[FAB-8039] Split Endorsement Handler

Split the endorsement handler into two
handlers:

- Proposal Processor Handler
- Endorsement Handler

This allows for more granular
reuse/replacement of handlers.

Change-Id: I122ef44fdfb5b7a1de3c62a646f06cd8244269f6
Signed-off-by: Bob Stasyszyn <bob.stasyszyn@securekey.com>

Author: bstasyszyn

api/apitxn/chclient/chclient.go

@@ -40,12 +40,6 @@ type Opts struct {
 //Option func for each Opts argument
 type Option func(opts *Opts) error
 
-// TxProposalResponseFilter allows the user to inspect/modify response before commit
-type TxProposalResponseFilter interface {
-	// process transaction proposal response (there will be no commit if an error is returned)
-	ProcessTxProposalResponse(txProposalResponse []*apifabclient.TransactionProposalResponse) ([]*apifabclient.TransactionProposalResponse, error)
-}
-
 // Registration is a handle that is returned from a successful Register Chaincode Event.
 // This handle should be used in Unregister in order to unregister the event.
 type Registration interface {

pkg/fabric-client/channel/channel.go

@@ -35,9 +35,6 @@ type Channel struct {
 // is enforced by the ordering service and must be unique within the blockchain network.
 // client: Provides operational context such as submitting User etc.
 func New(ctx fab.Context, cfg fab.ChannelCfg) (*Channel, error) {
-	if cfg.Name() == "" {
-		return nil, errors.Errorf("name is required")
-	}
 	if ctx == nil {
 		return nil, errors.Errorf("client is required")
 	}

pkg/fabric-client/channel/channel_test.go

@@ -45,11 +45,8 @@ func TestChannelMethods(t *testing.T) {
 	}
 
 	_, err = New(ctx, mocks.NewMockChannelCfg(""))
-	if err == nil {
-		t.Fatalf("New didn't return error")
-	}
-	if err.Error() != "name is required" {
-		t.Fatalf("New didn't return right error")
+	if err != nil {
+		t.Fatalf("Got error creating channel with empty channel ID: %s", err)
 	}
 
 	_, err = New(nil, mocks.NewMockChannelCfg("testChannel"))
@@ -178,9 +175,13 @@ func isValueInList(value string, list []string) bool {
 }
 
 func setupTestChannel() (*Channel, error) {
+	return setupChannel("testChannel")
+}
+
+func setupChannel(channelID string) (*Channel, error) {
 	user := mocks.NewMockUser("test")
 	ctx := mocks.NewMockContext(user)
-	return New(ctx, mocks.NewMockChannelCfg("testChannel"))
+	return New(ctx, mocks.NewMockChannelCfg(channelID))
 }
 
 func setupMassiveTestChannel(numberOfPeers int, numberOfOrderers int) (*Channel, error) {

pkg/fabric-client/channel/query_test.go

@@ -56,6 +56,24 @@ func TestQueryMethods(t *testing.T) {
 
 }
 
+func TestQueryOnSystemChannel(t *testing.T) {
+	channel, _ := setupChannel(systemChannel)
+	peer := mocks.MockPeer{MockName: "Peer1", MockURL: "http://peer1.com", MockRoles: []string{}, MockCert: nil}
+	err := channel.AddPeer(&peer)
+	if err != nil {
+		t.Fatalf("Error adding peer to channel: %s", err)
+	}
+
+	request := fab.ChaincodeInvokeRequest{
+		ChaincodeID: "ccID",
+		Fcn:         "method",
+		Args:        [][]byte{[]byte("arg")},
+	}
+	if _, err := channel.QueryByChaincode(request); err != nil {
+		t.Fatalf("Error invoking chaincode on system channel: %s", err)
+	}
+}
+
 func TestChannelQueryBlock(t *testing.T) {
 
 	channel, _ := setupTestChannel()

pkg/fabric-txn/chclient/chclient_test.go

@@ -20,7 +20,9 @@ import (
 	"github.com/hyperledger/fabric-sdk-go/pkg/fabric-client/channel"
 	fcmocks "github.com/hyperledger/fabric-sdk-go/pkg/fabric-client/mocks"
 	"github.com/hyperledger/fabric-sdk-go/pkg/fabric-client/peer"
+	"github.com/hyperledger/fabric-sdk-go/pkg/fabric-txn/internal"
 	txnmocks "github.com/hyperledger/fabric-sdk-go/pkg/fabric-txn/mocks"
+	"github.com/hyperledger/fabric-sdk-go/pkg/fabric-txn/txnhandler"
 	pb "github.com/hyperledger/fabric-sdk-go/third_party/github.com/hyperledger/fabric/protos/peer"
 	"github.com/pkg/errors"
 )
@@ -211,6 +213,64 @@ func TestInvokeHandler(t *testing.T) {
 	}
 }
 
+// customEndorsementHandler ignores the channel in the ClientContext
+// and instead sends the proposal to the given channel
+type customEndorsementHandler struct {
+	channel apifabclient.Channel
+	next    chclient.Handler
+}
+
+func (h *customEndorsementHandler) Handle(requestContext *chclient.RequestContext, clientContext *chclient.ClientContext) {
+	transactionProposalResponses, txnID, err := internal.CreateAndSendTransactionProposal(h.channel,
+		requestContext.Request.ChaincodeID, requestContext.Request.Fcn, requestContext.Request.Args, requestContext.Opts.ProposalProcessors, requestContext.Request.TransientMap)
+
+	requestContext.Response.TransactionID = txnID
+
+	if err != nil {
+		requestContext.Error = err
+		return
+	}
+
+	requestContext.Response.Responses = transactionProposalResponses
+	if len(transactionProposalResponses) > 0 {
+		requestContext.Response.Payload = transactionProposalResponses[0].ProposalResponse.GetResponse().Payload
+	}
+
+	//Delegate to next step if any
+	if h.next != nil {
+		h.next.Handle(requestContext, clientContext)
+	}
+}
+
+func TestQueryWithCustomEndorser(t *testing.T) {
+	chClient := setupChannelClient(nil, t)
+
+	// Use the customEndorsementHandler to send the proposal to
+	// the system channel instead of the channel in context
+
+	systemChannel, err := setupChannel("")
+	if err != nil {
+		t.Fatalf("Error getting system channel: %s", err)
+	}
+
+	response, err := chClient.InvokeHandler(
+		txnhandler.NewProposalProcessorHandler(
+			&customEndorsementHandler{
+				channel: systemChannel,
+				next:    txnhandler.NewEndorsementValidationHandler(),
+			},
+		),
+		chclient.Request{ChaincodeID: "testCC", Fcn: "invoke", Args: [][]byte{[]byte("query"), []byte("b")}},
+	)
+	if err != nil {
+		t.Fatalf("Failed to invoke test cc: %s", err)
+	}
+
+	if response.Payload != nil {
+		t.Fatalf("Expecting nil, got %s", response.Payload)
+	}
+}
+
 func TestExecuteTxDiscoveryError(t *testing.T) {
 	chClient := setupChannelClientWithError(errors.New("Test Error"), nil, nil, t)
 
@@ -326,8 +386,12 @@ func TestExecuteTxWithRetries(t *testing.T) {
 }
 
 func setupTestChannel() (*channel.Channel, error) {
+	return setupChannel("testChannel")
+}
+
+func setupChannel(channelID string) (*channel.Channel, error) {
 	ctx := setupTestContext()
-	return channel.New(ctx, fcmocks.NewMockChannelCfg("testChannel"))
+	return channel.New(ctx, fcmocks.NewMockChannelCfg(channelID))
 }
 
 func setupTestContext() apifabclient.Context {

pkg/fabric-txn/txnhandler/txnhandler.go

@@ -20,18 +20,45 @@ import (
 	"github.com/pkg/errors"
 )
 
-//EndorseTxHandler for handling endorse transactions
-type EndorseTxHandler struct {
+//EndorsementHandler for handling endorse transactions
+type EndorsementHandler struct {
 	next chclient.Handler
 }
 
 //Handle for endorsing transactions
-func (e *EndorseTxHandler) Handle(requestContext *chclient.RequestContext, clientContext *chclient.ClientContext) {
+func (e *EndorsementHandler) Handle(requestContext *chclient.RequestContext, clientContext *chclient.ClientContext) {
+	// Endorse Tx
+	transactionProposalResponses, txnID, err := internal.CreateAndSendTransactionProposal(clientContext.Channel,
+		requestContext.Request.ChaincodeID, requestContext.Request.Fcn, requestContext.Request.Args, requestContext.Opts.ProposalProcessors, requestContext.Request.TransientMap)
+
+	requestContext.Response.TransactionID = txnID
+
+	if err != nil {
+		requestContext.Error = err
+		return
+	}
+
+	requestContext.Response.Responses = transactionProposalResponses
+	if len(transactionProposalResponses) > 0 {
+		requestContext.Response.Payload = transactionProposalResponses[0].ProposalResponse.GetResponse().Payload
+	}
+
+	//Delegate to next step if any
+	if e.next != nil {
+		e.next.Handle(requestContext, clientContext)
+	}
+}
+
+//ProposalProcessorHandler for selecting proposal processors
+type ProposalProcessorHandler struct {
+	next chclient.Handler
+}
 
+//Handle selects proposal processors
+func (h *ProposalProcessorHandler) Handle(requestContext *chclient.RequestContext, clientContext *chclient.ClientContext) {
 	//Get proposal processor, if not supplied then use discovery service to get available peers as endorser
 	//If selection service available then get endorser peers for this chaincode
-	txProcessors := requestContext.Opts.ProposalProcessors
-	if len(txProcessors) == 0 {
+	if len(requestContext.Opts.ProposalProcessors) == 0 {
 		// Use discovery service to figure out proposal processors
 		peers, err := clientContext.Discovery.GetPeers()
 		if err != nil {
@@ -46,28 +73,12 @@ func (e *EndorseTxHandler) Handle(requestContext *chclient.RequestContext, clien
 				return
 			}
 		}
-		txProcessors = peer.PeersToTxnProcessors(endorsers)
-	}
-
-	// Endorse Tx
-	transactionProposalResponses, txnID, err := internal.CreateAndSendTransactionProposal(clientContext.Channel,
-		requestContext.Request.ChaincodeID, requestContext.Request.Fcn, requestContext.Request.Args, txProcessors, requestContext.Request.TransientMap)
-
-	requestContext.Response.TransactionID = txnID
-
-	if err != nil {
-		requestContext.Error = err
-		return
-	}
-
-	requestContext.Response.Responses = transactionProposalResponses
-	if len(transactionProposalResponses) > 0 {
-		requestContext.Response.Payload = transactionProposalResponses[0].ProposalResponse.GetResponse().Payload
+		requestContext.Opts.ProposalProcessors = peer.PeersToTxnProcessors(endorsers)
 	}
 
 	//Delegate to next step if any
-	if e.next != nil {
-		e.next.Handle(requestContext, clientContext)
+	if h.next != nil {
+		h.next.Handle(requestContext, clientContext)
 	}
 }
 
@@ -160,17 +171,30 @@ func (c *CommitTxHandler) Handle(requestContext *chclient.RequestContext, client
 
 //NewQueryHandler returns query handler with EndorseTxHandler & EndorsementValidationHandler Chained
 func NewQueryHandler(next ...chclient.Handler) chclient.Handler {
-	return NewEndorseHandler(NewEndorsementValidationHandler(next...))
+	return NewProposalProcessorHandler(
+		NewEndorsementHandler(
+			NewEndorsementValidationHandler(next...),
+		),
+	)
 }
 
 //NewExecuteHandler returns query handler with EndorseTxHandler, EndorsementValidationHandler & CommitTxHandler Chained
 func NewExecuteHandler(next ...chclient.Handler) chclient.Handler {
-	return NewEndorseHandler(NewEndorsementValidationHandler(NewCommitHandler(next...)))
+	return NewProposalProcessorHandler(
+		NewEndorsementHandler(
+			NewEndorsementValidationHandler(NewCommitHandler(next...)),
+		),
+	)
+}
+
+//NewProposalProcessorHandler returns a handler that selects proposal processors
+func NewProposalProcessorHandler(next ...chclient.Handler) *ProposalProcessorHandler {
+	return &ProposalProcessorHandler{next: getNext(next)}
 }
 
-//NewEndorseHandler returns a handler that endorses a transaction proposal
-func NewEndorseHandler(next ...chclient.Handler) *EndorseTxHandler {
-	return &EndorseTxHandler{next: getNext(next)}
+//NewEndorsementHandler returns a handler that endorses a transaction proposal
+func NewEndorsementHandler(next ...chclient.Handler) *EndorsementHandler {
+	return &EndorsementHandler{next: getNext(next)}
 }
 
 //NewEndorsementValidationHandler returns a handler that validates an endorsement

pkg/fabric-txn/txnhandler/txnhandler_test.go

@@ -104,6 +104,60 @@ func TestQueryHandlerErrors(t *testing.T) {
 	}
 }
 
+func TestEndorsementHandler(t *testing.T) {
+	request := chclient.Request{ChaincodeID: "test", Fcn: "invoke", Args: [][]byte{[]byte("move"), []byte("a"), []byte("b"), []byte("1")}}
+
+	requestContext := prepareRequestContext(request, chclient.Opts{ProposalProcessors: []apifabclient.ProposalProcessor{fcmocks.NewMockPeer("p2", "")}}, t)
+	clientContext := setupChannelClientContext(nil, nil, nil, t)
+
+	handler := NewEndorsementHandler()
+	handler.Handle(requestContext, clientContext)
+	assert.Nil(t, requestContext.Error)
+}
+
+func TestProposalProcessorHandler(t *testing.T) {
+	peer1 := fcmocks.NewMockPeer("p1", "")
+	peer2 := fcmocks.NewMockPeer("p2", "")
+	discoveryPeers := []apifabclient.Peer{peer1, peer2}
+
+	//Get query handler
+	handler := NewProposalProcessorHandler()
+
+	request := chclient.Request{ChaincodeID: "testCC", Fcn: "invoke", Args: [][]byte{[]byte("query"), []byte("b")}}
+
+	selectionErr := errors.New("Some selection error")
+	requestContext := prepareRequestContext(request, chclient.Opts{}, t)
+	handler.Handle(requestContext, setupChannelClientContext(nil, selectionErr, discoveryPeers, t))
+	if requestContext.Error == nil || !strings.Contains(requestContext.Error.Error(), selectionErr.Error()) {
+		t.Fatal("Expected error: ", selectionErr, ", Received error:", requestContext.Error)
+	}
+
+	requestContext = prepareRequestContext(request, chclient.Opts{}, t)
+	handler.Handle(requestContext, setupChannelClientContext(nil, nil, discoveryPeers, t))
+	if requestContext.Error != nil {
+		t.Fatalf("Got error: %s", requestContext.Error)
+	}
+	if len(requestContext.Opts.ProposalProcessors) != len(discoveryPeers) {
+		t.Fatalf("Expecting %d proposal processors but got %d", len(discoveryPeers), len(requestContext.Opts.ProposalProcessors))
+	}
+	if requestContext.Opts.ProposalProcessors[0] != peer1 || requestContext.Opts.ProposalProcessors[1] != peer2 {
+		t.Fatalf("Didn't get expected peers")
+	}
+
+	// Directly pass in the proposal processors. In this case it should use those directly
+	requestContext = prepareRequestContext(request, chclient.Opts{ProposalProcessors: []apifabclient.ProposalProcessor{peer2}}, t)
+	handler.Handle(requestContext, setupChannelClientContext(nil, nil, discoveryPeers, t))
+	if requestContext.Error != nil {
+		t.Fatalf("Got error: %s", requestContext.Error)
+	}
+	if len(requestContext.Opts.ProposalProcessors) != 1 {
+		t.Fatalf("Expecting 1 proposal processor but got %d", len(requestContext.Opts.ProposalProcessors))
+	}
+	if requestContext.Opts.ProposalProcessors[0] != peer2 {
+		t.Fatalf("Didn't get expected peers")
+	}
+}
+
 //prepareHandlerContexts prepares context objects for handlers
 func prepareRequestContext(request chclient.Request, opts chclient.Opts, t *testing.T) *chclient.RequestContext {
 

test/integration/sdk/channel_client_test.go

@@ -176,19 +176,21 @@ func testInvokeHandler(ccID string, chClient chclient.ChannelClient, t *testing.
 	txValidationCode := pb.TxValidationCode(-1)
 
 	response, err := chClient.InvokeHandler(
-		txnhandler.NewEndorseHandler(
-			txnhandler.NewEndorsementValidationHandler(
-				&testHandler{
-					t:        t,
-					txID:     &txID,
-					endorser: &endorser,
-					next: txnhandler.NewCommitHandler(
-						&testHandler{
-							t:                t,
-							txValidationCode: &txValidationCode,
-						},
-					),
-				},
+		txnhandler.NewProposalProcessorHandler(
+			txnhandler.NewEndorsementHandler(
+				txnhandler.NewEndorsementValidationHandler(
+					&testHandler{
+						t:        t,
+						txID:     &txID,
+						endorser: &endorser,
+						next: txnhandler.NewCommitHandler(
+							&testHandler{
+								t:                t,
+								txValidationCode: &txValidationCode,
+							},
+						),
+					},
+				),
 			),
 		),
 		chclient.Request{