rpc: support subscriptions under custom namespaces

rpc/client.go

@@ -27,6 +27,7 @@ import (
 	"net/url"
 	"reflect"
 	"strconv"
+	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -373,14 +374,14 @@ func (c *Client) EthSubscribe(ctx context.Context, channel interface{}, args ...
 		return nil, ErrNotificationsUnsupported
 	}
 
-	msg, err := c.newMessage(subscribeMethod, args...)
+	msg, err := c.newMessage("eth"+subscribeMethodSuffix, args...)
 	if err != nil {
 		return nil, err
 	}
 	op := &requestOp{
 		ids:  []json.RawMessage{msg.ID},
 		resp: make(chan *jsonrpcMessage),
-		sub:  newClientSubscription(c, chanVal),
+		sub:  newClientSubscription(c, "eth", chanVal),
 	}
 
 	// Send the subscription request.
@@ -575,7 +576,7 @@ func (c *Client) closeRequestOps(err error) {
 }
 
 func (c *Client) handleNotification(msg *jsonrpcMessage) {
-	if msg.Method != notificationMethod {
+	if !strings.HasSuffix(msg.Method, notificationMethodSuffix) {
 		log.Debug(fmt.Sprint("dropping non-subscription message: ", msg))
 		return
 	}
@@ -653,11 +654,12 @@ func (c *Client) read(conn net.Conn) error {
 
 // A ClientSubscription represents a subscription established through EthSubscribe.
 type ClientSubscription struct {
-	client  *Client
-	etype   reflect.Type
-	channel reflect.Value
-	subid   string
-	in      chan json.RawMessage
+	client    *Client
+	etype     reflect.Type
+	channel   reflect.Value
+	namespace string
+	subid     string
+	in        chan json.RawMessage
 
 	quitOnce sync.Once     // ensures quit is closed once
 	quit     chan struct{} // quit is closed when the subscription exits
@@ -665,14 +667,15 @@ type ClientSubscription struct {
 	err      chan error
 }
 
-func newClientSubscription(c *Client, channel reflect.Value) *ClientSubscription {
+func newClientSubscription(c *Client, namespace string, channel reflect.Value) *ClientSubscription {
 	sub := &ClientSubscription{
-		client:  c,
-		etype:   channel.Type().Elem(),
-		channel: channel,
-		quit:    make(chan struct{}),
-		err:     make(chan error, 1),
-		in:      make(chan json.RawMessage),
+		client:    c,
+		namespace: namespace,
+		etype:     channel.Type().Elem(),
+		channel:   channel,
+		quit:      make(chan struct{}),
+		err:       make(chan error, 1),
+		in:        make(chan json.RawMessage),
 	}
 	return sub
 }
@@ -774,5 +777,5 @@ func (sub *ClientSubscription) unmarshal(result json.RawMessage) (interface{}, e
 
 func (sub *ClientSubscription) requestUnsubscribe() error {
 	var result interface{}
-	return sub.client.Call(&result, unsubscribeMethod, sub.subid)
+	return sub.client.Call(&result, sub.namespace+unsubscribeMethodSuffix, sub.subid)
 }

rpc/json.go

@@ -30,11 +30,11 @@ import (
 )
 
 const (
-	jsonrpcVersion         = "2.0"
-	serviceMethodSeparator = "_"
-	subscribeMethod        = "eth_subscribe"
-	unsubscribeMethod      = "eth_unsubscribe"
-	notificationMethod     = "eth_subscription"
+	jsonrpcVersion           = "2.0"
+	serviceMethodSeparator   = "_"
+	subscribeMethodSuffix    = "_subscribe"
+	unsubscribeMethodSuffix  = "_unsubscribe"
+	notificationMethodSuffix = "_subscription"
 )
 
 type jsonRequest struct {
@@ -164,7 +164,7 @@ func parseRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, Error) {
 	}
 
 	// subscribe are special, they will always use `subscribeMethod` as first param in the payload
-	if in.Method == subscribeMethod {
+	if strings.HasSuffix(in.Method, subscribeMethodSuffix) {
 		reqs := []rpcRequest{{id: &in.Id, isPubSub: true}}
 		if len(in.Payload) > 0 {
 			// first param must be subscription name
@@ -174,17 +174,16 @@ func parseRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, Error) {
 				return nil, false, &invalidRequestError{"Unable to parse subscription request"}
 			}
 
-			// all subscriptions are made on the eth service
-			reqs[0].service, reqs[0].method = "eth", subscribeMethod[0]
+			reqs[0].service, reqs[0].method = strings.TrimSuffix(in.Method, subscribeMethodSuffix), subscribeMethod[0]
 			reqs[0].params = in.Payload
 			return reqs, false, nil
 		}
 		return nil, false, &invalidRequestError{"Unable to parse subscription request"}
 	}
 
-	if in.Method == unsubscribeMethod {
+	if strings.HasSuffix(in.Method, unsubscribeMethodSuffix) {
 		return []rpcRequest{{id: &in.Id, isPubSub: true,
-			method: unsubscribeMethod, params: in.Payload}}, false, nil
+			method: in.Method, params: in.Payload}}, false, nil
 	}
 
 	elems := strings.Split(in.Method, serviceMethodSeparator)
@@ -216,8 +215,8 @@ func parseBatchRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, Error)
 
 		id := &in[i].Id
 
-		// subscribe are special, they will always use `subscribeMethod` as first param in the payload
-		if r.Method == subscribeMethod {
+		// subscribe are special, they will always use `subscriptionMethod` as first param in the payload
+		if strings.HasSuffix(r.Method, subscribeMethodSuffix) {
 			requests[i] = rpcRequest{id: id, isPubSub: true}
 			if len(r.Payload) > 0 {
 				// first param must be subscription name
@@ -227,8 +226,7 @@ func parseBatchRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, Error)
 					return nil, false, &invalidRequestError{"Unable to parse subscription request"}
 				}
 
-				// all subscriptions are made on the eth service
-				requests[i].service, requests[i].method = "eth", subscribeMethod[0]
+				requests[i].service, requests[i].method = strings.TrimSuffix(r.Method, subscribeMethodSuffix), subscribeMethod[0]
 				requests[i].params = r.Payload
 				continue
 			}
@@ -236,8 +234,8 @@ func parseBatchRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, Error)
 			return nil, true, &invalidRequestError{"Unable to parse (un)subscribe request arguments"}
 		}
 
-		if r.Method == unsubscribeMethod {
-			requests[i] = rpcRequest{id: id, isPubSub: true, method: unsubscribeMethod, params: r.Payload}
+		if strings.HasSuffix(r.Method, unsubscribeMethodSuffix) {
+			requests[i] = rpcRequest{id: id, isPubSub: true, method: r.Method, params: r.Payload}
 			continue
 		}
 
@@ -325,13 +323,13 @@ func (c *jsonCodec) CreateErrorResponseWithInfo(id interface{}, err Error, info
 }
 
 // CreateNotification will create a JSON-RPC notification with the given subscription id and event as params.
-func (c *jsonCodec) CreateNotification(subid string, event interface{}) interface{} {
+func (c *jsonCodec) CreateNotification(subid, namespace string, event interface{}) interface{} {
 	if isHexNum(reflect.TypeOf(event)) {
-		return &jsonNotification{Version: jsonrpcVersion, Method: notificationMethod,
+		return &jsonNotification{Version: jsonrpcVersion, Method: namespace + notificationMethodSuffix,
 			Params: jsonSubscription{Subscription: subid, Result: fmt.Sprintf(`%#x`, event)}}
 	}
 
-	return &jsonNotification{Version: jsonrpcVersion, Method: notificationMethod,
+	return &jsonNotification{Version: jsonrpcVersion, Method: namespace + notificationMethodSuffix,
 		Params: jsonSubscription{Subscription: subid, Result: event}}
 }
 

rpc/server.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"reflect"
 	"runtime"
+	"strings"
 	"sync"
 	"sync/atomic"
 
@@ -96,32 +97,30 @@ func (s *Server) RegisterName(name string, rcvr interface{}) error {
 		return fmt.Errorf("%s is not exported", reflect.Indirect(rcvrVal).Type().Name())
 	}
 
+	methods, subscriptions := suitableCallbacks(rcvrVal, svc.typ)
+
 	// already a previous service register under given sname, merge methods/subscriptions
 	if regsvc, present := s.services[name]; present {
-		methods, subscriptions := suitableCallbacks(rcvrVal, svc.typ)
 		if len(methods) == 0 && len(subscriptions) == 0 {
 			return fmt.Errorf("Service %T doesn't have any suitable methods/subscriptions to expose", rcvr)
 		}
-
 		for _, m := range methods {
 			regsvc.callbacks[formatName(m.method.Name)] = m
 		}
 		for _, s := range subscriptions {
 			regsvc.subscriptions[formatName(s.method.Name)] = s
 		}
-
 		return nil
 	}
 
 	svc.name = name
-	svc.callbacks, svc.subscriptions = suitableCallbacks(rcvrVal, svc.typ)
+	svc.callbacks, svc.subscriptions = methods, subscriptions
 
 	if len(svc.callbacks) == 0 && len(svc.subscriptions) == 0 {
 		return fmt.Errorf("Service %T doesn't have any suitable methods/subscriptions to expose", rcvr)
 	}
 
 	s.services[svc.name] = svc
-
 	return nil
 }
 
@@ -303,7 +302,7 @@ func (s *Server) handle(ctx context.Context, codec ServerCodec, req *serverReque
 		// active the subscription after the sub id was successfully sent to the client
 		activateSub := func() {
 			notifier, _ := NotifierFromContext(ctx)
-			notifier.activate(subid)
+			notifier.activate(subid, req.svcname)
 		}
 
 		return codec.CreateResponse(req.id, subid), activateSub
@@ -383,7 +382,7 @@ func (s *Server) execBatch(ctx context.Context, codec ServerCodec, requests []*s
 		codec.Close()
 	}
 
-	// when request holds one of more subscribe requests this allows these subscriptions to be actived
+	// when request holds one of more subscribe requests this allows these subscriptions to be activated
 	for _, c := range callbacks {
 		c()
 	}
@@ -410,7 +409,7 @@ func (s *Server) readRequest(codec ServerCodec) ([]*serverRequest, bool, Error)
 			continue
 		}
 
-		if r.isPubSub && r.method == unsubscribeMethod {
+		if r.isPubSub && strings.HasSuffix(r.method, unsubscribeMethodSuffix) {
 			requests[i] = &serverRequest{id: r.id, isUnsubscribe: true}
 			argTypes := []reflect.Type{reflect.TypeOf("")} // expect subscription id as first arg
 			if args, err := codec.ParseRequestArguments(argTypes, r.params); err == nil {
@@ -439,7 +438,7 @@ func (s *Server) readRequest(codec ServerCodec) ([]*serverRequest, bool, Error)
 					}
 				}
 			} else {
-				requests[i] = &serverRequest{id: r.id, err: &methodNotFoundError{subscribeMethod, r.method}}
+				requests[i] = &serverRequest{id: r.id, err: &methodNotFoundError{r.method, r.method}}
 			}
 			continue
 		}

rpc/subscription.go

@@ -35,8 +35,9 @@ type ID string
 // a Subscription is created by a notifier and tight to that notifier. The client can use
 // this subscription to wait for an unsubscribe request for the client, see Err().
 type Subscription struct {
-	ID  ID
-	err chan error // closed on unsubscribe
+	ID        ID
+	namespace string
+	err       chan error // closed on unsubscribe
 }
 
 // Err returns a channel that is closed when the client send an unsubscribe request.
@@ -78,7 +79,7 @@ func NotifierFromContext(ctx context.Context) (*Notifier, bool) {
 // are dropped until the subscription is marked as active. This is done
 // by the RPC server after the subscription ID is send to the client.
 func (n *Notifier) CreateSubscription() *Subscription {
-	s := &Subscription{NewID(), make(chan error)}
+	s := &Subscription{ID: NewID(), err: make(chan error)}
 	n.subMu.Lock()
 	n.inactive[s.ID] = s
 	n.subMu.Unlock()
@@ -91,9 +92,9 @@ func (n *Notifier) Notify(id ID, data interface{}) error {
 	n.subMu.RLock()
 	defer n.subMu.RUnlock()
 
-	_, active := n.active[id]
+	sub, active := n.active[id]
 	if active {
-		notification := n.codec.CreateNotification(string(id), data)
+		notification := n.codec.CreateNotification(string(id), sub.namespace, data)
 		if err := n.codec.Write(notification); err != nil {
 			n.codec.Close()
 			return err
@@ -124,10 +125,11 @@ func (n *Notifier) unsubscribe(id ID) error {
 // notifications are dropped. This method is called by the RPC server after
 // the subscription ID was sent to client. This prevents notifications being
 // send to the client before the subscription ID is send to the client.
-func (n *Notifier) activate(id ID) {
+func (n *Notifier) activate(id ID, namespace string) {
 	n.subMu.Lock()
 	defer n.subMu.Unlock()
 	if sub, found := n.inactive[id]; found {
+		sub.namespace = namespace
 		n.active[id] = sub
 		delete(n.inactive, id)
 	}

rpc/subscription_test.go

@@ -19,6 +19,7 @@ package rpc
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"net"
 	"sync"
 	"testing"
@@ -162,3 +163,162 @@ func TestNotifications(t *testing.T) {
 		t.Error("unsubscribe callback not called after closing connection")
 	}
 }
+
+func waitForMessages(t *testing.T, in *json.Decoder, successes chan<- jsonSuccessResponse,
+	failures chan<- jsonErrResponse, notifications chan<- jsonNotification) {
+
+	// read and parse server messages
+	for {
+		var rmsg json.RawMessage
+		if err := in.Decode(&rmsg); err != nil {
+			return
+		}
+
+		var responses []map[string]interface{}
+		if rmsg[0] == '[' {
+			if err := json.Unmarshal(rmsg, &responses); err != nil {
+				t.Fatalf("Received invalid message: %s", rmsg)
+			}
+		} else {
+			var msg map[string]interface{}
+			if err := json.Unmarshal(rmsg, &msg); err != nil {
+				t.Fatalf("Received invalid message: %s", rmsg)
+			}
+			responses = append(responses, msg)
+		}
+
+		for _, msg := range responses {
+			// determine what kind of msg was received and broadcast
+			// it to over the corresponding channel
+			if _, found := msg["result"]; found {
+				successes <- jsonSuccessResponse{
+					Version: msg["jsonrpc"].(string),
+					Id:      msg["id"],
+					Result:  msg["result"],
+				}
+				continue
+			}
+			if _, found := msg["error"]; found {
+				params := msg["params"].(map[string]interface{})
+				failures <- jsonErrResponse{
+					Version: msg["jsonrpc"].(string),
+					Id:      msg["id"],
+					Error:   jsonError{int(params["subscription"].(float64)), params["message"].(string), params["data"]},
+				}
+				continue
+			}
+			if _, found := msg["params"]; found {
+				params := msg["params"].(map[string]interface{})
+				notifications <- jsonNotification{
+					Version: msg["jsonrpc"].(string),
+					Method:  msg["method"].(string),
+					Params:  jsonSubscription{params["subscription"].(string), params["result"]},
+				}
+				continue
+			}
+			t.Fatalf("Received invalid message: %s", msg)
+		}
+	}
+}
+
+// TestSubscriptionMultipleNamespaces ensures that subscriptions can exists
+// for multiple different namespaces.
+func TestSubscriptionMultipleNamespaces(t *testing.T) {
+	var (
+		namespaces             = []string{"eth", "shh", "bzz"}
+		server                 = NewServer()
+		service                = NotificationTestService{}
+		clientConn, serverConn = net.Pipe()
+
+		out           = json.NewEncoder(clientConn)
+		in            = json.NewDecoder(clientConn)
+		successes     = make(chan jsonSuccessResponse)
+		failures      = make(chan jsonErrResponse)
+		notifications = make(chan jsonNotification)
+	)
+
+	// setup and start server
+	for _, namespace := range namespaces {
+		if err := server.RegisterName(namespace, &service); err != nil {
+			t.Fatalf("unable to register test service %v", err)
+		}
+	}
+
+	go server.ServeCodec(NewJSONCodec(serverConn), OptionMethodInvocation|OptionSubscriptions)
+	defer server.Stop()
+
+	// wait for message and write them to the given channels
+	go waitForMessages(t, in, successes, failures, notifications)
+
+	// create subscriptions one by one
+	n := 3
+	for i, namespace := range namespaces {
+		request := map[string]interface{}{
+			"id":      i,
+			"method":  fmt.Sprintf("%s_subscribe", namespace),
+			"version": "2.0",
+			"params":  []interface{}{"someSubscription", n, i},
+		}
+
+		if err := out.Encode(&request); err != nil {
+			t.Fatalf("Could not create subscription: %v", err)
+		}
+	}
+
+	// create all subscriptions in 1 batch
+	var requests []interface{}
+	for i, namespace := range namespaces {
+		requests = append(requests, map[string]interface{}{
+			"id":      i,
+			"method":  fmt.Sprintf("%s_subscribe", namespace),
+			"version": "2.0",
+			"params":  []interface{}{"someSubscription", n, i},
+		})
+	}
+
+	if err := out.Encode(&requests); err != nil {
+		t.Fatalf("Could not create subscription in batch form: %v", err)
+	}
+
+	timeout := time.After(30 * time.Second)
+	subids := make(map[string]string, 2*len(namespaces))
+	count := make(map[string]int, 2*len(namespaces))
+
+	for {
+		done := true
+		for id, _ := range count {
+			if count, found := count[id]; !found || count < (2*n) {
+				done = false
+			}
+		}
+
+		if done && len(count) == len(namespaces) {
+			break
+		}
+
+		select {
+		case suc := <-successes: // subscription created
+			subids[namespaces[int(suc.Id.(float64))]] = suc.Result.(string)
+		case failure := <-failures:
+			t.Errorf("received error: %v", failure.Error)
+		case notification := <-notifications:
+			if cnt, found := count[notification.Params.Subscription]; found {
+				count[notification.Params.Subscription] = cnt + 1
+			} else {
+				count[notification.Params.Subscription] = 1
+			}
+		case <-timeout:
+			for _, namespace := range namespaces {
+				subid, found := subids[namespace]
+				if !found {
+					t.Errorf("Subscription for '%s' not created", namespace)
+					continue
+				}
+				if count, found := count[subid]; !found || count < n {
+					t.Errorf("Didn't receive all notifications (%d<%d) in time for namespace '%s'", count, n, namespace)
+				}
+			}
+			return
+		}
+	}
+}

rpc/types.go

@@ -104,17 +104,17 @@ type ServerCodec interface {
 	// Read next request
 	ReadRequestHeaders() ([]rpcRequest, bool, Error)
 	// Parse request argument to the given types
-	ParseRequestArguments([]reflect.Type, interface{}) ([]reflect.Value, Error)
+	ParseRequestArguments(argTypes []reflect.Type, params interface{}) ([]reflect.Value, Error)
 	// Assemble success response, expects response id and payload
-	CreateResponse(interface{}, interface{}) interface{}
+	CreateResponse(id interface{}, reply interface{}) interface{}
 	// Assemble error response, expects response id and error
-	CreateErrorResponse(interface{}, Error) interface{}
+	CreateErrorResponse(id interface{}, err Error) interface{}
 	// Assemble error response with extra information about the error through info
 	CreateErrorResponseWithInfo(id interface{}, err Error, info interface{}) interface{}
 	// Create notification response
-	CreateNotification(string, interface{}) interface{}
+	CreateNotification(id, namespace string, event interface{}) interface{}
 	// Write msg to client.
-	Write(interface{}) error
+	Write(msg interface{}) error
 	// Close underlying data stream
 	Close()
 	// Closed when underlying connection is closed