it.unimi.dsi.fastutil.objects.AbstractReferenceBigList Maven / Gradle / Ivy
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/*
* Copyright (C) 2010-2023 Sebastiano Vigna
*
* Licensed 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 it.unimi.dsi.fastutil.objects;
import static it.unimi.dsi.fastutil.BigArrays.ensureOffsetLength;
import static it.unimi.dsi.fastutil.BigArrays.length;
import it.unimi.dsi.fastutil.BigArrays;
import it.unimi.dsi.fastutil.Stack;
import java.util.function.Consumer;
import java.util.Iterator;
import java.util.Collection;
import java.util.NoSuchElementException;
import it.unimi.dsi.fastutil.BigList;
import it.unimi.dsi.fastutil.BigListIterator;
/**
* An abstract class providing basic methods for big lists implementing a type-specific big list
* interface.
*
*
* Most of the methods in this class are optimized with the assumption that the List will have
* {@link java.util.RandomAccess have constant-time random access}. If this is not the case, you
* should probably at least override {@link #listIterator(long)} and the {@code xAll()}
* methods (such as {@link #addAll}) with a more appropriate iteration scheme. Note the
* {@link #subList(long, long)} method is cognizant of random-access or not, so that need not be
* reimplemented.
*/
public abstract class AbstractReferenceBigList extends AbstractReferenceCollection implements ReferenceBigList, Stack {
protected AbstractReferenceBigList() {
}
/**
* Ensures that the given index is nonnegative and not greater than this big-list size.
*
* @param index an index.
* @throws IndexOutOfBoundsException if the given index is negative or greater than this big-list
* size.
*/
protected void ensureIndex(final long index) {
if (index < 0) throw new IndexOutOfBoundsException("Index (" + index + ") is negative");
if (index > size64()) throw new IndexOutOfBoundsException("Index (" + index + ") is greater than list size (" + (size64()) + ")");
}
/**
* Ensures that the given index is nonnegative and smaller than this big-list size.
*
* @param index an index.
* @throws IndexOutOfBoundsException if the given index is negative or not smaller than this
* big-list size.
*/
protected void ensureRestrictedIndex(final long index) {
if (index < 0) throw new IndexOutOfBoundsException("Index (" + index + ") is negative");
if (index >= size64()) throw new IndexOutOfBoundsException("Index (" + index + ") is greater than or equal to list size (" + (size64()) + ")");
}
/**
* {@inheritDoc}
*
* @implSpec This implementation always throws an {@link UnsupportedOperationException}.
*/
@Override
public void add(final long index, final K k) {
throw new UnsupportedOperationException();
}
/**
* {@inheritDoc}
*
* @implSpec This implementation delegates to the type-specific version of
* {@link BigList#add(long, Object)}.
*/
@Override
public boolean add(final K k) {
add(size64(), k);
return true;
}
/**
* {@inheritDoc}
*
* @implSpec This implementation always throws an {@link UnsupportedOperationException}.
*/
@Override
public K remove(long i) {
throw new UnsupportedOperationException();
}
/**
* {@inheritDoc}
*
* @implSpec This implementation always throws an {@link UnsupportedOperationException}.
*/
@Override
public K set(final long index, final K k) {
throw new UnsupportedOperationException();
}
/** Adds all of the elements in the specified collection to this list (optional operation). */
@Override
public boolean addAll(long index, final Collection c) {
ensureIndex(index);
final Iterator i = c.iterator();
final boolean retVal = i.hasNext();
while (i.hasNext()) add(index++, i.next());
return retVal;
}
/**
* {@inheritDoc}
*
* @implSpec This implementation delegates to the type-specific version of
* {@link BigList#addAll(long, Collection)}.
*/
@Override
public boolean addAll(final Collection c) {
return addAll(size64(), c);
}
/**
* {@inheritDoc}
*
* @implSpec This implementation delegates to {@link #listIterator()}.
*/
@Override
public ObjectBigListIterator iterator() {
return listIterator();
}
/**
* {@inheritDoc}
*
* @implSpec This implementation delegates to {@link BigList#listIterator(long) listIterator(0)}.
*/
@Override
public ObjectBigListIterator listIterator() {
return listIterator(0L);
}
/**
* {@inheritDoc}
*
* @implSpec This implementation is based on the random-access methods.
*/
@Override
public ObjectBigListIterator listIterator(final long index) {
ensureIndex(index);
return new ObjectBigListIterators.AbstractIndexBasedBigListIterator(0, index) {
@Override
protected final K get(long i) {
return AbstractReferenceBigList.this.get(i);
}
@Override
protected final void add(long i, K k) {
AbstractReferenceBigList.this.add(i, k);
}
@Override
protected final void set(long i, K k) {
AbstractReferenceBigList.this.set(i, k);
}
@Override
protected final void remove(long i) {
AbstractReferenceBigList.this.remove(i);
}
@Override
protected final long getMaxPos() {
return AbstractReferenceBigList.this.size64();
}
};
}
static final class IndexBasedSpliterator extends ObjectBigSpliterators.LateBindingSizeIndexBasedSpliterator {
final ReferenceBigList l;
IndexBasedSpliterator(ReferenceBigList l, long pos) {
super(pos);
this.l = l;
}
IndexBasedSpliterator(ReferenceBigList l, long pos, long maxPos) {
super(pos, maxPos);
this.l = l;
}
@Override
protected final long getMaxPosFromBackingStore() {
return l.size64();
}
@Override
protected final K get(long i) {
return l.get(i);
}
@Override
protected final IndexBasedSpliterator makeForSplit(long pos, long maxPos) {
return new IndexBasedSpliterator<>(l, pos, maxPos);
}
}
/**
* Returns true if this list contains the specified element.
*
* @implSpec This implementation delegates to {@code indexOf()}.
* @see BigList#contains(Object)
*/
@Override
public boolean contains(final Object k) {
return indexOf(k) >= 0;
}
@Override
public long indexOf(final Object k) {
final ObjectBigListIterator i = listIterator();
K e;
while (i.hasNext()) {
e = i.next();
if (((k) == (e))) return i.previousIndex();
}
return -1;
}
@Override
public long lastIndexOf(final Object k) {
ObjectBigListIterator i = listIterator(size64());
K e;
while (i.hasPrevious()) {
e = i.previous();
if (((k) == (e))) return i.nextIndex();
}
return -1;
}
@Override
public void size(final long size) {
long i = size64();
if (size > i) while (i++ < size) add((null));
else while (i-- != size) remove(i);
}
@Override
public ReferenceBigList subList(final long from, final long to) {
ensureIndex(from);
ensureIndex(to);
if (from > to) throw new IndexOutOfBoundsException("Start index (" + from + ") is greater than end index (" + to + ")");
return this instanceof java.util.RandomAccess ? new ReferenceRandomAccessSubList<>(this, from, to) : new ReferenceSubList<>(this, from, to);
}
/**
* {@inheritDoc}
*
* @implSpec If this list is {@link java.util.RandomAccess}, will iterate using a for loop and the
* type-specific {@link java.util.List#get(int)} method. Otherwise it will fallback to
* using the iterator based loop implementation from the superinterface.
*/
@Override
public void forEach(final Consumer action) {
if (this instanceof java.util.RandomAccess) {
for (long i = 0, max = size64(); i < max; ++i) {
action.accept(get(i));
}
} else {
super.forEach(action);
}
}
/**
* {@inheritDoc}
*
*
* This is a trivial iterator-based implementation. It is expected that implementations will
* override this method with a more optimized version.
*/
@Override
public void removeElements(final long from, final long to) {
ensureIndex(to);
ObjectBigListIterator i = listIterator(from);
long n = to - from;
if (n < 0) throw new IllegalArgumentException("Start index (" + from + ") is greater than end index (" + to + ")");
while (n-- != 0) {
i.next();
i.remove();
}
}
/**
* {@inheritDoc}
*
*
* This is a trivial iterator-based implementation. It is expected that implementations will
* override this method with a more optimized version.
*/
@Override
public void addElements(long index, final K a[][], long offset, long length) {
ensureIndex(index);
ensureOffsetLength(a, offset, length);
if (this instanceof java.util.RandomAccess) {
while (length-- != 0) add(index++, BigArrays.get(a, offset++));
} else {
ObjectBigListIterator iter = listIterator(index);
while (length-- != 0) iter.add(BigArrays.get(a, offset++));
}
}
/**
* {@inheritDoc}
*
* @implSpec This implementation delegates to the analogous method for big-array fragments.
*/
@Override
public void addElements(final long index, final K a[][]) {
addElements(index, a, 0, length(a));
}
/**
* {@inheritDoc}
*
*
* This is a trivial iterator-based implementation. It is expected that implementations will
* override this method with a more optimized version.
*/
@Override
public void getElements(final long from, final Object a[][], long offset, long length) {
ensureIndex(from);
ensureOffsetLength(a, offset, length);
if (from + length > size64()) throw new IndexOutOfBoundsException("End index (" + (from + length) + ") is greater than list size (" + size64() + ")");
if (this instanceof java.util.RandomAccess) {
long current = from;
while (length-- != 0) BigArrays.set(a, offset++, get(current++));
} else {
ObjectBigListIterator i = listIterator(from);
while (length-- != 0) BigArrays.set(a, offset++, i.next());
}
}
@Override
public void setElements(long index, K a[][], long offset, long length) {
ensureIndex(index);
ensureOffsetLength(a, offset, length);
if (index + length > size64()) throw new IndexOutOfBoundsException("End index (" + (index + length) + ") is greater than list size (" + size64() + ")");
if (this instanceof java.util.RandomAccess) {
for (long i = 0; i < length; ++i) {
set(i + index, BigArrays.get(a, i + offset));
}
} else {
ObjectBigListIterator iter = listIterator(index);
long i = 0;
while (i < length) {
iter.next();
iter.set(BigArrays.get(a, offset + i++));
}
}
}
/**
* {@inheritDoc}
*
* @implSpec This implementation delegates to {@link #removeElements(long, long)}.
*/
@Override
public void clear() {
removeElements(0, size64());
}
/**
* {@inheritDoc}
*
* @implSpec This implementation delegates to {@link #size64()}.
* @deprecated Please use {@link #size64()} instead.
*/
@Override
@Deprecated
public int size() {
return (int)Math.min(Integer.MAX_VALUE, size64());
}
/**
* Returns the hash code for this big list, which is identical to {@link java.util.List#hashCode()}.
*
* @return the hash code for this big list.
*/
@Override
public int hashCode() {
ObjectIterator i = iterator();
int h = 1;
long s = size64();
while (s-- != 0) {
K k = i.next();
h = 31 * h + (System.identityHashCode(k));
}
return h;
}
@Override
public boolean equals(final Object o) {
if (o == this) return true;
if (!(o instanceof BigList)) return false;
final BigList l = (BigList)o;
long s = size64();
if (s != l.size64()) return false;
final BigListIterator i1 = listIterator(), i2 = l.listIterator();
while (s-- != 0) if (i1.next() != i2.next()) return false;
return true;
}
@Override
public void push(K o) {
add(o);
}
@Override
public K pop() {
if (isEmpty()) throw new NoSuchElementException();
return remove(size64() - 1);
}
@Override
public K top() {
if (isEmpty()) throw new NoSuchElementException();
return get(size64() - 1);
}
@Override
public K peek(int i) {
return get(size64() - 1 - i);
}
@Override
public String toString() {
final StringBuilder s = new StringBuilder();
final ObjectIterator i = iterator();
long n = size64();
K k;
boolean first = true;
s.append("[");
while (n-- != 0) {
if (first) first = false;
else s.append(", ");
k = i.next();
if (this == k) s.append("(this big list)");
else s.append(String.valueOf(k));
}
s.append("]");
return s.toString();
}
/** A class implementing a sublist view. */
public static class ReferenceSubList extends AbstractReferenceBigList implements java.io.Serializable {
private static final long serialVersionUID = -7046029254386353129L;
/** The list this sublist restricts. */
protected final ReferenceBigList l;
/** Initial (inclusive) index of this sublist. */
protected final long from;
/** Final (exclusive) index of this sublist. */
protected long to;
public ReferenceSubList(final ReferenceBigList l, final long from, final long to) {
this.l = l;
this.from = from;
this.to = to;
}
private boolean assertRange() {
assert from <= l.size64();
assert to <= l.size64();
assert to >= from;
return true;
}
@Override
public boolean add(final K k) {
l.add(to, k);
to++;
assert assertRange();
return true;
}
@Override
public void add(final long index, final K k) {
ensureIndex(index);
l.add(from + index, k);
to++;
assert assertRange();
}
@Override
public boolean addAll(final long index, final Collection c) {
ensureIndex(index);
to += c.size();
return l.addAll(from + index, c);
}
@Override
public K get(long index) {
ensureRestrictedIndex(index);
return l.get(from + index);
}
@Override
public K remove(long index) {
ensureRestrictedIndex(index);
to--;
return l.remove(from + index);
}
@Override
public K set(long index, K k) {
ensureRestrictedIndex(index);
return l.set(from + index, k);
}
@Override
public long size64() {
return to - from;
}
@Override
public void getElements(final long from, final Object[][] a, final long offset, final long length) {
ensureIndex(from);
if (from + length > size64()) throw new IndexOutOfBoundsException("End index (" + from + length + ") is greater than list size (" + size64() + ")");
l.getElements(this.from + from, a, offset, length);
}
@Override
public void removeElements(final long from, final long to) {
ensureIndex(from);
ensureIndex(to);
l.removeElements(this.from + from, this.from + to);
this.to -= (to - from);
assert assertRange();
}
@Override
public void addElements(final long index, final K a[][], long offset, long length) {
ensureIndex(index);
l.addElements(this.from + index, a, offset, length);
this.to += length;
assert assertRange();
}
private final class RandomAccessIter extends ObjectBigListIterators.AbstractIndexBasedBigListIterator {
// We don't set the minPos to be "from" because we need to call our containing class'
// add, set, and remove methods with 0 relative to the start of the sublist, not the
// start of the original list.
// Thus pos is relative to the start of the SubList, not the start of the original list.
RandomAccessIter(long pos) {
super(0, pos);
}
@Override
protected final K get(long i) {
return l.get(from + i);
}
// Remember, these are calling SUBLIST's methods, meaning 0 is the start of the sublist for these.
@Override
protected final void add(long i, K k) {
ReferenceSubList.this.add(i, k);
}
@Override
protected final void set(long i, K k) {
ReferenceSubList.this.set(i, k);
}
@Override
protected final void remove(long i) {
ReferenceSubList.this.remove(i);
}
@Override
protected final long getMaxPos() {
return to - from;
}
@Override
public void add(K k) {
super.add(k);
assert assertRange();
}
@Override
public void remove() {
super.remove();
assert assertRange();
}
}
private class ParentWrappingIter implements ObjectBigListIterator {
private ObjectBigListIterator parent;
ParentWrappingIter(ObjectBigListIterator parent) {
this.parent = parent;
}
@Override
public long nextIndex() {
return parent.nextIndex() - from;
}
@Override
public long previousIndex() {
return parent.previousIndex() - from;
}
@Override
public boolean hasNext() {
return parent.nextIndex() < to;
}
@Override
public boolean hasPrevious() {
return parent.previousIndex() >= from;
}
@Override
public K next() {
if (!hasNext()) throw new NoSuchElementException();
return parent.next();
}
@Override
public K previous() {
if (!hasPrevious()) throw new NoSuchElementException();
return parent.previous();
}
@Override
public void add(K k) {
parent.add(k);
}
@Override
public void set(K k) {
parent.set(k);
}
@Override
public void remove() {
parent.remove();
}
@Override
public long back(long n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
long currentPos = parent.previousIndex();
long parentNewPos = currentPos - n;
// Remember, the minimum acceptable previousIndex is not from but (from - 1), since (from - 1)
// means this subList is at the beginning of our sub range.
// Same reason why previousIndex()'s minimum for the full list is not 0 but -1.
if (parentNewPos < (from - 1)) parentNewPos = (from - 1);
long toSkip = parentNewPos - currentPos;
return parent.back(toSkip);
}
@Override
public long skip(long n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
long currentPos = parent.nextIndex();
long parentNewPos = currentPos + n;
if (parentNewPos > to) parentNewPos = to;
long toSkip = parentNewPos - currentPos;
return parent.skip(toSkip);
}
}
@Override
public ObjectBigListIterator listIterator(final long index) {
ensureIndex(index);
// If this class wasn't public, then RandomAccessIter would live in SUBLISTRandomAccess,
// and the switching would be done in sublist(long, long). However, this is a public class
// that may have existing implementors, so to get the benefit of RandomAccessIter class for
// for existing uses, it has to be done in this class.
return l instanceof java.util.RandomAccess ? new RandomAccessIter(index) : new ParentWrappingIter(l.listIterator(index + from));
}
@Override
public ObjectSpliterator spliterator() {
return l instanceof java.util.RandomAccess ? new IndexBasedSpliterator<>(l, from, to) : super.spliterator();
}
@Override
public ReferenceBigList subList(final long from, final long to) {
ensureIndex(from);
ensureIndex(to);
if (from > to) throw new IllegalArgumentException("Start index (" + from + ") is greater than end index (" + to + ")");
// Sadly we have to rewrap this, because if there is a sublist of a sublist, and the
// subsublist adds, both sublists need to update their "to" value.
return new ReferenceSubList<>(this, from, to);
}
}
public static class ReferenceRandomAccessSubList extends ReferenceSubList implements java.util.RandomAccess {
private static final long serialVersionUID = -107070782945191929L;
public ReferenceRandomAccessSubList(final ReferenceBigList l, final long from, final long to) {
super(l, from, to);
}
@Override
public ReferenceBigList subList(final long from, final long to) {
ensureIndex(from);
ensureIndex(to);
if (from > to) throw new IllegalArgumentException("Start index (" + from + ") is greater than end index (" + to + ")");
// Sadly we have to rewrap this, because if there is a sublist of a sublist, and the
// subsublist adds, both sublists need to update their "to" value.
return new ReferenceRandomAccessSubList<>(this, from, to);
}
}
}