feat(GraphSyncMessage): use Cid for root

Use a Cid as a root instead of a node, so that only one round trip is neccesary

docs/go-graphsync.puml

@@ -25,8 +25,8 @@ package "go-selector" {
   interface "GetBlockFunc func(cid) block.Block" as GetBlockFunc
 
   interface SelectorQuerier {
-    Select(Selector, root Node) SelectionTraverser
-    Validate(Selector, root Node, incomingResponses SelectionTraverser) SelectionTraverser
+    Select(Selector, root Cid) SelectionTraverser
+    Validate(Selector, root Cid, incomingResponses SelectionTraverser) SelectionTraverser
   }
 
   object "Package Public Functions" as goSelectorPF {
@@ -45,7 +45,7 @@ package "go-graphsync" {
       responseManager: ResponseManager
       selectorQuerier: SelectorQuerier
 
-      Request(p peer.ID, selector Selector, root Node) SelectionTraverser
+      Request(p peer.ID, selector Selector, root Cid) SelectionTraverser
       ReceiveMessage(ctx context.Context, sender peer.ID, incoming GraphSyncMessage)
       ReceiveError(error)
     }
@@ -74,8 +74,7 @@ package "go-graphsync" {
     object "Package Public Functions" as goGraphSyncNetworkPF {
       NewLibP2PNetwork(host libp2pHost.Host,
       decodeSelectionResponseFunc: DecodeSelectionResponseFunc,
-      decodeSelectorFunc: DecodeSelectorFunc,
-      decodeRootNodeFunc: DecodeRootNodeFunc) GraphSyncNetwork
+      decodeSelectorFunc: DecodeSelectorFunc) GraphSyncNetwork
     }
     goGraphSyncNetworkPF .. libP2PGraphSyncNetwork 
   }
@@ -85,7 +84,7 @@ package "go-graphsync" {
     network : GraphSyncNetwork
     selectorQuerier: SelectorQuerier
 
-    SendRequest(p peer.ID, selector Selector, node rootNode) SelectionTraverser
+    SendRequest(p peer.ID, selector Selector, root Cid) SelectionTraverser
     ProcessResponses(responses []GraphSyncResponse)
   }
   SelectorQuerier --* RequestManager
@@ -118,19 +117,17 @@ package "go-graphsync" {
   package message {
     interface "DecodeSelectionResponseFunc func([]byte) SelectionResponse" as DecodeSelectionResponseFunc
   interface "DecodeSelectorFunc func([]byte) Selector" as DecodeSelectorFunc
-  interface "DecodeRootNodeFunc func([]byte) Node" as DecodeRootNodeFunc
 
     object "Package Public Functions" as goGraphSyncMessagePF {
       func FromPBReader(pbr ggio.Reader,
       decodeSelectionResponseFunc: DecodeSelectionResponseFunc,
-      decodeSelectorFunc: DecodeSelectorFunc,
-      decodeRootNodeFunc: DecodeRootNodeFunc) (GraphSyncMessage, error)
+      decodeSelectorFunc: DecodeSelectorFunc) (GraphSyncMessage, error)
     }
     goGraphSyncMessagePF .. libP2PGraphSyncNetwork
 
     interface GraphSyncRequest {
       Selector() Selector
-      Root()     Node
+      Root()     Cid
       Priority() Priority
       ID()       int
       IsCancel() bool
@@ -169,7 +166,6 @@ package "go-filecoin" {
     host: libp2pHost.Host
     decodeSelectionResponseFunc: DecodeSelectionResponseFunc
     decodeSelectorFunc: DecodeSelectorFunc
-    decodeRootNodeFunc: DecodeRootNodeFunc
   }
 
   "go-filecoin" *-- GraphSync

message/message.go

@@ -4,9 +4,9 @@ import (
 	"fmt"
 
 	ggio "github.com/gogo/protobuf/io"
+	cid "github.com/ipfs/go-cid"
 	pb "github.com/ipfs/go-graphsync/message/pb"
 	gsselector "github.com/ipfs/go-graphsync/selector"
-	ipld "github.com/ipfs/go-ipld-format"
 )
 
 // GraphSyncRequestID is a unique identifier for a GraphSync request.
@@ -64,7 +64,7 @@ const (
 // GraphSyncMessage.
 type GraphSyncRequest interface {
 	Selector() gsselector.Selector
-	Root() ipld.Node
+	Root() cid.Cid
 	Priority() GraphSyncPriority
 	ID() GraphSyncRequestID
 	IsCancel() bool
@@ -87,7 +87,7 @@ type GraphSyncMessage interface {
 
 	AddRequest(id GraphSyncRequestID,
 		selector gsselector.Selector,
-		root ipld.Node,
+		root cid.Cid,
 		priority GraphSyncPriority)
 
 	Cancel(id GraphSyncRequestID)
@@ -109,7 +109,7 @@ type Exportable interface {
 
 type graphSyncRequest struct {
 	selector gsselector.Selector
-	root     ipld.Node
+	root     cid.Cid
 	priority GraphSyncPriority
 	id       GraphSyncRequestID
 	isCancel bool
@@ -130,10 +130,6 @@ type graphSyncMessage struct {
 // the Selector interface from a raw byte array.
 type DecodeSelectorFunc func([]byte) gsselector.Selector
 
-// DecodeRootNodeFunc is a function that can build a type that satisfies
-// the ipld.Node interface from a raw byte array.
-type DecodeRootNodeFunc func([]byte) ipld.Node
-
 // DecodeSelectionResponseFunc is a function that can build a type that satisfies
 // the SelectionResponse interface from a raw byte array.
 type DecodeSelectionResponseFunc func([]byte) gsselector.SelectionResponse
@@ -151,13 +147,15 @@ func newMsg() *graphSyncMessage {
 }
 
 func newMessageFromProto(pbm pb.Message,
-	decodeRootNode DecodeRootNodeFunc,
 	decodeSelector DecodeSelectorFunc,
 	decodeSelectionResponse DecodeSelectionResponseFunc) (GraphSyncMessage, error) {
 	gsm := newMsg()
 	for _, req := range pbm.Reqlist {
 		selector := decodeSelector(req.Selector)
-		root := decodeRootNode(req.Root)
+		root, err := cid.Cast([]byte(req.Root))
+		if err != nil {
+			return nil, fmt.Errorf("incorrectly formatted cid in request queery: %s", err)
+		}
 		gsm.addRequest(GraphSyncRequestID(req.Id), selector, root, GraphSyncPriority(req.Priority), req.Cancel)
 	}
 
@@ -187,12 +185,12 @@ func (gsm *graphSyncMessage) Responses() []GraphSyncResponse {
 
 func (gsm *graphSyncMessage) Cancel(id GraphSyncRequestID) {
 	delete(gsm.requests, id)
-	gsm.addRequest(id, nil, nil, 0, true)
+	gsm.addRequest(id, nil, cid.Cid{}, 0, true)
 }
 
 func (gsm *graphSyncMessage) AddRequest(id GraphSyncRequestID,
 	selector gsselector.Selector,
-	root ipld.Node,
+	root cid.Cid,
 	priority GraphSyncPriority,
 ) {
 	gsm.addRequest(id, selector, root, priority, false)
@@ -200,7 +198,7 @@ func (gsm *graphSyncMessage) AddRequest(id GraphSyncRequestID,
 
 func (gsm *graphSyncMessage) addRequest(id GraphSyncRequestID,
 	selector gsselector.Selector,
-	root ipld.Node,
+	root cid.Cid,
 	priority GraphSyncPriority,
 	isCancel bool) {
 	gsm.requests[id] = &graphSyncRequest{
@@ -224,7 +222,6 @@ func (gsm *graphSyncMessage) AddResponse(requestID GraphSyncRequestID,
 
 // FromPBReader can deserialize a protobuf message into a GraphySyncMessage.
 func FromPBReader(pbr ggio.Reader,
-	decodeRootNode DecodeRootNodeFunc,
 	decodeSelector DecodeSelectorFunc,
 	decodeSelectionResponse DecodeSelectionResponseFunc) (GraphSyncMessage, error) {
 	pb := new(pb.Message)
@@ -232,7 +229,7 @@ func FromPBReader(pbr ggio.Reader,
 		return nil, err
 	}
 
-	return newMessageFromProto(*pb, decodeRootNode, decodeSelector, decodeSelectionResponse)
+	return newMessageFromProto(*pb, decodeSelector, decodeSelectionResponse)
 }
 
 func (gsm *graphSyncMessage) ToProto() *pb.Message {
@@ -241,7 +238,7 @@ func (gsm *graphSyncMessage) ToProto() *pb.Message {
 	for _, request := range gsm.requests {
 		pbm.Reqlist = append(pbm.Reqlist, pb.Message_Request{
 			Id:       int32(request.id),
-			Root:     request.root.RawData(),
+			Root:     request.root.Bytes(),
 			Selector: request.selector.RawData(),
 			Priority: int32(request.priority),
 			Cancel:   request.isCancel,
@@ -275,7 +272,7 @@ func (gsm *graphSyncMessage) Loggable() map[string]interface{} {
 }
 
 func (gsr *graphSyncRequest) ID() GraphSyncRequestID        { return gsr.id }
-func (gsr *graphSyncRequest) Root() ipld.Node               { return gsr.root }
+func (gsr *graphSyncRequest) Root() cid.Cid                 { return gsr.root }
 func (gsr *graphSyncRequest) Selector() gsselector.Selector { return gsr.selector }
 func (gsr *graphSyncRequest) Priority() GraphSyncPriority   { return gsr.priority }
 func (gsr *graphSyncRequest) IsCancel() bool                { return gsr.isCancel }

message/message_test.go

@@ -10,12 +10,12 @@ import (
 
 func TestAppendingRequests(t *testing.T) {
 	selector := testselector.GenerateSelector()
-	rootNode := testselector.GenerateRootNode()
+	root := testselector.GenerateRootCid()
 	id := GraphSyncRequestID(rand.Int31())
 	priority := GraphSyncPriority(rand.Int31())
 
 	gsm := New()
-	gsm.AddRequest(id, selector, rootNode, priority)
+	gsm.AddRequest(id, selector, root, priority)
 	requests := gsm.Requests()
 	if len(requests) != 1 {
 		t.Fatal("Did not add request to message")
@@ -24,7 +24,7 @@ func TestAppendingRequests(t *testing.T) {
 	if request.ID() != id ||
 		request.IsCancel() != false ||
 		request.Priority() != priority ||
-		!reflect.DeepEqual(request.Root(), rootNode) ||
+		!reflect.DeepEqual(request.Root(), root) ||
 		!reflect.DeepEqual(request.Selector(), selector) {
 		t.Fatal("Did not properly add request to message")
 	}
@@ -34,13 +34,12 @@ func TestAppendingRequests(t *testing.T) {
 	if pbRequest.Id != int32(id) ||
 		pbRequest.Priority != int32(priority) ||
 		pbRequest.Cancel != false ||
-		!reflect.DeepEqual(pbRequest.Root, rootNode.RawData()) ||
+		!reflect.DeepEqual(pbRequest.Root, root.Bytes()) ||
 		!reflect.DeepEqual(pbRequest.Selector, selector.RawData()) {
 		t.Fatal("Did not properly serialize message to protobuf")
 	}
 
 	deserialized, err := newMessageFromProto(*pbMessage,
-		testselector.MockDecodeRootNodeFunc,
 		testselector.MockDecodeSelectorFunc,
 		testselector.MockDecodeSelectionResponseFunc,
 	)
@@ -55,7 +54,7 @@ func TestAppendingRequests(t *testing.T) {
 	if deserializedRequest.ID() != id ||
 		deserializedRequest.IsCancel() != false ||
 		deserializedRequest.Priority() != priority ||
-		!reflect.DeepEqual(deserializedRequest.Root(), rootNode) ||
+		!reflect.DeepEqual(deserializedRequest.Root(), root) ||
 		!reflect.DeepEqual(deserializedRequest.Selector(), selector) {
 		t.Fatal("Did not properly deserialize protobuf messages so requests are equal")
 	}
@@ -88,7 +87,6 @@ func TestAppendingResponses(t *testing.T) {
 	}
 
 	deserialized, err := newMessageFromProto(*pbMessage,
-		testselector.MockDecodeRootNodeFunc,
 		testselector.MockDecodeSelectorFunc,
 		testselector.MockDecodeSelectionResponseFunc,
 	)
@@ -109,12 +107,12 @@ func TestAppendingResponses(t *testing.T) {
 
 func TestRequestCancel(t *testing.T) {
 	selector := testselector.GenerateSelector()
-	rootNode := testselector.GenerateRootNode()
+	root := testselector.GenerateRootCid()
 	id := GraphSyncRequestID(rand.Int31())
 	priority := GraphSyncPriority(rand.Int31())
 
 	gsm := New()
-	gsm.AddRequest(id, selector, rootNode, priority)
+	gsm.AddRequest(id, selector, root, priority)
 
 	gsm.Cancel(id)
 

selector/selector.go

 package selector
 
 import (
+	cid "github.com/ipfs/go-cid"
 	ipld "github.com/ipfs/go-ipld-format"
 )
 
@@ -24,6 +25,6 @@ type SelectionTraverser interface {
 
 // SelectorQuerier can be used to make and validate selector queries.
 type SelectorQuerier interface {
-	Select(Selector, root ipld.Node) SelectionTraverser
-	Validate(Selector, root ipld.Node, incomingResponses SelectionTraverser) SelectionTraverser
+	Select(Selector, root cid.Cid) SelectionTraverser
+	Validate(Selector, root cid.Cid, incomingResponses SelectionTraverser) SelectionTraverser
 }

testselector/testselector.go

@@ -126,9 +126,9 @@ func GenerateSelectionResponse() gsselector.SelectionResponse {
 	return node
 }
 
-// GenerateRootNode generates a new mock ipld Node to serve as a root node
-func GenerateRootNode() ipld.Node {
+// GenerateRootCid generates a new mock CID to serve as a root
+func GenerateRootCid() cid.Cid {
 	node := newNode(randomBytes(blockSize, seedSeq))
 	seedSeq++
-	return node
+	return node.Cid()
 }