io.deephaven.engine.table.impl.join.dupcompact.IntReverseDupCompactKernel Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of deephaven-engine-table Show documentation
Engine Table: Implementation and closely-coupled utilities
There is a newer version: 0.37.1
Show newest version
/**
 * Copyright (c) 2016-2022 Deephaven Data Labs and Patent Pending
 */
/*
 * ---------------------------------------------------------------------------------------------------------------------
 * AUTO-GENERATED CLASS - DO NOT EDIT MANUALLY - for any changes edit CharDupCompactKernel and regenerate
 * ---------------------------------------------------------------------------------------------------------------------
 */
package io.deephaven.engine.table.impl.join.dupcompact;

import io.deephaven.chunk.*;
import io.deephaven.chunk.attributes.Any;
import io.deephaven.chunk.attributes.ChunkPositions;
import io.deephaven.engine.rowset.chunkattributes.RowKeys;
import org.jetbrains.annotations.NotNull;

public class IntReverseDupCompactKernel implements DupCompactKernel {

    static final IntReverseDupCompactKernel INSTANCE = new IntReverseDupCompactKernel();

    private IntReverseDupCompactKernel() {
        // Use the singleton INSTANCE
    }

    @Override
    public int compactDuplicates(
            @NotNull final WritableChunk chunkToCompact,
            @NotNull final WritableLongChunk rowKeys) {
        return compactDuplicates(chunkToCompact.asWritableIntChunk(), rowKeys);
    }

    @Override
    public int compactDuplicatesPreferFirst(
            @NotNull final WritableChunk chunkToCompact,
            @NotNull final WritableIntChunk chunkPositions) {
        return compactDuplicatesPreferFirst(chunkToCompact.asWritableIntChunk(), chunkPositions);
    }

    private static int compactDuplicates(
            @NotNull final WritableIntChunk chunkToCompact,
            @NotNull final WritableLongChunk rowKeys) {
        final int inputSize = chunkToCompact.size();
        if (inputSize == 0) {
            return -1;
        }

        int wpos = 0;
        int rpos = 0;

        int last = chunkToCompact.get(0);

        while (rpos < inputSize) {
            final int current = chunkToCompact.get(rpos);
            if (!leq(last, current)) {
                return rpos;
            }
            last = current;

            while (rpos < inputSize - 1 && eq(current, chunkToCompact.get(rpos + 1))) {
                rpos++;
            }
            chunkToCompact.set(wpos, current);
            rowKeys.set(wpos, rowKeys.get(rpos));
            rpos++;
            wpos++;
        }
        chunkToCompact.setSize(wpos);
        rowKeys.setSize(wpos);

        return -1;
    }

    private static int compactDuplicatesPreferFirst(
            @NotNull final WritableIntChunk chunkToCompact,
            @NotNull final WritableIntChunk chunkPositions) {
        final int inputSize = chunkToCompact.size();
        if (inputSize == 0) {
            return -1;
        }

        int wpos = 0;
        int rpos = 0;

        int last = chunkToCompact.get(0);

        while (rpos < inputSize) {
            final int current = chunkToCompact.get(rpos);
            if (!leq(last, current)) {
                return rpos;
            }
            last = current;

            chunkToCompact.set(wpos, current);
            chunkPositions.set(wpos, chunkPositions.get(rpos));
            rpos++;
            wpos++;

            while (rpos < inputSize && eq(current, chunkToCompact.get(rpos))) {
                rpos++;
            }
        }
        chunkToCompact.setSize(wpos);
        chunkPositions.setSize(wpos);

        return -1;
    }

    // region comparison functions
    // note that this is a descending kernel, thus the comparisons here are backwards (e.g., the lt function is in terms of the sort direction, so is implemented by gt)
    private static int doComparison(int lhs, int rhs) {
        return -1 * Integer.compare(lhs, rhs);
    }
    // endregion comparison functions

    private static boolean leq(int lhs, int rhs) {
        return doComparison(lhs, rhs) <= 0;
    }

    private static boolean eq(int lhs, int rhs) {
        // region equality function
        return lhs == rhs;
        // endregion equality function
    }
}