io.netty.channel.DefaultMaxMessagesRecvByteBufAllocator Maven / Gradle / Ivy
Go to download
This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* Copyright 2015 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:
*
* https://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.channel;
import static io.netty.util.internal.ObjectUtil.checkPositive;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.util.UncheckedBooleanSupplier;
/**
* Default implementation of {@link MaxMessagesRecvByteBufAllocator} which respects {@link ChannelConfig#isAutoRead()}
* and also prevents overflow.
*/
public abstract class DefaultMaxMessagesRecvByteBufAllocator implements MaxMessagesRecvByteBufAllocator {
private final boolean ignoreBytesRead;
private volatile int maxMessagesPerRead;
private volatile boolean respectMaybeMoreData = true;
public DefaultMaxMessagesRecvByteBufAllocator() {
this(1);
}
public DefaultMaxMessagesRecvByteBufAllocator(int maxMessagesPerRead) {
this(maxMessagesPerRead, false);
}
DefaultMaxMessagesRecvByteBufAllocator(int maxMessagesPerRead, boolean ignoreBytesRead) {
this.ignoreBytesRead = ignoreBytesRead;
maxMessagesPerRead(maxMessagesPerRead);
}
@Override
public int maxMessagesPerRead() {
return maxMessagesPerRead;
}
@Override
public MaxMessagesRecvByteBufAllocator maxMessagesPerRead(int maxMessagesPerRead) {
checkPositive(maxMessagesPerRead, "maxMessagesPerRead");
this.maxMessagesPerRead = maxMessagesPerRead;
return this;
}
/**
* Determine if future instances of {@link #newHandle()} will stop reading if we think there is no more data.
* @param respectMaybeMoreData
*
* - {@code true} to stop reading if we think there is no more data. This may save a system call to read from
* the socket, but if data has arrived in a racy fashion we may give up our {@link #maxMessagesPerRead()}
* quantum and have to wait for the selector to notify us of more data.
* - {@code false} to keep reading (up to {@link #maxMessagesPerRead()}) or until there is no data when we
* attempt to read.
*
* @return {@code this}.
*/
public DefaultMaxMessagesRecvByteBufAllocator respectMaybeMoreData(boolean respectMaybeMoreData) {
this.respectMaybeMoreData = respectMaybeMoreData;
return this;
}
/**
* Get if future instances of {@link #newHandle()} will stop reading if we think there is no more data.
* @return
*
* - {@code true} to stop reading if we think there is no more data. This may save a system call to read from
* the socket, but if data has arrived in a racy fashion we may give up our {@link #maxMessagesPerRead()}
* quantum and have to wait for the selector to notify us of more data.
* - {@code false} to keep reading (up to {@link #maxMessagesPerRead()}) or until there is no data when we
* attempt to read.
*
*/
public final boolean respectMaybeMoreData() {
return respectMaybeMoreData;
}
/**
* Focuses on enforcing the maximum messages per read condition for {@link #continueReading()}.
*/
public abstract class MaxMessageHandle implements ExtendedHandle {
private ChannelConfig config;
private int maxMessagePerRead;
private int totalMessages;
private int totalBytesRead;
private int attemptedBytesRead;
private int lastBytesRead;
private final boolean respectMaybeMoreData = DefaultMaxMessagesRecvByteBufAllocator.this.respectMaybeMoreData;
private final UncheckedBooleanSupplier defaultMaybeMoreSupplier = new UncheckedBooleanSupplier() {
@Override
public boolean get() {
return attemptedBytesRead == lastBytesRead;
}
};
/**
* Only {@link ChannelConfig#getMaxMessagesPerRead()} is used.
*/
@Override
public void reset(ChannelConfig config) {
this.config = config;
maxMessagePerRead = maxMessagesPerRead();
totalMessages = totalBytesRead = 0;
}
@Override
public ByteBuf allocate(ByteBufAllocator alloc) {
return alloc.ioBuffer(guess());
}
@Override
public final void incMessagesRead(int amt) {
totalMessages += amt;
}
@Override
public void lastBytesRead(int bytes) {
lastBytesRead = bytes;
if (bytes > 0) {
totalBytesRead += bytes;
}
}
@Override
public final int lastBytesRead() {
return lastBytesRead;
}
@Override
public boolean continueReading() {
return continueReading(defaultMaybeMoreSupplier);
}
@Override
public boolean continueReading(UncheckedBooleanSupplier maybeMoreDataSupplier) {
return config.isAutoRead() &&
(!respectMaybeMoreData || maybeMoreDataSupplier.get()) &&
totalMessages < maxMessagePerRead && (ignoreBytesRead || totalBytesRead > 0);
}
@Override
public void readComplete() {
}
@Override
public int attemptedBytesRead() {
return attemptedBytesRead;
}
@Override
public void attemptedBytesRead(int bytes) {
attemptedBytesRead = bytes;
}
protected final int totalBytesRead() {
return totalBytesRead < 0 ? Integer.MAX_VALUE : totalBytesRead;
}
}
}