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/*
* Copyright 2011 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 io.netty.handler.traffic;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufHolder;
import io.netty.channel.Channel;
import io.netty.channel.ChannelDuplexHandler;
import io.netty.channel.ChannelConfig;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelOutboundBuffer;
import io.netty.channel.ChannelPromise;
import io.netty.util.Attribute;
import io.netty.util.AttributeKey;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
import java.util.concurrent.TimeUnit;
/**
* AbstractTrafficShapingHandler allows to limit the global bandwidth
* (see {@link GlobalTrafficShapingHandler}) or per session
* bandwidth (see {@link ChannelTrafficShapingHandler}), as traffic shaping.
* It allows you 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.
*
* 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:
*
* - configure allows you to change read or write limits, or the checkInterval
* - getTrafficCounter 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.
*
*/
public abstract class AbstractTrafficShapingHandler extends ChannelDuplexHandler {
private static final InternalLogger logger =
InternalLoggerFactory.getInstance(AbstractTrafficShapingHandler.class);
/**
* Default delay between two checks: 1s
*/
public static final long DEFAULT_CHECK_INTERVAL = 1000;
/**
* Default max delay in case of traffic shaping
* (during which no communication will occur).
* Shall be less than TIMEOUT. Here half of "standard" 30s
*/
public static final long DEFAULT_MAX_TIME = 15000;
/**
* Default max size to not exceed in buffer (write only).
*/
static final long DEFAULT_MAX_SIZE = 4 * 1024 * 1024L;
/**
* Default minimal time to wait: 10ms
*/
static final long MINIMAL_WAIT = 10;
/**
* Traffic Counter
*/
protected TrafficCounter trafficCounter;
/**
* Limit in B/s to apply to write
*/
private volatile long writeLimit;
/**
* Limit in B/s to apply to read
*/
private volatile long readLimit;
/**
* Max delay in wait
*/
protected volatile long maxTime = DEFAULT_MAX_TIME; // default 15 s
/**
* Delay between two performance snapshots
*/
protected volatile long checkInterval = DEFAULT_CHECK_INTERVAL; // default 1 s
static final AttributeKey READ_SUSPENDED = AttributeKey
.valueOf(AbstractTrafficShapingHandler.class.getName() + ".READ_SUSPENDED");
static final AttributeKey REOPEN_TASK = AttributeKey.valueOf(AbstractTrafficShapingHandler.class
.getName() + ".REOPEN_TASK");
/**
* Max time to delay before proposing to stop writing new objects from next handlers
*/
volatile long maxWriteDelay = 4 * DEFAULT_CHECK_INTERVAL; // default 4 s
/**
* Max size in the list before proposing to stop writing new objects from next handlers
*/
volatile long maxWriteSize = DEFAULT_MAX_SIZE; // default 4MB
/**
* Rank in UserDefinedWritability (1 for Channel, 2 for Global TrafficShapingHandler).
* Set in final constructor. Must be between 1 and 31
*/
final int userDefinedWritabilityIndex;
/**
* Default value for Channel UserDefinedWritability index
*/
static final int CHANNEL_DEFAULT_USER_DEFINED_WRITABILITY_INDEX = 1;
/**
* Default value for Global UserDefinedWritability index
*/
static final int GLOBAL_DEFAULT_USER_DEFINED_WRITABILITY_INDEX = 2;
/**
* Default value for GlobalChannel UserDefinedWritability index
*/
static final int GLOBALCHANNEL_DEFAULT_USER_DEFINED_WRITABILITY_INDEX = 3;
/**
* @param newTrafficCounter
* the TrafficCounter to set
*/
void setTrafficCounter(TrafficCounter newTrafficCounter) {
trafficCounter = newTrafficCounter;
}
/**
* @return the index to be used by the TrafficShapingHandler to manage the user defined writability.
* For Channel TSH it is defined as {@value #CHANNEL_DEFAULT_USER_DEFINED_WRITABILITY_INDEX},
* for Global TSH it is defined as {@value #GLOBAL_DEFAULT_USER_DEFINED_WRITABILITY_INDEX},
* for GlobalChannel TSH it is defined as
* {@value #GLOBALCHANNEL_DEFAULT_USER_DEFINED_WRITABILITY_INDEX}.
*/
protected int userDefinedWritabilityIndex() {
return CHANNEL_DEFAULT_USER_DEFINED_WRITABILITY_INDEX;
}
/**
* @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.
* @param maxTime
* The maximum delay to wait in case of traffic excess.
* Must be positive.
*/
protected AbstractTrafficShapingHandler(long writeLimit, long readLimit, long checkInterval, long maxTime) {
if (maxTime <= 0) {
throw new IllegalArgumentException("maxTime must be positive");
}
userDefinedWritabilityIndex = userDefinedWritabilityIndex();
this.writeLimit = writeLimit;
this.readLimit = readLimit;
this.checkInterval = checkInterval;
this.maxTime = maxTime;
}
/**
* Constructor using default max time as delay allowed value of {@value #DEFAULT_MAX_TIME} ms.
* @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(long writeLimit, long readLimit, long checkInterval) {
this(writeLimit, readLimit, checkInterval, DEFAULT_MAX_TIME);
}
/**
* Constructor using default Check Interval value of {@value #DEFAULT_CHECK_INTERVAL} ms and
* default max time as delay allowed value of {@value #DEFAULT_MAX_TIME} ms.
*
* @param writeLimit
* 0 or a limit in bytes/s
* @param readLimit
* 0 or a limit in bytes/s
*/
protected AbstractTrafficShapingHandler(long writeLimit, long readLimit) {
this(writeLimit, readLimit, DEFAULT_CHECK_INTERVAL, DEFAULT_MAX_TIME);
}
/**
* Constructor using NO LIMIT, default Check Interval value of {@value #DEFAULT_CHECK_INTERVAL} ms and
* default max time as delay allowed value of {@value #DEFAULT_MAX_TIME} ms.
*/
protected AbstractTrafficShapingHandler() {
this(0, 0, DEFAULT_CHECK_INTERVAL, DEFAULT_MAX_TIME);
}
/**
* Constructor using NO LIMIT and
* default max time as delay allowed value of {@value #DEFAULT_MAX_TIME} ms.
*
* @param checkInterval
* The delay between two computations of performances for
* channels or 0 if no stats are to be computed.
*/
protected AbstractTrafficShapingHandler(long checkInterval) {
this(0, 0, checkInterval, DEFAULT_MAX_TIME);
}
/**
* Change the underlying limitations and check interval.
* Note the change will be taken as best effort, meaning
* that all already scheduled traffics will not be
* changed, but only applied to new traffics.
* So the expected usage of this method is to be used not too often,
* accordingly to the traffic shaping configuration.
*
* @param newWriteLimit The new write limit (in bytes)
* @param newReadLimit The new read limit (in bytes)
* @param newCheckInterval The new check interval (in milliseconds)
*/
public void configure(long newWriteLimit, long newReadLimit,
long newCheckInterval) {
configure(newWriteLimit, newReadLimit);
configure(newCheckInterval);
}
/**
* Change the underlying limitations.
* Note the change will be taken as best effort, meaning
* that all already scheduled traffics will not be
* changed, but only applied to new traffics.
* So the expected usage of this method is to be used not too often,
* accordingly to the traffic shaping configuration.
*
* @param newWriteLimit The new write limit (in bytes)
* @param newReadLimit The new read limit (in bytes)
*/
public void configure(long newWriteLimit, long newReadLimit) {
writeLimit = newWriteLimit;
readLimit = newReadLimit;
if (trafficCounter != null) {
trafficCounter.resetAccounting(TrafficCounter.milliSecondFromNano());
}
}
/**
* Change the check interval.
*
* @param newCheckInterval The new check interval (in milliseconds)
*/
public void configure(long newCheckInterval) {
checkInterval = newCheckInterval;
if (trafficCounter != null) {
trafficCounter.configure(checkInterval);
}
}
/**
* @return the writeLimit
*/
public long getWriteLimit() {
return writeLimit;
}
/**
* Note the change will be taken as best effort, meaning
* that all already scheduled traffics will not be
* changed, but only applied to new traffics.
* So the expected usage of this method is to be used not too often,
* accordingly to the traffic shaping configuration.
*
* @param writeLimit the writeLimit to set
*/
public void setWriteLimit(long writeLimit) {
this.writeLimit = writeLimit;
if (trafficCounter != null) {
trafficCounter.resetAccounting(TrafficCounter.milliSecondFromNano());
}
}
/**
* @return the readLimit
*/
public long getReadLimit() {
return readLimit;
}
/**
* Note the change will be taken as best effort, meaning
* that all already scheduled traffics will not be
* changed, but only applied to new traffics.
* So the expected usage of this method is to be used not too often,
* accordingly to the traffic shaping configuration.
*
* @param readLimit the readLimit to set
*/
public void setReadLimit(long readLimit) {
this.readLimit = readLimit;
if (trafficCounter != null) {
trafficCounter.resetAccounting(TrafficCounter.milliSecondFromNano());
}
}
/**
* @return the checkInterval
*/
public long getCheckInterval() {
return checkInterval;
}
/**
* @param checkInterval the interval in ms between each step check to set, default value being 1000 ms.
*/
public void setCheckInterval(long checkInterval) {
this.checkInterval = checkInterval;
if (trafficCounter != null) {
trafficCounter.configure(checkInterval);
}
}
/**
* Note the change will be taken as best effort, meaning
* that all already scheduled traffics will not be
* changed, but only applied to new traffics.
* So the expected usage of this method is to be used not too often,
* accordingly to the traffic shaping configuration.
*
* @param maxTime
* Max delay in wait, shall be less than TIME OUT in related protocol.
* Must be positive.
*/
public void setMaxTimeWait(long maxTime) {
if (maxTime <= 0) {
throw new IllegalArgumentException("maxTime must be positive");
}
this.maxTime = maxTime;
}
/**
* @return the max delay in wait to prevent TIME OUT
*/
public long getMaxTimeWait() {
return maxTime;
}
/**
* @return the maxWriteDelay
*/
public long getMaxWriteDelay() {
return maxWriteDelay;
}
/**
* Note the change will be taken as best effort, meaning
* that all already scheduled traffics will not be
* changed, but only applied to new traffics.
* So the expected usage of this method is to be used not too often,
* accordingly to the traffic shaping configuration.
*
* @param maxWriteDelay the maximum Write Delay in ms in the buffer allowed before write suspension is set.
* Must be positive.
*/
public void setMaxWriteDelay(long maxWriteDelay) {
if (maxWriteDelay <= 0) {
throw new IllegalArgumentException("maxWriteDelay must be positive");
}
this.maxWriteDelay = maxWriteDelay;
}
/**
* @return the maxWriteSize default being {@value #DEFAULT_MAX_SIZE} bytes.
*/
public long getMaxWriteSize() {
return maxWriteSize;
}
/**
* Note that this limit is a best effort on memory limitation to prevent Out Of
* Memory Exception. To ensure it works, the handler generating the write should
* use one of the way provided by Netty to handle the capacity:
* - the {@code Channel.isWritable()} property and the corresponding
* {@code channelWritabilityChanged()}
* - the {@code ChannelFuture.addListener(new GenericFutureListener())}
*
* @param maxWriteSize the maximum Write Size allowed in the buffer
* per channel before write suspended is set,
* default being {@value #DEFAULT_MAX_SIZE} bytes.
*/
public void setMaxWriteSize(long maxWriteSize) {
this.maxWriteSize = maxWriteSize;
}
/**
* 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
*/
static final class ReopenReadTimerTask implements Runnable {
final ChannelHandlerContext ctx;
ReopenReadTimerTask(ChannelHandlerContext ctx) {
this.ctx = ctx;
}
@Override
public void run() {
Channel channel = ctx.channel();
ChannelConfig config = channel.config();
if (!config.isAutoRead() && isHandlerActive(ctx)) {
// If AutoRead is False and Active is True, user make a direct setAutoRead(false)
// Then Just reset the status
if (logger.isDebugEnabled()) {
logger.debug("Not unsuspend: " + config.isAutoRead() + ':' +
isHandlerActive(ctx));
}
channel.attr(READ_SUSPENDED).set(false);
} else {
// Anything else allows the handler to reset the AutoRead
if (logger.isDebugEnabled()) {
if (config.isAutoRead() && !isHandlerActive(ctx)) {
if (logger.isDebugEnabled()) {
logger.debug("Unsuspend: " + config.isAutoRead() + ':' +
isHandlerActive(ctx));
}
} else {
if (logger.isDebugEnabled()) {
logger.debug("Normal unsuspend: " + config.isAutoRead() + ':'
+ isHandlerActive(ctx));
}
}
}
channel.attr(READ_SUSPENDED).set(false);
config.setAutoRead(true);
channel.read();
}
if (logger.isDebugEnabled()) {
logger.debug("Unsuspend final status => " + config.isAutoRead() + ':'
+ isHandlerActive(ctx));
}
}
}
/**
* Release the Read suspension
*/
void releaseReadSuspended(ChannelHandlerContext ctx) {
Channel channel = ctx.channel();
channel.attr(READ_SUSPENDED).set(false);
channel.config().setAutoRead(true);
}
@Override
public void channelRead(final ChannelHandlerContext ctx, final Object msg) throws Exception {
long size = calculateSize(msg);
long now = TrafficCounter.milliSecondFromNano();
if (size > 0) {
// compute the number of ms to wait before reopening the channel
long wait = trafficCounter.readTimeToWait(size, readLimit, maxTime, now);
wait = checkWaitReadTime(ctx, wait, now);
if (wait >= MINIMAL_WAIT) { // At least 10ms seems a minimal
// time in order to try to limit the traffic
// Only AutoRead AND HandlerActive True means Context Active
Channel channel = ctx.channel();
ChannelConfig config = channel.config();
if (logger.isDebugEnabled()) {
logger.debug("Read suspend: " + wait + ':' + config.isAutoRead() + ':'
+ isHandlerActive(ctx));
}
if (config.isAutoRead() && isHandlerActive(ctx)) {
config.setAutoRead(false);
channel.attr(READ_SUSPENDED).set(true);
// Create a Runnable to reactive the read if needed. If one was create before it will just be
// reused to limit object creation
Attribute attr = channel.attr(REOPEN_TASK);
Runnable reopenTask = attr.get();
if (reopenTask == null) {
reopenTask = new ReopenReadTimerTask(ctx);
attr.set(reopenTask);
}
ctx.executor().schedule(reopenTask, wait, TimeUnit.MILLISECONDS);
if (logger.isDebugEnabled()) {
logger.debug("Suspend final status => " + config.isAutoRead() + ':'
+ isHandlerActive(ctx) + " will reopened at: " + wait);
}
}
}
}
informReadOperation(ctx, now);
ctx.fireChannelRead(msg);
}
/**
* Method overridden in GTSH to take into account specific timer for the channel.
* @param wait the wait delay computed in ms
* @param now the relative now time in ms
* @return the wait to use according to the context
*/
long checkWaitReadTime(final ChannelHandlerContext ctx, long wait, final long now) {
// no change by default
return wait;
}
/**
* Method overridden in GTSH to take into account specific timer for the channel.
* @param now the relative now time in ms
*/
void informReadOperation(final ChannelHandlerContext ctx, final long now) {
// default noop
}
protected static boolean isHandlerActive(ChannelHandlerContext ctx) {
Boolean suspended = ctx.channel().attr(READ_SUSPENDED).get();
return suspended == null || Boolean.FALSE.equals(suspended);
}
@Override
public void read(ChannelHandlerContext ctx) {
if (isHandlerActive(ctx)) {
// For Global Traffic (and Read when using EventLoop in pipeline) : check if READ_SUSPENDED is False
ctx.read();
}
}
@Override
public void write(final ChannelHandlerContext ctx, final Object msg, final ChannelPromise promise)
throws Exception {
long size = calculateSize(msg);
long now = TrafficCounter.milliSecondFromNano();
if (size > 0) {
// compute the number of ms to wait before continue with the channel
long wait = trafficCounter.writeTimeToWait(size, writeLimit, maxTime, now);
if (wait >= MINIMAL_WAIT) {
if (logger.isDebugEnabled()) {
logger.debug("Write suspend: " + wait + ':' + ctx.channel().config().isAutoRead() + ':'
+ isHandlerActive(ctx));
}
submitWrite(ctx, msg, size, wait, now, promise);
return;
}
}
// to maintain order of write
submitWrite(ctx, msg, size, 0, now, promise);
}
@Deprecated
protected void submitWrite(final ChannelHandlerContext ctx, final Object msg,
final long delay, final ChannelPromise promise) {
submitWrite(ctx, msg, calculateSize(msg),
delay, TrafficCounter.milliSecondFromNano(), promise);
}
abstract void submitWrite(
ChannelHandlerContext ctx, Object msg, long size, long delay, long now, ChannelPromise promise);
@Override
public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
setUserDefinedWritability(ctx, true);
super.channelRegistered(ctx);
}
void setUserDefinedWritability(ChannelHandlerContext ctx, boolean writable) {
ChannelOutboundBuffer cob = ctx.channel().unsafe().outboundBuffer();
if (cob != null) {
cob.setUserDefinedWritability(userDefinedWritabilityIndex, writable);
}
}
/**
* Check the writability according to delay and size for the channel.
* Set if necessary setUserDefinedWritability status.
* @param delay the computed delay
* @param queueSize the current queueSize
*/
void checkWriteSuspend(ChannelHandlerContext ctx, long delay, long queueSize) {
if (queueSize > maxWriteSize || delay > maxWriteDelay) {
setUserDefinedWritability(ctx, false);
}
}
/**
* Explicitly release the Write suspended status.
*/
void releaseWriteSuspended(ChannelHandlerContext ctx) {
setUserDefinedWritability(ctx, true);
}
/**
* @return the current TrafficCounter (if
* channel is still connected)
*/
public TrafficCounter trafficCounter() {
return trafficCounter;
}
@Override
public String toString() {
StringBuilder builder = new StringBuilder(290)
.append("TrafficShaping with Write Limit: ").append(writeLimit)
.append(" Read Limit: ").append(readLimit)
.append(" CheckInterval: ").append(checkInterval)
.append(" maxDelay: ").append(maxWriteDelay)
.append(" maxSize: ").append(maxWriteSize)
.append(" and Counter: ");
if (trafficCounter != null) {
builder.append(trafficCounter);
} else {
builder.append("none");
}
return builder.toString();
}
/**
* Calculate the size of the given {@link Object}.
*
* This implementation supports {@link ByteBuf} and {@link ByteBufHolder}. Sub-classes may override this.
* @param msg the msg for which the size should be calculated.
* @return size the size of the msg or {@code -1} if unknown.
*/
protected long calculateSize(Object msg) {
if (msg instanceof ByteBuf) {
return ((ByteBuf) msg).readableBytes();
}
if (msg instanceof ByteBufHolder) {
return ((ByteBufHolder) msg).content().readableBytes();
}
return -1;
}
}