[#235] services/object: Implement new GetRange algorithm

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

pkg/services/object/get/prm.go

@@ -11,6 +11,17 @@ import (
 
 // Prm groups parameters of Get service call.
 type Prm struct {
+	commonPrm
+}
+
+// RangePrm groups parameters of GetRange service call.
+type RangePrm struct {
+	commonPrm
+
+	rng *objectSDK.Range
+}
+
+type commonPrm struct {
 	objWriter ObjectWriter
 
 	// TODO: replace key and callOpts to CommonPrm
@@ -20,16 +31,19 @@ type Prm struct {
 
 	common *util.CommonPrm
 
-	// TODO: use parameters from NeoFS SDK
-	addr *objectSDK.Address
+	client.GetObjectParams
+}
 
-	raw bool
+// ChunkWriter is an interface of target component
+// to write payload chunk.
+type ChunkWriter interface {
+	WriteChunk([]byte) error
 }
 
 // ObjectWriter is an interface of target component to write object.
 type ObjectWriter interface {
 	WriteHeader(*object.Object) error
-	WriteChunk([]byte) error
+	ChunkWriter
 }
 
 // SetObjectWriter sets target component to write the object.
@@ -38,22 +52,23 @@ func (p *Prm) SetObjectWriter(w ObjectWriter) {
 }
 
 // SetPrivateKey sets private key to use during execution.
-func (p *Prm) SetPrivateKey(key *ecdsa.PrivateKey) {
+func (p *commonPrm) SetPrivateKey(key *ecdsa.PrivateKey) {
 	p.key = key
 }
 
 // SetRemoteCallOptions sets call options remote remote client calls.
-func (p *Prm) SetRemoteCallOptions(opts ...client.CallOption) {
+func (p *commonPrm) SetRemoteCallOptions(opts ...client.CallOption) {
 	p.callOpts = opts
 }
 
-// SetAddress sets address of the requested object.
-func (p *Prm) SetAddress(addr *objectSDK.Address) {
-	p.addr = addr
+// SetObjectWriter sets target component to write the object payload range.
+func (p *RangePrm) SetChunkWriter(w ChunkWriter) {
+	p.objWriter = &rangeWriter{
+		chunkWriter: w,
+	}
 }
 
-// SetRaw sets raw flag. If flag is set,
-// object assembling will not be undertaken.
-func (p *Prm) SetRaw(raw bool) {
-	p.raw = raw
+// SetRange sets range of the requested payload data.
+func (p *RangePrm) SetRange(rng *objectSDK.Range) {
+	p.rng = rng
 }