org.apache.lucene.util.packed.PagedGrowableWriter Maven / Gradle / Ivy
/*
* 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.
*/
package org.apache.lucene.util.packed;
import org.apache.lucene.util.packed.PackedInts.Mutable;
/**
* A {@link PagedGrowableWriter}. This class slices data into fixed-size blocks
* which have independent numbers of bits per value and grow on-demand.
* You should use this class instead of the {@link PackedLongValues} related ones only when
* you need random write-access. Otherwise this class will likely be slower and
* less memory-efficient.
* @lucene.internal
*/
public final class PagedGrowableWriter extends AbstractPagedMutable {
final float acceptableOverheadRatio;
/**
* Create a new {@link PagedGrowableWriter} instance.
*
* @param size the number of values to store.
* @param pageSize the number of values per page
* @param startBitsPerValue the initial number of bits per value
* @param acceptableOverheadRatio an acceptable overhead ratio
*/
public PagedGrowableWriter(long size, int pageSize,
int startBitsPerValue, float acceptableOverheadRatio) {
this(size, pageSize, startBitsPerValue, acceptableOverheadRatio, true);
}
PagedGrowableWriter(long size, int pageSize,int startBitsPerValue, float acceptableOverheadRatio, boolean fillPages) {
super(startBitsPerValue, size, pageSize);
this.acceptableOverheadRatio = acceptableOverheadRatio;
if (fillPages) {
fillPages();
}
}
@Override
protected Mutable newMutable(int valueCount, int bitsPerValue) {
return new GrowableWriter(bitsPerValue, valueCount, acceptableOverheadRatio);
}
@Override
protected PagedGrowableWriter newUnfilledCopy(long newSize) {
return new PagedGrowableWriter(newSize, pageSize(), bitsPerValue, acceptableOverheadRatio, false);
}
@Override
protected long baseRamBytesUsed() {
return super.baseRamBytesUsed() + Float.BYTES;
}
}