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/*
* Copyright (C) 2002-2022 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.longs;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.RandomAccess;
import java.util.NoSuchElementException;
/**
* A type-specific array-based list; provides some additional methods that use polymorphism to avoid
* (un)boxing.
*
*
* This class implements a lightweight, fast, open, optimized, reuse-oriented version of array-based
* lists. Instances of this class represent a list with an array that is enlarged as needed when new
* entries are created (by increasing its current length by 50%), but is never made smaller
* (even on a {@link #clear()}). A family of {@linkplain #trim() trimming methods} lets you control
* the size of the backing array; this is particularly useful if you reuse instances of this class.
* Range checks are equivalent to those of {@code java.util}'s classes, but they are delayed as much
* as possible. The backing array is exposed by the {@link #elements()} method.
*
*
* This class implements the bulk methods {@code removeElements()}, {@code addElements()} and
* {@code getElements()} using high-performance system calls (e.g.,
* {@link System#arraycopy(Object,int,Object,int,int) System.arraycopy()}) instead of expensive
* loops.
*
* @see java.util.ArrayList
*/
public class LongArrayList extends AbstractLongList implements RandomAccess, Cloneable, java.io.Serializable {
private static final long serialVersionUID = -7046029254386353130L;
/** The initial default capacity of an array list. */
public static final int DEFAULT_INITIAL_CAPACITY = 10;
/** The backing array. */
protected transient long a[];
/** The current actual size of the list (never greater than the backing-array length). */
protected int size;
/**
* Ensures that the component type of the given array is the proper type. This is irrelevant for
* primitive types, so it will just do a trivial copy. But for Reference types, you can have a
* {@code String[]} masquerading as an {@code Object[]}, which is a case we need to prepare for
* because we let the user give an array to use directly with {@link #wrap}.
*/
private static final long[] copyArraySafe(long[] a, int length) {
if (length == 0) return LongArrays.EMPTY_ARRAY;
return java.util.Arrays.copyOf(a, length);
}
private static final long[] copyArrayFromSafe(LongArrayList l) {
return copyArraySafe(l.a, l.size);
}
/**
* Creates a new array list using a given array.
*
*
* This constructor is only meant to be used by the wrapping methods.
*
* @param a the array that will be used to back this array list.
*/
protected LongArrayList(final long a[], @SuppressWarnings("unused") boolean wrapped) {
this.a = a;
}
private void initArrayFromCapacity(final int capacity) {
if (capacity < 0) throw new IllegalArgumentException("Initial capacity (" + capacity + ") is negative");
if (capacity == 0) a = LongArrays.EMPTY_ARRAY;
else a = new long[capacity];
}
/**
* Creates a new array list with given capacity.
*
* @param capacity the initial capacity of the array list (may be 0).
*/
public LongArrayList(final int capacity) {
initArrayFromCapacity(capacity);
}
/** Creates a new array list with {@link #DEFAULT_INITIAL_CAPACITY} capacity. */
public LongArrayList() {
a = LongArrays.DEFAULT_EMPTY_ARRAY; // We delay allocation
}
/**
* Creates a new array list and fills it with a given collection.
*
* @param c a collection that will be used to fill the array list.
*/
public LongArrayList(final Collection c) {
if (c instanceof LongArrayList) {
a = copyArrayFromSafe((LongArrayList)c);
size = a.length;
} else {
initArrayFromCapacity(c.size());
if (c instanceof LongList) {
((LongList)c).getElements(0, a, 0, size = c.size());
} else {
size = LongIterators.unwrap(LongIterators.asLongIterator(c.iterator()), a);
}
}
}
/**
* Creates a new array list and fills it with a given type-specific collection.
*
* @param c a type-specific collection that will be used to fill the array list.
*/
public LongArrayList(final LongCollection c) {
if (c instanceof LongArrayList) {
a = copyArrayFromSafe((LongArrayList)c);
size = a.length;
} else {
initArrayFromCapacity(c.size());
if (c instanceof LongList) {
((LongList)c).getElements(0, a, 0, size = c.size());
} else {
size = LongIterators.unwrap(c.iterator(), a);
}
}
}
/**
* Creates a new array list and fills it with a given type-specific list.
*
* @param l a type-specific list that will be used to fill the array list.
*/
public LongArrayList(final LongList l) {
if (l instanceof LongArrayList) {
a = copyArrayFromSafe((LongArrayList)l);
size = a.length;
} else {
initArrayFromCapacity(l.size());
l.getElements(0, a, 0, size = l.size());
}
}
/**
* Creates a new array list and fills it with the elements of a given array.
*
* @param a an array whose elements will be used to fill the array list.
*/
public LongArrayList(final long a[]) {
this(a, 0, a.length);
}
/**
* Creates a new array list and fills it with the elements of a given array.
*
* @param a an array whose elements will be used to fill the array list.
* @param offset the first element to use.
* @param length the number of elements to use.
*/
public LongArrayList(final long a[], final int offset, final int length) {
this(length);
System.arraycopy(a, offset, this.a, 0, length);
size = length;
}
/**
* Creates a new array list and fills it with the elements returned by an iterator..
*
* @param i an iterator whose returned elements will fill the array list.
*/
public LongArrayList(final Iterator i) {
this();
while (i.hasNext()) this.add((i.next()).longValue());
}
/**
* Creates a new array list and fills it with the elements returned by a type-specific iterator..
*
* @param i a type-specific iterator whose returned elements will fill the array list.
*/
public LongArrayList(final LongIterator i) {
this();
while (i.hasNext()) this.add(i.nextLong());
}
/**
* Returns the backing array of this list.
*
* @return the backing array.
*/
public long[] elements() {
return a;
}
/**
* Wraps a given array into an array list of given size.
*
*
* Note it is guaranteed that the type of the array returned by {@link #elements()} will be the same
* (see the comments in the class documentation).
*
* @param a an array to wrap.
* @param length the length of the resulting array list.
* @return a new array list of the given size, wrapping the given array.
*/
public static LongArrayList wrap(final long a[], final int length) {
if (length > a.length) throw new IllegalArgumentException("The specified length (" + length + ") is greater than the array size (" + a.length + ")");
final LongArrayList l = new LongArrayList(a, true);
l.size = length;
return l;
}
/**
* Wraps a given array into an array list.
*
*
* Note it is guaranteed that the type of the array returned by {@link #elements()} will be the same
* (see the comments in the class documentation).
*
* @param a an array to wrap.
* @return a new array list wrapping the given array.
*/
public static LongArrayList wrap(final long a[]) {
return wrap(a, a.length);
}
/**
* Creates a new empty array list.
*
* @return a new empty array list.
*/
public static LongArrayList of() {
return new LongArrayList();
}
/**
* Creates an array list using an array of elements.
*
* @param init a the array the will become the new backing array of the array list.
* @return a new array list backed by the given array.
* @see #wrap
*/
public static LongArrayList of(final long... init) {
return wrap(init);
}
/**
* Collects the result of a primitive {@code Stream} into a new ArrayList.
*
*
* This method performs a terminal operation on the given {@code Stream}
*
* @apiNote Taking a primitive stream instead of returning something like a
* {@link java.util.stream.Collector Collector} is necessary because there is no primitive
* {@code Collector} equivalent in the Java API.
*/
public static LongArrayList toList(java.util.stream.LongStream stream) {
return stream.collect(LongArrayList::new, LongArrayList::add, LongArrayList::addAll);
}
/**
* Collects the result of a primitive {@code Stream} into a new ArrayList, potentially pre-allocated
* to handle the given size.
*
*
* This method performs a terminal operation on the given {@code Stream}
*
* @apiNote Taking a primitive stream instead returning something like a
* {@link java.util.stream.Collector Collector} is necessary because there is no primitive
* {@code Collector} equivalent in the Java API.
*/
public static LongArrayList toListWithExpectedSize(java.util.stream.LongStream stream, int expectedSize) {
if (expectedSize <= DEFAULT_INITIAL_CAPACITY) {
// Already below default capacity. Just use all default construction instead of fiddling with
// atomics in SizeDecreasingSupplier
return toList(stream);
}
return stream.collect(new LongCollections.SizeDecreasingSupplier(expectedSize, (int size) -> size <= DEFAULT_INITIAL_CAPACITY ? new LongArrayList() : new LongArrayList(size)), LongArrayList::add, LongArrayList::addAll);
}
/**
* Ensures that this array list can contain the given number of entries without resizing.
*
* @param capacity the new minimum capacity for this array list.
*/
public void ensureCapacity(final int capacity) {
if (capacity <= a.length || (a == LongArrays.DEFAULT_EMPTY_ARRAY && capacity <= DEFAULT_INITIAL_CAPACITY)) return;
a = LongArrays.ensureCapacity(a, capacity, size);
assert size <= a.length;
}
/**
* Grows this array list, ensuring that it can contain the given number of entries without resizing,
* and in case increasing the current capacity at least by a factor of 50%.
*
* @param capacity the new minimum capacity for this array list.
*/
private void grow(int capacity) {
if (capacity <= a.length) return;
if (a != LongArrays.DEFAULT_EMPTY_ARRAY) capacity = (int)Math.max(Math.min((long)a.length + (a.length >> 1), it.unimi.dsi.fastutil.Arrays.MAX_ARRAY_SIZE), capacity);
else if (capacity < DEFAULT_INITIAL_CAPACITY) capacity = DEFAULT_INITIAL_CAPACITY;
a = LongArrays.forceCapacity(a, capacity, size);
assert size <= a.length;
}
@Override
public void add(final int index, final long k) {
ensureIndex(index);
grow(size + 1);
if (index != size) System.arraycopy(a, index, a, index + 1, size - index);
a[index] = k;
size++;
assert size <= a.length;
}
@Override
public boolean add(final long k) {
grow(size + 1);
a[size++] = k;
assert size <= a.length;
return true;
}
@Override
public long getLong(final int index) {
if (index >= size) throw new IndexOutOfBoundsException("Index (" + index + ") is greater than or equal to list size (" + size + ")");
return a[index];
}
@Override
public int indexOf(final long k) {
for (int i = 0; i < size; i++) if (((k) == (a[i]))) return i;
return -1;
}
@Override
public int lastIndexOf(final long k) {
for (int i = size; i-- != 0;) if (((k) == (a[i]))) return i;
return -1;
}
@Override
public long removeLong(final int index) {
if (index >= size) throw new IndexOutOfBoundsException("Index (" + index + ") is greater than or equal to list size (" + size + ")");
final long old = a[index];
size--;
if (index != size) System.arraycopy(a, index + 1, a, index, size - index);
assert size <= a.length;
return old;
}
@Override
public boolean rem(final long k) {
int index = indexOf(k);
if (index == -1) return false;
removeLong(index);
assert size <= a.length;
return true;
}
@Override
public long set(final int index, final long k) {
if (index >= size) throw new IndexOutOfBoundsException("Index (" + index + ") is greater than or equal to list size (" + size + ")");
long old = a[index];
a[index] = k;
return old;
}
@Override
public void clear() {
size = 0;
assert size <= a.length;
}
@Override
public int size() {
return size;
}
@Override
public void size(final int size) {
if (size > a.length) a = LongArrays.forceCapacity(a, size, this.size);
if (size > this.size) Arrays.fill(a, this.size, size, (0));
this.size = size;
}
@Override
public boolean isEmpty() {
return size == 0;
}
/**
* Trims this array list so that the capacity is equal to the size.
*
* @see java.util.ArrayList#trimToSize()
*/
public void trim() {
trim(0);
}
/**
* Trims the backing array if it is too large.
*
* If the current array length is smaller than or equal to {@code n}, this method does nothing.
* Otherwise, it trims the array length to the maximum between {@code n} and {@link #size()}.
*
*
* This method is useful when reusing lists. {@linkplain #clear() Clearing a list} leaves the array
* length untouched. If you are reusing a list many times, you can call this method with a typical
* size to avoid keeping around a very large array just because of a few large transient lists.
*
* @param n the threshold for the trimming.
*/
public void trim(final int n) {
// TODO: use Arrays.trim() and preserve type only if necessary
if (n >= a.length || size == a.length) return;
final long t[] = new long[Math.max(n, size)];
System.arraycopy(a, 0, t, 0, size);
a = t;
assert size <= a.length;
}
private class SubList extends AbstractLongList.LongRandomAccessSubList {
private static final long serialVersionUID = -3185226345314976296L;
protected SubList(int from, int to) {
super(LongArrayList.this, from, to);
}
// Most of the inherited methods should be fine, but we can override a few of them for performance.
// Needed because we can't access the parent class' instance variables directly in a different
// instance of SubList.
private long[] getParentArray() {
return a;
}
@Override
public long getLong(int i) {
ensureRestrictedIndex(i);
return a[i + from];
}
private final class SubListIterator extends LongIterators.AbstractIndexBasedListIterator {
// We are using pos == 0 to be 0 relative to SubList.from (meaning you need to do a[from + i] when
// accessing array).
SubListIterator(int index) {
super(0, index);
}
@Override
protected final long get(int i) {
return a[from + i];
}
@Override
protected final void add(int i, long k) {
SubList.this.add(i, k);
}
@Override
protected final void set(int i, long k) {
SubList.this.set(i, k);
}
@Override
protected final void remove(int i) {
SubList.this.removeLong(i);
}
@Override
protected final int getMaxPos() {
return to - from;
}
@Override
public long nextLong() {
if (!hasNext()) throw new NoSuchElementException();
return a[from + (lastReturned = pos++)];
}
@Override
public long previousLong() {
if (!hasPrevious()) throw new NoSuchElementException();
return a[from + (lastReturned = --pos)];
}
@Override
public void forEachRemaining(final java.util.function.LongConsumer action) {
final int max = to - from;
while (pos < max) {
action.accept(a[from + (lastReturned = pos++)]);
}
}
}
@Override
public LongListIterator listIterator(int index) {
return new SubListIterator(index);
}
private final class SubListSpliterator extends LongSpliterators.LateBindingSizeIndexBasedSpliterator {
// We are using pos == 0 to be 0 relative to real array 0
SubListSpliterator() {
super(from);
}
private SubListSpliterator(int pos, int maxPos) {
super(pos, maxPos);
}
@Override
protected final int getMaxPosFromBackingStore() {
return to;
}
@Override
protected final long get(int i) {
return a[i];
}
@Override
protected final SubListSpliterator makeForSplit(int pos, int maxPos) {
return new SubListSpliterator(pos, maxPos);
}
@Override
public boolean tryAdvance(final java.util.function.LongConsumer action) {
if (pos >= getMaxPos()) return false;
action.accept(a[pos++]);
return true;
}
@Override
public void forEachRemaining(final java.util.function.LongConsumer action) {
final int max = getMaxPos();
while (pos < max) {
action.accept(a[pos++]);
}
}
}
@Override
public LongSpliterator spliterator() {
return new SubListSpliterator();
}
boolean contentsEquals(long[] otherA, int otherAFrom, int otherATo) {
if (a == otherA && from == otherAFrom && to == otherATo) return true;
if (otherATo - otherAFrom != size()) {
return false;
}
int pos = from, otherPos = otherAFrom;
// We have already assured that the two ranges are the same size, so we only need to check one
// bound.
// TODO When minimum version of Java becomes Java 9, use the Arrays.equals which takes bounds, which
// is vectorized.
// Make sure to split out the reference equality case when you do this.
while (pos < to) if (a[pos++] != otherA[otherPos++]) return false;
return true;
}
@Override
public boolean equals(Object o) {
if (o == this) return true;
if (o == null) return false;
if (!(o instanceof java.util.List)) return false;
if (o instanceof LongArrayList) {
LongArrayList other = (LongArrayList)o;
return contentsEquals(other.a, 0, other.size());
}
if (o instanceof LongArrayList.SubList) {
LongArrayList.SubList other = (LongArrayList.SubList)o;
return contentsEquals(other.getParentArray(), other.from, other.to);
}
return super.equals(o);
}
int contentsCompareTo(long[] otherA, int otherAFrom, int otherATo) {
if (a == otherA && from == otherAFrom && to == otherATo) return 0;
// TODO When minimum version of Java becomes Java 9, use Arrays.compare, which vectorizes.
long e1, e2;
int r, i, j;
for (i = from, j = otherAFrom; i < to && i < otherATo; i++, j++) {
e1 = a[i];
e2 = otherA[j];
if ((r = (Long.compare((e1), (e2)))) != 0) return r;
}
return i < otherATo ? -1 : (i < to ? 1 : 0);
}
@Override
public int compareTo(final java.util.List l) {
if (l instanceof LongArrayList) {
LongArrayList other = (LongArrayList)l;
return contentsCompareTo(other.a, 0, other.size());
}
if (l instanceof LongArrayList.SubList) {
LongArrayList.SubList other = (LongArrayList.SubList)l;
return contentsCompareTo(other.getParentArray(), other.from, other.to);
}
return super.compareTo(l);
}
// We don't override subList as we want AbstractList's "sub-sublist" nesting handling,
// which would be tricky to do here.
// TODO Do override it so array access isn't sent through N indirections.
// This will likely mean making this class static.
}
@Override
public LongList subList(int from, int to) {
if (from == 0 && to == size()) return this;
ensureIndex(from);
ensureIndex(to);
if (from > to) throw new IndexOutOfBoundsException("Start index (" + from + ") is greater than end index (" + to + ")");
return new SubList(from, to);
}
/**
* Copies element of this type-specific list into the given array using optimized system calls.
*
* @param from the start index (inclusive).
* @param a the destination array.
* @param offset the offset into the destination array where to store the first element copied.
* @param length the number of elements to be copied.
*/
@Override
public void getElements(final int from, final long[] a, final int offset, final int length) {
LongArrays.ensureOffsetLength(a, offset, length);
System.arraycopy(this.a, from, a, offset, length);
}
/**
* Removes elements of this type-specific list using optimized system calls.
*
* @param from the start index (inclusive).
* @param to the end index (exclusive).
*/
@Override
public void removeElements(final int from, final int to) {
it.unimi.dsi.fastutil.Arrays.ensureFromTo(size, from, to);
System.arraycopy(a, to, a, from, size - to);
size -= (to - from);
}
/**
* Adds elements to this type-specific list using optimized system calls.
*
* @param index the index at which to add elements.
* @param a the array containing the elements.
* @param offset the offset of the first element to add.
* @param length the number of elements to add.
*/
@Override
public void addElements(final int index, final long a[], final int offset, final int length) {
ensureIndex(index);
LongArrays.ensureOffsetLength(a, offset, length);
grow(size + length);
System.arraycopy(this.a, index, this.a, index + length, size - index);
System.arraycopy(a, offset, this.a, index, length);
size += length;
}
/**
* Sets elements to this type-specific list using optimized system calls.
*
* @param index the index at which to start setting elements.
* @param a the array containing the elements.
* @param offset the offset of the first element to add.
* @param length the number of elements to add.
*/
@Override
public void setElements(final int index, final long a[], final int offset, final int length) {
ensureIndex(index);
LongArrays.ensureOffsetLength(a, offset, length);
if (index + length > size) throw new IndexOutOfBoundsException("End index (" + (index + length) + ") is greater than list size (" + size + ")");
System.arraycopy(a, offset, this.a, index, length);
}
@Override
public void forEach(final java.util.function.LongConsumer action) {
for (int i = 0; i < size; ++i) {
action.accept(a[i]);
}
}
@Override
public boolean addAll(int index, final LongCollection c) {
if (c instanceof LongList) {
return addAll(index, (LongList)c);
}
ensureIndex(index);
int n = c.size();
if (n == 0) return false;
grow(size + n);
System.arraycopy(a, index, a, index + n, size - index);
final LongIterator i = c.iterator();
size += n;
while (n-- != 0) a[index++] = i.nextLong();
assert size <= a.length;
return true;
}
@Override
public boolean addAll(final int index, final LongList l) {
ensureIndex(index);
final int n = l.size();
if (n == 0) return false;
grow(size + n);
System.arraycopy(a, index, a, index + n, size - index);
l.getElements(0, a, index, n);
size += n;
assert size <= a.length;
return true;
}
@Override
public boolean removeAll(final LongCollection c) {
final long[] a = this.a;
int j = 0;
for (int i = 0; i < size; i++) if (!c.contains(a[i])) a[j++] = a[i];
final boolean modified = size != j;
size = j;
return modified;
}
@Override
public long[] toArray(long a[]) {
if (a == null || a.length < size) a = java.util.Arrays.copyOf(a, size);
System.arraycopy(this.a, 0, a, 0, size);
return a;
}
@Override
public LongListIterator listIterator(final int index) {
ensureIndex(index);
return new LongListIterator() {
int pos = index, last = -1;
@Override
public boolean hasNext() {
return pos < size;
}
@Override
public boolean hasPrevious() {
return pos > 0;
}
@Override
public long nextLong() {
if (!hasNext()) throw new NoSuchElementException();
return a[last = pos++];
}
@Override
public long previousLong() {
if (!hasPrevious()) throw new NoSuchElementException();
return a[last = --pos];
}
@Override
public int nextIndex() {
return pos;
}
@Override
public int previousIndex() {
return pos - 1;
}
@Override
public void add(long k) {
LongArrayList.this.add(pos++, k);
last = -1;
}
@Override
public void set(long k) {
if (last == -1) throw new IllegalStateException();
LongArrayList.this.set(last, k);
}
@Override
public void remove() {
if (last == -1) throw new IllegalStateException();
LongArrayList.this.removeLong(last);
/* If the last operation was a next(), we are removing an element *before* us, and we must decrease pos correspondingly. */
if (last < pos) pos--;
last = -1;
}
@Override
public void forEachRemaining(final java.util.function.LongConsumer action) {
while (pos < size) {
action.accept(a[last = pos++]);
}
}
@Override
public int back(int n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
final int remaining = size - pos;
if (n < remaining) {
pos -= n;
} else {
n = remaining;
pos = 0;
}
last = pos;
return n;
}
@Override
public int skip(int n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
final int remaining = size - pos;
if (n < remaining) {
pos += n;
} else {
n = remaining;
pos = size;
}
last = pos - 1;
return n;
}
};
}
// If you update this, you will probably want to update ArraySet as well
private final class Spliterator implements LongSpliterator {
// Until we split, we will track the size of the list.
// Once we split, then we stop updating on structural modifications.
// Aka, size is late-binding.
boolean hasSplit = false;
int pos, max;
public Spliterator() {
this(0, LongArrayList.this.size, false);
}
private Spliterator(int pos, int max, boolean hasSplit) {
assert pos <= max : "pos " + pos + " must be <= max " + max;
this.pos = pos;
this.max = max;
this.hasSplit = hasSplit;
}
private int getWorkingMax() {
return hasSplit ? max : LongArrayList.this.size;
}
@Override
public int characteristics() {
return LongSpliterators.LIST_SPLITERATOR_CHARACTERISTICS;
}
@Override
public long estimateSize() {
return getWorkingMax() - pos;
}
@Override
public boolean tryAdvance(final java.util.function.LongConsumer action) {
if (pos >= getWorkingMax()) return false;
action.accept(a[pos++]);
return true;
}
@Override
public void forEachRemaining(final java.util.function.LongConsumer action) {
for (final int max = getWorkingMax(); pos < max; ++pos) {
action.accept(a[pos]);
}
}
@Override
public long skip(long n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
final int max = getWorkingMax();
if (pos >= max) return 0;
final int remaining = max - pos;
if (n < remaining) {
pos = it.unimi.dsi.fastutil.SafeMath.safeLongToInt(pos + n);
return n;
}
n = remaining;
pos = max;
return n;
}
@Override
public LongSpliterator trySplit() {
final int max = getWorkingMax();
int retLen = (max - pos) >> 1;
if (retLen <= 1) return null;
// Update instance max with the last seen list size (if needed) before continuing
this.max = max;
int myNewPos = pos + retLen;
int retMax = myNewPos;
int oldPos = pos;
this.pos = myNewPos;
this.hasSplit = true;
return new Spliterator(oldPos, retMax, true);
}
}
/**
* {@inheritDoc}
*
*
* The returned spliterator is late-binding; it will track structural changes after the current
* index, up until the first {@link java.util.Spliterator#trySplit() trySplit()}, at which point the
* maximum index will be fixed.
* Structural changes before the current index or after the first
* {@link java.util.Spliterator#trySplit() trySplit()} will result in unspecified behavior.
*/
@Override
public LongSpliterator spliterator() {
// If it wasn't for the possibility of the list being expanded or shrunk,
// we could return SPLITERATORS.wrap(a, 0, size).
return new Spliterator();
}
@Override
public void sort(final LongComparator comp) {
if (comp == null) {
LongArrays.stableSort(a, 0, size);
} else {
LongArrays.stableSort(a, 0, size, comp);
}
}
@Override
public void unstableSort(final LongComparator comp) {
if (comp == null) {
LongArrays.unstableSort(a, 0, size);
} else {
LongArrays.unstableSort(a, 0, size, comp);
}
}
@Override
public LongArrayList clone() {
LongArrayList cloned = null;
// Test for fastpath we can do if exactly an ArrayList
if (getClass() == LongArrayList.class) {
// Preserve backwards compatibility and make new list have Object[] even if it was wrapped from some
// subclass.
cloned = new LongArrayList(copyArraySafe(a, size), false);
cloned.size = size;
} else {
try {
cloned = (LongArrayList)super.clone();
} catch (CloneNotSupportedException err) {
// Can't happen
throw new InternalError(err);
}
// Preserve backwards compatibility and make new list have Object[] even if it was wrapped from some
// subclass.
cloned.a = copyArraySafe(a, size);
}
return cloned;
}
/**
* Compares this type-specific array list to another one.
*
* @apiNote This method exists only for sake of efficiency. The implementation inherited from the
* abstract implementation would already work.
*
* @param l a type-specific array list.
* @return true if the argument contains the same elements of this type-specific array list.
*/
public boolean equals(final LongArrayList l) {
// TODO When minimum version of Java becomes Java 9, use the Arrays.equals which takes bounds, which
// is vectorized.
if (l == this) return true;
int s = size();
if (s != l.size()) return false;
final long[] a1 = a;
final long[] a2 = l.a;
if (a1 == a2 && s == l.size()) return true;
while (s-- != 0) if (a1[s] != a2[s]) return false;
return true;
}
@SuppressWarnings("unlikely-arg-type")
@Override
public boolean equals(final Object o) {
if (o == this) return true;
if (o == null) return false;
if (!(o instanceof java.util.List)) return false;
if (o instanceof LongArrayList) {
// Safe cast because we are only going to take elements from other list, never give them
return equals((LongArrayList)o);
}
if (o instanceof LongArrayList.SubList) {
// Safe cast because we are only going to take elements from other list, never give them
// Sublist has an optimized sub-array based comparison, reuse that.
return ((LongArrayList.SubList)o).equals(this);
}
return super.equals(o);
}
/**
* Compares this array list to another array list.
*
* @apiNote This method exists only for sake of efficiency. The implementation inherited from the
* abstract implementation would already work.
*
* @param l an array list.
* @return a negative integer, zero, or a positive integer as this list is lexicographically less
* than, equal to, or greater than the argument.
*/
public int compareTo(final LongArrayList l) {
final int s1 = size(), s2 = l.size();
final long a1[] = a, a2[] = l.a;
if (a1 == a2 && s1 == s2) return 0;
// TODO When minimum version of Java becomes Java 9, use Arrays.compare, which vectorizes.
long e1, e2;
int r, i;
for (i = 0; i < s1 && i < s2; i++) {
e1 = a1[i];
e2 = a2[i];
if ((r = (Long.compare((e1), (e2)))) != 0) return r;
}
return i < s2 ? -1 : (i < s1 ? 1 : 0);
}
@Override
public int compareTo(final java.util.List l) {
if (l instanceof LongArrayList) {
return compareTo((LongArrayList)l);
}
if (l instanceof LongArrayList.SubList) {
// Must negate because we are inverting the order of the comparison.
return -((LongArrayList.SubList)l).compareTo(this);
}
return super.compareTo(l);
}
private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException {
s.defaultWriteObject();
for (int i = 0; i < size; i++) s.writeLong(a[i]);
}
private void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException {
s.defaultReadObject();
a = new long[size];
for (int i = 0; i < size; i++) a[i] = s.readLong();
}
}