Class BigIntArray

server/src/main/java/org/elasticsearch/common/util/BigIntArray.java:33–118

Int array abstraction able to support more than 2B values. This implementation slices data into fixed-sized blocks of configurable length.

 * configurable length.
 */
final class BigIntArray extends AbstractBigArray implements IntArray {

    private static final BigIntArray ESTIMATOR = new BigIntArray(0, BigArrays.NON_RECYCLING_INSTANCE, false);

    private int[][] pages;

    /** Constructor. */
    BigIntArray(long size, BigArrays bigArrays, boolean clearOnResize) {
        super(INT_PAGE_SIZE, bigArrays, clearOnResize);
        this.size = size;
        pages = new int[numPages(size)][];
        for (int i = 0; i < pages.length; ++i) {
            pages[i] = newIntPage(i);
        }
    }

    @Override
    public int get(long index) {
        final int pageIndex = pageIndex(index);
        final int indexInPage = indexInPage(index);
        return pages[pageIndex][indexInPage];
    }

    @Override
    public int set(long index, int value) {
        final int pageIndex = pageIndex(index);
        final int indexInPage = indexInPage(index);
        final int[] page = pages[pageIndex];
        final int ret = page[indexInPage];
        page[indexInPage] = value;
        return ret;
    }

    @Override
    public int increment(long index, int inc) {
        final int pageIndex = pageIndex(index);
        final int indexInPage = indexInPage(index);
        return pages[pageIndex][indexInPage] += inc;
    }

    @Override
    public void fill(long fromIndex, long toIndex, int value) {
        if (fromIndex > toIndex) {
            throw new IllegalArgumentException();
        }
        final int fromPage = pageIndex(fromIndex);
        final int toPage = pageIndex(toIndex - 1);
        if (fromPage == toPage) {
            Arrays.fill(pages[fromPage], indexInPage(fromIndex), indexInPage(toIndex - 1) + 1, value);
        } else {
            Arrays.fill(pages[fromPage], indexInPage(fromIndex), pages[fromPage].length, value);
            for (int i = fromPage + 1; i < toPage; ++i) {
                Arrays.fill(pages[i], value);
            }
            Arrays.fill(pages[toPage], 0, indexInPage(toIndex - 1) + 1, value);
        }
    }