Importing upstream Jetty jetty-9.2.1.v20140609

[gigi.git] / lib / jetty / org / eclipse / jetty / io / ArrayByteBufferPool.java

diff --git a/lib/jetty/org/eclipse/jetty/io/ArrayByteBufferPool.java b/lib/jetty/org/eclipse/jetty/io/ArrayByteBufferPool.java
new file mode 100644 (file)
index 0000000..fa3a01d
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+++ b/lib/jetty/org/eclipse/jetty/io/ArrayByteBufferPool.java
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+//
+//  ========================================================================
+//  Copyright (c) 1995-2014 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.ConcurrentLinkedQueue;
+
+import org.eclipse.jetty.util.BufferUtil;
+
+public class ArrayByteBufferPool implements ByteBufferPool
+{
+    private final int _min;
+    private final Bucket[] _direct;
+    private final Bucket[] _indirect;
+    private final int _inc;
+
+    public ArrayByteBufferPool()
+    {
+        this(0,1024,64*1024);
+    }
+
+    public ArrayByteBufferPool(int minSize, int increment, int maxSize)
+    {
+        if (minSize>=increment)
+            throw new IllegalArgumentException("minSize >= increment");
+        if ((maxSize%increment)!=0 || increment>=maxSize)
+            throw new IllegalArgumentException("increment must be a divisor of maxSize");
+        _min=minSize;
+        _inc=increment;
+
+        _direct=new Bucket[maxSize/increment];
+        _indirect=new Bucket[maxSize/increment];
+
+        int size=0;
+        for (int i=0;i<_direct.length;i++)
+        {
+            size+=_inc;
+            _direct[i]=new Bucket(size);
+            _indirect[i]=new Bucket(size);
+        }
+    }
+
+    @Override
+    public ByteBuffer acquire(int size, boolean direct)
+    {
+        Bucket bucket = bucketFor(size,direct);
+        ByteBuffer buffer = bucket==null?null:bucket._queue.poll();
+
+        if (buffer == null)
+        {
+            int capacity = bucket==null?size:bucket._size;
+            buffer = direct ? BufferUtil.allocateDirect(capacity) : BufferUtil.allocate(capacity);
+        }
+
+        return buffer;
+    }
+
+    @Override
+    public void release(ByteBuffer buffer)
+    {
+        if (buffer!=null)
+        {    
+            Bucket bucket = bucketFor(buffer.capacity(),buffer.isDirect());
+            if (bucket!=null)
+            {
+                BufferUtil.clear(buffer);
+                bucket._queue.offer(buffer);
+            }
+        }
+    }
+
+    public void clear()
+    {
+        for (int i=0;i<_direct.length;i++)
+        {
+            _direct[i]._queue.clear();
+            _indirect[i]._queue.clear();
+        }
+    }
+
+    private Bucket bucketFor(int size,boolean direct)
+    {
+        if (size<=_min)
+            return null;
+        int b=(size-1)/_inc;
+        if (b>=_direct.length)
+            return null;
+        Bucket bucket = direct?_direct[b]:_indirect[b];
+                
+        return bucket;
+    }
+
+    public static class Bucket
+    {
+        public final int _size;
+        public final Queue<ByteBuffer> _queue= new ConcurrentLinkedQueue<>();
+
+        Bucket(int size)
+        {
+            _size=size;
+        }
+        
+        @Override
+        public String toString()
+        {
+            return String.format("Bucket@%x{%d,%d}",hashCode(),_size,_queue.size());
+        }
+    }
+    
+
+    // Package local for testing
+    Bucket[] bucketsFor(boolean direct)
+    {
+        return direct ? _direct : _indirect;
+    }
+}