rpc: refactor subscriptions and filters

1 files changed, 165 insertions, 0 deletions

diff --git a/rpc/subscription_test.go b/rpc/subscription_test.go
new file mode 100644
index 000000000..8bb341694
--- /dev/null
+++ b/rpc/subscription_test.go
@@ -0,0 +1,165 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package rpc
+
+import (
+	"encoding/json"
+	"net"
+	"sync"
+	"testing"
+	"time"
+
+	"golang.org/x/net/context"
+)
+
+type NotificationTestService struct {
+	mu           sync.Mutex
+	unsubscribed bool
+
+	gotHangSubscriptionReq  chan struct{}
+	unblockHangSubscription chan struct{}
+}
+
+func (s *NotificationTestService) Echo(i int) int {
+	return i
+}
+
+func (s *NotificationTestService) wasUnsubCallbackCalled() bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.unsubscribed
+}
+
+func (s *NotificationTestService) Unsubscribe(subid string) {
+	s.mu.Lock()
+	s.unsubscribed = true
+	s.mu.Unlock()
+}
+
+func (s *NotificationTestService) SomeSubscription(ctx context.Context, n, val int) (*Subscription, error) {
+	notifier, supported := NotifierFromContext(ctx)
+	if !supported {
+		return nil, ErrNotificationsUnsupported
+	}
+
+	// by explicitly creating an subscription we make sure that the subscription id is send back to the client
+	// before the first subscription.Notify is called. Otherwise the events might be send before the response
+	// for the eth_subscribe method.
+	subscription := notifier.CreateSubscription()
+
+	go func() {
+		// test expects n events, if we begin sending event immediatly some events
+		// will probably be dropped since the subscription ID might not be send to
+		// the client.
+		time.Sleep(5 * time.Second)
+		for i := 0; i < n; i++ {
+			if err := notifier.Notify(subscription.ID, val+i); err != nil {
+				return
+			}
+		}
+
+		select {
+		case <-notifier.Closed():
+			s.mu.Lock()
+			s.unsubscribed = true
+			s.mu.Unlock()
+		case <-subscription.Err():
+			s.mu.Lock()
+			s.unsubscribed = true
+			s.mu.Unlock()
+		}
+	}()
+
+	return subscription, nil
+}
+
+// HangSubscription blocks on s.unblockHangSubscription before
+// sending anything.
+func (s *NotificationTestService) HangSubscription(ctx context.Context, val int) (*Subscription, error) {
+	notifier, supported := NotifierFromContext(ctx)
+	if !supported {
+		return nil, ErrNotificationsUnsupported
+	}
+
+	s.gotHangSubscriptionReq <- struct{}{}
+	<-s.unblockHangSubscription
+	subscription := notifier.CreateSubscription()
+
+	go func() {
+		notifier.Notify(subscription.ID, val)
+	}()
+	return subscription, nil
+}
+
+func TestNotifications(t *testing.T) {
+	server := NewServer()
+	service := &NotificationTestService{}
+
+	if err := server.RegisterName("eth", service); err != nil {
+		t.Fatalf("unable to register test service %v", err)
+	}
+
+	clientConn, serverConn := net.Pipe()
+
+	go server.ServeCodec(NewJSONCodec(serverConn), OptionMethodInvocation|OptionSubscriptions)
+
+	out := json.NewEncoder(clientConn)
+	in := json.NewDecoder(clientConn)
+
+	n := 5
+	val := 12345
+	request := map[string]interface{}{
+		"id":      1,
+		"method":  "eth_subscribe",
+		"version": "2.0",
+		"params":  []interface{}{"someSubscription", n, val},
+	}
+
+	// create subscription
+	if err := out.Encode(request); err != nil {
+		t.Fatal(err)
+	}
+
+	var subid string
+	response := jsonSuccessResponse{Result: subid}
+	if err := in.Decode(&response); err != nil {
+		t.Fatal(err)
+	}
+
+	var ok bool
+	if subid, ok = response.Result.(string); !ok {
+		t.Fatalf("expected subscription id, got %T", response.Result)
+	}
+
+	for i := 0; i < n; i++ {
+		var notification jsonNotification
+		if err := in.Decode(&notification); err != nil {
+			t.Fatalf("%v", err)
+		}
+
+		if int(notification.Params.Result.(float64)) != val+i {
+			t.Fatalf("expected %d, got %d", val+i, notification.Params.Result)
+		}
+	}
+
+	clientConn.Close() // causes notification unsubscribe callback to be called
+	time.Sleep(1 * time.Second)
+
+	if !service.wasUnsubCallbackCalled() {
+		t.Error("unsubscribe callback not called after closing connection")
+	}
+}