2 // ========================================================================
3 // Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
4 // ------------------------------------------------------------------------
5 // All rights reserved. This program and the accompanying materials
6 // are made available under the terms of the Eclipse Public License v1.0
7 // and Apache License v2.0 which accompanies this distribution.
9 // The Eclipse Public License is available at
10 // http://www.eclipse.org/legal/epl-v10.html
12 // The Apache License v2.0 is available at
13 // http://www.opensource.org/licenses/apache2.0.php
15 // You may elect to redistribute this code under either of these licenses.
16 // ========================================================================
19 package org.eclipse.jetty.io;
21 import java.nio.ByteBuffer;
22 import java.util.Queue;
23 import java.util.concurrent.ConcurrentHashMap;
24 import java.util.concurrent.ConcurrentLinkedQueue;
25 import java.util.concurrent.ConcurrentMap;
27 import org.eclipse.jetty.util.BufferUtil;
29 public class MappedByteBufferPool implements ByteBufferPool
31 private final ConcurrentMap<Integer, Queue<ByteBuffer>> directBuffers = new ConcurrentHashMap<>();
32 private final ConcurrentMap<Integer, Queue<ByteBuffer>> heapBuffers = new ConcurrentHashMap<>();
33 private final int factor;
35 public MappedByteBufferPool()
40 public MappedByteBufferPool(int factor)
46 public ByteBuffer acquire(int size, boolean direct)
48 int bucket = bucketFor(size);
49 ConcurrentMap<Integer, Queue<ByteBuffer>> buffers = buffersFor(direct);
51 ByteBuffer result = null;
52 Queue<ByteBuffer> byteBuffers = buffers.get(bucket);
53 if (byteBuffers != null)
54 result = byteBuffers.poll();
58 int capacity = bucket * factor;
59 result = direct ? BufferUtil.allocateDirect(capacity) : BufferUtil.allocate(capacity);
62 BufferUtil.clear(result);
67 public void release(ByteBuffer buffer)
70 return; // nothing to do
72 // validate that this buffer is from this pool
73 assert((buffer.capacity() % factor) == 0);
75 int bucket = bucketFor(buffer.capacity());
76 ConcurrentMap<Integer, Queue<ByteBuffer>> buffers = buffersFor(buffer.isDirect());
78 // Avoid to create a new queue every time, just to be discarded immediately
79 Queue<ByteBuffer> byteBuffers = buffers.get(bucket);
80 if (byteBuffers == null)
82 byteBuffers = new ConcurrentLinkedQueue<>();
83 Queue<ByteBuffer> existing = buffers.putIfAbsent(bucket, byteBuffers);
85 byteBuffers = existing;
88 BufferUtil.clear(buffer);
89 byteBuffers.offer(buffer);
94 directBuffers.clear();
98 private int bucketFor(int size)
100 int bucket = size / factor;
101 if (size % factor > 0)
106 // Package local for testing
107 ConcurrentMap<Integer, Queue<ByteBuffer>> buffersFor(boolean direct)
109 return direct ? directBuffers : heapBuffers;