Payment channels: expose whether a channel was initiated or resumed in the ClientConnection interface.

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

@@ -117,11 +117,15 @@ public interface IPaymentChannelClient {
 
         /**
          * <p>Indicates the channel has been successfully opened and
-         * {@link com.google.bitcoin.protocols.channels.PaymentChannelClient#incrementPayment(java.math.BigInteger)} may be called at will.</p>
+         * {@link com.google.bitcoin.protocols.channels.PaymentChannelClient#incrementPayment(java.math.BigInteger)}
+         * may be called at will.</p>
          *
-         * <p>Called while holding a lock on the {@link com.google.bitcoin.protocols.channels.PaymentChannelClient} object - be careful about reentrancy</p>
+         * <p>Called while holding a lock on the {@link com.google.bitcoin.protocols.channels.PaymentChannelClient}
+         * object - be careful about reentrancy</p>
+         *
+         * @param wasInitiated If true, the channel is newly opened. If false, it was resumed.
          */
-        void channelOpen();
+        void channelOpen(boolean wasInitiated);
     }
 
     /**

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

@@ -169,12 +169,16 @@ public class PaymentChannelClient implements IPaymentChannelClient {
         checkState(step == InitStep.WAITING_FOR_CHANNEL_OPEN || (step == InitStep.WAITING_FOR_INITIATE && storedChannel != null), step);
         log.info("Got CHANNEL_OPEN message, ready to pay");
 
-        if (step == InitStep.WAITING_FOR_INITIATE)
+        boolean wasInitiated = true;
+        if (step == InitStep.WAITING_FOR_INITIATE) {
+            // We skipped the initiate step, because a previous channel that's still valid was resumed.
+            wasInitiated  = false;
             state = new PaymentChannelClientState(storedChannel, wallet);
+        }
         step = InitStep.CHANNEL_OPEN;
         // channelOpen should disable timeouts, but
         // TODO accomodate high latency between PROVIDE_CONTRACT and here
-        conn.channelOpen();
+        conn.channelOpen(wasInitiated);
     }
 
     /**

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

@@ -76,7 +76,7 @@ public class PaymentChannelClientConnection {
             }
 
             @Override
-            public void channelOpen() {
+            public void channelOpen(boolean wasInitiated) {
                 wireParser.setSocketTimeout(0);
                 // Inform the API user that we're done and ready to roll.
                 channelOpenFuture.set(PaymentChannelClientConnection.this);

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

@@ -282,7 +282,7 @@ public class ChannelConnectionTest extends TestWithWallet {
         broadcasts.take();
         client.receiveMessage(pair.serverRecorder.checkNextMsg(MessageType.CHANNEL_OPEN));
         Sha256Hash contractHash = (Sha256Hash) pair.serverRecorder.q.take();
-        pair.clientRecorder.checkOpened();
+        pair.clientRecorder.checkInitiated();
         assertNull(pair.serverRecorder.q.poll());
         assertNull(pair.clientRecorder.q.poll());
         // Send a bitcent.
@@ -601,7 +601,7 @@ public class ChannelConnectionTest extends TestWithWallet {
         broadcasts.take();
         client.receiveMessage(pair.serverRecorder.checkNextMsg(MessageType.CHANNEL_OPEN));
         Sha256Hash contractHash = (Sha256Hash) pair.serverRecorder.q.take();
-        pair.clientRecorder.checkOpened();
+        pair.clientRecorder.checkInitiated();
         assertNull(pair.serverRecorder.q.poll());
         assertNull(pair.clientRecorder.q.poll());
         // Send the whole channel at once. The server will broadcast the final contract and settle the channel for us.
@@ -646,7 +646,7 @@ public class ChannelConnectionTest extends TestWithWallet {
             broadcasts.take();
             client.receiveMessage(pair.serverRecorder.checkNextMsg(MessageType.CHANNEL_OPEN));
             Sha256Hash contractHash = (Sha256Hash) pair.serverRecorder.q.take();
-            pair.clientRecorder.checkOpened();
+            pair.clientRecorder.checkInitiated();
             assertNull(pair.serverRecorder.q.poll());
             assertNull(pair.clientRecorder.q.poll());
             ListenableFuture<BigInteger> future = client.incrementPayment(Utils.CENT);
@@ -699,7 +699,7 @@ public class ChannelConnectionTest extends TestWithWallet {
             broadcasts.take();
             client.receiveMessage(pair.serverRecorder.checkNextMsg(MessageType.CHANNEL_OPEN));
             Sha256Hash contractHash = (Sha256Hash) pair.serverRecorder.q.take();
-            pair.clientRecorder.checkOpened();
+            pair.clientRecorder.checkInitiated();
             assertNull(pair.serverRecorder.q.poll());
             assertNull(pair.clientRecorder.q.poll());
             client.incrementPayment(Utils.CENT);

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

@@ -59,6 +59,7 @@ public class ChannelTestUtils {
         public BlockingQueue<Object> q = new LinkedBlockingQueue<Object>();
 
         // An arbitrary sentinel object for equality testing.
+        public static final Object CHANNEL_INITIATED = new Object();
         public static final Object CHANNEL_OPEN = new Object();
 
         @Override
@@ -72,7 +73,9 @@ public class ChannelTestUtils {
         }
 
         @Override
-        public void channelOpen() {
+        public void channelOpen(boolean wasInitiated) {
+            if (wasInitiated)
+                q.add(CHANNEL_INITIATED);
             q.add(CHANNEL_OPEN);
         }
 
@@ -89,6 +92,11 @@ public class ChannelTestUtils {
         public void checkOpened() throws InterruptedException {
             assertEquals(CHANNEL_OPEN, q.take());
         }
+
+        public void checkInitiated() throws InterruptedException {
+            assertEquals(CHANNEL_INITIATED, q.take());
+            checkOpened();
+        }
     }
 
     public static class RecordingPair {