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Elasticsearch subproject :server
/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.common.util;
import org.apache.lucene.util.ArrayUtil;
import org.apache.lucene.util.RamUsageEstimator;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.VarHandle;
import java.nio.ByteOrder;
import java.util.Arrays;
import static org.elasticsearch.common.util.PageCacheRecycler.LONG_PAGE_SIZE;
/**
* Long array abstraction able to support more than 2B values. This implementation slices data into fixed-sized blocks of
* configurable length.
*/
final class BigLongArray extends AbstractBigArray implements LongArray {
private static final BigLongArray ESTIMATOR = new BigLongArray(0, BigArrays.NON_RECYCLING_INSTANCE, false);
static final VarHandle VH_PLATFORM_NATIVE_LONG = MethodHandles.byteArrayViewVarHandle(long[].class, ByteOrder.nativeOrder());
private byte[][] pages;
/** Constructor. */
BigLongArray(long size, BigArrays bigArrays, boolean clearOnResize) {
super(LONG_PAGE_SIZE, bigArrays, clearOnResize);
this.size = size;
pages = new byte[numPages(size)][];
for (int i = 0; i < pages.length; ++i) {
pages[i] = newBytePage(i);
}
}
@Override
public long get(long index) {
final int pageIndex = pageIndex(index);
final int indexInPage = indexInPage(index);
return (long) VH_PLATFORM_NATIVE_LONG.get(pages[pageIndex], indexInPage << 3);
}
@Override
public long set(long index, long value) {
final int pageIndex = pageIndex(index);
final int indexInPage = indexInPage(index);
final byte[] page = pages[pageIndex];
final long ret = (long) VH_PLATFORM_NATIVE_LONG.get(page, indexInPage << 3);
VH_PLATFORM_NATIVE_LONG.set(page, indexInPage << 3, value);
return ret;
}
@Override
public long increment(long index, long inc) {
final int pageIndex = pageIndex(index);
final int indexInPage = indexInPage(index);
final byte[] page = pages[pageIndex];
final long newVal = (long) VH_PLATFORM_NATIVE_LONG.get(page, indexInPage << 3) + inc;
VH_PLATFORM_NATIVE_LONG.set(page, indexInPage << 3, newVal);
return newVal;
}
@Override
protected int numBytesPerElement() {
return Long.BYTES;
}
/** Change the size of this array. Content between indexes 0
and min(size(), newSize)
will be preserved. */
@Override
public void resize(long newSize) {
final int numPages = numPages(newSize);
if (numPages > pages.length) {
pages = Arrays.copyOf(pages, ArrayUtil.oversize(numPages, RamUsageEstimator.NUM_BYTES_OBJECT_REF));
}
for (int i = numPages - 1; i >= 0 && pages[i] == null; --i) {
pages[i] = newBytePage(i);
}
for (int i = numPages; i < pages.length && pages[i] != null; ++i) {
pages[i] = null;
releasePage(i);
}
this.size = newSize;
}
@Override
public void fill(long fromIndex, long toIndex, long value) {
if (fromIndex > toIndex) {
throw new IllegalArgumentException();
}
if (fromIndex == toIndex) {
return; // empty range
}
final int fromPage = pageIndex(fromIndex);
final int toPage = pageIndex(toIndex - 1);
if (fromPage == toPage) {
fill(pages[fromPage], indexInPage(fromIndex), indexInPage(toIndex - 1) + 1, value);
} else {
fill(pages[fromPage], indexInPage(fromIndex), pageSize(), value);
for (int i = fromPage + 1; i < toPage; ++i) {
fill(pages[i], 0, pageSize(), value);
}
fill(pages[toPage], 0, indexInPage(toIndex - 1) + 1, value);
}
}
public static void fill(byte[] page, int from, int to, long value) {
if (from < to) {
VH_PLATFORM_NATIVE_LONG.set(page, from << 3, value);
fillBySelfCopy(page, from << 3, to << 3, Long.BYTES);
}
}
/** Estimates the number of bytes that would be consumed by an array of the given size. */
public static long estimateRamBytes(final long size) {
return ESTIMATOR.ramBytesEstimated(size);
}
@Override
public void set(long index, byte[] buf, int offset, int len) {
set(index, buf, offset, len, pages, 3);
}
}