org.xnio.conduits.FramingMessageSourceConduit 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 java.util.concurrent.TimeUnit;
import org.xnio.Buffers;
import org.xnio.Pooled;
/**
* A message source conduit which implements a simple message framing protocol over a stream conduit.
*
* @author David M. Lloyd
*/
public final class FramingMessageSourceConduit extends AbstractSourceConduit implements MessageSourceConduit {
private final Pooled receiveBuffer;
private boolean ready;
/**
* Construct a new instance.
*
* @param next the delegate conduit to set
* @param receiveBuffer the transmit buffer to use
*/
public FramingMessageSourceConduit(final StreamSourceConduit next, final Pooled receiveBuffer) {
super(next);
this.receiveBuffer = receiveBuffer;
}
public void resumeReads() {
if (ready) next.wakeupReads(); else next.resumeReads();
}
public void awaitReadable(final long time, final TimeUnit timeUnit) throws IOException {
if (! ready) next.awaitReadable(time, timeUnit);
}
public void awaitReadable() throws IOException {
if (! ready) next.awaitReadable();
}
public void terminateReads() throws IOException {
receiveBuffer.free();
next.terminateReads();
}
public int receive(final ByteBuffer dst) throws IOException {
final ByteBuffer receiveBuffer = this.receiveBuffer.getResource();
int res;
do {
res = next.read(receiveBuffer);
} while (res > 0);
if (receiveBuffer.position() < 4) {
if (res == -1) {
receiveBuffer.clear();
}
ready = false;
return res;
}
receiveBuffer.flip();
try {
final int length = receiveBuffer.getInt();
if (length < 0 || length > receiveBuffer.capacity() - 4) {
Buffers.unget(receiveBuffer, 4);
throw msg.recvInvalidMsgLength(length);
}
if (receiveBuffer.remaining() < length) {
if (res == -1) {
receiveBuffer.clear();
} else {
Buffers.unget(receiveBuffer, 4);
}
ready = false;
// must be <= 0
return res;
}
if (dst.hasRemaining()) {
return Buffers.copy(length, dst, receiveBuffer);
} else {
Buffers.skip(receiveBuffer, length);
return 0;
}
} finally {
if (res != -1) {
receiveBuffer.compact();
if (receiveBuffer.position() >= 4 && receiveBuffer.position() >= 4 + receiveBuffer.getInt(0)) {
// there's another packet ready to go
ready = true;
}
}
}
}
public long receive(final ByteBuffer[] dsts, final int offs, final int len) throws IOException {
final ByteBuffer receiveBuffer = this.receiveBuffer.getResource();
int res;
do {
res = next.read(receiveBuffer);
} while (res > 0);
if (receiveBuffer.position() < 4) {
if (res == -1) {
receiveBuffer.clear();
}
ready = false;
return res;
}
receiveBuffer.flip();
try {
final int length = receiveBuffer.getInt();
if (length < 0 || length > receiveBuffer.capacity() - 4) {
Buffers.unget(receiveBuffer, 4);
throw msg.recvInvalidMsgLength(length);
}
if (receiveBuffer.remaining() < length) {
if (res == -1) {
receiveBuffer.clear();
} else {
Buffers.unget(receiveBuffer, 4);
}
ready = false;
// must be <= 0
return res;
}
if (Buffers.hasRemaining(dsts, offs, len)) {
return Buffers.copy(length, dsts, offs, len, receiveBuffer);
} else {
Buffers.skip(receiveBuffer, length);
return 0;
}
} finally {
if (res != -1) {
receiveBuffer.compact();
if (receiveBuffer.position() >= 4 && receiveBuffer.position() >= 4 + receiveBuffer.getInt(0)) {
// there's another packet ready to go
ready = true;
}
}
}
}
}