com.signalfx.shaded.jetty.io.ByteBufferPool 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.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import java.util.function.IntConsumer;
import com.signalfx.shaded.jetty.util.BufferUtil;
/**
* A {@link ByteBuffer} pool.
* Acquired buffers may be {@link #release(ByteBuffer) released} but they do not need to;
* if they are released, they may be recycled and reused, otherwise they will be garbage
* collected as usual.
*/
public interface ByteBufferPool
{
/**
* Requests a {@link ByteBuffer} of the given size.
* The returned buffer may have a bigger capacity than the size being
* requested but it will have the limit set to the given size.
*
* @param size the size of the buffer
* @param direct whether the buffer must be direct or not
* @return the requested buffer
* @see #release(ByteBuffer)
*/
ByteBuffer acquire(int size, boolean direct);
/**
* Returns a {@link ByteBuffer}, usually obtained with {@link #acquire(int, boolean)}
* (but not necessarily), making it available for recycling and reuse.
*
* @param buffer the buffer to return
* @see #acquire(int, boolean)
*/
void release(ByteBuffer buffer);
/**
* Removes a {@link ByteBuffer} that was previously obtained with {@link #acquire(int, boolean)}.
* The buffer will not be available for further reuse.
*
* @param buffer the buffer to remove
* @see #acquire(int, boolean)
* @see #release(ByteBuffer)
*/
default void remove(ByteBuffer buffer)
{
}
/**
* Creates a new ByteBuffer of the given capacity and the given directness.
*
* @param capacity the ByteBuffer capacity
* @param direct the ByteBuffer directness
* @return a newly allocated ByteBuffer
*/
default ByteBuffer newByteBuffer(int capacity, boolean direct)
{
return direct ? BufferUtil.allocateDirect(capacity) : BufferUtil.allocate(capacity);
}
class Lease
{
private final ByteBufferPool byteBufferPool;
private final List buffers;
private final List recycles;
public Lease(ByteBufferPool byteBufferPool)
{
this.byteBufferPool = byteBufferPool;
this.buffers = new ArrayList<>();
this.recycles = new ArrayList<>();
}
public ByteBuffer acquire(int capacity, boolean direct)
{
ByteBuffer buffer = byteBufferPool.acquire(capacity, direct);
BufferUtil.clearToFill(buffer);
return buffer;
}
public void append(ByteBuffer buffer, boolean recycle)
{
buffers.add(buffer);
recycles.add(recycle);
}
public void insert(int index, ByteBuffer buffer, boolean recycle)
{
buffers.add(index, buffer);
recycles.add(index, recycle);
}
public List getByteBuffers()
{
return buffers;
}
public long getTotalLength()
{
long length = 0;
for (ByteBuffer buffer : buffers)
{
length += buffer.remaining();
}
return length;
}
public int getSize()
{
return buffers.size();
}
public void recycle()
{
for (int i = 0; i < buffers.size(); ++i)
{
ByteBuffer buffer = buffers.get(i);
if (recycles.get(i))
release(buffer);
}
buffers.clear();
recycles.clear();
}
public void release(ByteBuffer buffer)
{
byteBufferPool.release(buffer);
}
}
class Bucket
{
private final Queue _queue = new ConcurrentLinkedQueue<>();
private final ByteBufferPool _pool;
private final int _capacity;
private final int _maxSize;
private final AtomicInteger _size;
private final AtomicLong _lastUpdate = new AtomicLong(System.nanoTime());
private final IntConsumer _memoryFunction;
@Deprecated
public Bucket(ByteBufferPool pool, int capacity, int maxSize)
{
this(pool, capacity, maxSize, i -> {});
}
public Bucket(ByteBufferPool pool, int capacity, int maxSize, IntConsumer memoryFunction)
{
_pool = pool;
_capacity = capacity;
_maxSize = maxSize;
_size = maxSize > 0 ? new AtomicInteger() : null;
_memoryFunction = Objects.requireNonNull(memoryFunction);
}
public ByteBuffer acquire()
{
ByteBuffer buffer = _queue.poll();
if (buffer != null)
{
if (_size != null)
_size.decrementAndGet();
_memoryFunction.accept(-buffer.capacity());
}
return buffer;
}
/**
* @param direct whether to create a direct buffer when none is available
* @return a ByteBuffer
* @deprecated use {@link #acquire()} instead
*/
@Deprecated
public ByteBuffer acquire(boolean direct)
{
ByteBuffer buffer = acquire();
if (buffer == null)
return _pool.newByteBuffer(_capacity, direct);
return buffer;
}
public void release(ByteBuffer buffer)
{
resetUpdateTime();
BufferUtil.reset(buffer);
if (_size == null || _size.incrementAndGet() <= _maxSize)
{
_queue.offer(buffer);
_memoryFunction.accept(buffer.capacity());
}
else
{
_size.decrementAndGet();
}
}
void resetUpdateTime()
{
_lastUpdate.lazySet(System.nanoTime());
}
public void clear()
{
int size = _size == null ? 0 : _size.get() - 1;
while (size >= 0)
{
ByteBuffer buffer = acquire();
if (buffer == null)
break;
if (_size != null)
--size;
}
}
boolean isEmpty()
{
return _queue.isEmpty();
}
int size()
{
return _queue.size();
}
long getLastUpdate()
{
return _lastUpdate.get();
}
@Override
public String toString()
{
return String.format("%s@%x{capacity=%d, size=%d, maxSize=%d}", getClass().getSimpleName(), hashCode(), _capacity, size(), _maxSize);
}
}
}