From c18423fde35a2774eee11384270c4a1c5770cf26 Mon Sep 17 00:00:00 2001
From: Mike Hearn <mike@plan99.net>
Date: Wed, 17 Dec 2014 18:58:32 +0100
Subject: [PATCH] Peer: utility for requesting addr data

---
 .../src/main/java/org/bitcoinj/core/Peer.java | 23 +++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/core/src/main/java/org/bitcoinj/core/Peer.java b/core/src/main/java/org/bitcoinj/core/Peer.java
index 6a92d0ae..fb3846e7 100644
--- a/core/src/main/java/org/bitcoinj/core/Peer.java
+++ b/core/src/main/java/org/bitcoinj/core/Peer.java
@@ -132,6 +132,7 @@ public class Peer extends PeerSocketHandler {
         SettableFuture future;
     }
     private final CopyOnWriteArrayList<GetDataRequest> getDataFutures;
+    @GuardedBy("getAddrFutures") private final LinkedList<SettableFuture<AddressMessage>> getAddrFutures;
 
     // Outstanding pings against this peer and how long the last one took to complete.
     private final ReentrantLock lastPingTimesLock = new ReentrantLock();
@@ -207,6 +208,7 @@ public class Peer extends PeerSocketHandler {
         this.vDownloadData = chain != null;
         this.getDataFutures = new CopyOnWriteArrayList<GetDataRequest>();
         this.eventListeners = new CopyOnWriteArrayList<PeerListenerRegistration>();
+        this.getAddrFutures = new LinkedList<SettableFuture<AddressMessage>>();
         this.fastCatchupTimeSecs = params.getGenesisBlock().getTimeSeconds();
         this.isAcked = false;
         this.pendingPings = new CopyOnWriteArrayList<PendingPing>();
@@ -355,6 +357,7 @@ public class Peer extends PeerSocketHandler {
             // We don't care about addresses of the network right now. But in future,
             // we should save them in the wallet so we don't put too much load on the seed nodes and can
             // properly explore the network.
+            processAddressMessage((AddressMessage) m);
         } else if (m instanceof HeadersMessage) {
             processHeaders((HeadersMessage) m);
         } else if (m instanceof AlertMessage) {
@@ -399,6 +402,16 @@ public class Peer extends PeerSocketHandler {
         }
     }
 
+    private void processAddressMessage(AddressMessage m) {
+        SettableFuture<AddressMessage> future;
+        synchronized (getAddrFutures) {
+            future = getAddrFutures.poll();
+            if (future == null)  // Not an addr message we are waiting for.
+                return;
+        }
+        future.set(m);
+    }
+
     private void processVersionMessage(VersionMessage m) throws ProtocolException {
         if (vPeerVersionMessage != null)
             throw new ProtocolException("Got two version messages from peer");
@@ -1173,6 +1186,16 @@ public class Peer extends PeerSocketHandler {
         return req.future;
     }
 
+    /** Sends a getaddr request to the peer and returns a future that completes with the answer once the peer has replied. */
+    public ListenableFuture<AddressMessage> getAddr() {
+        SettableFuture<AddressMessage> future = SettableFuture.create();
+        synchronized (getAddrFutures) {
+            getAddrFutures.add(future);
+        }
+        sendMessage(new GetAddrMessage(params));
+        return future;
+    }
+
     /**
      * When downloading the block chain, the bodies will be skipped for blocks created before the given date. Any
      * transactions relevant to the wallet will therefore not be found, but if you know your wallet has no such