//
// ========================================================================
// Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package org.eclipse.jetty.websocket.common.message;
import java.io.IOException;
import java.io.Writer;
import java.nio.ByteBuffer;
import org.eclipse.jetty.io.ByteBufferPool;
import org.eclipse.jetty.util.BufferUtil;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
import org.eclipse.jetty.websocket.api.BatchMode;
import org.eclipse.jetty.websocket.api.WriteCallback;
import org.eclipse.jetty.websocket.api.extensions.OutgoingFrames;
import org.eclipse.jetty.websocket.common.BlockingWriteCallback;
import org.eclipse.jetty.websocket.common.WebSocketSession;
import org.eclipse.jetty.websocket.common.BlockingWriteCallback.WriteBlocker;
import org.eclipse.jetty.websocket.common.frames.TextFrame;
/**
* Support for writing a single WebSocket TEXT message via a {@link Writer}
* <p/>
* Note: Per WebSocket spec, all WebSocket TEXT messages must be encoded in UTF-8
*/
public class MessageWriter extends Writer
{
private static final Logger LOG = Log.getLogger(MessageWriter.class);
private final OutgoingFrames outgoing;
private final ByteBufferPool bufferPool;
private final BlockingWriteCallback blocker;
private long frameCount;
private TextFrame frame;
private ByteBuffer buffer;
private Utf8CharBuffer utf;
private WriteCallback callback;
private boolean closed;
public MessageWriter(WebSocketSession session)
{
this(session.getOutgoingHandler(), session.getPolicy().getMaxTextMessageBufferSize(), session.getBufferPool());
}
public MessageWriter(OutgoingFrames outgoing, int bufferSize, ByteBufferPool bufferPool)
{
this.outgoing = outgoing;
this.bufferPool = bufferPool;
this.blocker = new BlockingWriteCallback();
this.buffer = bufferPool.acquire(bufferSize, true);
BufferUtil.flipToFill(buffer);
this.frame = new TextFrame();
this.utf = Utf8CharBuffer.wrap(buffer);
}
@Override
public void write(char[] chars, int off, int len) throws IOException
{
try
{
send(chars, off, len);
}
catch (Throwable x)
{
// Notify without holding locks.
notifyFailure(x);
throw x;
}
}
@Override
public void write(int c) throws IOException
{
try
{
send(new char[]{(char)c}, 0, 1);
}
catch (Throwable x)
{
// Notify without holding locks.
notifyFailure(x);
throw x;
}
}
@Override
public void flush() throws IOException
{
try
{
flush(false);
}
catch (Throwable x)
{
// Notify without holding locks.
notifyFailure(x);
throw x;
}
}
@Override
public void close() throws IOException
{
try
{
flush(true);
bufferPool.release(buffer);
LOG.debug("Stream closed, {} frames sent", frameCount);
// Notify without holding locks.
notifySuccess();
}
catch (Throwable x)
{
// Notify without holding locks.
notifyFailure(x);
throw x;
}
}
private void flush(boolean fin) throws IOException
{
synchronized (this)
{
if (closed)
throw new IOException("Stream is closed");
closed = fin;
ByteBuffer data = utf.getByteBuffer();
LOG.debug("flush({}): {}", fin, BufferUtil.toDetailString(buffer));
frame.setPayload(data);
frame.setFin(fin);
try (WriteBlocker b = blocker.acquireWriteBlocker())
{
outgoing.outgoingFrame(frame, b, BatchMode.OFF);
b.block();
}
++frameCount;
// Any flush after the first will be a CONTINUATION frame.
frame.setIsContinuation();
utf.clear();
}
}
private void send(char[] chars, int offset, int length) throws IOException
{
synchronized (this)
{
if (closed)
throw new IOException("Stream is closed");
while (length > 0)
{
// There may be no space available, we want
// to handle correctly when space == 0.
int space = utf.remaining();
int size = Math.min(space, length);
utf.append(chars, offset, size);
offset += size;
length -= size;
if (length > 0)
{
// If we could not write everything, it means
// that the buffer was full, so flush it.
flush(false);
}
}
}
}
public void setCallback(WriteCallback callback)
{
synchronized (this)
{
this.callback = callback;
}
}
private void notifySuccess()
{
WriteCallback callback;
synchronized (this)
{
callback = this.callback;
}
if (callback != null)
{
callback.writeSuccess();
}
}
private void notifyFailure(Throwable failure)
{
WriteCallback callback;
synchronized (this)
{
callback = this.callback;
}
if (callback != null)
{
callback.writeFailed(failure);
}
}
}