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 * as indicated by the @author tags.
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 * 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
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package io.undertow.channels;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.util.concurrent.TimeUnit;

import io.undertow.UndertowLogger;
import org.xnio.ChannelListener;
import org.xnio.ChannelListeners;
import org.xnio.Option;
import org.xnio.XnioExecutor;
import org.xnio.XnioIoThread;
import org.xnio.XnioWorker;
import org.xnio.channels.StreamSinkChannel;
import org.xnio.channels.StreamSourceChannel;
import org.xnio.conduits.ConduitStreamSourceChannel;

import io.undertow.UndertowMessages;

A stream source channel that can be marked as detached. Once this is marked as detached then calls will no longer be forwarded to the delegate.
Author:Stuart Douglas
/** * A stream source channel that can be marked as detached. Once this is marked as detached then * calls will no longer be forwarded to the delegate. * * @author Stuart Douglas */
public abstract class DetachableStreamSourceChannel implements StreamSourceChannel{ protected final StreamSourceChannel delegate; protected ChannelListener.SimpleSetter<DetachableStreamSourceChannel> readSetter; protected ChannelListener.SimpleSetter<DetachableStreamSourceChannel> closeSetter; public DetachableStreamSourceChannel(final StreamSourceChannel delegate) { this.delegate = delegate; } protected abstract boolean isFinished(); @Override public void resumeReads() { if (isFinished()) { return; } delegate.resumeReads(); } public long transferTo(final long position, final long count, final FileChannel target) throws IOException { if (isFinished()) { return -1; } return delegate.transferTo(position, count, target); } public void awaitReadable() throws IOException { if (isFinished()) { return; } delegate.awaitReadable(); } public void suspendReads() { if (isFinished()) { return; } delegate.suspendReads(); } public long transferTo(final long count, final ByteBuffer throughBuffer, final StreamSinkChannel target) throws IOException { if (isFinished()) { return -1; } return delegate.transferTo(count, throughBuffer, target); } public XnioWorker getWorker() { return delegate.getWorker(); } public boolean isReadResumed() { if (isFinished()) { return false; } return delegate.isReadResumed(); } public <T> T setOption(final Option<T> option, final T value) throws IllegalArgumentException, IOException { if (isFinished()) { throw UndertowMessages.MESSAGES.channelIsClosed(); } return delegate.setOption(option, value); } public boolean supportsOption(final Option<?> option) { return delegate.supportsOption(option); } public void shutdownReads() throws IOException { if (isFinished()) { return; } delegate.shutdownReads(); } public ChannelListener.Setter<? extends StreamSourceChannel> getReadSetter() { if (readSetter == null) { readSetter = new ChannelListener.SimpleSetter<>(); if (!isFinished()) { if(delegate instanceof ConduitStreamSourceChannel) { ((ConduitStreamSourceChannel)delegate).setReadListener(new SetterDelegatingListener((ChannelListener.SimpleSetter)readSetter, this)); } else { delegate.getReadSetter().set(new SetterDelegatingListener((ChannelListener.SimpleSetter)readSetter, this)); } } } return readSetter; } public boolean isOpen() { if (isFinished()) { return false; } return delegate.isOpen(); } public long read(final ByteBuffer[] dsts) throws IOException { if (isFinished()) { return -1; } return delegate.read(dsts); } public long read(final ByteBuffer[] dsts, final int offset, final int length) throws IOException { if (isFinished()) { return -1; } return delegate.read(dsts, offset, length); } public void wakeupReads() { if (isFinished()) { return; } delegate.wakeupReads(); } public XnioExecutor getReadThread() { return delegate.getReadThread(); } public void awaitReadable(final long time, final TimeUnit timeUnit) throws IOException { if (isFinished()) { throw UndertowMessages.MESSAGES.channelIsClosed(); } delegate.awaitReadable(time, timeUnit); } public ChannelListener.Setter<? extends StreamSourceChannel> getCloseSetter() { if (closeSetter == null) { closeSetter = new ChannelListener.SimpleSetter<>(); if (!isFinished()) { if(delegate instanceof ConduitStreamSourceChannel) { ((ConduitStreamSourceChannel)delegate).setCloseListener(ChannelListeners.delegatingChannelListener(this, closeSetter)); } else { delegate.getCloseSetter().set(ChannelListeners.delegatingChannelListener(this, closeSetter)); } } } return closeSetter; } public void close() throws IOException { if (isFinished()) { return; } delegate.close(); } public <T> T getOption(final Option<T> option) throws IOException { if (isFinished()) { throw UndertowMessages.MESSAGES.streamIsClosed(); } return delegate.getOption(option); } public int read(final ByteBuffer dst) throws IOException { if (isFinished()) { return -1; } return delegate.read(dst); } @Override public XnioIoThread getIoThread() { return delegate.getIoThread(); } private static class SetterDelegatingListener implements ChannelListener<StreamSourceChannel> { private final SimpleSetter<StreamSourceChannel> setter; private final StreamSourceChannel channel; SetterDelegatingListener(final SimpleSetter<StreamSourceChannel> setter, final StreamSourceChannel channel) { this.setter = setter; this.channel = channel; } public void handleEvent(final StreamSourceChannel channel) { ChannelListener<? super StreamSourceChannel> channelListener = setter.get(); if(channelListener != null) { ChannelListeners.invokeChannelListener(this.channel, channelListener); } else { UndertowLogger.REQUEST_LOGGER.debugf("suspending reads on %s to prevent listener runaway", channel); channel.suspendReads(); } } public String toString() { return "Setter delegating channel listener -> " + setter; } } }