br.com.objectos.http.Channel Maven / Gradle / Ivy

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/*
 * Copyright 2016 Objectos, Fábrica de Software LTDA.
 *
 * 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 br.com.objectos.http;

import java.io.IOException;
import java.net.InetSocketAddress;
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.util.Iterator;
import java.util.Set;

/**
 * @author [email protected] (Marcio Endo)
 */
class Channel implements AutoCloseable {

  private final ServerSocketChannel channel;
  private final Selector selector;

  private final ByteBuffer buffer = ByteBuffer.allocate(8192);

  private Channel(ServerSocketChannel channel, Selector selector) {
    this.channel = channel;
    this.selector = selector;
  }

  public static Channel get(int port) throws IOException {
    ServerSocketChannel channel = ServerSocketChannel.open();
    channel.bind(new InetSocketAddress(port));
    channel.configureBlocking(false);

    Selector selector = Selector.open();
    channel.register(selector, SelectionKey.OP_ACCEPT);

    return new Channel(channel, selector);
  }

  public Socket accept() throws IOException {
    Socket selected = NoopSocket.instance();

    int select = selector.select();
    if (select != 0) {
      selected = select();
    }

    return selected;
  }

  @Override
  public void close() throws IOException {
    try {
      channel.close();
    } finally {
      selector.close();
    }
  }

  private Socket select() throws IOException {
    Socket selected = NoopSocket.instance();

    Set selectedKeys = selector.selectedKeys();
    Iterator keyIterator = selectedKeys.iterator();
    while (keyIterator.hasNext()) {
      SelectionKey selectedKey = keyIterator.next();
      keyIterator.remove();

      if (!selectedKey.isValid()) {
        continue;
      }

      if (selectedKey.isAcceptable()) {
        SocketChannel accepted = channel.accept();
        selected = HttpSocket.of(accepted, buffer);
        break;
      }
    }

    return selected;
  }

}