/*
* Copyright (c) 2013, OpenCloudDB/MyCAT and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software;Designed and Developed mainly by many Chinese
* opensource volunteers. you can redistribute it and/or modify it under the
* terms of the GNU General Public License version 2 only, as published by the
* Free Software Foundation.
*
* This code 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 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Any questions about this component can be directed to it's project Web address
* https://code.google.com/p/opencloudb/.
*
*/
package org.opencloudb.mysql.nio.handler;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.List;
import org.apache.log4j.Logger;
import org.opencloudb.MycatConfig;
import org.opencloudb.MycatServer;
import org.opencloudb.backend.BackendConnection;
import org.opencloudb.backend.ConnectionMeta;
import org.opencloudb.backend.PhysicalDBNode;
import org.opencloudb.cache.MysqlDataSetService;
import org.opencloudb.config.ErrorCode;
import org.opencloudb.net.mysql.ErrorPacket;
import org.opencloudb.net.mysql.OkPacket;
import org.opencloudb.route.RouteResultsetNode;
import org.opencloudb.server.NonBlockingSession;
import org.opencloudb.server.ServerConnection;
import org.opencloudb.util.StringUtil;
/**
* @author mycat
*/
public class SingleNodeHandler implements ResponseHandler, Terminatable {
private static final Logger LOGGER = Logger
.getLogger(SingleNodeHandler.class);
private final RouteResultsetNode node;
private final NonBlockingSession session;
// only one thread access at one time no need lock
private volatile byte packetId;
private volatile ByteBuffer buffer;
private volatile boolean isRunning;
private Runnable terminateCallBack;
private static final MysqlDataSetService dataSetSrv = MysqlDataSetService
.getInstance();
public SingleNodeHandler(RouteResultsetNode route,
NonBlockingSession session) {
if (route == null) {
throw new IllegalArgumentException("routeNode is null!");
}
if (session == null) {
throw new IllegalArgumentException("session is null!");
}
this.session = session;
this.node = route;
}
@Override
public void terminate(Runnable callback) {
boolean zeroReached = false;
if (isRunning) {
terminateCallBack = callback;
} else {
zeroReached = true;
}
if (zeroReached) {
callback.run();
}
}
private void endRunning() {
Runnable callback = null;
if (isRunning) {
isRunning = false;
callback = terminateCallBack;
terminateCallBack = null;
}
if (callback != null) {
callback.run();
}
}
private void recycleResources() {
ByteBuffer buf = buffer;
if (buf != null) {
buffer = null;
session.getSource().recycle(buffer);
}
}
public void execute() throws Exception {
ServerConnection sc = session.getSource();
this.isRunning = true;
this.packetId = 0;
final BackendConnection conn = session.getTarget(node);
if (!session.tryExistsCon(conn, node, new Runnable() {
@Override
public void run() {
_execute(conn);
}
})) {
// create new connection
MycatConfig conf = MycatServer.getInstance().getConfig();
PhysicalDBNode dn = conf.getDataNodes().get(node.getName());
ConnectionMeta conMeta = new ConnectionMeta(dn.getDatabase(),
sc.getCharset(), sc.getCharsetIndex(), sc.isAutocommit());
dn.getConnection(conMeta, node, this, node);
}
}
@Override
public void connectionAcquired(final BackendConnection conn) {
conn.setRunning(true);
session.bindConnection(node, conn);
session.getSource().getProcessor().getExecutor()
.execute(new Runnable() {
@Override
public void run() {
_execute(conn);
}
});
}
private void _execute(BackendConnection conn) {
if (session.closed()) {
conn.setRunning(false);
endRunning();
session.clearResources();
return;
}
conn.setResponseHandler(this);
try {
conn.execute(node, session.getSource(), session.getSource()
.isAutocommit());
} catch (IOException e1) {
executeException(conn);
return;
}
}
private void executeException(BackendConnection c) {
ErrorPacket err = new ErrorPacket();
err.packetId = ++packetId;
err.errno = ErrorCode.ER_YES;
err.message = StringUtil.encode(
"unknown backend charset: " + c.getCharset(), session
.getSource().getCharset());
this.backConnectionErr(err, c);
}
@Override
public void connectionError(Throwable e, BackendConnection conn) {
conn.setRunning(false);
endRunning();
ErrorPacket err = new ErrorPacket();
err.packetId = ++packetId;
err.errno = ErrorCode.ER_YES;
err.message = StringUtil.encode(e.getMessage(), session.getSource()
.getCharset());
ServerConnection source = session.getSource();
source.write(err.write(allocBuffer(), source, true));
}
@Override
public void errorResponse(byte[] data, BackendConnection conn) {
ErrorPacket err = new ErrorPacket();
err.read(data);
err.packetId = ++packetId;
backConnectionErr(err, conn);
}
private void backConnectionErr(ErrorPacket errPkg, BackendConnection conn) {
conn.setRunning(false);
endRunning();
String errmgs= " errno:" + errPkg.errno +" "+new String(errPkg.message) ;
LOGGER.warn("execute sql err :"+errmgs+ " con:" + conn);
session.releaseConnectionIfSafe(conn, LOGGER.isDebugEnabled());
ServerConnection source = session.getSource();
source.setTxInterrupt(errmgs);
errPkg.write(source);
recycleResources();
}
@Override
public void okResponse(byte[] data, BackendConnection conn) {
boolean executeResponse = conn.syncAndExcute();
if (executeResponse) {
conn.setRunning(false);
session.releaseConnectionIfSafe(conn, LOGGER.isDebugEnabled());
endRunning();
ServerConnection source = session.getSource();
OkPacket ok = new OkPacket();
ok.read(data);
ok.packetId = ++packetId;
recycleResources();
source.setLastInsertId(ok.insertId);
ok.write(source);
}
}
@Override
public void rowEofResponse(byte[] eof, BackendConnection conn) {
ServerConnection source = session.getSource();
conn.setRunning(false);
conn.recordSql(source.getHost(), source.getSchema(),
node.getStatement());
session.releaseConnectionIfSafe(conn, LOGGER.isDebugEnabled());
endRunning();
eof[3] = ++packetId;
buffer = source.writeToBuffer(eof, allocBuffer());
source.write(buffer);
}
/**
* lazy create ByteBuffer only when needed
*
* @return
*/
private ByteBuffer allocBuffer() {
if (buffer == null) {
buffer = session.getSource().allocate();
}
return buffer;
}
@Override
public void fieldEofResponse(byte[] header, List<byte[]> fields,
byte[] eof, BackendConnection conn) {
header[3] = ++packetId;
ServerConnection source = session.getSource();
buffer = source.writeToBuffer(header, allocBuffer());
for (int i = 0, len = fields.size(); i < len; ++i) {
byte[] field = fields.get(i);
field[3] = ++packetId;
buffer = source.writeToBuffer(field, buffer);
}
eof[3] = ++packetId;
buffer = source.writeToBuffer(eof, buffer);
}
@Override
public void rowResponse(byte[] row, BackendConnection conn) {
row[3] = ++packetId;
buffer = session.getSource().writeToBuffer(row, allocBuffer());
}
@Override
public void writeQueueAvailable() {
}
@Override
public void connectionClose(BackendConnection conn, String reason) {
ErrorPacket err = new ErrorPacket();
err.packetId = ++packetId;
err.errno = ErrorCode.ER_YES;
err.message = StringUtil.encode(reason, session.getSource()
.getCharset());
this.backConnectionErr(err, conn);
}
public void clearResources() {
}
@Override
public String toString() {
return "SingleNodeHandler [node=" + node + ", packetId=" + packetId
+ "]";
}
}