io.netty.util.internal.shaded.org.jctools.queues.MpscGrowableArrayQueue Maven / Gradle / Ivy
/*
* Licensed 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.
*/
package io.netty.util.internal.shaded.org.jctools.queues;
import io.netty.util.internal.shaded.org.jctools.util.Pow2;
import io.netty.util.internal.shaded.org.jctools.util.RangeUtil;
import static io.netty.util.internal.shaded.org.jctools.queues.LinkedArrayQueueUtil.length;
/**
* An MPSC array queue which starts at initialCapacity and grows to maxCapacity in linked chunks
* of the initial size. The queue grows only when the current buffer is full and elements are not copied on
* resize, instead a link to the new buffer is stored in the old buffer for the consumer to follow.
*
* @param
*/
public class MpscGrowableArrayQueue extends MpscChunkedArrayQueue
{
public MpscGrowableArrayQueue(int maxCapacity)
{
super(Math.max(2, Pow2.roundToPowerOfTwo(maxCapacity / 8)), maxCapacity);
}
/**
* @param initialCapacity the queue initial capacity. If chunk size is fixed this will be the chunk size.
* Must be 2 or more.
* @param maxCapacity the maximum capacity will be rounded up to the closest power of 2 and will be the
* upper limit of number of elements in this queue. Must be 4 or more and round up to a larger
* power of 2 than initialCapacity.
*/
public MpscGrowableArrayQueue(int initialCapacity, int maxCapacity)
{
super(initialCapacity, maxCapacity);
}
@Override
protected int getNextBufferSize(E[] buffer)
{
final long maxSize = maxQueueCapacity / 2;
RangeUtil.checkLessThanOrEqual(length(buffer), maxSize, "buffer.length");
final int newSize = 2 * (length(buffer) - 1);
return newSize + 1;
}
@Override
protected long getCurrentBufferCapacity(long mask)
{
return (mask + 2 == maxQueueCapacity) ? maxQueueCapacity : mask;
}
}