Make PaymentChannel.ServerConnection.paymentIncrease asynchronous.

core/src/main/java/com/google/bitcoin/jni/NativePaymentChannelServerConnectionEventHandler.java

@@ -3,6 +3,7 @@ package com.google.bitcoin.jni;
 import com.google.bitcoin.core.*;
 import com.google.bitcoin.protocols.channels.PaymentChannelCloseException;
 import com.google.bitcoin.protocols.channels.ServerConnectionEventHandler;
+import com.google.common.util.concurrent.ListenableFuture;
 import com.google.protobuf.ByteString;
 
 /**
@@ -17,7 +18,7 @@ public class NativePaymentChannelServerConnectionEventHandler extends ServerConn
     public native void channelOpen(Sha256Hash channelId);
 
     @Override
-    public native ByteString paymentIncrease(Coin by, Coin to, ByteString info);
+    public native ListenableFuture<ByteString> paymentIncrease(Coin by, Coin to, ByteString info);
 
     @Override
     public native void channelClosed(PaymentChannelCloseException.CloseReason reason);

core/src/main/java/com/google/bitcoin/protocols/channels/PaymentChannelCloseException.java

@@ -61,6 +61,9 @@ public class PaymentChannelCloseException extends Exception {
 
         /** The connection was closed without an ERROR/CLOSE message */
         CONNECTION_CLOSED,
+
+        /** The server failed processing an UpdatePayment message */
+        UPDATE_PAYMENT_FAILED,
     }
 
     private final CloseReason error;

core/src/main/java/com/google/bitcoin/protocols/channels/PaymentChannelServer.java

@@ -21,6 +21,7 @@ import com.google.bitcoin.protocols.channels.PaymentChannelCloseException.CloseR
 import com.google.bitcoin.utils.Threading;
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.ListenableFuture;
 import com.google.protobuf.ByteString;
 import net.jcip.annotations.GuardedBy;
 import org.bitcoin.paymentchannel.Protos;
@@ -103,10 +104,10 @@ public class PaymentChannelServer {
          * @param by The increase in total payment
          * @param to The new total payment to us (not including fees which may be required to claim the payment)
          * @param info Information about this payment increase, used to extend this protocol.
-         * @return An ack message that will be included in the PaymentAck message to the client. Use null for no ack message.
+         * @return A future that completes with the ack message that will be included in the PaymentAck message to the client. Use null for no ack message.
          */
         @Nullable
-        public ByteString paymentIncrease(Coin by, Coin to, @Nullable ByteString info);
+        public ListenableFuture<ByteString> paymentIncrease(Coin by, Coin to, @Nullable ByteString info);
     }
     private final ServerConnection conn;
 
@@ -368,17 +369,32 @@ public class PaymentChannelServer {
         boolean stillUsable = state.incrementPayment(refundSize, msg.getSignature().toByteArray());
         Coin bestPaymentChange = state.getBestValueToMe().subtract(lastBestPayment);
 
-        ByteString ackInfo = null;
+        ListenableFuture<ByteString> ackInfoFuture = null;
         if (bestPaymentChange.signum() > 0) {
             ByteString info = (msg.hasInfo()) ? msg.getInfo() : null;
-            ackInfo = conn.paymentIncrease(bestPaymentChange, state.getBestValueToMe(), info);
+            ackInfoFuture = conn.paymentIncrease(bestPaymentChange, state.getBestValueToMe(), info);
         }
 
         if (sendAck) {
-            Protos.TwoWayChannelMessage.Builder ack = Protos.TwoWayChannelMessage.newBuilder();
+            final Protos.TwoWayChannelMessage.Builder ack = Protos.TwoWayChannelMessage.newBuilder();
             ack.setType(Protos.TwoWayChannelMessage.MessageType.PAYMENT_ACK);
-            if (ackInfo != null) ack.setPaymentAck(ack.getPaymentAckBuilder().setInfo(ackInfo));
+            if (ackInfoFuture == null) {
-            conn.sendToClient(ack.build());
+                conn.sendToClient(ack.build());
+            } else {
+                Futures.addCallback(ackInfoFuture, new FutureCallback<ByteString>() {
+                    @Override
+                    public void onSuccess(@Nullable ByteString result) {
+                        if (result != null) ack.setPaymentAck(ack.getPaymentAckBuilder().setInfo(result));
+                        conn.sendToClient(ack.build());
+                    }
+
+                    @Override
+                    public void onFailure(Throwable t) {
+                        log.info("Failed retrieving paymentIncrease info future");
+                        error("Failed processing payment update", Protos.Error.ErrorCode.OTHER, CloseReason.UPDATE_PAYMENT_FAILED);
+                    }
+                });
+            }
         }
 
         if (!stillUsable) {
@@ -551,7 +567,7 @@ public class PaymentChannelServer {
      * <p>Closes the connection by generating a settle message for the client and calls
      * {@link ServerConnection#destroyConnection(CloseReason)}. Note that this does not broadcast
      * the payment transaction and the client may still resume the same channel if they reconnect</p>
-     *
+     * <p>
      * <p>Note that {@link PaymentChannelServer#connectionClosed()} must still be called after the connection fully
      * closes.</p>
      */

core/src/main/java/com/google/bitcoin/protocols/channels/PaymentChannelServerListener.java

@@ -25,6 +25,7 @@ import com.google.bitcoin.net.NioServer;
 import com.google.bitcoin.net.ProtobufParser;
 import com.google.bitcoin.net.StreamParserFactory;
 
+import com.google.common.util.concurrent.ListenableFuture;
 import com.google.protobuf.ByteString;
 import org.bitcoin.paymentchannel.Protos;
 
@@ -83,7 +84,7 @@ public class PaymentChannelServerListener {
                     eventHandler.channelOpen(contractHash);
                 }
 
-                @Override public ByteString paymentIncrease(Coin by, Coin to, @Nullable ByteString info) {
+                @Override public ListenableFuture<ByteString> paymentIncrease(Coin by, Coin to, @Nullable ByteString info) {
                     return eventHandler.paymentIncrease(by, to, info);
                 }
             });

core/src/main/java/com/google/bitcoin/protocols/channels/ServerConnectionEventHandler.java

@@ -20,6 +20,7 @@ import com.google.bitcoin.core.Coin;
 import com.google.bitcoin.core.Sha256Hash;
 import com.google.bitcoin.net.ProtobufParser;
 
+import com.google.common.util.concurrent.ListenableFuture;
 import com.google.protobuf.ByteString;
 import org.bitcoin.paymentchannel.Protos;
 
@@ -74,7 +75,7 @@ public abstract class ServerConnectionEventHandler {
      * @return acknowledgment information to be sent to the client.
      */
     @Nullable
-    public abstract ByteString paymentIncrease(Coin by, Coin to, ByteString info);
+    public abstract ListenableFuture<ByteString> paymentIncrease(Coin by, Coin to, ByteString info);
 
     /**
      * <p>Called when the channel was closed for some reason. May be called without a call to

core/src/test/java/com/google/bitcoin/protocols/channels/ChannelConnectionTest.java

@@ -21,6 +21,7 @@ import com.google.bitcoin.store.WalletProtobufSerializer;
 import com.google.bitcoin.testing.TestWithWallet;
 import com.google.bitcoin.utils.Threading;
 import com.google.bitcoin.wallet.WalletFiles;
+import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.SettableFuture;
 import com.google.protobuf.ByteString;
@@ -35,6 +36,7 @@ import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.concurrent.*;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -131,9 +133,9 @@ public class ChannelConnectionTest extends TestWithWallet {
                             }
 
                             @Override
-                            public ByteString paymentIncrease(Coin by, Coin to, ByteString info) {
+                            public ListenableFuture<ByteString> paymentIncrease(Coin by, Coin to, ByteString info) {
                                 q.add(new ChannelTestUtils.UpdatePair(to, info));
-                                return null;
+                                return Futures.immediateFuture(info);
                             }
 
                             @Override
@@ -174,11 +176,16 @@ public class ChannelConnectionTest extends TestWithWallet {
         Thread.sleep(1250); // No timeouts once the channel is open
         Coin amount = client.state().getValueSpent();
         q.take().assertPair(amount, null);
-        ByteString[] infos = new ByteString[]{null, ByteString.copyFromUtf8("one"),ByteString.copyFromUtf8("two")};
+        for (String info : new String[] {null, "one", "two"} ) {
-        for (ByteString info : infos) {
+            final ByteString bytes = (info==null) ? null :ByteString.copyFromUtf8(info);
-            client.incrementPayment(CENT, info).get();
+            final PaymentIncrementAck ack = client.incrementPayment(CENT, bytes).get();
+            if (info != null) {
+                final ByteString ackInfo = ack.getInfo();
+                assertNotNull("Ack info is null", ackInfo);
+                assertEquals("Ack info differs ", info, ackInfo.toStringUtf8());
+            }
             amount = amount.add(CENT);
-            q.take().assertPair(amount, info);
+            q.take().assertPair(amount, bytes);
         }
         latch.await();
 

core/src/test/java/com/google/bitcoin/protocols/channels/ChannelTestUtils.java

@@ -5,6 +5,9 @@ import com.google.bitcoin.core.Sha256Hash;
 import com.google.bitcoin.core.TransactionBroadcaster;
 import com.google.bitcoin.core.Wallet;
 
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.SettableFuture;
 import com.google.protobuf.ByteString;
 import org.bitcoin.paymentchannel.Protos;
 
@@ -37,9 +40,9 @@ public class ChannelTestUtils {
         }
 
         @Override
-        public ByteString paymentIncrease(Coin by, Coin to, @Nullable ByteString info) {
+        public ListenableFuture<ByteString> paymentIncrease(Coin by, Coin to, @Nullable ByteString info) {
             q.add(new UpdatePair(to, info));
-            return ByteString.copyFromUtf8(by.toPlainString());
+            return Futures.immediateFuture(ByteString.copyFromUtf8(by.toPlainString()));
         }
 
         public Protos.TwoWayChannelMessage getNextMsg() throws InterruptedException {

examples/src/main/java/com/google/bitcoin/examples/ExamplePaymentChannelServer.java

@@ -28,6 +28,7 @@ import com.google.bitcoin.protocols.channels.*;
 import com.google.bitcoin.utils.BriefLogFormatter;
 import com.google.common.collect.ImmutableList;
 
+import com.google.common.util.concurrent.ListenableFuture;
 import com.google.protobuf.ByteString;
 import org.slf4j.LoggerFactory;
 
@@ -102,7 +103,7 @@ public class ExamplePaymentChannelServer implements PaymentChannelServerListener
             }
 
             @Override
-            public ByteString paymentIncrease(Coin by, Coin to, ByteString info) {
+            public ListenableFuture<ByteString> paymentIncrease(Coin by, Coin to, ByteString info) {
                 log.info("Client {} paid increased payment by {} for a total of " + to.toString(), clientAddress, by);
                 return null;
             }