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JDBC Type 4 driver for MySQL
/*
* Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License, version 2.0, as published by the
* Free Software Foundation.
*
* This program is also distributed with certain software (including but not
* limited to OpenSSL) that is licensed under separate terms, as designated in a
* particular file or component or in included license documentation. The
* authors of MySQL hereby grant you an additional permission to link the
* program and your derivative works with the separately licensed software that
* they have included with MySQL.
*
* Without limiting anything contained in the foregoing, this file, which is
* part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
* version 1.0, a copy of which can be found at
* http://oss.oracle.com/licenses/universal-foss-exception.
*
* 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 General Public License, version 2.0,
* for more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package com.mysql.cj.protocol.x;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import com.google.protobuf.CodedOutputStream;
import com.google.protobuf.MessageLite;
import com.mysql.cj.Messages;
import com.mysql.cj.exceptions.CJCommunicationsException;
import com.mysql.cj.exceptions.CJPacketTooBigException;
import com.mysql.cj.protocol.MessageSender;
import com.mysql.cj.protocol.SerializingBufferWriter;
/**
* Asynchronous message writer.
*/
public class AsyncMessageSender implements MessageSender {
/**
* Header length of X Protocol packet.
*/
private static final int HEADER_LEN = 5;
private int maxAllowedPacket = -1;
/**
* Channel wrapper is the destination to which we write marshalled messages.
*/
private SerializingBufferWriter bufferWriter;
public AsyncMessageSender(AsynchronousSocketChannel channel) {
this.bufferWriter = new SerializingBufferWriter(channel);
}
public void send(XMessage message) {
CompletableFuture f = new CompletableFuture<>();
// write a message asynchronously that will notify the future when complete
send(message, new ErrorToFutureCompletionHandler(f, () -> f.complete(null)));
// wait on the future to return
try {
f.get();
} catch (ExecutionException ex) {
throw new CJCommunicationsException("Failed to write message", ex.getCause());
} catch (InterruptedException ex) {
throw new CJCommunicationsException("Failed to write message", ex);
}
}
public void send(XMessage message, CompletionHandler callback) {
MessageLite msg = message.getMessage();
int type = MessageConstants.getTypeForMessageClass(msg.getClass());
int size = msg.getSerializedSize();
int payloadSize = size + 1;
// we check maxAllowedPacket against payloadSize as that's considered the "packet size" (not including 4 byte size header)
if (this.maxAllowedPacket > 0 && payloadSize > this.maxAllowedPacket) {
throw new CJPacketTooBigException(Messages.getString("PacketTooBigException.1", new Object[] { size, this.maxAllowedPacket }));
}
// for debugging
//System.err.println("Initiating write of message (size=" + payloadSize + ", tag=" + com.mysql.cj.mysqlx.protobuf.Mysqlx.ClientMessages.Type.valueOf(type) + ")");
ByteBuffer messageBuf = ByteBuffer.allocate(HEADER_LEN + size).order(ByteOrder.LITTLE_ENDIAN).putInt(payloadSize);
messageBuf.put((byte) type);
try {
// directly access the ByteBuffer's backing array as protobuf's CodedOutputStream.newInstance(ByteBuffer) is giving a stream that doesn't actually
// write any data
msg.writeTo(CodedOutputStream.newInstance(messageBuf.array(), HEADER_LEN, size));
messageBuf.position(messageBuf.limit());
} catch (IOException ex) {
throw new CJCommunicationsException("Unable to write message", ex);
}
messageBuf.flip();
this.bufferWriter.queueBuffer(messageBuf, callback);
}
public void setMaxAllowedPacket(int maxAllowedPacket) {
this.maxAllowedPacket = maxAllowedPacket;
}
/**
* Allow overwriting the channel once the writer has been established. Required for SSL/TLS connections when the encryption doesn't start until we send the
* capability flag to X Plugin.
*
* @param channel
* {@link AsynchronousSocketChannel}
*/
public void setChannel(AsynchronousSocketChannel channel) {
this.bufferWriter.setChannel(channel);
}
}