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/*
* Copyright (C) 2002-2023 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 java.util.Collection;
import java.util.Iterator;
import java.util.RandomAccess;
import java.util.NoSuchElementException;
import it.unimi.dsi.fastutil.BigArrays;
import static it.unimi.dsi.fastutil.BigArrays.length;
import it.unimi.dsi.fastutil.BigList;
import it.unimi.dsi.fastutil.Size64;
import java.util.function.Consumer;
import java.util.stream.Collector;
/**
* A type-specific big-array-based big list; provides some additional methods that use polymorphism
* to avoid (un)boxing.
*
*
* This class implements a lightweight, fast, open, optimized, reuse-oriented version of
* big-array-based big lists. Instances of this class represent a big list with a big array that is
* enlarged as needed when new entries are created (by increasing its current length to 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 big array; this is particularly useful
* if you reuse instances of this class. Range checks are equivalent to those of {@link java.util}'s
* classes, but they are delayed as much as possible.
*
*
* The backing big array is exposed by the {@link #elements()} method. If an instance of this class
* was created {@linkplain #wrap(Object[][],long) by wrapping}, backing-array reallocations will be
* performed using reflection, so that {@link #elements()} can return a big array of the same type
* of the original big array; the comments about efficiency made in
* {@link it.unimi.dsi.fastutil.objects.ObjectArrays} apply here.
*
*
* 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 ObjectBigArrayBigList extends AbstractObjectBigList implements RandomAccess, Cloneable, java.io.Serializable {
private static final long serialVersionUID = -7046029254386353131L;
/** The initial default capacity of a big-array big list. */
public static final int DEFAULT_INITIAL_CAPACITY = 10;
/**
* Whether the backing big array was passed to {@code wrap()}. In this case, we must reallocate with
* the same type of big array.
*/
protected final boolean wrapped;
/** The backing big array. */
protected transient K a[][];
/** The current actual size of the big list (never greater than the backing-array length). */
protected long size;
/**
* Creates a new big-array big list using a given array.
*
*
* This constructor is only meant to be used by the wrapping methods.
*
* @param a the big array that will be used to back this big-array big list.
*/
protected ObjectBigArrayBigList(final K a[][], @SuppressWarnings("unused") boolean dummy) {
this.a = a;
this.wrapped = true;
}
/**
* Creates a new big-array big list with given capacity.
*
* @param capacity the initial capacity of the array list (may be 0).
*/
@SuppressWarnings("unchecked")
public ObjectBigArrayBigList(final long capacity) {
if (capacity < 0) throw new IllegalArgumentException("Initial capacity (" + capacity + ") is negative");
if (capacity == 0) a = (K[][])ObjectBigArrays.EMPTY_BIG_ARRAY;
else a = (K[][])ObjectBigArrays.newBigArray(capacity);
wrapped = false;
}
/** Creates a new big-array big list with {@link #DEFAULT_INITIAL_CAPACITY} capacity. */
@SuppressWarnings("unchecked")
public ObjectBigArrayBigList() {
a = (K[][])ObjectBigArrays.DEFAULT_EMPTY_BIG_ARRAY; // We delay allocation
wrapped = false;
}
/**
* Creates a new big-array big 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 ObjectBigArrayBigList(final ObjectCollection c) {
this(Size64.sizeOf(c));
if (c instanceof ObjectBigList) {
((ObjectBigList)c).getElements(0, a, 0, size = Size64.sizeOf(c));
} else {
for (ObjectIterator i = c.iterator(); i.hasNext();) add(i.next());
}
}
/**
* Creates a new big-array big list and fills it with a given collection.
*
* @param c a collection that will be used to fill the array list.
*/
public ObjectBigArrayBigList(final Collection c) {
this(Size64.sizeOf(c));
if (c instanceof ObjectBigList) {
((ObjectBigList)c).getElements(0, a, 0, size = Size64.sizeOf(c));
} else {
for (Iterator i = c.iterator(); i.hasNext();) add(i.next());
}
}
/**
* Creates a new big-array big 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 ObjectBigArrayBigList(final ObjectBigList l) {
this(l.size64());
l.getElements(0, a, 0, size = l.size64());
}
/**
* Creates a new big-array big list and fills it with the elements of a given big array.
*
* @param a a big array whose elements will be used to fill the array list.
*/
public ObjectBigArrayBigList(final K a[][]) {
this(a, 0, length(a));
}
/**
* Creates a new big-array big list and fills it with the elements of a given big array.
*
* @param a a big 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 ObjectBigArrayBigList(final K a[][], final long offset, final long length) {
this(length);
BigArrays.copy(a, offset, this.a, 0, length);
size = length;
}
/**
* Creates a new big-array big list and fills it with the elements returned by an iterator..
*
* @param i an iterator whose returned elements will fill the array list.
*/
public ObjectBigArrayBigList(final Iterator i) {
this();
while (i.hasNext()) this.add((i.next()));
}
/**
* Creates a new big-array big 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 ObjectBigArrayBigList(final ObjectIterator i) {
this();
while (i.hasNext()) this.add(i.next());
}
/**
* Returns the backing big array of this big list.
*
*
* If this big-array big list was created by wrapping a given big array, it is guaranteed that the
* type of the returned big array will be the same. Otherwise, the returned big array will be an big
* array of objects.
*
* @return the backing big array.
*/
public K[][] elements() {
return a;
}
/**
* Wraps a given big array into a big-array list of given size.
*
* @param a a big array to wrap.
* @param length the length of the resulting big-array list.
* @return a new big-array list of the given size, wrapping the given big array.
*/
public static ObjectBigArrayBigList wrap(final K a[][], final long length) {
if (length > length(a)) throw new IllegalArgumentException("The specified length (" + length + ") is greater than the array size (" + length(a) + ")");
final ObjectBigArrayBigList l = new ObjectBigArrayBigList<>(a, false);
l.size = length;
return l;
}
/**
* Wraps a given big array into a big-array big list.
*
* @param a a big array to wrap.
* @return a new big-array big list wrapping the given array.
*/
public static ObjectBigArrayBigList wrap(final K a[][]) {
return wrap(a, length(a));
}
/**
* Creates a new empty big array list.
*
* @return a new empty big-array big list.
*/
public static ObjectBigArrayBigList of() {
return new ObjectBigArrayBigList<>();
}
/**
* Creates a big array list using a list of elements.
*
* @param init a list of elements that will be used to initialize the big list. It is possible (but
* not assured) that the returned big-array big list will be backed by the given array in
* one of its segments.
* @return a new big-array big list containing the given elements.
* @see BigArrays#wrap
*/
@SafeVarargs
public static ObjectBigArrayBigList of(final K... init) {
return wrap(BigArrays.wrap(init));
}
// Collector wants a function that returns the collection being added to.
private ObjectBigArrayBigList combine(ObjectBigArrayBigList toAddFrom) {
addAll(toAddFrom);
return this;
}
private static final Collector> TO_LIST_COLLECTOR = Collector.of(ObjectBigArrayBigList::new, ObjectBigArrayBigList::add, ObjectBigArrayBigList::combine);
/** Returns a {@link Collector} that collects a {@code Stream}'s elements into a new ArrayList. */
@SuppressWarnings({ "unchecked", "rawtypes" })
public static Collector> toBigList() {
return (Collector)TO_LIST_COLLECTOR;
}
/**
* Returns a {@link Collector} that collects a {@code Stream}'s elements into a new ArrayList.
*
* @implNote The current implementation preallocates the full size for every worker thread when used
* on parallel streams. This can be quite wasteful, as worker threads other then the first
* don't usually handle the contents of the full stream.
*/
public static Collector> toBigListWithExpectedSize(long expectedSize) {
return Collector.of(() -> new ObjectBigArrayBigList(expectedSize), ObjectBigArrayBigList::add, ObjectBigArrayBigList::combine);
}
/**
* Ensures that this big-array big list can contain the given number of entries without resizing.
*
* @param capacity the new minimum capacity for this big-array big list.
*/
@SuppressWarnings("unchecked")
public void ensureCapacity(final long capacity) {
if (capacity <= length(a) || a == ObjectBigArrays.DEFAULT_EMPTY_BIG_ARRAY) return;
if (wrapped) a = BigArrays.forceCapacity(a, capacity, size);
else {
if (capacity > length(a)) {
final Object t[][] = ObjectBigArrays.newBigArray(capacity);
BigArrays.copy(a, 0, t, 0, size);
a = (K[][])t;
}
}
assert size <= length(a);
}
/**
* Grows this big-array big list, ensuring that it can contain the given number of entries without
* resizing, and in case increasing current capacity at least by a factor of 50%.
*
* @param capacity the new minimum capacity for this big-array big list.
*/
@SuppressWarnings("unchecked")
private void grow(long capacity) {
final long oldLength = length(a);
if (capacity <= oldLength) return;
if (a != ObjectBigArrays.DEFAULT_EMPTY_BIG_ARRAY) capacity = Math.max(oldLength + (oldLength >> 1), capacity);
else if (capacity < DEFAULT_INITIAL_CAPACITY) capacity = DEFAULT_INITIAL_CAPACITY;
if (wrapped) a = BigArrays.forceCapacity(a, capacity, size);
else {
final Object t[][] = ObjectBigArrays.newBigArray(capacity);
BigArrays.copy(a, 0, t, 0, size);
a = (K[][])t;
}
assert size <= length(a);
}
@Override
public void add(final long index, final K k) {
ensureIndex(index);
grow(size + 1);
if (index != size) BigArrays.copy(a, index, a, index + 1, size - index);
BigArrays.set(a, index, k);
size++;
assert size <= length(a);
}
@Override
public boolean add(final K k) {
grow(size + 1);
BigArrays.set(a, size++, k);
assert size <= length(a);
return true;
}
@Override
public K get(final long index) {
if (index >= size) throw new IndexOutOfBoundsException("Index (" + index + ") is greater than or equal to list size (" + size + ")");
return BigArrays.get(a, index);
}
@Override
public long indexOf(final Object k) {
for (long i = 0; i < size; i++) if (java.util.Objects.equals(k, BigArrays.get(a, i))) return i;
return -1;
}
@Override
public long lastIndexOf(final Object k) {
for (long i = size; i-- != 0;) if (java.util.Objects.equals(k, BigArrays.get(a, i))) return i;
return -1;
}
@Override
public K remove(final long index) {
if (index >= size) throw new IndexOutOfBoundsException("Index (" + index + ") is greater than or equal to list size (" + size + ")");
final K old = BigArrays.get(a, index);
size--;
if (index != size) BigArrays.copy(a, index + 1, a, index, size - index);
BigArrays.set(a, size, null);
assert size <= length(a);
return old;
}
@Override
public boolean remove(final Object k) {
final long index = indexOf(k);
if (index == -1) return false;
remove(index);
assert size <= length(a);
return true;
}
@Override
public K set(final long index, final K k) {
if (index >= size) throw new IndexOutOfBoundsException("Index (" + index + ") is greater than or equal to list size (" + size + ")");
K old = BigArrays.get(a, index);
BigArrays.set(a, index, k);
return old;
}
@Override
public boolean removeAll(final Collection c) {
K[] s = null, d = null;
int ss = -1, sd = BigArrays.SEGMENT_SIZE, ds = -1, dd = BigArrays.SEGMENT_SIZE;
for (long i = 0; i < size; i++) {
if (sd == BigArrays.SEGMENT_SIZE) {
sd = 0;
s = a[++ss];
}
if (!c.contains((s[sd]))) {
if (dd == BigArrays.SEGMENT_SIZE) {
d = a[++ds];
dd = 0;
}
d[dd++] = s[sd];
}
sd++;
}
final long j = BigArrays.index(ds, dd);
BigArrays.fill(a, j, size, null);
final boolean modified = size != j;
size = j;
return modified;
}
@Override
public boolean addAll(long index, final Collection c) {
if (c instanceof ObjectList) {
return addAll(index, (ObjectList)c);
}
if (c instanceof ObjectBigList) {
return addAll(index, (ObjectBigList)c);
}
ensureIndex(index);
int n = c.size();
if (n == 0) return false;
grow(size + n);
BigArrays.copy(a, index, a, index + n, size - index);
final Iterator i = c.iterator();
size += n;
assert size <= length(a);
while (n-- != 0) BigArrays.set(a, index++, i.next());
return true;
}
@Override
public boolean addAll(final long index, final ObjectBigList list) {
ensureIndex(index);
final long n = list.size64();
if (n == 0) return false;
grow(size + n);
BigArrays.copy(a, index, a, index + n, size - index);
list.getElements(0, a, index, n);
size += n;
assert size <= length(a);
return true;
}
@Override
public boolean addAll(final long index, final ObjectList list) {
ensureIndex(index);
int n = list.size();
if (n == 0) return false;
grow(size + n);
BigArrays.copy(a, index, a, index + n, size - index);
size += n;
assert size <= length(a);
int segment = BigArrays.segment(index);
int displ = BigArrays.displacement(index);
int pos = 0;
while (n > 0) {
final int l = Math.min(a[segment].length - displ, n);
list.getElements(pos, a[segment], displ, l);
if ((displ += l) == BigArrays.SEGMENT_SIZE) {
displ = 0;
segment++;
}
pos += l;
n -= l;
}
return true;
}
@Override
public void clear() {
BigArrays.fill(a, 0, size, null);
size = 0;
assert size <= length(a);
}
@Override
public long size64() {
return size;
}
@Override
public void size(final long size) {
if (size > length(a)) a = BigArrays.forceCapacity(a, size, this.size);
if (size > this.size) BigArrays.fill(a, this.size, size, (null));
else BigArrays.fill(a, size, this.size, (null));
this.size = size;
}
@Override
public boolean isEmpty() {
return size == 0;
}
/**
* Trims this big-array big list so that the capacity is equal to the size.
*
* @see java.util.ArrayList#trimToSize()
*/
public void trim() {
trim(0);
}
/**
* Trims the backing big array if it is too large.
*
* If the current big array length is smaller than or equal to {@code n}, this method does nothing.
* Otherwise, it trims the big-array length to the maximum between {@code n} and {@link #size64()}.
*
*
* This method is useful when reusing big lists. {@linkplain #clear() Clearing a big list} leaves
* the big-array length untouched. If you are reusing a big list many times, you can call this
* method with a typical size to avoid keeping around a very large big array just because of a few
* large transient big lists.
*
* @param n the threshold for the trimming.
*/
public void trim(final long n) {
final long arrayLength = length(a);
if (n >= arrayLength || size == arrayLength) return;
a = BigArrays.trim(a, Math.max(n, size));
assert size <= length(a);
}
private class SubList extends AbstractObjectBigList.ObjectRandomAccessSubList {
private static final long serialVersionUID = -3185226345314976296L;
protected SubList(long from, long to) {
super(ObjectBigArrayBigList.this, from, to);
}
// Needed because we can't access the parent class' instance variables directly in a different
// instance of SubList.
private K[][] getParentArray() {
return a;
}
// Most of the inherited methods should be fine, but we can override a few of them for performance.
@Override
public K get(long i) {
ensureRestrictedIndex(i);
return BigArrays.get(a, i + from);
}
private final class SubListIterator extends ObjectBigListIterators.AbstractIndexBasedBigListIterator {
// We are using pos == 0 to be 0 relative to SubList.from (meaning you need to do a[from + i] when
// accessing array).
SubListIterator(long index) {
super(0, index);
}
@Override
protected final K get(long i) {
return BigArrays.get(a, from + i);
}
@Override
protected final void add(long i, K k) {
SubList.this.add(i, k);
}
@Override
protected final void set(long i, K k) {
SubList.this.set(i, k);
}
@Override
protected final void remove(long i) {
SubList.this.remove(i);
}
@Override
protected final long getMaxPos() {
return to - from;
}
@Override
public K next() {
if (!hasNext()) throw new NoSuchElementException();
return BigArrays.get(a, from + (lastReturned = pos++));
}
@Override
public K previous() {
if (!hasPrevious()) throw new NoSuchElementException();
return BigArrays.get(a, from + (lastReturned = --pos));
}
@Override
public void forEachRemaining(final Consumer action) {
final long max = to - from;
while (pos < max) {
action.accept(BigArrays.get(a, from + (lastReturned = pos++)));
}
}
}
@Override
public ObjectBigListIterator listIterator(long index) {
return new SubListIterator(index);
}
private final class SubListSpliterator extends ObjectBigSpliterators.LateBindingSizeIndexBasedSpliterator {
// We are using pos == 0 to be 0 relative to real array 0
SubListSpliterator() {
super(from);
}
private SubListSpliterator(long pos, long maxPos) {
super(pos, maxPos);
}
@Override
protected final long getMaxPosFromBackingStore() {
return to;
}
@Override
protected final K get(long i) {
return BigArrays.get(a, i);
}
@Override
protected final SubListSpliterator makeForSplit(long pos, long maxPos) {
return new SubListSpliterator(pos, maxPos);
}
@Override
protected final long computeSplitPoint() {
long defaultSplit = super.computeSplitPoint();
// Align to outer array starting point if possible.
// We add/subtract one to the bounds to ensure the new pos will always shrink the range
return BigArrays.nearestSegmentStart(defaultSplit, pos + 1, getMaxPos() - 1);
}
@Override
public boolean tryAdvance(final Consumer action) {
if (pos >= getMaxPos()) return false;
action.accept(BigArrays.get(a, pos++));
return true;
}
@Override
public void forEachRemaining(final Consumer action) {
final long max = getMaxPos();
while (pos < max) {
action.accept(BigArrays.get(a, pos++));
}
}
}
@Override
public ObjectSpliterator spliterator() {
return new SubListSpliterator();
}
boolean contentsEquals(K[][] otherA, long otherAFrom, long otherATo) {
if (a == otherA && from == otherAFrom && to == otherATo) return true;
if (otherATo - otherAFrom != size64()) {
return false;
}
long pos = to, otherPos = otherATo;
// We have already assured that the two ranges are the same size, so we only need to check one
// bound.
// If BigArrays.equals ever gets an overload that accepts bounds, use that instead
// (but make sure to break out the reference equality case).
while (--pos >= from) if (!java.util.Objects.equals(BigArrays.get(a, pos), BigArrays.get(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 BigList)) return false;
if (o instanceof ObjectBigArrayBigList) {
@SuppressWarnings("unchecked")
ObjectBigArrayBigList other = (ObjectBigArrayBigList)o;
return contentsEquals(other.a, 0, other.size64());
}
if (o instanceof ObjectBigArrayBigList.SubList) {
@SuppressWarnings("unchecked")
ObjectBigArrayBigList.SubList other = (ObjectBigArrayBigList.SubList)o;
return contentsEquals(other.getParentArray(), other.from, other.to);
}
return super.equals(o);
}
@SuppressWarnings("unchecked")
int contentsCompareTo(K[][] otherA, long otherAFrom, long otherATo) {
// TODO When minimum version of Java becomes Java 9, use Arrays.compare, which vectorizes.
K e1, e2;
int r;
long i, j;
for (i = from, j = otherAFrom; i < to && i < otherATo; i++, j++) {
e1 = BigArrays.get(a, i);
e2 = BigArrays.get(otherA, j);
if ((r = (((Comparable)(e1)).compareTo(e2))) != 0) return r;
}
return i < otherATo ? -1 : (i < to ? 1 : 0);
}
@SuppressWarnings("unchecked")
@Override
public int compareTo(final BigList l) {
if (l instanceof ObjectBigArrayBigList) {
@SuppressWarnings("unchecked")
ObjectBigArrayBigList other = (ObjectBigArrayBigList)l;
return contentsCompareTo(other.a, 0, other.size64());
}
if (l instanceof ObjectBigArrayBigList.SubList) {
@SuppressWarnings("unchecked")
ObjectBigArrayBigList.SubList other = (ObjectBigArrayBigList.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 ObjectBigList subList(long from, long to) {
if (from == 0 && to == size64()) 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 big array using optimized system calls.
*
* @param from the start index (inclusive).
* @param a the destination big 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 long from, final Object[][] a, final long offset, final long length) {
BigArrays.copy(this.a, from, a, offset, length);
}
/**
* 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 long from, final Object[] a, final int offset, final int length) {
BigArrays.copyFromBig(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 long from, final long to) {
BigArrays.ensureFromTo(size, from, to);
BigArrays.copy(a, to, a, from, size - to);
size -= (to - from);
BigArrays.fill(a, size, size + to - from, null);
}
/**
* Adds elements to this type-specific list using optimized system calls.
*
* @param index the index at which to add elements.
* @param a the big 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 long index, final K a[][], final long offset, final long length) {
ensureIndex(index);
BigArrays.ensureOffsetLength(a, offset, length);
grow(size + length);
BigArrays.copy(this.a, index, this.a, index + length, size - index);
BigArrays.copy(a, offset, this.a, index, length);
size += length;
}
/**
* Copies elements in the given big array into this type-specific list using optimized system calls.
*
* @param index the start index (inclusive).
* @param a the destination big 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 setElements(final long index, final Object[][] a, final long offset, final long length) {
BigArrays.copy(a, offset, this.a, index, length);
}
@Override
public void forEach(final Consumer action) {
for (long i = 0; i < size; ++i) {
action.accept(BigArrays.get(a, i));
}
}
@Override
public ObjectBigListIterator listIterator(final long index) {
ensureIndex(index);
return new ObjectBigListIterator() {
long pos = index, last = -1;
@Override
public boolean hasNext() {
return pos < size;
}
@Override
public boolean hasPrevious() {
return pos > 0;
}
@Override
public K next() {
if (!hasNext()) throw new NoSuchElementException();
return BigArrays.get(a, last = pos++);
}
@Override
public K previous() {
if (!hasPrevious()) throw new NoSuchElementException();
return BigArrays.get(a, last = --pos);
}
@Override
public long nextIndex() {
return pos;
}
@Override
public long previousIndex() {
return pos - 1;
}
@Override
public void add(K k) {
ObjectBigArrayBigList.this.add(pos++, k);
last = -1;
}
@Override
public void set(K k) {
if (last == -1) throw new IllegalStateException();
ObjectBigArrayBigList.this.set(last, k);
}
@Override
public void remove() {
if (last == -1) throw new IllegalStateException();
ObjectBigArrayBigList.this.remove(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 Consumer action) {
while (pos < size) {
action.accept(BigArrays.get(a, last = pos++));
}
}
@Override
public long back(long n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
final long remaining = size - pos;
if (n < remaining) {
pos -= n;
} else {
n = remaining;
pos = 0;
}
last = pos;
return n;
}
@Override
public long skip(long n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
final long remaining = size - pos;
if (n < remaining) {
pos += n;
} else {
n = remaining;
pos = size;
}
last = pos - 1;
return n;
}
};
}
private final class Spliterator implements ObjectSpliterator {
// 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;
long pos, max;
public Spliterator() {
this(0, ObjectBigArrayBigList.this.size, false);
}
private Spliterator(long pos, long max, boolean hasSplit) {
assert pos <= max : "pos " + pos + " must be <= max " + max;
this.pos = pos;
this.max = max;
this.hasSplit = hasSplit;
}
private long getWorkingMax() {
return hasSplit ? max : ObjectBigArrayBigList.this.size;
}
@Override
public int characteristics() {
return ObjectSpliterators.LIST_SPLITERATOR_CHARACTERISTICS;
}
@Override
public long estimateSize() {
return getWorkingMax() - pos;
}
@Override
public boolean tryAdvance(final Consumer action) {
if (pos >= getWorkingMax()) return false;
action.accept(BigArrays.get(a, pos++));
return true;
}
@Override
public void forEachRemaining(final Consumer action) {
for (final long max = getWorkingMax(); pos < max; ++pos) {
action.accept(BigArrays.get(a, pos));
}
}
@Override
public long skip(long n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
final long max = getWorkingMax();
if (pos >= max) return 0;
final long remaining = max - pos;
if (n < remaining) {
pos += n;
return n;
}
n = remaining;
pos = max;
return n;
}
@Override
public ObjectSpliterator trySplit() {
final long max = getWorkingMax();
long 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;
long myNewPos = pos + retLen;
// Align to an outer array boundary if possible
// We add/subtract one to the bounds to ensure the new pos will always shrink the range
myNewPos = BigArrays.nearestSegmentStart(myNewPos, pos + 1, max - 1);
long retMax = myNewPos;
long oldPos = pos;
this.pos = myNewPos;
this.hasSplit = true;
return new Spliterator(oldPos, retMax, true);
}
}
@Override
public ObjectSpliterator spliterator() {
return new Spliterator();
}
@SuppressWarnings("unchecked")
@Override
public ObjectBigArrayBigList clone() {
ObjectBigArrayBigList c;
// Test for fastpath we can do if exactly an BigArrayBigList
if (getClass() == ObjectBigArrayBigList.class) {
c = new ObjectBigArrayBigList<>(size);
c.size = size;
} else {
try {
c = (ObjectBigArrayBigList)super.clone();
} catch (CloneNotSupportedException e) {
// Can't happen
throw new InternalError(e);
}
c.a = (K[][])ObjectBigArrays.newBigArray(size);
}
BigArrays.copy(a, 0, c.a, 0, size);
return c;
}
/**
* Compares this type-specific big-array list to another one.
*
*
* This method exists only for sake of efficiency. The implementation inherited from the abstract
* implementation would already work.
*
* @param l a type-specific big-array list.
* @return true if the argument contains the same elements of this type-specific big-array list.
*/
public boolean equals(final ObjectBigArrayBigList l) {
if (l == this) return true;
long s = size64();
if (s != l.size64()) return false;
final K[][] a1 = a;
final K[][] a2 = l.a;
// Already checked s == l.size64 above
if (a1 == a2) return true;
// Backwards loop is faster then forwards loop, at least in Java 8 and below.
while (s-- != 0) if (!java.util.Objects.equals(BigArrays.get(a1, s), BigArrays.get(a2, s))) return false;
return true;
}
@SuppressWarnings({ "unchecked", "unlikely-arg-type" })
@Override
public boolean equals(final Object o) {
if (o == this) return true;
if (o == null) return false;
if (!(o instanceof BigList)) return false;
if (o instanceof ObjectBigArrayBigList) {
// Safe cast because we are only going to take elements from other list, never give them
return equals((ObjectBigArrayBigList)o);
}
if (o instanceof ObjectBigArrayBigList.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 ((ObjectBigArrayBigList.SubList)o).equals(this);
}
return super.equals(o);
}
/**
* Compares this big list to another big list.
*
*
* This method exists only for sake of efficiency. The implementation inherited from the abstract
* implementation would already work.
*
* @param l a big list.
* @return a negative integer, zero, or a positive integer as this big list is lexicographically
* less than, equal to, or greater than the argument.
*/
@SuppressWarnings("unchecked")
public int compareTo(final ObjectBigArrayBigList l) {
final long s1 = size64(), s2 = l.size64();
final K a1[][] = a, a2[][] = l.a;
K e1, e2;
int r, i;
for (i = 0; i < s1 && i < s2; i++) {
e1 = BigArrays.get(a1, i);
e2 = BigArrays.get(a2, i);
if ((r = (((Comparable)(e1)).compareTo(e2))) != 0) return r;
}
return i < s2 ? -1 : (i < s1 ? 1 : 0);
}
@SuppressWarnings("unchecked")
@Override
public int compareTo(final BigList l) {
if (l instanceof ObjectBigArrayBigList) {
return compareTo((ObjectBigArrayBigList)l);
}
if (l instanceof ObjectBigArrayBigList.SubList) {
// Must negate because we are inverting the order of the comparison.
return -((ObjectBigArrayBigList.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.writeObject(BigArrays.get(a, i));
}
@SuppressWarnings("unchecked")
private void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException {
s.defaultReadObject();
a = (K[][])ObjectBigArrays.newBigArray(size);
for (int i = 0; i < size; i++) BigArrays.set(a, i, (K)s.readObject());
}
}