PeerGroup first draft - new files

This commit is contained in:
Miron Cuperman (devrandom) 2011-07-06 20:39:17 +00:00
parent cd2f4c655b
commit 6053c9087c
3 changed files with 313 additions and 0 deletions

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/**
* Copyright 2011 Google Inc.
*
* 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 com.google.bitcoin.core;
import java.math.BigInteger;
// TODO: Make this be an interface with a convenience abstract impl.
/**
* Implementing a subclass WalletEventListener allows you to learn when the contents of the wallet changes due to
* receiving money or a block chain re-organize. Methods are called with the event listener object locked so your
* implementation does not have to be thread safe. The default method implementations do nothing.
*/
public interface PeerEventListener {
/**
* This is called on a Peer thread when a block is received.
*
* @param peer The peer receiving the block
* @param blocksLeft The number of blocks left to download
*/
public void onBlocksDownloaded(Peer peer, int blocksLeft);
}

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// Copyright 2011 Google Inc. All Rights Reserved.
package com.google.bitcoin.core;
import com.google.bitcoin.store.BlockStore;
import com.google.bitcoin.store.BlockStoreException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
/**
* @author miron@google.com (Miron Cuperman a.k.a devrandom)
*
*/
public class PeerGroup {
private static final Logger log = LoggerFactory.getLogger(PeerGroup.class);
private static final int CONNECTION_DELAY_MILLIS = 5 * 1000;
private static final int CORE_THREADS = 1;
private static final int THREAD_KEEP_ALIVE_SECONDS = 1;
// Maximum number of connections this peerGroup will make
private int maxConnections;
private BlockingQueue<PeerAddress> inactives;
private Thread thread;
private boolean running;
private ThreadPoolExecutor executor;
private NetworkParameters params;
private BlockStore blockStore;
private BlockChain chain;
private Set<Peer> peers;
private Peer downloadPeer;
private PeerEventListener downloadListener;
/**
*/
public PeerGroup(int maxConnections, BlockStore blockStore, NetworkParameters params, BlockChain chain) {
this.maxConnections = maxConnections;
this.blockStore = blockStore;
this.params = params;
this.chain = chain;
inactives = new LinkedBlockingQueue<PeerAddress>();
peers = Collections.synchronizedSet(new HashSet<Peer>());
executor = new ThreadPoolExecutor(CORE_THREADS, this.maxConnections,
THREAD_KEEP_ALIVE_SECONDS, TimeUnit.SECONDS,
new LinkedBlockingQueue<Runnable>(1),
new PeerGroupThreadFactory());
}
/** Add an address to the list of potential peers to connect to */
public void addAddress(PeerAddress peerAddress) {
inactives.add(peerAddress);
}
/** Starts the background thread that makes connections. */
public void start() {
this.thread = new Thread(new PeerExecutionRunnable(), "Peer group thread");
running = true;
this.thread.start();
}
/**
* Stop this PeerGroup
*/
public synchronized void stop() {
if (running) {
thread.interrupt();
}
}
/**
* Broadcast a transaction to all connected peers
*
* @return whether we sent to at least one peer
*/
public boolean broadcastTransaction(Transaction tx) {
boolean success = false;
for (Peer peer : peers) {
try {
peer.broadcastTransaction(tx);
success = true;
} catch (IOException e) {
log.error("failed to broadcast to " + peer, e);
}
}
return success;
}
private final class PeerExecutionRunnable implements Runnable {
/**
* Repeatedly get the next peer address from the inactive queue
* and try to connect.
*/
@Override
public void run() {
try {
while (running) {
tryNextPeer();
// We started a new peer connection, delay before trying another one
Thread.sleep(CONNECTION_DELAY_MILLIS);
}
} catch (InterruptedException ex) {
synchronized (this) {
running = false;
}
}
executor.shutdownNow();
for (Peer peer : peers) {
peer.disconnect();
}
}
/*
* Try connecting to a peer. If we exceed the number of connections, delay and try
* again.
*/
private void tryNextPeer() throws InterruptedException {
final PeerAddress address = inactives.take();
while (true) {
try {
final Peer peer = new Peer(params, address,
blockStore.getChainHead().getHeight(), chain);
Runnable command = new Runnable() {
@Override
public void run() {
try {
log.info("connecting to " + peer);
peer.connect();
peers.add(peer);
handleNewPeer(peer);
log.info("running " + peer);
peer.run();
}
finally {
// In all cases, put the address back on the queue
inactives.add(address);
peers.remove(peer);
handlePeerDeath(peer);
}
}
};
executor.execute(command);
break;
}
catch (RejectedExecutionException e) {
// Reached maxConnections, try again after a delay
} catch (BlockStoreException e) {
log.error("block store corrupt?", e);
}
// If we got here, we should retry this address because an error unrelated
// to the peer has occurred.
Thread.sleep(CONNECTION_DELAY_MILLIS);
}
}
}
/**
* Start downloading the blockchain from the first available peer.
*
* <p>If no peers are currently connected, the download will be started
* once a peer starts. If the peer dies, the download will resume with another peer.
*/
public synchronized void startBlockChainDownload(PeerEventListener listener) {
this.downloadListener = listener;
if (!peers.isEmpty())
startBlockChainDownloadFromPeer(peers.iterator().next());
}
protected synchronized void handleNewPeer(Peer peer) {
if (downloadListener != null && downloadPeer == null)
startBlockChainDownloadFromPeer(peer);
}
protected synchronized void handlePeerDeath(Peer peer) {
if (peer == downloadPeer) {
downloadPeer = null;
if (downloadListener != null && !peers.isEmpty())
startBlockChainDownloadFromPeer(peers.iterator().next());
}
}
private void startBlockChainDownloadFromPeer(Peer peer) {
peer.addEventListener(downloadListener);
try {
peer.startBlockChainDownload();
} catch (IOException e) {
log.error("failed to start block chain download from " + peer, e);
return;
}
downloadPeer = peer;
}
static class PeerGroupThreadFactory implements ThreadFactory {
static final AtomicInteger poolNumber = new AtomicInteger(1);
final ThreadGroup group;
final AtomicInteger threadNumber = new AtomicInteger(1);
final String namePrefix;
PeerGroupThreadFactory() {
SecurityManager s = System.getSecurityManager();
group = (s != null)? s.getThreadGroup() :
Thread.currentThread().getThreadGroup();
namePrefix = "PeerGroup-" +
poolNumber.getAndIncrement() +
"-thread-";
}
@Override
public Thread newThread(Runnable r) {
Thread t = new Thread(group, r,
namePrefix + threadNumber.getAndIncrement(),
0);
t.setDaemon(true);
return t;
}
}
}

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// Copyright 2011 Google Inc. All Rights Reserved.
package com.google.bitcoin.examples;
import com.google.bitcoin.core.Peer;
import com.google.bitcoin.core.PeerEventListener;
import java.util.concurrent.Semaphore;
class DownloadListener implements PeerEventListener {
private int originalBlocksLeft = -1;
private int lastPercent = -1;
Semaphore done = new Semaphore(0);
@Override
public void onBlocksDownloaded(Peer peer, int blocksLeft) {
if (blocksLeft == 0) {
System.out.println("Done downloading block chain");
done.release();
}
if (blocksLeft <= 0)
return;
if (originalBlocksLeft < 0) {
System.out.println("Downloading block chain of size " + blocksLeft + ". " +
(lastPercent > 1000 ? "This may take a while." : ""));
originalBlocksLeft = blocksLeft;
}
double pct = 100.0 - (100.0 * (blocksLeft / (double) originalBlocksLeft));
if ((int)pct != lastPercent) {
System.out.println(String.format("Chain download %d%% done", (int) pct));
lastPercent = (int)pct;
}
}
public void await() throws InterruptedException {
done.acquire();
}
}