/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package com.sun.xml.internal.stream.util;

import java.lang.ref.*;

This is a Singleton class that allows you to allocate buffer that
are stored in ThreadLocal. This class stores 3 types of char
buffers - small (< 128 bytes), medium (<2K) and large (> 2K) as
well as three byte buffers - small, medium and large.
The local storage is activated on the return of the buffer.
The buffer returns null if it is already allocated.
Author:
Binu.John@sun.com, Santiago.PericasGeertsen@sun.com/**
 * This is a Singleton class that allows you to allocate buffer that
 * are stored in ThreadLocal. This class stores 3 types of char
 * buffers - small (< 128 bytes), medium (<2K) and large (> 2K) as
 * well as three byte buffers - small, medium and large.
 * The local storage is activated on the return of the buffer.
 * The buffer returns null if it is already allocated.
 *
 * @author Binu.John@sun.com
 * @author Santiago.PericasGeertsen@sun.com
 */
public class ThreadLocalBufferAllocator {
   private static ThreadLocal<SoftReference> tlba = new ThreadLocal<>();

   public static BufferAllocator getBufferAllocator() {
        SoftReference<BufferAllocator> bAllocatorRef = tlba.get();
        if (bAllocatorRef == null || bAllocatorRef.get() == null) {
            bAllocatorRef = new SoftReference(new BufferAllocator());
            tlba.set(bAllocatorRef);
        }

        return bAllocatorRef.get();
   }
}