Ask peers for filtered blocks when appropriate and handle them.

core/src/main/java/com/google/bitcoin/core/BitcoinSerializer.java

@@ -71,6 +71,7 @@ public class BitcoinSerializer {
         names.put(GetAddrMessage.class, "getaddr");
         names.put(HeadersMessage.class, "headers");
         names.put(BloomFilter.class, "filterload");
+        names.put(FilteredBlock.class, "merkleblock");
     }
 
     /**
@@ -256,6 +257,8 @@ public class BitcoinSerializer {
             message = new InventoryMessage(params, payloadBytes, parseLazy, parseRetain, length);
         } else if (command.equals("block")) {
             message = new Block(params, payloadBytes, parseLazy, parseRetain, length);
+        } else if (command.equals("merkleblock")) {
+            message = new FilteredBlock(params, payloadBytes);
         } else if (command.equals("getdata")) {
             message = new GetDataMessage(params, payloadBytes, parseLazy, parseRetain, length);
         } else if (command.equals("tx")) {

core/src/main/java/com/google/bitcoin/core/BloomFilter.java

@@ -75,6 +75,11 @@ public class BloomFilter extends Message {
      * <p>Keep in mind that a remote node can do a pretty good job estimating the order of magnitude of the false positive
      * rate of a given filter you provide it when considering the anonymity of a given filter.</p>
      * 
+     * <p>In order for filtered block download to function efficiently, the number of matched transactions in any given
+     * block should be less than (with some headroom) the maximum size of the MemoryPool used by the Peer
+     * doing the downloading (default is {@link MemoryPool#MAX_SIZE}). See the comment in processBlock(FilteredBlock)
+     * for more information on this restriction.</p>
+     * 
      * <p>randomNonce is a tweak for the hash function used to prevent some theoretical DoS attacks.
      * It should be a random value, however secureness of the random value is of no great consequence.</p>
      */

core/src/main/java/com/google/bitcoin/core/InventoryItem.java

@@ -26,7 +26,8 @@ public class InventoryItem {
     public enum Type {
         Error,
         Transaction,
-        Block
+        Block,
+        FilteredBlock
     }
 
     public final Type type;

core/src/main/java/com/google/bitcoin/core/Peer.java

@@ -16,6 +16,7 @@
 
 package com.google.bitcoin.core;
 
+import com.google.bitcoin.core.InventoryItem.Type;
 import com.google.bitcoin.store.BlockStore;
 import com.google.bitcoin.store.BlockStoreException;
 import com.google.bitcoin.utils.EventListenerInvoker;
@@ -73,6 +74,8 @@ public class Peer {
     // set AND our best block is before that date, switch to false until block headers beyond that point have been
     // received at which point it gets set to true again. This isn't relevant unless downloadData is true.
     private boolean downloadBlockBodies = true;
+    // Whether to request filtered blocks instead of full blocks if the protocol version allows for them.
+    private boolean useFilteredBlocks = false;
     // Keeps track of things we requested internally with getdata but didn't receive yet, so we can avoid re-requests.
     // It's not quite the same as getDataFutures, as this is used only for getdatas done as part of downloading
     // the chain and so is lighter weight (we just keep a bunch of hashes not futures).
@@ -206,6 +209,8 @@ public class Peer {
             e.getChannel().close();
         }
 
+        private FilteredBlock currentFilteredBlock = null;
+        
         /** Handle incoming Bitcoin messages */
         @Override
         public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
@@ -223,13 +228,27 @@ public class Peer {
             }
 
             if (m == null) return;
+            
+            if (currentFilteredBlock != null && !(m instanceof Transaction)) {
+                processBlock(currentFilteredBlock);
+                currentFilteredBlock = null;
+            }
 
             if (m instanceof InventoryMessage) {
                 processInv((InventoryMessage) m);
             } else if (m instanceof Block) {
                 processBlock((Block) m);
+            } else if (m instanceof FilteredBlock) {
+                currentFilteredBlock = (FilteredBlock)m;
             } else if (m instanceof Transaction) {
-                processTransaction((Transaction) m);
+                if (currentFilteredBlock != null) {
+                    if (!currentFilteredBlock.provideTransaction((Transaction)m)) {
+                        processBlock(currentFilteredBlock);
+                        currentFilteredBlock = null;
+                        processTransaction((Transaction) m);
+                    }
+                } else
+                    processTransaction((Transaction) m);
             } else if (m instanceof GetDataMessage) {
                 processGetData((GetDataMessage) m);
             } else if (m instanceof AddressMessage) {
@@ -407,6 +426,50 @@ public class Peer {
                 // no matter how many blocks are solved, and therefore that the (2) duplicate filtering can work.
                 blockChainDownload(blockChain.getOrphanRoot(m.getHash()).getHash());
             }
+        } catch (VerificationException e) {
+            // We don't want verification failures to kill the thread.
+            log.warn("FilteredBlock verification failed", e);
+        } catch (PrunedException e) {
+            // Unreachable when in SPV mode.
+            throw new RuntimeException(e);
+        }
+    }
+    
+    private synchronized void processBlock(FilteredBlock m) throws IOException {
+        log.debug("{}: Received broadcast filtered block {}", address, m.getHash().toString());
+        try {
+            if (!downloadData) {
+                log.warn("Received block we did not ask for: {}", m.getHash().toString());
+                return;
+            }
+            
+            // Note that we currently do nothing about peers which do not include transactions which
+            // actually match our filter or which do not send us all the transactions (TODO: Do something about that).
+            
+            pendingBlockDownloads.remove(m.getBlockHeader().getHash());
+            // Otherwise it's a block sent to us because the peer thought we needed it, so add it to the block chain.
+            // This call will synchronize on blockChain.
+            if (blockChain.add(m)) {
+                // The block was successfully linked into the chain. Notify the user of our progress.
+                invokeOnBlocksDownloaded(m.getBlockHeader());
+            } else {
+                // This block is an orphan - we don't know how to get from it back to the genesis block yet. That
+                // must mean that there are blocks we are missing, so do another getblocks with a new block locator
+                // to ask the peer to send them to us. This can happen during the initial block chain download where
+                // the peer will only send us 500 at a time and then sends us the head block expecting us to request
+                // the others.
+                //
+                // We must do two things here:
+                // (1) Request from current top of chain to the oldest ancestor of the received block in the orphan set
+                // (2) Filter out duplicate getblock requests (done in blockChainDownload).
+                //
+                // The reason for (1) is that otherwise if new blocks were solved during the middle of chain download
+                // we'd do a blockChainDownload() on the new best chain head, which would cause us to try and grab the
+                // chain twice (or more!) on the same connection! The block chain would filter out the duplicates but
+                // only at a huge speed penalty. By finding the orphan root we ensure every getblocks looks the same
+                // no matter how many blocks are solved, and therefore that the (2) duplicate filtering can work.
+                blockChainDownload(blockChain.getOrphanRoot(m.getHash()).getHash());
+            }
         } catch (VerificationException e) {
             // We don't want verification failures to kill the thread.
             log.warn("Block verification failed", e);
@@ -503,6 +566,10 @@ public class Peer {
                 memoryPool.seen(item.hash, this.getAddress());
             }
         }
+        
+        // If we are requesting filteredblocks we have to send a ping after the getdata so that we have a clear
+        // end to the final FilteredBlock's transactions (in the form of a pong) sent to us
+        boolean pingAfterGetData = false;
 
         if (blocks.size() > 0 && downloadData && blockChain != null) {
             // Ideally, we'd only ask for the data here if we actually needed it. However that can imply a lot of
@@ -526,7 +593,11 @@ public class Peer {
                     // the duplicate check in blockChainDownload(). But the satoshi client may change in future so
                     // it's better to be safe here.
                     if (!pendingBlockDownloads.contains(item.hash)) {
-                        getdata.addItem(item);
+                        if (getPeerVersionMessage().clientVersion > 70000 && useFilteredBlocks) {
+                            getdata.addItem(new InventoryItem(InventoryItem.Type.FilteredBlock, item.hash));
+                            pingAfterGetData = true;
+                        } else
+                            getdata.addItem(item);
                         pendingBlockDownloads.add(item.hash);
                     }
                 }
@@ -542,6 +613,9 @@ public class Peer {
             // This will cause us to receive a bunch of block or tx messages.
             sendMessage(getdata);
         }
+        
+        if (pingAfterGetData)
+            sendMessage(new Ping((long) Math.random() * Long.MAX_VALUE));
     }
 
     /**
@@ -574,7 +648,7 @@ public class Peer {
      *
      * @param secondsSinceEpoch Time in seconds since the epoch or 0 to reset to always downloading block bodies.
      */
-    public synchronized void setFastCatchupTime(long secondsSinceEpoch) {
+    public synchronized void setDownloadParameters(long secondsSinceEpoch, boolean useFilteredBlocks) {
         Preconditions.checkNotNull(blockChain);
         if (secondsSinceEpoch == 0) {
             fastCatchupTimeSecs = params.genesisBlock.getTimeSeconds();
@@ -587,6 +661,7 @@ public class Peer {
                 downloadBlockBodies = false;
             }
         }
+        this.useFilteredBlocks = useFilteredBlocks;
     }
 
     /**

core/src/main/java/com/google/bitcoin/core/PeerGroup.java

@@ -559,7 +559,6 @@ public class PeerGroup extends AbstractIdleService {
             earliestKeyTime = Math.min(earliestKeyTime, w.getEarliestKeyCreationTime());
             elements += w.getBloomFilterElementCount();
         }
-        setFastCatchupTimeSecs(earliestKeyTime);
 
         if (chain == null || !chain.shouldVerifyTransactions()) {
             long nTweak = new Random().nextLong();
@@ -574,6 +573,8 @@ public class PeerGroup extends AbstractIdleService {
                     peer.sendMessage(filter);
                 } catch (IOException e) { }
         }
+        //Do this last so that bloomFilter is already set when it gets called
+        setFastCatchupTimeSecs(earliestKeyTime);
     }
     
     /**
@@ -826,7 +827,7 @@ public class PeerGroup extends AbstractIdleService {
             log.info("Setting download peer: {}", downloadPeer);
             downloadPeer.setDownloadData(true);
             if (chain != null)
-                downloadPeer.setFastCatchupTime(fastCatchupTimeSecs);
+                downloadPeer.setDownloadParameters(fastCatchupTimeSecs, bloomFilter != null);
         }
     }
 
@@ -849,7 +850,7 @@ public class PeerGroup extends AbstractIdleService {
         Preconditions.checkState(chain == null || !chain.shouldVerifyTransactions(), "Fast catchup is incompatible with fully verifying");
         fastCatchupTimeSecs = secondsSinceEpoch;
         if (downloadPeer != null) {
-            downloadPeer.setFastCatchupTime(secondsSinceEpoch);
+            downloadPeer.setDownloadParameters(secondsSinceEpoch, bloomFilter != null);
         }
     }
 

core/src/test/java/com/google/bitcoin/core/PeerGroupTest.java

@@ -18,6 +18,8 @@ package com.google.bitcoin.core;
 
 import com.google.bitcoin.discovery.PeerDiscovery;
 import com.google.bitcoin.discovery.PeerDiscoveryException;
+import com.google.bitcoin.store.MemoryBlockStore;
+
 import org.jboss.netty.bootstrap.ClientBootstrap;
 import org.jboss.netty.channel.*;
 import org.junit.After;
@@ -34,42 +36,15 @@ import java.util.concurrent.TimeUnit;
 
 import static org.junit.Assert.*;
 
-public class PeerGroupTest extends TestWithNetworkConnections {
+public class PeerGroupTest extends TestWithPeerGroup {
     static final NetworkParameters params = NetworkParameters.unitTests();
-
+    
-    private PeerGroup peerGroup;
-
-    private VersionMessage remoteVersionMessage;
-
     @Override
     @Before
     public void setUp() throws Exception {
-        super.setUp();
+        super.setUp(new MemoryBlockStore(NetworkParameters.unitTests()));
-
-        remoteVersionMessage = new VersionMessage(params, 1);
         
-        ClientBootstrap bootstrap = new ClientBootstrap(new ChannelFactory() {
-            public void releaseExternalResources() {}
-            public Channel newChannel(ChannelPipeline pipeline) {
-                ChannelSink sink = new FakeChannelSink();
-                return new FakeChannel(this, pipeline, sink);
-            }
-        });
-        bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
-            public ChannelPipeline getPipeline() throws Exception {
-                VersionMessage ver = new VersionMessage(params, 1);
-                ChannelPipeline p = Channels.pipeline();
-                
-                Peer peer = new Peer(params, blockChain, ver);
-                peer.addLifecycleListener(peerGroup.startupListener);
-                p.addLast("peer", peer.getHandler());
-                return p;
-            }
-
-        });
-        peerGroup = new PeerGroup(params, blockChain, bootstrap);
         peerGroup.addWallet(wallet);
-        peerGroup.setPingIntervalMsec(0);  // Disable the pings as they just get in the way of most tests.
     }
 
     @After
@@ -148,18 +123,6 @@ public class PeerGroupTest extends TestWithNetworkConnections {
         peerGroup.stop();
     }
 
-    private FakeChannel connectPeer(int id) {
-        return connectPeer(id, remoteVersionMessage);
-    }
-
-    private FakeChannel connectPeer(int id, VersionMessage versionMessage) {
-        InetSocketAddress remoteAddress = new InetSocketAddress("127.0.0.1", 2000 + id);
-        FakeChannel p = (FakeChannel) peerGroup.connectTo(remoteAddress).getChannel();
-        assertTrue(p.nextEvent() instanceof ChannelStateEvent);
-        inbound(p, versionMessage);
-        return p;
-    }
-
     @Test
     public void singleDownloadPeer1() throws Exception {
         // Check that we don't attempt to retrieve blocks on multiple peers.

core/src/test/java/com/google/bitcoin/core/PeerTest.java

@@ -407,7 +407,7 @@ public class PeerTest extends TestWithNetworkConnections {
         Block b4 = makeSolvedTestBlock(unitTestParams, b3);
 
         // Request headers until the last 2 blocks.
-        peer.setFastCatchupTime((Utils.now().getTime() / 1000) - (600*2) + 1);
+        peer.setDownloadParameters((Utils.now().getTime() / 1000) - (600*2) + 1, false);
         peer.startBlockChainDownload();
         GetHeadersMessage getheaders = (GetHeadersMessage) event.getValue().getMessage();
         List<Sha256Hash> expectedLocator = new ArrayList<Sha256Hash>();

core/src/test/java/com/google/bitcoin/core/TestWithNetworkConnections.java

@@ -16,6 +16,7 @@
 
 package com.google.bitcoin.core;
 
+import com.google.bitcoin.store.BlockStore;
 import com.google.bitcoin.store.MemoryBlockStore;
 import com.google.bitcoin.utils.BriefLogFormatter;
 import org.easymock.EasyMock;
@@ -36,7 +37,7 @@ import static org.easymock.EasyMock.expect;
 public class TestWithNetworkConnections {
     protected IMocksControl control;
     protected NetworkParameters unitTestParams;
-    protected MemoryBlockStore blockStore;
+    protected BlockStore blockStore;
     protected BlockChain blockChain;
     protected Wallet wallet;
     protected ECKey key;
@@ -48,13 +49,17 @@ public class TestWithNetworkConnections {
     protected ChannelPipeline pipeline;
     
     public void setUp() throws Exception {
+        setUp(new MemoryBlockStore(NetworkParameters.unitTests()));
+    }
+    
+    public void setUp(BlockStore blockStore) throws Exception {
         BriefLogFormatter.init();
 
         control = createStrictControl();
         control.checkOrder(false);
 
         unitTestParams = NetworkParameters.unitTests();
-        blockStore = new MemoryBlockStore(unitTestParams);
+        this.blockStore = blockStore;
         wallet = new Wallet(unitTestParams);
         key = new ECKey();
         address = key.toAddress(unitTestParams);

core/src/test/java/com/google/bitcoin/core/TestWithPeerGroup.java

@@ -0,0 +1,66 @@
+package com.google.bitcoin.core;
+
+import static org.junit.Assert.assertTrue;
+
+import java.net.InetSocketAddress;
+
+import org.jboss.netty.bootstrap.ClientBootstrap;
+import org.jboss.netty.channel.Channel;
+import org.jboss.netty.channel.ChannelFactory;
+import org.jboss.netty.channel.ChannelPipeline;
+import org.jboss.netty.channel.ChannelPipelineFactory;
+import org.jboss.netty.channel.ChannelSink;
+import org.jboss.netty.channel.ChannelStateEvent;
+import org.jboss.netty.channel.Channels;
+import org.junit.Before;
+
+import com.google.bitcoin.store.BlockStore;
+
+/**
+ * Utility class that makes it easy to work with mock NetworkConnections in PeerGroups.
+ */
+public class TestWithPeerGroup extends TestWithNetworkConnections {
+    protected PeerGroup peerGroup;
+
+    protected VersionMessage remoteVersionMessage;
+
+    public void setUp(BlockStore blockStore) throws Exception {
+        super.setUp(blockStore);
+
+        remoteVersionMessage = new VersionMessage(unitTestParams, 1);
+        
+        ClientBootstrap bootstrap = new ClientBootstrap(new ChannelFactory() {
+            public void releaseExternalResources() {}
+            public Channel newChannel(ChannelPipeline pipeline) {
+                ChannelSink sink = new FakeChannelSink();
+                return new FakeChannel(this, pipeline, sink);
+            }
+        });
+        bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
+            public ChannelPipeline getPipeline() throws Exception {
+                VersionMessage ver = new VersionMessage(unitTestParams, 1);
+                ChannelPipeline p = Channels.pipeline();
+                
+                Peer peer = new Peer(unitTestParams, blockChain, ver);
+                peer.addLifecycleListener(peerGroup.startupListener);
+                p.addLast("peer", peer.getHandler());
+                return p;
+            }
+
+        });
+        peerGroup = new PeerGroup(unitTestParams, blockChain, bootstrap);
+        peerGroup.setPingIntervalMsec(0);  // Disable the pings as they just get in the way of most tests.
+    }
+    
+    protected FakeChannel connectPeer(int id) {
+        return connectPeer(id, remoteVersionMessage);
+    }
+
+    protected FakeChannel connectPeer(int id, VersionMessage versionMessage) {
+        InetSocketAddress remoteAddress = new InetSocketAddress("127.0.0.1", 2000 + id);
+        FakeChannel p = (FakeChannel) peerGroup.connectTo(remoteAddress).getChannel();
+        assertTrue(p.nextEvent() instanceof ChannelStateEvent);
+        inbound(p, versionMessage);
+        return p;
+    }
+}