rpc: Subscribe to methods in custom namespaces

Signed-off-by: Lewis Marshall <lewis@lmars.net>
This commit is contained in:
Lewis Marshall 2017-05-06 15:37:37 +01:00
parent 6de09120d3
commit e4ac128657
2 changed files with 42 additions and 5 deletions

View file

@ -357,19 +357,24 @@ func (c *Client) BatchCallContext(ctx context.Context, b []BatchElem) error {
return err
}
// EthSubscribe calls the "eth_subscribe" method with the given arguments,
// EthSubscribe registers a subscripion under the "eth" namespace.
func (c *Client) EthSubscribe(ctx context.Context, channel interface{}, args ...interface{}) (*ClientSubscription, error) {
return c.Subscribe(ctx, "eth", channel, args)
}
// Subscribe calls the "<namespace>_subscribe" method with the given arguments,
// registering a subscription. Server notifications for the subscription are
// sent to the given channel. The element type of the channel must match the
// expected type of content returned by the subscription.
//
// The context argument cancels the RPC request that sets up the subscription but has no
// effect on the subscription after EthSubscribe has returned.
// effect on the subscription after Subscribe has returned.
//
// Slow subscribers will be dropped eventually. Client buffers up to 8000 notifications
// before considering the subscriber dead. The subscription Err channel will receive
// ErrSubscriptionQueueOverflow. Use a sufficiently large buffer on the channel or ensure
// that the channel usually has at least one reader to prevent this issue.
func (c *Client) EthSubscribe(ctx context.Context, channel interface{}, args ...interface{}) (*ClientSubscription, error) {
func (c *Client) Subscribe(ctx context.Context, namespace string, channel interface{}, args ...interface{}) (*ClientSubscription, error) {
// Check type of channel first.
chanVal := reflect.ValueOf(channel)
if chanVal.Kind() != reflect.Chan || chanVal.Type().ChanDir()&reflect.SendDir == 0 {
@ -382,14 +387,14 @@ func (c *Client) EthSubscribe(ctx context.Context, channel interface{}, args ...
return nil, ErrNotificationsUnsupported
}
msg, err := c.newMessage("eth"+subscribeMethodSuffix, args...)
msg, err := c.newMessage(namespace+subscribeMethodSuffix, args...)
if err != nil {
return nil, err
}
op := &requestOp{
ids: []json.RawMessage{msg.ID},
resp: make(chan *jsonrpcMessage),
sub: newClientSubscription(c, "eth", chanVal),
sub: newClientSubscription(c, namespace, chanVal),
}
// Send the subscription request.

View file

@ -251,6 +251,38 @@ func TestClientSubscribe(t *testing.T) {
}
}
func TestClientSubscribeCustomNamespace(t *testing.T) {
namespace := "custom"
server := newTestServer(namespace, new(NotificationTestService))
defer server.Stop()
client := DialInProc(server)
defer client.Close()
nc := make(chan int)
count := 10
sub, err := client.Subscribe(context.Background(), namespace, nc, "someSubscription", count, 0)
if err != nil {
t.Fatal("can't subscribe:", err)
}
for i := 0; i < count; i++ {
if val := <-nc; val != i {
t.Fatalf("value mismatch: got %d, want %d", val, i)
}
}
sub.Unsubscribe()
select {
case v := <-nc:
t.Fatal("received value after unsubscribe:", v)
case err := <-sub.Err():
if err != nil {
t.Fatalf("Err returned a non-nil error after explicit unsubscribe: %q", err)
}
case <-time.After(1 * time.Second):
t.Fatalf("subscription not closed within 1s after unsubscribe")
}
}
// In this test, the connection drops while EthSubscribe is
// waiting for a response.
func TestClientSubscribeClose(t *testing.T) {