com.signalfx.shaded.jetty.io.ArrayByteBufferPool Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995-2022 Mort Bay Consulting Pty Ltd and others.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
//
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
//
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
//
package com.signalfx.shaded.jetty.io;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;
import com.signalfx.shaded.jetty.util.BufferUtil;
import com.signalfx.shaded.jetty.util.annotation.ManagedAttribute;
import com.signalfx.shaded.jetty.util.annotation.ManagedObject;
import com.signalfx.shaded.jetty.util.component.Dumpable;
import com.signalfx.shaded.jetty.util.component.DumpableCollection;
import com.signalfx.shaded.jetty.util.log.Log;
import com.signalfx.shaded.jetty.util.log.Logger;
/**
* A ByteBuffer pool where ByteBuffers are held in queues that are held in array elements.
* Given a capacity {@code factor} of 1024, the first array element holds a queue of ByteBuffers
* each of capacity 1024, the second array element holds a queue of ByteBuffers each of capacity
* 2048, and so on.
*/
@ManagedObject
public class ArrayByteBufferPool extends AbstractByteBufferPool implements Dumpable
{
private static final Logger LOG = Log.getLogger(ArrayByteBufferPool.class);
private final int _maxCapacity;
private final int _minCapacity;
private final ByteBufferPool.Bucket[] _direct;
private final ByteBufferPool.Bucket[] _indirect;
private boolean _detailedDump = false;
/**
* Creates a new ArrayByteBufferPool with a default configuration.
*/
public ArrayByteBufferPool()
{
this(-1, -1, -1);
}
/**
* Creates a new ArrayByteBufferPool with the given configuration.
*
* @param minCapacity the minimum ByteBuffer capacity
* @param factor the capacity factor
* @param maxCapacity the maximum ByteBuffer capacity
*/
public ArrayByteBufferPool(int minCapacity, int factor, int maxCapacity)
{
this(minCapacity, factor, maxCapacity, -1, 0, 0);
}
/**
* Creates a new ArrayByteBufferPool with the given configuration.
*
* @param minCapacity the minimum ByteBuffer capacity
* @param factor the capacity factor
* @param maxCapacity the maximum ByteBuffer capacity
* @param maxQueueLength the maximum ByteBuffer queue length
*/
public ArrayByteBufferPool(int minCapacity, int factor, int maxCapacity, int maxQueueLength)
{
this(minCapacity, factor, maxCapacity, maxQueueLength, 0, 0);
}
/**
* Creates a new ArrayByteBufferPool with the given configuration.
*
* @param minCapacity the minimum ByteBuffer capacity
* @param factor the capacity factor
* @param maxCapacity the maximum ByteBuffer capacity
* @param maxQueueLength the maximum ByteBuffer queue length
* @param maxHeapMemory the max heap memory in bytes, -1 for unlimited memory or 0 to use default heuristic.
* @param maxDirectMemory the max direct memory in bytes, -1 for unlimited memory or 0 to use default heuristic.
*/
public ArrayByteBufferPool(int minCapacity, int factor, int maxCapacity, int maxQueueLength, long maxHeapMemory, long maxDirectMemory)
{
super(factor, maxQueueLength, maxHeapMemory, maxDirectMemory);
factor = getCapacityFactor();
if (minCapacity <= 0)
minCapacity = 0;
if (maxCapacity <= 0)
maxCapacity = 64 * 1024;
if ((maxCapacity % factor) != 0 || factor >= maxCapacity)
throw new IllegalArgumentException("The capacity factor must be a divisor of maxCapacity");
_maxCapacity = maxCapacity;
_minCapacity = minCapacity;
// Initialize all buckets in constructor and never modify the array again.
int length = bucketFor(maxCapacity) + 1;
_direct = new ByteBufferPool.Bucket[length];
_indirect = new ByteBufferPool.Bucket[length];
for (int i = 0; i < length; i++)
{
_direct[i] = newBucket(i, true);
_indirect[i] = newBucket(i, false);
}
}
@Override
public ByteBuffer acquire(int size, boolean direct)
{
int capacity = size < _minCapacity ? size : capacityFor(bucketFor(size));
ByteBufferPool.Bucket bucket = bucketFor(size, direct);
if (bucket == null)
return newByteBuffer(capacity, direct);
ByteBuffer buffer = bucket.acquire();
if (buffer == null)
return newByteBuffer(capacity, direct);
return buffer;
}
@Override
public void release(ByteBuffer buffer)
{
if (buffer == null)
return;
int capacity = buffer.capacity();
// Validate that this buffer is from this pool.
if (capacity != capacityFor(bucketFor(capacity)))
{
if (LOG.isDebugEnabled())
LOG.debug("ByteBuffer {} does not belong to this pool, discarding it", BufferUtil.toDetailString(buffer));
return;
}
// Don't release into the pool if greater than the maximum ByteBuffer capacity.
if (capacity > _maxCapacity)
return;
boolean direct = buffer.isDirect();
ByteBufferPool.Bucket bucket = bucketFor(capacity, direct);
if (bucket != null)
{
bucket.release(buffer);
releaseExcessMemory(direct, this::releaseMemory);
}
}
private Bucket newBucket(int key, boolean direct)
{
return new Bucket(this, capacityFor(key), getMaxQueueLength(), updateMemory(direct));
}
@Override
public void clear()
{
super.clear();
for (int i = 0; i < _direct.length; ++i)
{
_direct[i].clear();
_indirect[i].clear();
}
}
protected void releaseMemory(boolean direct)
{
long oldest = Long.MAX_VALUE;
int index = -1;
Bucket[] buckets = bucketsFor(direct);
for (int i = 0; i < buckets.length; ++i)
{
Bucket bucket = buckets[i];
if (bucket.isEmpty())
continue;
long lastUpdate = bucket.getLastUpdate();
if (lastUpdate < oldest)
{
oldest = lastUpdate;
index = i;
}
}
if (index >= 0)
{
Bucket bucket = buckets[index];
bucket.clear();
}
}
protected int bucketFor(int capacity)
{
return (int)Math.ceil((double)capacity / getCapacityFactor());
}
protected int capacityFor(int bucket)
{
return bucket * getCapacityFactor();
}
private ByteBufferPool.Bucket bucketFor(int capacity, boolean direct)
{
if (capacity < _minCapacity)
return null;
int bucket = bucketFor(capacity);
if (bucket >= _direct.length)
return null;
Bucket[] buckets = bucketsFor(direct);
return buckets[bucket];
}
@ManagedAttribute("The number of pooled direct ByteBuffers")
public long getDirectByteBufferCount()
{
return getByteBufferCount(true);
}
@ManagedAttribute("The number of pooled heap ByteBuffers")
public long getHeapByteBufferCount()
{
return getByteBufferCount(false);
}
private long getByteBufferCount(boolean direct)
{
return Arrays.stream(bucketsFor(direct))
.filter(Objects::nonNull)
.mapToLong(Bucket::size)
.sum();
}
// Package local for testing
ByteBufferPool.Bucket[] bucketsFor(boolean direct)
{
return direct ? _direct : _indirect;
}
public boolean isDetailedDump()
{
return _detailedDump;
}
public void setDetailedDump(boolean detailedDump)
{
_detailedDump = detailedDump;
}
@Override
public void dump(Appendable out, String indent) throws IOException
{
List