PeerGroup.java 文件源码

/**
 * <p>Creates a PeerGroup for the given network and chain, using the provided Netty {@link ClientBootstrap} object.
 * </p>
 *
 * <p>A ClientBootstrap creates raw (TCP) connections to other nodes on the network. Normally you won't need to
 * provide one - use the other constructors. Providing your own bootstrap is useful if you want to control
 * details like how many network threads are used, the connection timeout value and so on. To do this, you can
 * use {@link PeerGroup#createClientBootstrap()} method and then customize the resulting object. Example:</p>
 *
 * <pre>
 *   ClientBootstrap bootstrap = PeerGroup.createClientBootstrap();
 *   bootstrap.setOption("connectTimeoutMillis", 3000);
 *   PeerGroup peerGroup = new PeerGroup(params, chain, bootstrap);
 * </pre>
 *
 * <p>The ClientBootstrap provided does not need a channel pipeline factory set. If one wasn't set, the provided
 * bootstrap will be modified to have one that sets up the pipelines correctly.</p>
 */
public PeerGroup(NetworkParameters params, AbstractBlockChain chain, ClientBootstrap bootstrap) {
    this.params = params;
    this.chain = chain;  // Can be null.
    this.fastCatchupTimeSecs = params.genesisBlock.getTimeSeconds();
    this.wallets = new CopyOnWriteArrayList<Wallet>();

    // This default sentinel value will be overridden by one of two actions:
    //   - adding a peer discovery source sets it to the default
    //   - using connectTo() will increment it by one
    this.maxConnections = 0;

    int height = chain == null ? 0 : chain.getBestChainHeight();
    // We never request that the remote node wait for a bloom filter yet, as we have no wallets
    this.versionMessage = new VersionMessage(params, height, true);

    memoryPool = new MemoryPool();

    // Configure Netty. The "ClientBootstrap" creates connections to other nodes. It can be configured in various
    // ways to control the network.
    if (bootstrap == null) {
        this.bootstrap = createClientBootstrap();
        this.bootstrap.setPipelineFactory(makePipelineFactory(params, chain));
    } else {
        this.bootstrap = bootstrap;
    }

    inactives = Collections.synchronizedList(new ArrayList<PeerAddress>());
    peers = new ArrayList<Peer>();
    pendingPeers = new ArrayList<Peer>();
    channels = new DefaultChannelGroup();
    peerDiscoverers = new CopyOnWriteArraySet<PeerDiscovery>(); 
    peerEventListeners = new CopyOnWriteArrayList<PeerEventListener>();
}