/*
* Copyright 2015 Red Hat, Inc. and/or its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.eclipse.webdav.http.client;
import java.util.Vector;
import org.eclipse.webdav.internal.kernel.utils.Assert;
/**
* A <code>BufferPool</code> holds on to a collection of buffers (byte
* arrays) so they can be reused without having to allocate and release
* memory.
* <p>
* <b>Note:</b> This class/interface is part of an interim API that is still under
* development and expected to change significantly before reaching stability.
* It is being made available at this early stage to solicit feedback from pioneering
* adopters on the understanding that any code that uses this API will almost
* certainly be broken (repeatedly) as the API evolves.
* </p>
*/
public class BufferPool {
/**
* The size of each buffer in the pool.
*/
private static int BUFFER_SIZE = 8 * 1024;
/**
* The maximum number of buffers in the pool.
*/
private static int MAX_BUFFERS = 5;
/**
* The buffer pool.
*/
private Vector pool = new Vector(MAX_BUFFERS);
/**
* Returns a buffer (byte array) of size <code>BUFFER_SIZE</code> from the
* pool. When the buffer is no longer needed, it should be put back in the
* pool for future use by calling <code>putBuffer</code>.
*
* @return a buffer
* @see #putBuffer(byte[])
*/
public synchronized byte[] getBuffer() {
if (pool.isEmpty())
return new byte[BUFFER_SIZE];
byte[] buffer = (byte[]) pool.lastElement();
pool.removeElementAt(pool.size() - 1);
return buffer;
}
/**
* Puts the given buffer into the pool for future use. The size of the
* buffer must be <code>BUFFER_SIZE</code>.
*
* @param buffer the buffer to be put back into the buffer pool
* @see #getBuffer()
*/
public synchronized void putBuffer(byte[] buffer) {
Assert.isNotNull(buffer);
Assert.isTrue(buffer.length == BUFFER_SIZE);
if (pool.size() < MAX_BUFFERS)
pool.addElement(buffer);
}
}