NetworkDNS/src-wip/org/xbill/DNS2/clients/Client.java

// Copyright (c) 2005 Brian Wellington (bwelling@xbill.org)

package org.xbill.DNS2.clients;

import java.io.IOException;
import java.net.SocketAddress;
import java.net.SocketTimeoutException;
import java.nio.channels.SelectableChannel;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;

import dorkbox.network.dns.utils.Options;

class Client {

    protected long endTime;
    protected SelectionKey key;

    /**
     * Packet logger, if available.
     */
    private static PacketLogger packetLogger = null;

    protected
    Client(SelectableChannel channel, long endTime) throws IOException {
        boolean done = false;
        Selector selector = null;
        this.endTime = endTime;
        try {
            selector = Selector.open();
            channel.configureBlocking(false);
            key = channel.register(selector, SelectionKey.OP_READ);
            done = true;
        } finally {
            if (!done && selector != null) {
                selector.close();
            }
            if (!done) {
                channel.close();
            }
        }
    }

    static protected
    void blockUntil(SelectionKey key, long endTime) throws IOException {
        long timeout = endTime - System.currentTimeMillis();
        int nkeys = 0;
        if (timeout > 0) {
            nkeys = key.selector()
                       .select(timeout);
        }
        else if (timeout == 0) {
            nkeys = key.selector()
                       .selectNow();
        }
        if (nkeys == 0) {
            throw new SocketTimeoutException();
        }
    }

    static protected
    void verboseLog(String prefix, SocketAddress local, SocketAddress remote, byte[] data) {
        if (Options.check("verbosemsg")) {
            System.err.println(hexdump.dump(prefix, data));
        }
        if (packetLogger != null) {
            packetLogger.log(prefix, local, remote, data);
        }
    }

    void cleanup() throws IOException {
        key.selector()
           .close();
        key.channel()
           .close();
    }

    static
    void setPacketLogger(PacketLogger logger) {
        packetLogger = logger;
    }

}