com.sun.webkit.network.ByteBufferPool Maven / Gradle / Ivy
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* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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package com.sun.webkit.network;
import java.nio.ByteBuffer;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.Semaphore;
/**
* A pool of byte buffers that can be shared by multiple concurrent
* clients.
*/
final class ByteBufferPool {
/**
* The shared collection of byte buffers.
*/
private final Queue byteBuffers =
new ConcurrentLinkedQueue();
/**
* The size of each byte buffer.
*/
private final int bufferSize;
/**
* Creates a new pool.
*/
private ByteBufferPool(int bufferSize) {
this.bufferSize = bufferSize;
}
/**
* Creates a new pool.
*/
static ByteBufferPool newInstance(int bufferSize) {
return new ByteBufferPool(bufferSize);
}
/**
* Creates a new allocator associated with this pool.
* The allocator will allow its client to allocate and release
* buffers and will ensure that there are no more than
* {@code maxBufferCount} buffers allocated through this allocator
* at any given time moment.
*/
ByteBufferAllocator newAllocator(int maxBufferCount) {
return new ByteBufferAllocatorImpl(maxBufferCount);
}
/**
* The allocator implementation.
*/
private final class ByteBufferAllocatorImpl implements ByteBufferAllocator {
/**
* The semaphore used to limit the number of buffers
* allocated through this allocator.
*/
private final Semaphore semaphore;
/**
* Creates a new allocator.
*/
private ByteBufferAllocatorImpl(int maxBufferCount) {
semaphore = new Semaphore(maxBufferCount);
}
/**
* {@inheritDoc}
*/
@Override
public ByteBuffer allocate() throws InterruptedException {
semaphore.acquire();
ByteBuffer byteBuffer = byteBuffers.poll();
if (byteBuffer == null) {
byteBuffer = ByteBuffer.allocateDirect(bufferSize);
}
return byteBuffer;
}
/**
* {@inheritDoc}
*/
@Override
public void release(ByteBuffer byteBuffer) {
byteBuffers.add(byteBuffer);
semaphore.release();
}
}
}
/**
* An object that can allocate and release byte buffers.
*/
interface ByteBufferAllocator {
/**
* Allocates a byte buffer.
*/
ByteBuffer allocate() throws InterruptedException;
/**
* Releases a byte buffer.
*/
void release(ByteBuffer byteBuffer);
}