ZMQ actors should subscribe to a single topic (#1793)

We use one actor per topic, but each actor previously registered to multiple
topics so we received duplicate events and consumed twice the necessary
bandwidth.

Author: t-bast

eclair-core/src/main/scala/fr/acinq/eclair/Setup.scala

@@ -235,8 +235,8 @@ class Setup(datadir: File,
 
       extendedBitcoinClient = new ExtendedBitcoinClient(new BatchingBitcoinJsonRPCClient(bitcoin))
       watcher = {
-        system.actorOf(SimpleSupervisor.props(Props(new ZMQActor(config.getString("bitcoind.zmqblock"), Some(zmqBlockConnected))), "zmqblock", SupervisorStrategy.Restart))
-        system.actorOf(SimpleSupervisor.props(Props(new ZMQActor(config.getString("bitcoind.zmqtx"), Some(zmqTxConnected))), "zmqtx", SupervisorStrategy.Restart))
+        system.actorOf(SimpleSupervisor.props(Props(new ZMQActor(config.getString("bitcoind.zmqblock"), ZMQActor.Topics.RawBlock, Some(zmqBlockConnected))), "zmqblock", SupervisorStrategy.Restart))
+        system.actorOf(SimpleSupervisor.props(Props(new ZMQActor(config.getString("bitcoind.zmqtx"), ZMQActor.Topics.RawTx, Some(zmqTxConnected))), "zmqtx", SupervisorStrategy.Restart))
         system.spawn(Behaviors.supervise(ZmqWatcher(nodeParams.chainHash, blockCount, extendedBitcoinClient)).onFailure(typed.SupervisorStrategy.resume), "watcher")
       }
 

eclair-core/src/main/scala/fr/acinq/eclair/blockchain/bitcoind/zmq/ZMQActor.scala

@@ -31,7 +31,7 @@ import scala.util.Try
 /**
  * Created by PM on 04/04/2017.
  */
-class ZMQActor(address: String, connected: Option[Promise[Done]] = None) extends Actor with ActorLogging {
+class ZMQActor(address: String, topic: String, connected: Option[Promise[Done]] = None) extends Actor with ActorLogging {
 
   import ZMQActor._
 
@@ -40,8 +40,7 @@ class ZMQActor(address: String, connected: Option[Promise[Done]] = None) extends
   val subscriber = ctx.createSocket(SocketType.SUB)
   subscriber.monitor("inproc://events", ZMQ.EVENT_CONNECTED | ZMQ.EVENT_DISCONNECTED)
   subscriber.connect(address)
-  subscriber.subscribe("rawblock".getBytes(ZMQ.CHARSET))
-  subscriber.subscribe("rawtx".getBytes(ZMQ.CHARSET))
+  subscriber.subscribe(topic.getBytes(ZMQ.CHARSET))
 
   val monitor = ctx.createSocket(SocketType.PAIR)
   monitor.connect("inproc://events")
@@ -114,4 +113,9 @@ object ZMQActor {
   case object ZMQDisconnected extends ZMQEvent
   // @formatter:on
 
+  object Topics {
+    val RawBlock: String = "rawblock"
+    val RawTx: String = "rawtx"
+  }
+
 }

eclair-core/src/test/scala/fr/acinq/eclair/blockchain/bitcoind/ZmqWatcherSpec.scala

@@ -51,8 +51,8 @@ class ZmqWatcherSpec extends TestKitBaseClass with AnyFunSuiteLike with Bitcoind
     waitForBitcoindReady()
     logger.info("starting zmq actors")
     val (zmqBlockConnected, zmqTxConnected) = (Promise[Done](), Promise[Done]())
-    zmqBlock = system.actorOf(Props(new ZMQActor(s"tcp://127.0.0.1:$bitcoindZmqBlockPort", Some(zmqBlockConnected))))
-    zmqTx = system.actorOf(Props(new ZMQActor(s"tcp://127.0.0.1:$bitcoindZmqTxPort", Some(zmqTxConnected))))
+    zmqBlock = system.actorOf(Props(new ZMQActor(s"tcp://127.0.0.1:$bitcoindZmqBlockPort", ZMQActor.Topics.RawBlock, Some(zmqBlockConnected))))
+    zmqTx = system.actorOf(Props(new ZMQActor(s"tcp://127.0.0.1:$bitcoindZmqTxPort", ZMQActor.Topics.RawTx, Some(zmqTxConnected))))
     awaitCond(zmqBlockConnected.isCompleted && zmqTxConnected.isCompleted)
     super.beforeAll()
   }