io.netty.buffer.AbstractByteBufAllocator Maven / Gradle / Ivy
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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).
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/*
* 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:
*
* 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.buffer;
import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
import io.netty.util.ResourceLeakDetector;
import io.netty.util.ResourceLeakTracker;
import io.netty.util.internal.MathUtil;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.StringUtil;
/**
* Skeletal {@link ByteBufAllocator} implementation to extend.
*/
public abstract class AbstractByteBufAllocator implements ByteBufAllocator {
static final int DEFAULT_INITIAL_CAPACITY = 256;
static final int DEFAULT_MAX_CAPACITY = Integer.MAX_VALUE;
static final int DEFAULT_MAX_COMPONENTS = 16;
static final int CALCULATE_THRESHOLD = 1048576 * 4; // 4 MiB page
static {
ResourceLeakDetector.addExclusions(AbstractByteBufAllocator.class, "toLeakAwareBuffer");
}
protected static ByteBuf toLeakAwareBuffer(ByteBuf buf) {
ResourceLeakTracker leak;
switch (ResourceLeakDetector.getLevel()) {
case SIMPLE:
leak = AbstractByteBuf.leakDetector.track(buf);
if (leak != null) {
buf = new SimpleLeakAwareByteBuf(buf, leak);
}
break;
case ADVANCED:
case PARANOID:
leak = AbstractByteBuf.leakDetector.track(buf);
if (leak != null) {
buf = new AdvancedLeakAwareByteBuf(buf, leak);
}
break;
default:
break;
}
return buf;
}
protected static CompositeByteBuf toLeakAwareBuffer(CompositeByteBuf buf) {
ResourceLeakTracker leak;
switch (ResourceLeakDetector.getLevel()) {
case SIMPLE:
leak = AbstractByteBuf.leakDetector.track(buf);
if (leak != null) {
buf = new SimpleLeakAwareCompositeByteBuf(buf, leak);
}
break;
case ADVANCED:
case PARANOID:
leak = AbstractByteBuf.leakDetector.track(buf);
if (leak != null) {
buf = new AdvancedLeakAwareCompositeByteBuf(buf, leak);
}
break;
default:
break;
}
return buf;
}
private final boolean directByDefault;
private final ByteBuf emptyBuf;
/**
* Instance use heap buffers by default
*/
protected AbstractByteBufAllocator() {
this(false);
}
/**
* Create new instance
*
* @param preferDirect {@code true} if {@link #buffer(int)} should try to allocate a direct buffer rather than
* a heap buffer
*/
protected AbstractByteBufAllocator(boolean preferDirect) {
directByDefault = preferDirect && PlatformDependent.hasUnsafe();
emptyBuf = new EmptyByteBuf(this);
}
@Override
public ByteBuf buffer() {
if (directByDefault) {
return directBuffer();
}
return heapBuffer();
}
@Override
public ByteBuf buffer(int initialCapacity) {
if (directByDefault) {
return directBuffer(initialCapacity);
}
return heapBuffer(initialCapacity);
}
@Override
public ByteBuf buffer(int initialCapacity, int maxCapacity) {
if (directByDefault) {
return directBuffer(initialCapacity, maxCapacity);
}
return heapBuffer(initialCapacity, maxCapacity);
}
@Override
public ByteBuf ioBuffer() {
if (PlatformDependent.hasUnsafe() || isDirectBufferPooled()) {
return directBuffer(DEFAULT_INITIAL_CAPACITY);
}
return heapBuffer(DEFAULT_INITIAL_CAPACITY);
}
@Override
public ByteBuf ioBuffer(int initialCapacity) {
if (PlatformDependent.hasUnsafe() || isDirectBufferPooled()) {
return directBuffer(initialCapacity);
}
return heapBuffer(initialCapacity);
}
@Override
public ByteBuf ioBuffer(int initialCapacity, int maxCapacity) {
if (PlatformDependent.hasUnsafe() || isDirectBufferPooled()) {
return directBuffer(initialCapacity, maxCapacity);
}
return heapBuffer(initialCapacity, maxCapacity);
}
@Override
public ByteBuf heapBuffer() {
return heapBuffer(DEFAULT_INITIAL_CAPACITY, DEFAULT_MAX_CAPACITY);
}
@Override
public ByteBuf heapBuffer(int initialCapacity) {
return heapBuffer(initialCapacity, DEFAULT_MAX_CAPACITY);
}
@Override
public ByteBuf heapBuffer(int initialCapacity, int maxCapacity) {
if (initialCapacity == 0 && maxCapacity == 0) {
return emptyBuf;
}
validate(initialCapacity, maxCapacity);
return newHeapBuffer(initialCapacity, maxCapacity);
}
@Override
public ByteBuf directBuffer() {
return directBuffer(DEFAULT_INITIAL_CAPACITY, DEFAULT_MAX_CAPACITY);
}
@Override
public ByteBuf directBuffer(int initialCapacity) {
return directBuffer(initialCapacity, DEFAULT_MAX_CAPACITY);
}
@Override
public ByteBuf directBuffer(int initialCapacity, int maxCapacity) {
if (initialCapacity == 0 && maxCapacity == 0) {
return emptyBuf;
}
validate(initialCapacity, maxCapacity);
return newDirectBuffer(initialCapacity, maxCapacity);
}
@Override
public CompositeByteBuf compositeBuffer() {
if (directByDefault) {
return compositeDirectBuffer();
}
return compositeHeapBuffer();
}
@Override
public CompositeByteBuf compositeBuffer(int maxNumComponents) {
if (directByDefault) {
return compositeDirectBuffer(maxNumComponents);
}
return compositeHeapBuffer(maxNumComponents);
}
@Override
public CompositeByteBuf compositeHeapBuffer() {
return compositeHeapBuffer(DEFAULT_MAX_COMPONENTS);
}
@Override
public CompositeByteBuf compositeHeapBuffer(int maxNumComponents) {
return toLeakAwareBuffer(new CompositeByteBuf(this, false, maxNumComponents));
}
@Override
public CompositeByteBuf compositeDirectBuffer() {
return compositeDirectBuffer(DEFAULT_MAX_COMPONENTS);
}
@Override
public CompositeByteBuf compositeDirectBuffer(int maxNumComponents) {
return toLeakAwareBuffer(new CompositeByteBuf(this, true, maxNumComponents));
}
private static void validate(int initialCapacity, int maxCapacity) {
checkPositiveOrZero(initialCapacity, "initialCapacity");
if (initialCapacity > maxCapacity) {
throw new IllegalArgumentException(String.format(
"initialCapacity: %d (expected: not greater than maxCapacity(%d)",
initialCapacity, maxCapacity));
}
}
/**
* Create a heap {@link ByteBuf} with the given initialCapacity and maxCapacity.
*/
protected abstract ByteBuf newHeapBuffer(int initialCapacity, int maxCapacity);
/**
* Create a direct {@link ByteBuf} with the given initialCapacity and maxCapacity.
*/
protected abstract ByteBuf newDirectBuffer(int initialCapacity, int maxCapacity);
@Override
public String toString() {
return StringUtil.simpleClassName(this) + "(directByDefault: " + directByDefault + ')';
}
@Override
public int calculateNewCapacity(int minNewCapacity, int maxCapacity) {
checkPositiveOrZero(minNewCapacity, "minNewCapacity");
if (minNewCapacity > maxCapacity) {
throw new IllegalArgumentException(String.format(
"minNewCapacity: %d (expected: not greater than maxCapacity(%d)",
minNewCapacity, maxCapacity));
}
final int threshold = CALCULATE_THRESHOLD; // 4 MiB page
if (minNewCapacity == threshold) {
return threshold;
}
// If over threshold, do not double but just increase by threshold.
if (minNewCapacity > threshold) {
int newCapacity = minNewCapacity / threshold * threshold;
if (newCapacity > maxCapacity - threshold) {
newCapacity = maxCapacity;
} else {
newCapacity += threshold;
}
return newCapacity;
}
// 64 <= newCapacity is a power of 2 <= threshold
final int newCapacity = MathUtil.findNextPositivePowerOfTwo(Math.max(minNewCapacity, 64));
return Math.min(newCapacity, maxCapacity);
}
}