/*
* Copyright 2012 The Netty Project
*
* The Netty Project 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.
*/
package com.facebook.presto.jdbc.internal.netty.handler.traffic;
import com.facebook.presto.jdbc.internal.netty.channel.Channel;
import com.facebook.presto.jdbc.internal.netty.channel.ChannelEvent;
import com.facebook.presto.jdbc.internal.netty.channel.ChannelHandlerContext;
import com.facebook.presto.jdbc.internal.netty.channel.ChannelState;
import com.facebook.presto.jdbc.internal.netty.channel.ChannelStateEvent;
import com.facebook.presto.jdbc.internal.netty.channel.MessageEvent;
import com.facebook.presto.jdbc.internal.netty.channel.SimpleChannelHandler;
import com.facebook.presto.jdbc.internal.netty.logging.InternalLogger;
import com.facebook.presto.jdbc.internal.netty.logging.InternalLoggerFactory;
import com.facebook.presto.jdbc.internal.netty.util.DefaultObjectSizeEstimator;
import com.facebook.presto.jdbc.internal.netty.util.ExternalResourceReleasable;
import com.facebook.presto.jdbc.internal.netty.util.ObjectSizeEstimator;
import com.facebook.presto.jdbc.internal.netty.util.Timeout;
import com.facebook.presto.jdbc.internal.netty.util.Timer;
import com.facebook.presto.jdbc.internal.netty.util.TimerTask;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* AbstractTrafficShapingHandler allows to limit the global bandwidth
* (see {@link GlobalTrafficShapingHandler}) or per session
* bandwidth (see {@link ChannelTrafficShapingHandler}), as traffic shaping.
* It allows too to implement an almost real time monitoring of the bandwidth using
* the monitors from {@link TrafficCounter} that will call back every checkInterval
* the method doAccounting of this handler.<br>
* <br>
*
* An {@link ObjectSizeEstimator} can be passed at construction to specify what
* is the size of the object to be read or write accordingly to the type of
* object. If not specified, it will used the {@link DefaultObjectSizeEstimator} implementation.<br><br>
*
* If you want for any particular reasons to stop the monitoring (accounting) or to change
* the read/write limit or the check interval, several methods allow that for you:<br>
* <ul>
* <li><tt>configure</tt> allows you to change read or write limits, or the checkInterval</li>
* <li><tt>getTrafficCounter</tt> allows you to have access to the TrafficCounter and so to stop
* or start the monitoring, to change the checkInterval directly, or to have access to its values.</li>
* <li></li>
* </ul>
*/
public abstract class AbstractTrafficShapingHandler extends
SimpleChannelHandler implements ExternalResourceReleasable {
/**
* Internal logger
*/
static InternalLogger logger = InternalLoggerFactory
.getInstance(AbstractTrafficShapingHandler.class);
/**
* Default delay between two checks: 1s
*/
public static final long DEFAULT_CHECK_INTERVAL = 1000;
/**
* Default minimal time to wait
*/
private static final long MINIMAL_WAIT = 10;
/**
* Traffic Counter
*/
protected TrafficCounter trafficCounter;
/**
* ObjectSizeEstimator
*/
private ObjectSizeEstimator objectSizeEstimator;
/**
* Timer to associated to any TrafficCounter
*/
protected Timer timer;
/**
* used in releaseExternalResources() to cancel the timer
*/
private volatile Timeout timeout;
/**
* Limit in B/s to apply to write
*/
private long writeLimit;
/**
* Limit in B/s to apply to read
*/
private long readLimit;
/**
* Delay between two performance snapshots
*/
protected long checkInterval = DEFAULT_CHECK_INTERVAL; // default 1 s
/**
* Boolean associated with the release of this TrafficShapingHandler.
* It will be true only once when the releaseExternalRessources is called
* to prevent waiting when shutdown.
*/
final AtomicBoolean release = new AtomicBoolean(false);
private void init(ObjectSizeEstimator newObjectSizeEstimator,
Timer newTimer, long newWriteLimit, long newReadLimit,
long newCheckInterval) {
objectSizeEstimator = newObjectSizeEstimator;
timer = newTimer;
writeLimit = newWriteLimit;
readLimit = newReadLimit;
checkInterval = newCheckInterval;
//logger.warn("TSH: "+writeLimit+":"+readLimit+":"+checkInterval);
}
/**
*
* @param newTrafficCounter the TrafficCounter to set
*/
void setTrafficCounter(TrafficCounter newTrafficCounter) {
trafficCounter = newTrafficCounter;
}
/**
* Constructor using default {@link ObjectSizeEstimator}
*
* @param timer
* created once for instance like HashedWheelTimer(10, TimeUnit.MILLISECONDS, 1024)
* @param writeLimit
* 0 or a limit in bytes/s
* @param readLimit
* 0 or a limit in bytes/s
* @param checkInterval
* The delay between two computations of performances for
* channels or 0 if no stats are to be computed
*/
protected AbstractTrafficShapingHandler(Timer timer, long writeLimit,
long readLimit, long checkInterval) {
init(new DefaultObjectSizeEstimator(), timer, writeLimit, readLimit, checkInterval);
}
/**
* Constructor using the specified ObjectSizeEstimator
*
* @param objectSizeEstimator
* the {@link ObjectSizeEstimator} that will be used to compute
* the size of the message
* @param timer
* created once for instance like HashedWheelTimer(10, TimeUnit.MILLISECONDS, 1024)
* @param writeLimit
* 0 or a limit in bytes/s
* @param readLimit
* 0 or a limit in bytes/s
* @param checkInterval
* The delay between two computations of performances for
* channels or 0 if no stats are to be computed
*/
protected AbstractTrafficShapingHandler(
ObjectSizeEstimator objectSizeEstimator, Timer timer,
long writeLimit, long readLimit, long checkInterval) {
init(objectSizeEstimator, timer, writeLimit, readLimit, checkInterval);
}
/**
* Constructor using default {@link ObjectSizeEstimator} and using default Check Interval
*
* @param timer
* created once for instance like HashedWheelTimer(10, TimeUnit.MILLISECONDS, 1024)
* @param writeLimit
* 0 or a limit in bytes/s
* @param readLimit
* 0 or a limit in bytes/s
*/
protected AbstractTrafficShapingHandler(Timer timer, long writeLimit,
long readLimit) {
init(new DefaultObjectSizeEstimator(), timer, writeLimit, readLimit, DEFAULT_CHECK_INTERVAL);
}
/**
* Constructor using the specified ObjectSizeEstimator and using default Check Interval
*
* @param objectSizeEstimator
* the {@link ObjectSizeEstimator} that will be used to compute
* the size of the message
* @param timer
* created once for instance like HashedWheelTimer(10, TimeUnit.MILLISECONDS, 1024)
* @param writeLimit
* 0 or a limit in bytes/s
* @param readLimit
* 0 or a limit in bytes/s
*/
protected AbstractTrafficShapingHandler(
ObjectSizeEstimator objectSizeEstimator, Timer timer,
long writeLimit, long readLimit) {
init(objectSizeEstimator, timer, writeLimit, readLimit, DEFAULT_CHECK_INTERVAL);
}
/**
* Constructor using default {@link ObjectSizeEstimator} and using NO LIMIT and default Check Interval
*
* @param timer
* created once for instance like HashedWheelTimer(10, TimeUnit.MILLISECONDS, 1024)
*/
protected AbstractTrafficShapingHandler(Timer timer) {
init(new DefaultObjectSizeEstimator(), timer, 0, 0, DEFAULT_CHECK_INTERVAL);
}
/**
* Constructor using the specified ObjectSizeEstimator and using NO LIMIT and default Check Interval
*
* @param objectSizeEstimator
* the {@link ObjectSizeEstimator} that will be used to compute
* the size of the message
* @param timer
* created once for instance like HashedWheelTimer(10, TimeUnit.MILLISECONDS, 1024)
*/
protected AbstractTrafficShapingHandler(
ObjectSizeEstimator objectSizeEstimator, Timer timer) {
init(objectSizeEstimator, timer, 0, 0, DEFAULT_CHECK_INTERVAL);
}
/**
* Constructor using default {@link ObjectSizeEstimator} and using NO LIMIT
*
* @param timer
* created once for instance like HashedWheelTimer(10, TimeUnit.MILLISECONDS, 1024)
* @param checkInterval
* The delay between two computations of performances for
* channels or 0 if no stats are to be computed
*/
protected AbstractTrafficShapingHandler(Timer timer, long checkInterval) {
init(new DefaultObjectSizeEstimator(), timer, 0, 0, checkInterval);
}
/**
* Constructor using the specified ObjectSizeEstimator and using NO LIMIT
*
* @param objectSizeEstimator
* the {@link ObjectSizeEstimator} that will be used to compute
* the size of the message
* @param timer
* created once for instance like HashedWheelTimer(10, TimeUnit.MILLISECONDS, 1024)
* @param checkInterval
* The delay between two computations of performances for
* channels or 0 if no stats are to be computed
*/
protected AbstractTrafficShapingHandler(
ObjectSizeEstimator objectSizeEstimator, Timer timer,
long checkInterval) {
init(objectSizeEstimator, timer, 0, 0, checkInterval);
}
/**
* Change the underlying limitations and check interval.
*/
public void configure(long newWriteLimit, long newReadLimit,
long newCheckInterval) {
configure(newWriteLimit, newReadLimit);
configure(newCheckInterval);
}
/**
* Change the underlying limitations.
*/
public void configure(long newWriteLimit, long newReadLimit) {
writeLimit = newWriteLimit;
readLimit = newReadLimit;
if (trafficCounter != null) {
trafficCounter.resetAccounting(System.currentTimeMillis() + 1);
}
}
/**
* Change the check interval.
*/
public void configure(long newCheckInterval) {
checkInterval = newCheckInterval;
if (trafficCounter != null) {
trafficCounter.configure(checkInterval);
}
}
/**
* Called each time the accounting is computed from the TrafficCounters.
* This method could be used for instance to implement almost real time accounting.
*
* @param counter
* the TrafficCounter that computes its performance
*/
protected void doAccounting(TrafficCounter counter) {
// NOOP by default
}
/**
* Class to implement setReadable at fix time
*/
private class ReopenReadTimerTask implements TimerTask {
final ChannelHandlerContext ctx;
ReopenReadTimerTask(ChannelHandlerContext ctx) {
this.ctx = ctx;
}
public void run(Timeout timeoutArg) throws Exception {
//logger.warn("Start RRTT: "+release.get());
if (release.get()) {
return;
}
/*
logger.warn("WAKEUP! "+
(ctx != null && ctx.getChannel() != null &&
ctx.getChannel().isConnected()));
*/
if (ctx != null && ctx.getChannel() != null &&
ctx.getChannel().isConnected()) {
//logger.warn(" setReadable TRUE: ");
// readSuspended = false;
ctx.setAttachment(null);
ctx.getChannel().setReadable(true);
}
}
}
/**
* @return the time that should be necessary to wait to respect limit. Can be negative time
*/
private static long getTimeToWait(long limit, long bytes, long lastTime, long curtime) {
long interval = curtime - lastTime;
if (interval <= 0) {
// Time is too short, so just lets continue
return 0;
}
return (bytes * 1000 / limit - interval) / 10 * 10;
}
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent evt)
throws Exception {
try {
long curtime = System.currentTimeMillis();
long size = objectSizeEstimator.estimateSize(evt.getMessage());
if (trafficCounter != null) {
trafficCounter.bytesRecvFlowControl(size);
if (readLimit == 0) {
// no action
return;
}
// compute the number of ms to wait before reopening the channel
long wait = getTimeToWait(readLimit,
trafficCounter.getCurrentReadBytes(),
trafficCounter.getLastTime(), curtime);
if (wait >= MINIMAL_WAIT) { // At least 10ms seems a minimal
// time in order to
Channel channel = ctx.getChannel();
// try to limit the traffic
if (channel != null && channel.isConnected()) {
// Channel version
if (timer == null) {
// Sleep since no executor
// logger.warn("Read sleep since no timer for "+wait+" ms for "+this);
if (release.get()) {
return;
}
Thread.sleep(wait);
return;
}
if (ctx.getAttachment() == null) {
// readSuspended = true;
ctx.setAttachment(Boolean.TRUE);
channel.setReadable(false);
// logger.warn("Read will wakeup after "+wait+" ms "+this);
TimerTask timerTask = new ReopenReadTimerTask(ctx);
timeout = timer.newTimeout(timerTask, wait,
TimeUnit.MILLISECONDS);
} else {
// should be waiting: but can occurs sometime so as
// a FIX
// logger.warn("Read sleep ok but should not be here: "+wait+" "+this);
if (release.get()) {
return;
}
Thread.sleep(wait);
}
} else {
// Not connected or no channel
// logger.warn("Read sleep "+wait+" ms for "+this);
if (release.get()) {
return;
}
Thread.sleep(wait);
}
}
}
} finally {
// The message is then just passed to the next handler
super.messageReceived(ctx, evt);
}
}
@Override
public void writeRequested(ChannelHandlerContext ctx, MessageEvent evt)
throws Exception {
try {
long curtime = System.currentTimeMillis();
long size = objectSizeEstimator.estimateSize(evt.getMessage());
if (trafficCounter != null) {
trafficCounter.bytesWriteFlowControl(size);
if (writeLimit == 0) {
return;
}
// compute the number of ms to wait before continue with the
// channel
long wait = getTimeToWait(writeLimit,
trafficCounter.getCurrentWrittenBytes(),
trafficCounter.getLastTime(), curtime);
if (wait >= MINIMAL_WAIT) {
// Global or Channel
if (release.get()) {
return;
}
Thread.sleep(wait);
}
}
} finally {
// The message is then just passed to the next handler
super.writeRequested(ctx, evt);
}
}
@Override
public void handleDownstream(ChannelHandlerContext ctx, ChannelEvent e)
throws Exception {
if (e instanceof ChannelStateEvent) {
ChannelStateEvent cse = (ChannelStateEvent) e;
if (cse.getState() == ChannelState.INTEREST_OPS &&
(((Integer) cse.getValue()).intValue() & Channel.OP_READ) != 0) {
// setReadable(true) requested
boolean readSuspended = ctx.getAttachment() != null;
if (readSuspended) {
// Drop the request silently if this handler has
// set the flag.
e.getFuture().setSuccess();
return;
}
}
}
super.handleDownstream(ctx, e);
}
/**
*
* @return the current TrafficCounter (if
* channel is still connected)
*/
public TrafficCounter getTrafficCounter() {
return trafficCounter;
}
public void releaseExternalResources() {
if (trafficCounter != null) {
trafficCounter.stop();
}
release.set(true);
if (timeout != null) {
timeout.cancel();
}
timer.stop();
}
@Override
public String toString() {
return "TrafficShaping with Write Limit: " + writeLimit +
" Read Limit: " + readLimit + " and Counter: " +
(trafficCounter != null? trafficCounter.toString() : "none");
}
}