Support BIP133 feefilter messages.

 Conflicts:
	examples/src/main/java/org/bitcoinj/examples/PeerMonitor.java

core/src/main/java/org/bitcoinj/core/BitcoinSerializer.java

@@ -77,6 +77,7 @@ public class BitcoinSerializer extends MessageSerializer {
         names.put(GetUTXOsMessage.class, "getutxos");
         names.put(UTXOsMessage.class, "utxos");
         names.put(SendHeadersMessage.class, "sendheaders");
+        names.put(FeeFilterMessage.class, "feefilter");
     }
 
     /**
@@ -261,6 +262,8 @@ private Message makeMessage(String command, int length, byte[] payloadBytes, byt
             return new GetUTXOsMessage(params, payloadBytes);
         } else if (command.equals("sendheaders")) {
             return new SendHeadersMessage(params, payloadBytes);
+        } else if (command.equals("feefilter")) {
+            return new FeeFilterMessage(params, payloadBytes, this, length);
         } else {
             return new UnknownMessage(params, command, payloadBytes);
         }

core/src/main/java/org/bitcoinj/core/Coin.java

@@ -115,6 +115,16 @@ public static Coin valueOf(final int coins, final int cents) {
         return coin;
     }
 
+    /**
+     * Create a {@code Coin} from a long integer number of satoshis.
+     *
+     * @param satoshis number of satoshis
+     * @return {@code Coin} object containing value in satoshis
+     */
+    public static Coin ofSat(long satoshis) {
+        return Coin.valueOf(satoshis);
+    }
+
     /**
      * <p>Parses an amount expressed in the way humans are used to.</p>
      * <p>This takes string in a format understood by {@link BigDecimal#BigDecimal(String)}, for example "0", "1", "0.10",

core/src/main/java/org/bitcoinj/core/FeeFilterMessage.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright by the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.bitcoinj.core;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.math.BigInteger;
+
+/**
+ * <p>Represents an "feefilter" message on the P2P network, which instructs a peer to filter transaction invs for
+ * transactions that fall below the feerate provided.</p>
+ *
+ * <p>See <a href="https://github.com/bitcoin/bips/blob/master/bip-0133.mediawiki">BIP133</a> for details.</p>
+ *
+ * <p>Instances of this class are not safe for use by multiple threads.</p>
+ */
+public class FeeFilterMessage extends Message {
+    private Coin feeRate;
+
+    public FeeFilterMessage(NetworkParameters params, byte[] payloadBytes, BitcoinSerializer serializer, int length) {
+        super(params, payloadBytes, 0, serializer, length);
+    }
+
+    @Override
+    protected void bitcoinSerializeToStream(OutputStream stream) throws IOException {
+        super.bitcoinSerializeToStream(stream);
+        Utils.uint64ToByteStreamLE(BigInteger.valueOf(feeRate.value), stream);
+    }
+
+    @Override
+    protected void parse() throws ProtocolException {
+        feeRate = Coin.ofSat(readUint64().longValue());
+    }
+
+    public Coin getFeeRate() {
+        return feeRate;
+    }
+
+    @Override
+    public String toString() {
+        return "feefilter: " + feeRate.toFriendlyString() + "/kB";
+    }
+}

core/src/main/java/org/bitcoinj/core/NetworkParameters.java

@@ -485,7 +485,8 @@ public static enum ProtocolVersion {
         BLOOM_FILTER(70000), // BIP37
         BLOOM_FILTER_BIP111(70011), // BIP111
         WITNESS_VERSION(70012),
-        CURRENT(70012);
+        FEEFILTER(70013), // BIP133
+        CURRENT(70013);
 
         private final int bitcoinProtocol;
 

core/src/main/java/org/bitcoinj/core/Peer.java

@@ -160,6 +160,7 @@ public GetDataRequest(Sha256Hash hash, SettableFuture future) {
     private static final int PING_MOVING_AVERAGE_WINDOW = 20;
 
     private volatile VersionMessage vPeerVersionMessage;
+    private volatile Coin vFeeFilter;
 
     // A settable future which completes (with this) when the connection is open
     private final SettableFuture<Peer> connectionOpenFuture = SettableFuture.create();
@@ -495,6 +496,8 @@ protected void processMessage(Message m) throws Exception {
             log.error("{} {}: Received {}", this, getPeerVersionMessage().subVer, m);
         } else if (m instanceof SendHeadersMessage) {
             // We ignore this message, because we don't announce new blocks.
+        } else if (m instanceof FeeFilterMessage) {
+            processFeeFilter((FeeFilterMessage) m);
         } else {
             log.warn("{}: Received unhandled message: {}", this, m);
         }
@@ -1606,6 +1609,11 @@ protected void processPong(Pong m) {
         }
     }
 
+    private void processFeeFilter(FeeFilterMessage m) {
+        log.info("{}: Announced fee filter: {}/kB", this, m.getFeeRate().toFriendlyString());
+        vFeeFilter = m.getFeeRate();
+    }
+
     /**
      * Returns the difference between our best chain height and the peers, which can either be positive if we are
      * behind the peer, or negative if the peer is ahead of us.
@@ -1647,6 +1655,11 @@ public VersionMessage getPeerVersionMessage() {
         return vPeerVersionMessage;
     }
 
+    /** Returns the fee filter announced by the remote peer, interpreted as satoshis per kB. */
+    public Coin getFeeFilter() {
+        return vFeeFilter;
+    }
+
     /** Returns version data we announce to our remote peers. */
     public VersionMessage getVersionMessage() {
         return versionMessage;

examples/src/main/java/org/bitcoinj/examples/PeerMonitor.java

@@ -17,21 +17,20 @@
 
 package org.bitcoinj.examples;
 
+import com.google.common.collect.Lists;
+import org.bitcoinj.core.*;
 import org.bitcoinj.core.listeners.PeerConnectedEventListener;
 import org.bitcoinj.core.listeners.PeerDisconnectedEventListener;
-import org.bitcoinj.core.NetworkParameters;
-import org.bitcoinj.core.Peer;
-import org.bitcoinj.core.PeerGroup;
 import org.bitcoinj.net.discovery.DnsDiscovery;
 import org.bitcoinj.params.MainNetParams;
 import org.bitcoinj.utils.BriefLogFormatter;
-import com.google.common.collect.Lists;
 
 import javax.swing.*;
 import javax.swing.event.ChangeEvent;
 import javax.swing.event.ChangeListener;
 import javax.swing.table.AbstractTableModel;
 import javax.swing.table.TableCellRenderer;
+import javax.swing.table.TableColumnModel;
 import java.awt.*;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
@@ -49,7 +48,8 @@ public class PeerMonitor {
     private PeerTableModel peerTableModel;
     private PeerTableRenderer peerTableRenderer;
 
-    private final HashMap<Peer, String> reverseDnsLookups = new HashMap<Peer, String>();
+    private final HashMap<Peer, String> reverseDnsLookups = new HashMap<>();
+    private final HashMap<Peer, AddressMessage> addressMessages = new HashMap<>();
 
     public static void main(String[] args) throws Exception {
         BriefLogFormatter.init();
@@ -144,7 +144,11 @@ public void stateChanged(ChangeEvent changeEvent) {
         peerTable.setDefaultRenderer(String.class, peerTableRenderer);
         peerTable.setDefaultRenderer(Integer.class, peerTableRenderer);
         peerTable.setDefaultRenderer(Long.class, peerTableRenderer);
-        peerTable.getColumnModel().getColumn(0).setPreferredWidth(300);
+        TableColumnModel columnModel = peerTable.getColumnModel();
+        columnModel.getColumn(PeerTableModel.IP_ADDRESS).setPreferredWidth(300);
+        columnModel.getColumn(PeerTableModel.USER_AGENT).setPreferredWidth(150);
+        columnModel.getColumn(PeerTableModel.FEE_FILTER).setPreferredWidth(150);
+        columnModel.getColumn(PeerTableModel.ADDRESSES).setPreferredWidth(400);
 
         JScrollPane scrollPane = new JScrollPane(peerTable);
         window.getContentPane().add(scrollPane, BorderLayout.CENTER);
@@ -166,8 +170,10 @@ private class PeerTableModel extends AbstractTableModel {
         public static final int PROTOCOL_VERSION = 1;
         public static final int USER_AGENT = 2;
         public static final int CHAIN_HEIGHT = 3;
-        public static final int PING_TIME = 4;
-        public static final int LAST_PING_TIME = 5;
+        public static final int FEE_FILTER = 4;
+        public static final int PING_TIME = 5;
+        public static final int LAST_PING_TIME = 6;
+        public static final int ADDRESSES = 7;
 
         public List<Peer> connectedPeers = Lists.newArrayList();
         public List<Peer> pendingPeers = Lists.newArrayList();
@@ -190,15 +196,17 @@ public String getColumnName(int i) {
                 case PROTOCOL_VERSION: return "Protocol version";
                 case USER_AGENT: return "User Agent";
                 case CHAIN_HEIGHT: return "Chain height";
+                case FEE_FILTER: return "Fee filter (per kB)";
                 case PING_TIME: return "Average ping";
                 case LAST_PING_TIME: return "Last ping";
+                case ADDRESSES: return "Peer addresses";
                 default: throw new RuntimeException();
             }
         }
 
         @Override
         public int getColumnCount() {
-            return 6;
+            return 8;
         }
 
         @Override
@@ -243,10 +251,15 @@ public Object getValueAt(int row, int col) {
                     return peer.getPeerVersionMessage().subVer;
                 case CHAIN_HEIGHT:
                     return peer.getBestHeight();
+                case FEE_FILTER:
+                    Coin feeFilter = peer.getFeeFilter();
+                    return feeFilter != null ? feeFilter.toFriendlyString() : "";
                 case PING_TIME:
                     return peer.getPingTime();
                 case LAST_PING_TIME:
                     return peer.getLastPingTime();
+                case ADDRESSES:
+                    return getAddressesForPeer(peer);
 
                 default: throw new RuntimeException();
             }
@@ -262,6 +275,13 @@ private Object getAddressForPeer(Peer peer) {
             else
                 return peer.getAddress().getAddr().getHostAddress();
         }
+
+        private String getAddressesForPeer(Peer peer) {
+            synchronized (addressMessages) {
+                AddressMessage addressMessage = addressMessages.get(peer);
+                return addressMessage != null ? addressMessage.toString() : "";
+            }
+        }
     }
 
     private class PeerTableRenderer extends JLabel implements TableCellRenderer {