/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.mina.transport.socket.nio;
import java.io.IOException;
import java.nio.channels.ByteChannel;
import java.nio.channels.SelectableChannel;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.util.Iterator;
import java.util.Set;
import java.util.concurrent.Executor;
import org.apache.mina.core.RuntimeIoException;
import org.apache.mina.core.buffer.IoBuffer;
import org.apache.mina.core.file.FileRegion;
import org.apache.mina.core.polling.AbstractPollingIoProcessor;
/**
* TODO Add documentation
*
* @author The Apache MINA Project (dev@mina.apache.org)
* @version $Rev: 751744 $, $Date: 2009-03-09 17:53:13 +0100 (Mon, 09 Mar 2009) $
*/
public final class NioProcessor extends AbstractPollingIoProcessor<NioSession> {
/** The selector associated with this processor */
private final Selector selector;
/**
*
* Creates a new instance of NioProcessor.
*
* @param executor
*/
public NioProcessor(Executor executor) {
super(executor);
try {
// Open a new selector
selector = Selector.open();
} catch (IOException e) {
throw new RuntimeIoException("Failed to open a selector.", e);
}
}
@Override
protected void dispose0() throws Exception {
selector.close();
}
@Override
protected int select(long timeout) throws Exception {
return selector.select(timeout);
}
@Override
protected int select() throws Exception {
return selector.select();
}
@Override
protected boolean isSelectorEmpty() {
return selector.keys().isEmpty();
}
@Override
protected void wakeup() {
selector.wakeup();
}
@Override
protected Iterator<NioSession> allSessions() {
return new IoSessionIterator(selector.keys());
}
@Override
protected Iterator<NioSession> selectedSessions() {
return new IoSessionIterator(selector.selectedKeys());
}
@Override
protected void init(NioSession session) throws Exception {
SelectableChannel ch = (SelectableChannel) session.getChannel();
ch.configureBlocking(false);
session.setSelectionKey(ch.register(selector, SelectionKey.OP_READ, session));
}
@Override
protected void destroy(NioSession session) throws Exception {
ByteChannel ch = session.getChannel();
SelectionKey key = session.getSelectionKey();
if (key != null) {
key.cancel();
}
ch.close();
}
@Override
protected SessionState state(NioSession session) {
SelectionKey key = session.getSelectionKey();
if (key == null) {
return SessionState.PREPARING;
}
return key.isValid()? SessionState.OPEN : SessionState.CLOSED;
}
@Override
protected boolean isReadable(NioSession session) {
SelectionKey key = session.getSelectionKey();
return key.isValid() && key.isReadable();
}
@Override
protected boolean isWritable(NioSession session) {
SelectionKey key = session.getSelectionKey();
return key.isValid() && key.isWritable();
}
@Override
protected boolean isInterestedInRead(NioSession session) {
SelectionKey key = session.getSelectionKey();
return key.isValid() && (key.interestOps() & SelectionKey.OP_READ) != 0;
}
@Override
protected boolean isInterestedInWrite(NioSession session) {
SelectionKey key = session.getSelectionKey();
return key.isValid() && (key.interestOps() & SelectionKey.OP_WRITE) != 0;
}
@Override
protected void setInterestedInRead(NioSession session, boolean value) throws Exception {
SelectionKey key = session.getSelectionKey();
int oldInterestOps = key.interestOps();
int newInterestOps;
if (value) {
newInterestOps = oldInterestOps | SelectionKey.OP_READ;
} else {
newInterestOps = oldInterestOps & ~SelectionKey.OP_READ;
}
if (oldInterestOps != newInterestOps) {
key.interestOps(newInterestOps);
}
}
@Override
protected void setInterestedInWrite(NioSession session, boolean value) throws Exception {
SelectionKey key = session.getSelectionKey();
int oldInterestOps = key.interestOps();
int newInterestOps;
if (value) {
newInterestOps = oldInterestOps | SelectionKey.OP_WRITE;
} else {
newInterestOps = oldInterestOps & ~SelectionKey.OP_WRITE;
}
if (oldInterestOps != newInterestOps) {
key.interestOps(newInterestOps);
}
}
@Override
protected int read(NioSession session, IoBuffer buf) throws Exception {
return session.getChannel().read(buf.buf());
}
@Override
protected int write(NioSession session, IoBuffer buf, int length) throws Exception {
if (buf.remaining() <= length) {
return session.getChannel().write(buf.buf());
} else {
int oldLimit = buf.limit();
buf.limit(buf.position() + length);
try {
return session.getChannel().write(buf.buf());
} finally {
buf.limit(oldLimit);
}
}
}
@Override
protected int transferFile(NioSession session, FileRegion region, int length) throws Exception {
try {
return (int) region.getFileChannel().transferTo(region.getPosition(), length, session.getChannel());
} catch (IOException e) {
// Check to see if the IOException is being thrown due to
// http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5103988
String message = e.getMessage();
if (message != null && message.contains("temporarily unavailable")) {
return 0;
} else {
throw e;
}
}
}
/**
* An encapsulating iterator around the {@link Selector#selectedKeys()}
* or the {@link Selector#keys()} iterator;
*/
protected static class IoSessionIterator implements Iterator<NioSession> {
private final Iterator<SelectionKey> iterator;
/**
* Create this iterator as a wrapper on top of the selectionKey
* Set.
* @param keys
*/
private IoSessionIterator(Set<SelectionKey> keys) {
iterator = keys.iterator();
}
/**
* {@inheritDoc}
*/
public boolean hasNext() {
return iterator.hasNext();
}
/**
* {@inheritDoc}
*/
public NioSession next() {
SelectionKey key = iterator.next();
NioSession nioSession = (NioSession) key.attachment();
return nioSession;
}
/**
* {@inheritDoc}
*/
public void remove() {
iterator.remove();
}
}
}