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/*
* Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* 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.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.sun.xml.internal.stream.util;
import java.lang.ref.*;
/**
* Buffer allocator for buffers of sizes 128 B, 2 KB and 8 KB. Includes
* methods for allocating and freeing buffers.
*
* @author Binu.John@sun.com
* @author Santiago.PericasGeertsen@sun.com
*/
public class BufferAllocator {
public static int SMALL_SIZE_LIMIT = 128;
public static int MEDIUM_SIZE_LIMIT = 2048;
public static int LARGE_SIZE_LIMIT = 8192;
char[] smallCharBuffer;
char[] mediumCharBuffer;
char[] largeCharBuffer;
byte[] smallByteBuffer;
byte[] mediumByteBuffer;
byte[] largeByteBuffer;
public BufferAllocator() {
}
public char[] getCharBuffer(int size) {
if (size <= SMALL_SIZE_LIMIT) {
char[] buffer = smallCharBuffer;
smallCharBuffer = null;
return buffer;
}
else if (size <= MEDIUM_SIZE_LIMIT) {
char[] buffer = mediumCharBuffer;
mediumCharBuffer = null;
return buffer;
}
else if (size <= LARGE_SIZE_LIMIT) {
char[] buffer = largeCharBuffer;
largeCharBuffer = null;
return buffer;
}
return null;
}
public void returnCharBuffer(char[] c) {
if (c == null) {
return;
}
if (c.length <= SMALL_SIZE_LIMIT) {
smallCharBuffer = c;
}
else if (c.length <= MEDIUM_SIZE_LIMIT) {
mediumCharBuffer = c;
}
else if (c.length <= LARGE_SIZE_LIMIT) {
largeCharBuffer = c;
}
}
public byte[] getByteBuffer(int size) {
if (size <= SMALL_SIZE_LIMIT) {
byte[] buffer = smallByteBuffer;
smallByteBuffer = null;
return buffer;
}
else if (size <= MEDIUM_SIZE_LIMIT) {
byte[] buffer = mediumByteBuffer;
mediumByteBuffer = null;
return buffer;
}
else if (size <= LARGE_SIZE_LIMIT) {
byte[] buffer = largeByteBuffer;
largeByteBuffer = null;
return buffer;
}
return null;
}
public void returnByteBuffer(byte[] b) {
if (b == null) {
return;
}
if (b.length <= SMALL_SIZE_LIMIT) {
smallByteBuffer = b;
}
else if (b.length <= MEDIUM_SIZE_LIMIT) {
mediumByteBuffer = b;
}
else if (b.length <= LARGE_SIZE_LIMIT) {
largeByteBuffer = b;
}
}
}
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