, err
+			}
+		default:
+			prm.callOpts = append(prm.callOpts,
+				client.WithXHeader(
+					pkg.NewXHeaderFromV2(xHdrs[i]),
+				),
+			)
+		}
 	}
 
-	return prm
+	return prm, nil
 }