de.tum.in.naturals.set.AbstractNatBitSetFactory Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of naturals-util Show documentation
Datastructures and utility classes for non-negative integers
The newest version!
/*
 * Copyright (C) 2018 Tobias Meggendorfer
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */

package de.tum.in.naturals.set;

import com.zaxxer.sparsebits.SparseBitSet;
import java.util.BitSet;
import java.util.function.IntConsumer;
import javax.annotation.Nonnegative;
import org.roaringbitmap.RoaringBitmap;

public abstract class AbstractNatBitSetFactory implements NatBitSetFactory {
    @Override
    public BoundedNatBitSet boundedSet(int domainSize, int expectedSize) {
        if (domainSize <= LongBoundedNatBitSet.maximalSize()) {
            return new LongBoundedNatBitSet(domainSize);
        }
        return makeBoundedSet(domainSize, expectedSize);
    }

    protected abstract BoundedNatBitSet makeBoundedSet(int domainSize, int expectedSize);

    @Override
    public boolean isModifiable(BoundedNatBitSet set) {
        return set instanceof LongBoundedNatBitSet
                || set instanceof SimpleBoundedNatBitSet
                || set instanceof SparseBoundedNatBitSet
                || set instanceof RoaringBoundedNatBitSet;
    }

    @Override
    public NatBitSet compact(NatBitSet set, boolean forceCopy) {
        if (set instanceof MutableSingletonNatBitSet || set instanceof FixedSizeNatBitSet) {
            return set;
        }
        if (set.isEmpty()) {
            return NatBitSets.emptySet();
        }
        if (set.size() == 1) {
            return NatBitSets.singleton(set.firstInt());
        }
        if (set.firstInt() == 0 && set.lastInt() == set.size() - 1) {
            return new FixedSizeNatBitSet(set.lastInt() + 1);
        }
        if (!(set instanceof LongNatBitSet) && set.lastInt() < LongNatBitSet.maximalSize()) {
            LongNatBitSet copy = new LongNatBitSet();
            set.forEach((IntConsumer) copy::set);
            return copy;
        }
        // TODO Determine optimal representation (Sparse vs non-sparse, direct vs. complement)
        return forceCopy ? set.clone() : set;
    }

    @Override
    public boolean isModifiable(NatBitSet set, int length) {
        if (length == 0) {
            return true;
        }
        if (set instanceof BoundedNatBitSet) {
            BoundedNatBitSet boundedSet = (BoundedNatBitSet) set;
            return length <= boundedSet.domainSize() && isModifiable(boundedSet);
        }
        if (set instanceof LongNatBitSet) {
            return length <= LongNatBitSet.maximalSize();
        }
        return set instanceof SimpleNatBitSet || set instanceof SparseNatBitSet || set instanceof RoaringNatBitSet;
    }

    @Override
    public BoundedNatBitSet ensureBounded(NatBitSet set, @Nonnegative int domainSize) {
        if (domainSize <= 0) {
            throw new IllegalArgumentException();
        }
        if (!set.isEmpty() && set.lastInt() >= domainSize) {
            throw new IndexOutOfBoundsException();
        }
        if (set instanceof BoundedNatBitSet) {
            BoundedNatBitSet boundedSet = (BoundedNatBitSet) set;
            int oldDomainSize = boundedSet.domainSize();
            if (oldDomainSize == domainSize) {
                return boundedSet;
            }
            if (set instanceof SimpleBoundedNatBitSet) {
                SimpleBoundedNatBitSet simpleBoundedSet = (SimpleBoundedNatBitSet) set;
                BitSet bitSetCopy = (BitSet) simpleBoundedSet.getBitSet().clone();
                if (simpleBoundedSet.isComplement()) {
                    if (domainSize < oldDomainSize) {
                        bitSetCopy.clear(domainSize, oldDomainSize);
                    } else {
                        bitSetCopy.set(oldDomainSize, domainSize);
                    }
                }
                BoundedNatBitSet copy = new SimpleBoundedNatBitSet(bitSetCopy, domainSize);
                return simpleBoundedSet.isComplement() ? copy.complement() : copy;
            } else if (set instanceof SparseBoundedNatBitSet) {
                SparseBoundedNatBitSet sparseBoundedSet = (SparseBoundedNatBitSet) set;
                SparseBitSet bitSetCopy = sparseBoundedSet.getBitSet().clone();
                if (sparseBoundedSet.isComplement()) {
                    if (domainSize < oldDomainSize) {
                        bitSetCopy.clear(domainSize, oldDomainSize);
                    } else {
                        bitSetCopy.set(oldDomainSize, domainSize);
                    }
                }
                BoundedNatBitSet copy = new SparseBoundedNatBitSet(bitSetCopy, domainSize);
                return sparseBoundedSet.isComplement() ? copy.complement() : copy;
            } else if (set instanceof MutableSingletonNatBitSet) {
                MutableSingletonNatBitSet singletonSet = (MutableSingletonNatBitSet) set;
                return singletonSet.isEmpty()
                        ? new BoundedMutableSingletonNatBitSet(domainSize)
                        : new BoundedMutableSingletonNatBitSet(singletonSet.firstInt(), domainSize);
            } else if (set instanceof RoaringBoundedNatBitSet) {
                RoaringBoundedNatBitSet sparseBoundedSet = (RoaringBoundedNatBitSet) set;
                RoaringBitmap bitmapCopy = sparseBoundedSet.bitmap().clone();
                if (sparseBoundedSet.isComplement()) {
                    if (domainSize < oldDomainSize) {
                        bitmapCopy.remove(domainSize, (long) oldDomainSize);
                    } else {
                        bitmapCopy.add(oldDomainSize, (long) domainSize);
                    }
                }
                BoundedNatBitSet copy = new RoaringBoundedNatBitSet(bitmapCopy, domainSize);
                return sparseBoundedSet.isComplement() ? copy.complement() : copy;
            }
        }
        BoundedNatBitSet copy = boundedSet(domainSize, set.size());
        copy.or(set);
        return copy;
    }
}