package de.twenty11.skysail.server.ext.osgi.monitor.agent.channel;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.channels.spi.SelectorProvider;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
public class CommandListener implements Runnable {
private int port;
private Selector selector;
private ServerSocketChannel serverChannel;
private EchoWorker worker;
// A list of PendingChange instances
private List<ChangeRequest> pendingChanges = new LinkedList<ChangeRequest>();
// Maps a SocketChannel to a list of ByteBuffer instances
private Map pendingData = new HashMap();
// The buffer into which we'll read data when it's available
private ByteBuffer readBuffer = ByteBuffer.allocate(8192);
public CommandListener(int port) throws IOException {
this.port = port;
this.selector = this.initSelector();
worker = new EchoWorker();
}
public void send(SocketChannel socket, byte[] data) {
synchronized (this.pendingChanges) {
// Indicate we want the interest ops set changed
this.pendingChanges.add(new ChangeRequest(socket, ChangeRequest.CHANGEOPS, SelectionKey.OP_WRITE));
// And queue the data we want written
synchronized (this.pendingData) {
List queue = (List) this.pendingData.get(socket);
if (queue == null) {
queue = new ArrayList();
this.pendingData.put(socket, queue);
}
queue.add(ByteBuffer.wrap(data));
}
}
// Finally, wake up our selecting thread so it can make the required changes
this.selector.wakeup();
}
@Override
public void run() {
// startServerSocketListener(port);
while (true) {
try {
// Process any pending changes
synchronized (this.pendingChanges) {
Iterator changes = this.pendingChanges.iterator();
while (changes.hasNext()) {
ChangeRequest change = (ChangeRequest) changes.next();
switch (change.type) {
case ChangeRequest.CHANGEOPS:
SelectionKey key = change.socket.keyFor(this.selector);
key.interestOps(change.ops);
}
}
this.pendingChanges.clear();
}
// Wait for an event one of the registered channels
this.selector.select();
// Iterate over the set of keys for which events are available
Iterator selectedKeys = this.selector.selectedKeys().iterator();
while (selectedKeys.hasNext()) {
SelectionKey key = (SelectionKey) selectedKeys.next();
selectedKeys.remove();
if (!key.isValid()) {
continue;
}
// Check what event is available and deal with it
if (key.isAcceptable()) {
this.accept(key);
} else if (key.isReadable()) {
this.read(key);
} else if (key.isWritable()) {
this.write(key);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
private void accept(SelectionKey key) throws IOException {
// For an accept to be pending the channel must be a server socket channel.
ServerSocketChannel serverSocketChannel = (ServerSocketChannel) key.channel();
// Accept the connection and make it non-blocking
SocketChannel socketChannel = serverSocketChannel.accept();
Socket socket = socketChannel.socket();
socketChannel.configureBlocking(false);
// Register the new SocketChannel with our Selector, indicating
// we'd like to be notified when there's data waiting to be read
socketChannel.register(this.selector, SelectionKey.OP_READ);
}
private void read(SelectionKey key) throws IOException {
SocketChannel socketChannel = (SocketChannel) key.channel();
this.readBuffer.clear();
int numRead;
try {
numRead = socketChannel.read(this.readBuffer);
} catch (IOException e) {
key.cancel();
socketChannel.close();
return;
}
if (numRead == -1) {
key.channel().close();
key.cancel();
return;
}
// pass data to worker thread
this.worker.processData(this, socketChannel, this.readBuffer.array(), numRead);
}
private void write(SelectionKey key) throws IOException {
SocketChannel socketChannel = (SocketChannel) key.channel();
synchronized (this.pendingData) {
List queue = (List) this.pendingData.get(socketChannel);
// Write until there's not more data ...
while (!queue.isEmpty()) {
ByteBuffer buf = (ByteBuffer) queue.get(0);
socketChannel.write(buf);
if (buf.remaining() > 0) {
// ... or the socket's buffer fills up
break;
}
queue.remove(0);
}
if (queue.isEmpty()) {
// We wrote away all data, so we're no longer interested
// in writing on this socket. Switch back to waiting for
// data.
key.interestOps(SelectionKey.OP_READ);
}
}
}
private Selector initSelector() throws IOException {
// Create a new selector
Selector socketSelector = SelectorProvider.provider().openSelector();
// Create a new non-blocking server socket channel
this.serverChannel = ServerSocketChannel.open();
serverChannel.configureBlocking(false);
// Bind the server socket to the specified address and port
InetSocketAddress isa = new InetSocketAddress("127.0.0.1", this.port);
serverChannel.socket().bind(isa);
// Register the server socket channel, indicating an interest in
// accepting new connections
serverChannel.register(socketSelector, SelectionKey.OP_ACCEPT);
return socketSelector;
}
}