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/*
* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you 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.
*/
/*
* Modifications Copyright OpenSearch Contributors. See
* GitHub history for details.
*/
package org.opensearch.nio;
import org.opensearch.common.concurrent.CompletableContext;
import org.opensearch.common.util.net.NetUtils;
import org.opensearch.nio.utils.ByteBufferUtils;
import org.opensearch.nio.utils.ExceptionsHelper;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.SocketOption;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.SocketChannel;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.function.BiConsumer;
import java.util.function.Consumer;
/**
* This context should implement the specific logic for a channel. When a channel receives a notification
* that it is ready to perform certain operations (read, write, etc) the {@link SocketChannelContext} will
* be called. This context will need to implement all protocol related logic. Additionally, if any special
* close behavior is required, it should be implemented in this context.
*
* The only methods of the context that should ever be called from a non-selector thread are
* {@link #closeChannel()} and {@link #sendMessage(Object, BiConsumer)}.
*/
public abstract class SocketChannelContext extends ChannelContext {
protected final NioSocketChannel channel;
protected final InboundChannelBuffer channelBuffer;
protected final AtomicBoolean isClosing = new AtomicBoolean(false);
private final NioChannelHandler channelHandler;
private final NioSelector selector;
private final Config.Socket socketConfig;
private final CompletableContext connectContext = new CompletableContext<>();
private final LinkedList pendingFlushes = new LinkedList<>();
private boolean closeNow;
private boolean socketOptionsSet;
private Exception connectException;
protected SocketChannelContext(
NioSocketChannel channel,
NioSelector selector,
Config.Socket socketConfig,
Consumer exceptionHandler,
NioChannelHandler channelHandler,
InboundChannelBuffer channelBuffer
) {
super(channel.getRawChannel(), exceptionHandler);
this.selector = selector;
this.channel = channel;
this.socketConfig = socketConfig;
this.channelHandler = channelHandler;
this.channelBuffer = channelBuffer;
}
@Override
public NioSelector getSelector() {
return selector;
}
@Override
public NioSocketChannel getChannel() {
return channel;
}
@Override
protected void register() throws IOException {
super.register();
configureSocket(rawChannel.socket(), false);
if (socketConfig.isAccepted() == false) {
InetSocketAddress remoteAddress = socketConfig.getRemoteAddress();
try {
connect(rawChannel, remoteAddress);
} catch (IOException e) {
throw new IOException("Failed to initiate socket channel connection {remoteAddress=" + remoteAddress + "}.", e);
}
}
}
public void addConnectListener(BiConsumer listener) {
connectContext.addListener(listener);
}
public boolean isConnectComplete() {
return connectContext.isDone() && connectContext.isCompletedExceptionally() == false;
}
/**
* This method will attempt to complete the connection process for this channel. It should be called for
* new channels or for a channel that has produced a OP_CONNECT event. If this method returns true then
* the connection is complete and the channel is ready for reads and writes. If it returns false, the
* channel is not yet connected and this method should be called again when a OP_CONNECT event is
* received.
*
* @return true if the connection process is complete
* @throws IOException if an I/O error occurs
*/
public boolean connect() throws IOException {
if (isConnectComplete()) {
return true;
} else if (connectContext.isCompletedExceptionally()) {
Exception exception = connectException;
if (exception == null) {
throw new AssertionError("Should have received connection exception");
} else if (exception instanceof IOException) {
throw (IOException) exception;
} else {
throw (RuntimeException) exception;
}
}
boolean isConnected = rawChannel.isConnected();
if (isConnected == false) {
try {
isConnected = rawChannel.finishConnect();
} catch (IOException | RuntimeException e) {
connectException = e;
connectContext.completeExceptionally(e);
throw e;
}
}
if (isConnected) {
connectContext.complete(null);
configureSocket(rawChannel.socket(), true);
}
return isConnected;
}
public void sendMessage(Object message, BiConsumer listener) {
if (isClosing.get()) {
listener.accept(null, new ClosedChannelException());
return;
}
WriteOperation writeOperation = channelHandler.createWriteOperation(this, message, listener);
getSelector().queueWrite(writeOperation);
}
public void queueWriteOperation(WriteOperation writeOperation) {
getSelector().assertOnSelectorThread();
pendingFlushes.addAll(channelHandler.writeToBytes(writeOperation));
}
public abstract int read() throws IOException;
public abstract void flushChannel() throws IOException;
protected void currentFlushOperationFailed(IOException e) {
FlushOperation flushOperation = pendingFlushes.pollFirst();
getSelector().executeFailedListener(flushOperation.getListener(), e);
}
protected void currentFlushOperationComplete() {
FlushOperation flushOperation = pendingFlushes.pollFirst();
getSelector().executeListener(flushOperation.getListener(), null);
}
protected FlushOperation getPendingFlush() {
return pendingFlushes.peekFirst();
}
@Override
protected void channelActive() throws IOException {
channelHandler.channelActive();
}
@Override
public void closeFromSelector() throws IOException {
getSelector().assertOnSelectorThread();
if (isOpen()) {
ArrayList closingExceptions = new ArrayList<>(3);
try {
super.closeFromSelector();
} catch (IOException e) {
closingExceptions.add(e);
}
// Set to true in order to reject new writes before queuing with selector
isClosing.set(true);
// Poll for new flush operations to close
pendingFlushes.addAll(channelHandler.pollFlushOperations());
FlushOperation flushOperation;
while ((flushOperation = pendingFlushes.pollFirst()) != null) {
selector.executeFailedListener(flushOperation.getListener(), new ClosedChannelException());
}
try {
channelHandler.close();
} catch (IOException e) {
closingExceptions.add(e);
}
channelBuffer.close();
if (closingExceptions.isEmpty() == false) {
ExceptionsHelper.rethrowAndSuppress(closingExceptions);
}
}
}
protected void handleReadBytes() throws IOException {
int bytesConsumed = Integer.MAX_VALUE;
while (isOpen() && bytesConsumed > 0 && channelBuffer.getIndex() > 0) {
bytesConsumed = channelHandler.consumeReads(channelBuffer);
channelBuffer.release(bytesConsumed);
}
// Some protocols might produce messages to flush during a read operation.
pendingFlushes.addAll(channelHandler.pollFlushOperations());
}
public boolean readyForFlush() {
getSelector().assertOnSelectorThread();
return pendingFlushes.isEmpty() == false;
}
/**
* This method indicates if a selector should close this channel.
*
* @return a boolean indicating if the selector should close
*/
public abstract boolean selectorShouldClose();
protected boolean closeNow() {
return closeNow || channelHandler.closeNow();
}
protected void setCloseNow() {
closeNow = true;
}
// When you read or write to a nio socket in java, the heap memory passed down must be copied to/from
// direct memory. The JVM internally does some buffering of the direct memory, however we can save space
// by reusing a thread-local direct buffer (provided by the NioSelector).
//
// Each network event loop is given a 64kb DirectByteBuffer. When we read we use this buffer and copy the
// data after the read. When we go to write, we copy the data to the direct memory before calling write.
// The choice of 64KB is rather arbitrary. We can explore different sizes in the future. However, any
// data that is copied to the buffer for a write, but not successfully flushed immediately, must be
// copied again on the next call.
protected int readFromChannel(InboundChannelBuffer channelBuffer) throws IOException {
ByteBuffer ioBuffer = getSelector().getIoBuffer();
int bytesRead;
try {
bytesRead = rawChannel.read(ioBuffer);
} catch (IOException e) {
closeNow = true;
throw e;
}
if (bytesRead < 0) {
closeNow = true;
return 0;
} else {
ioBuffer.flip();
channelBuffer.ensureCapacity(channelBuffer.getIndex() + ioBuffer.remaining());
ByteBuffer[] buffers = channelBuffer.sliceBuffersFrom(channelBuffer.getIndex());
int j = 0;
while (j < buffers.length && ioBuffer.remaining() > 0) {
ByteBuffer buffer = buffers[j++];
ByteBufferUtils.copyBytes(ioBuffer, buffer);
}
channelBuffer.incrementIndex(bytesRead);
return bytesRead;
}
}
// Currently we limit to 64KB. This is a trade-off which means more syscalls, in exchange for less
// copying.
private static final int WRITE_LIMIT = 1 << 16;
protected int flushToChannel(FlushOperation flushOperation) throws IOException {
ByteBuffer ioBuffer = getSelector().getIoBuffer();
boolean continueFlush = flushOperation.isFullyFlushed() == false;
int totalBytesFlushed = 0;
while (continueFlush) {
ioBuffer.clear();
ioBuffer.limit(Math.min(WRITE_LIMIT, ioBuffer.limit()));
ByteBuffer[] buffers = flushOperation.getBuffersToWrite(WRITE_LIMIT);
ByteBufferUtils.copyBytes(buffers, ioBuffer);
ioBuffer.flip();
int bytesFlushed;
try {
bytesFlushed = rawChannel.write(ioBuffer);
} catch (IOException e) {
closeNow = true;
throw e;
}
flushOperation.incrementIndex(bytesFlushed);
totalBytesFlushed += bytesFlushed;
continueFlush = ioBuffer.hasRemaining() == false && flushOperation.isFullyFlushed() == false;
}
return totalBytesFlushed;
}
private void configureSocket(Socket socket, boolean isConnectComplete) throws IOException {
if (socketOptionsSet) {
return;
}
try {
// Set reuse address first as it must be set before a bind call. Some implementations throw
// exceptions on other socket options if the channel is not connected. But setting reuse first,
// we ensure that it is properly set before any bind attempt.
socket.setReuseAddress(socketConfig.tcpReuseAddress());
socket.setKeepAlive(socketConfig.tcpKeepAlive());
if (socketConfig.tcpKeepAlive()) {
final Set> supportedOptions = socket.getChannel().supportedOptions();
if (socketConfig.tcpKeepIdle() >= 0) {
final SocketOption keepIdleOption = NetUtils.getTcpKeepIdleSocketOptionOrNull();
if (keepIdleOption != null && supportedOptions.contains(keepIdleOption)) {
socket.getChannel().setOption(keepIdleOption, socketConfig.tcpKeepIdle());
}
}
if (socketConfig.tcpKeepInterval() >= 0) {
final SocketOption keepIntervalOption = NetUtils.getTcpKeepIntervalSocketOptionOrNull();
if (keepIntervalOption != null && supportedOptions.contains(keepIntervalOption)) {
socket.getChannel().setOption(keepIntervalOption, socketConfig.tcpKeepInterval());
}
}
if (socketConfig.tcpKeepCount() >= 0) {
final SocketOption keepCountOption = NetUtils.getTcpKeepCountSocketOptionOrNull();
if (keepCountOption != null && supportedOptions.contains(keepCountOption)) {
socket.getChannel().setOption(keepCountOption, socketConfig.tcpKeepCount());
}
}
}
NetUtils.tryEnsureReasonableKeepAliveConfig(socket.getChannel());
socket.setTcpNoDelay(socketConfig.tcpNoDelay());
int tcpSendBufferSize = socketConfig.tcpSendBufferSize();
if (tcpSendBufferSize > 0) {
socket.setSendBufferSize(tcpSendBufferSize);
}
int tcpReceiveBufferSize = socketConfig.tcpReceiveBufferSize();
if (tcpReceiveBufferSize > 0) {
socket.setReceiveBufferSize(tcpReceiveBufferSize);
}
socketOptionsSet = true;
} catch (IOException e) {
if (isConnectComplete) {
throw e;
}
// Ignore if not connect complete. Some implementations fail on setting socket options if the
// socket is not connected. We will try again after connection.
}
}
@SuppressWarnings("removal")
private static void connect(SocketChannel socketChannel, InetSocketAddress remoteAddress) throws IOException {
try {
AccessController.doPrivileged((PrivilegedExceptionAction) () -> socketChannel.connect(remoteAddress));
} catch (PrivilegedActionException e) {
throw (IOException) e.getCause();
}
}
}