| // |
| // ======================================================================== |
| // Copyright (c) 1995-2017 Mort Bay Consulting Pty. Ltd. |
| // ------------------------------------------------------------------------ |
| // 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 org.eclipse.jetty.io; |
| |
| import java.nio.ByteBuffer; |
| import java.util.Queue; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentLinkedQueue; |
| import java.util.concurrent.ConcurrentMap; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| import org.eclipse.jetty.util.BufferUtil; |
| |
| public class MappedByteBufferPool implements ByteBufferPool |
| { |
| private final ConcurrentMap<Integer, Queue<ByteBuffer>> directBuffers = new ConcurrentHashMap<>(); |
| private final ConcurrentMap<Integer, Queue<ByteBuffer>> heapBuffers = new ConcurrentHashMap<>(); |
| private final int factor; |
| |
| public MappedByteBufferPool() |
| { |
| this(1024); |
| } |
| |
| public MappedByteBufferPool(int factor) |
| { |
| this.factor = factor; |
| } |
| |
| @Override |
| public ByteBuffer acquire(int size, boolean direct) |
| { |
| int bucket = bucketFor(size); |
| ConcurrentMap<Integer, Queue<ByteBuffer>> buffers = buffersFor(direct); |
| |
| ByteBuffer result = null; |
| Queue<ByteBuffer> byteBuffers = buffers.get(bucket); |
| if (byteBuffers != null) |
| result = byteBuffers.poll(); |
| |
| if (result == null) |
| { |
| int capacity = bucket * factor; |
| result = newByteBuffer(capacity, direct); |
| } |
| |
| BufferUtil.clear(result); |
| return result; |
| } |
| |
| protected ByteBuffer newByteBuffer(int capacity, boolean direct) |
| { |
| return direct ? BufferUtil.allocateDirect(capacity) |
| : BufferUtil.allocate(capacity); |
| } |
| |
| @Override |
| public void release(ByteBuffer buffer) |
| { |
| if (buffer == null) |
| return; // nothing to do |
| |
| // validate that this buffer is from this pool |
| assert((buffer.capacity() % factor) == 0); |
| |
| int bucket = bucketFor(buffer.capacity()); |
| ConcurrentMap<Integer, Queue<ByteBuffer>> buffers = buffersFor(buffer.isDirect()); |
| |
| // Avoid to create a new queue every time, just to be discarded immediately |
| Queue<ByteBuffer> byteBuffers = buffers.get(bucket); |
| if (byteBuffers == null) |
| { |
| byteBuffers = new ConcurrentLinkedQueue<>(); |
| Queue<ByteBuffer> existing = buffers.putIfAbsent(bucket, byteBuffers); |
| if (existing != null) |
| byteBuffers = existing; |
| } |
| |
| BufferUtil.clear(buffer); |
| byteBuffers.offer(buffer); |
| } |
| |
| public void clear() |
| { |
| directBuffers.clear(); |
| heapBuffers.clear(); |
| } |
| |
| private int bucketFor(int size) |
| { |
| int bucket = size / factor; |
| if (size % factor > 0) |
| ++bucket; |
| return bucket; |
| } |
| |
| // Package local for testing |
| ConcurrentMap<Integer, Queue<ByteBuffer>> buffersFor(boolean direct) |
| { |
| return direct ? directBuffers : heapBuffers; |
| } |
| |
| public static class Tagged extends MappedByteBufferPool |
| { |
| private final AtomicInteger tag = new AtomicInteger(); |
| |
| @Override |
| protected ByteBuffer newByteBuffer(int capacity, boolean direct) |
| { |
| ByteBuffer buffer = super.newByteBuffer(capacity + 4, direct); |
| buffer.limit(buffer.capacity()); |
| buffer.putInt(tag.incrementAndGet()); |
| ByteBuffer slice = buffer.slice(); |
| BufferUtil.clear(slice); |
| return slice; |
| } |
| } |
| } |