/* This file is part of VoltDB.
* Copyright (C) 2008-2014 VoltDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with VoltDB. If not, see <http://www.gnu.org/licenses/>.
*/
package org.voltcore.network;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.GatheringByteChannel;
import java.util.ArrayDeque;
import org.voltcore.logging.VoltLogger;
import org.voltcore.utils.DeferredSerialization;
/**
*
* Write stream implementation optimized for use on the server. Does no locking and
* backpressure tracking
*
*/
public class PicoNIOWriteStream extends NIOWriteStreamBase {
private static final VoltLogger networkLog = new VoltLogger("NETWORK");
/**
* Contains messages waiting to be serialized and written to the socket
*/
private final ArrayDeque<DeferredSerialization> m_queuedWrites = new ArrayDeque<DeferredSerialization>();
/*
* Return the number of messages waiting to be written to the network
*/
@Override
public int getOutstandingMessageCount()
{
return m_queuedWrites.size() + super.getOutstandingMessageCount();
}
@Override
public boolean isEmpty()
{
return super.isEmpty() && m_queuedWrites.isEmpty();
}
@Override
protected ArrayDeque<DeferredSerialization> getQueuedWrites() {
return m_queuedWrites;
}
/**
* Free the pool resources that are held by this WriteStream. The pool itself is thread local
* and will be freed when the thread terminates.
*/
@Override
synchronized void shutdown() {
super.shutdown();
DeferredSerialization ds = null;
while ((ds = m_queuedWrites.poll()) != null) {
ds.cancel();
}
}
@Override
protected void updateQueued(int queued, boolean noBackpressureSignal) {}
/**
* Drain pending buffers one at a time into the socket
* @param channel
* @return
* @throws IOException
*/
@Override
int drainTo (final GatheringByteChannel channel) throws IOException {
int bytesWritten = 0;
long rc = 0;
do {
/*
* Nothing to write
*/
if (m_currentWriteBuffer == null && m_queuedBuffers.isEmpty()) {
break;
}
ByteBuffer buffer = null;
if (m_currentWriteBuffer == null) {
m_currentWriteBuffer = m_queuedBuffers.poll();
buffer = m_currentWriteBuffer.b();
buffer.flip();
} else {
buffer = m_currentWriteBuffer.b();
}
rc = channel.write(buffer);
//Discard the buffer back to a pool if no data remains
if (!buffer.hasRemaining()) {
m_currentWriteBuffer.discard();
m_currentWriteBuffer = null;
m_messagesWritten++;
}
bytesWritten += rc;
} while (rc > 0);
m_bytesWritten += bytesWritten;
return bytesWritten;
}
public void enqueue(DeferredSerialization ds) {
if (m_isShutdown) {
ds.cancel();
return;
}
m_queuedWrites.offer(ds);
}
public void enqueue(final ByteBuffer buf) {
assert(!buf.isDirect());//Don't queue direct buffers, they leak memory without a container
if (buf.remaining() == 0) {
throw new IllegalArgumentException("Attempted to queue a zero length buffer");
}
if (m_isShutdown) return;
m_queuedWrites.offer(new DeferredSerialization() {
@Override
public void serialize(final ByteBuffer outbuf) throws IOException {
outbuf.put(buf);
}
@Override
public void cancel() {}
@Override
public int getSerializedSize() {
return buf.remaining();
}
});
}
}