org.xnio.conduits.FramingMessageSinkConduit Maven / Gradle / Ivy
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*
* Copyright 2013 Red Hat, Inc. and/or its affiliates.
*
* 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 org.xnio.conduits;
import static org.xnio._private.Messages.msg;
import java.io.IOException;
import java.nio.ByteBuffer;
import org.xnio.Buffers;
import org.xnio.Pooled;
/**
* A message sink conduit which implements a simple message framing protocol over a stream conduit.
*
* @author David M. Lloyd
*/
public final class FramingMessageSinkConduit extends AbstractSinkConduit implements MessageSinkConduit {
private final boolean longLengths;
private final Pooled transmitBuffer;
/**
* Construct a new instance.
*
* @param next the delegate conduit to set
* @param longLengths {@code true} to use 4-byte lengths, {@code false} to use 2-byte lengths
* @param transmitBuffer the transmit buffer to use
*/
public FramingMessageSinkConduit(final StreamSinkConduit next, final boolean longLengths, final Pooled transmitBuffer) {
super(next);
this.longLengths = longLengths;
this.transmitBuffer = transmitBuffer;
}
public boolean send(final ByteBuffer src) throws IOException {
if (!src.hasRemaining()) {
// no zero messages
return false;
}
final ByteBuffer transmitBuffer = this.transmitBuffer.getResource();
final int remaining = src.remaining();
final boolean longLengths = this.longLengths;
final int lengthFieldSize = longLengths ? 4 : 2;
if (remaining > transmitBuffer.capacity() - lengthFieldSize || ! longLengths && remaining > 65535) {
throw msg.txMsgTooLarge();
}
if (transmitBuffer.remaining() < lengthFieldSize + remaining && ! writeBuffer()) {
return false;
}
if (longLengths) {
transmitBuffer.putInt(remaining);
} else {
transmitBuffer.putShort((short) remaining);
}
transmitBuffer.put(src);
writeBuffer();
return true;
}
public boolean send(final ByteBuffer[] srcs, final int offs, final int len) throws IOException {
if (len == 1) {
return send(srcs[offs]);
} else if (! Buffers.hasRemaining(srcs, offs, len)) {
return false;
}
final ByteBuffer transmitBuffer = this.transmitBuffer.getResource();
final long remaining = Buffers.remaining(srcs, offs, len);
final boolean longLengths = this.longLengths;
final int lengthFieldSize = longLengths ? 4 : 2;
if (remaining > transmitBuffer.capacity() - lengthFieldSize || ! longLengths && remaining > 65535) {
throw msg.txMsgTooLarge();
}
if (transmitBuffer.remaining() < lengthFieldSize + remaining && ! writeBuffer()) {
return false;
}
if (longLengths) {
transmitBuffer.putInt((int) remaining);
} else {
transmitBuffer.putShort((short) remaining);
}
Buffers.copy(transmitBuffer, srcs, offs, len);
writeBuffer();
return true;
}
@Override
public boolean sendFinal(ByteBuffer src) throws IOException {
//TODO: non-naive implementation
return Conduits.sendFinalBasic(this, src);
}
@Override
public boolean sendFinal(ByteBuffer[] srcs, int offs, int len) throws IOException {
return Conduits.sendFinalBasic(this, srcs, offs, len);
}
private boolean writeBuffer() throws IOException {
final ByteBuffer buffer = transmitBuffer.getResource();
if (buffer.position() > 0) buffer.flip();
try {
while (buffer.hasRemaining()) {
final int res = next.write(buffer);
if (res == 0) {
return false;
}
}
return true;
} finally {
buffer.compact();
}
}
public boolean flush() throws IOException {
return writeBuffer() && next.flush();
}
public void terminateWrites() throws IOException {
transmitBuffer.free();
next.terminateWrites();
}
public void truncateWrites() throws IOException {
transmitBuffer.free();
next.truncateWrites();
}
}