org.apache.inlong.sort.filesystem.shaded.software.amazon.ion.impl.bin.PooledBlockAllocatorProvider Maven / Gradle / Ivy
/*
* Copyright 2015-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at:
*
* http://aws.amazon.com/apache2.0/
*
* or in the "license" file accompanying this file. This file 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 software.amazon.ion.impl.bin;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.ConcurrentMap;
/**
* A simple pooling implementation of {@link BlockAllocatorProvider} with a global thread-safe free block list
* for each block size.
*
* This implementation is thread-safe.
*/
/*package*/ final class PooledBlockAllocatorProvider extends BlockAllocatorProvider
{
/**
* A {@link BlockAllocator} of for a particular size that has a single thread-safe free list.
*
* This implementation is thread-safe.
*/
private final class PooledBlockAllocator extends BlockAllocator
{
private final int blockSize;
private final ConcurrentLinkedQueue freeBlocks;
public PooledBlockAllocator(final int blockSize)
{
this.blockSize = blockSize;
this.freeBlocks = new ConcurrentLinkedQueue();
}
@Override
public Block allocateBlock()
{
Block block = freeBlocks.poll();
if (block == null)
{
block = new Block(new byte[blockSize])
{
@Override
public void close()
{
reset();
freeBlocks.add(this);
}
};
}
return block;
}
@Override
public int getBlockSize()
{
return blockSize;
}
@Override
public void close() {}
}
private final ConcurrentMap allocators;
public PooledBlockAllocatorProvider()
{
allocators = new ConcurrentHashMap();
}
@Override
public BlockAllocator vendAllocator(final int blockSize)
{
if (blockSize <= 0)
{
throw new IllegalArgumentException("Invalid block size: " + blockSize);
}
BlockAllocator allocator = allocators.get(blockSize);
if (allocator == null)
{
allocator = new PooledBlockAllocator(blockSize);
final BlockAllocator existingAllocator = allocators.putIfAbsent(blockSize, allocator);
if (existingAllocator != null)
{
allocator = existingAllocator;
}
}
return allocator;
}
}