org.apache.lucene.store.bytebuffer.CachingByteBufferAllocator Maven / Gradle / Ivy
package org.apache.lucene.store.bytebuffer;
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* 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.
*/
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
/**
* The caching byte buffer allocator allows to define a global size for both the small and large buffers
* allocated. Those will be reused when possible.
*/
public class CachingByteBufferAllocator extends PlainByteBufferAllocator {
private final BlockingQueue smallCache;
private final BlockingQueue largeCache;
/**
* @param direct If set to true, will allocate direct buffers (off heap).
* @param smallBufferSizeInBytes The size (in bytes) of the small buffer allocation.
* @param largeBufferSizeInBytes The size (in bytes) of the large buffer allocation.
* @param smallCacheSizeInBytes The size of the small cache buffer in bytes.
* @param largeCacheSizeInBytes The size of the large cache buffer in bytes.
*/
public CachingByteBufferAllocator(boolean direct, int smallBufferSizeInBytes, int largeBufferSizeInBytes,
int smallCacheSizeInBytes, int largeCacheSizeInBytes) {
super(direct, smallBufferSizeInBytes, largeBufferSizeInBytes);
this.smallCache = new LinkedBlockingQueue(smallCacheSizeInBytes / smallBufferSizeInBytes);
this.largeCache = new LinkedBlockingQueue(largeCacheSizeInBytes / largeBufferSizeInBytes);
}
public ByteBuffer allocate(Type type) throws IOException {
ByteBuffer buffer = type == Type.SMALL ? smallCache.poll() : largeCache.poll();
if (buffer == null) {
buffer = super.allocate(type);
}
return buffer;
}
public void release(ByteBuffer buffer) {
if (buffer.capacity() == smallBufferSizeInBytes) {
boolean success = smallCache.offer(buffer);
if (!success) {
super.release(buffer);
}
} else if (buffer.capacity() == largeBufferSizeInBytes) {
boolean success = largeCache.offer(buffer);
if (!success) {
super.release(buffer);
}
}
// otherwise, just ignore it? not our allocation...
}
public void close() {
for (ByteBuffer buffer : smallCache) {
super.release(buffer);
}
smallCache.clear();
for (ByteBuffer buffer : largeCache) {
super.release(buffer);
}
largeCache.clear();
}
}