com.fluxtion.agrona.collections.IntArrayList Maven / Gradle / Ivy
/*
* Copyright 2014-2024 Real Logic Limited.
*
* 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
*
* https://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 com.fluxtion.agrona.collections;
import com.fluxtion.agrona.generation.DoNotSub;
import java.util.AbstractList;
import java.util.Arrays;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.RandomAccess;
import java.util.function.Consumer;
import java.util.function.IntConsumer;
import java.util.function.IntPredicate;
import java.util.stream.IntStream;
import static java.util.Objects.requireNonNull;
/**
* A {@link List} implementation that stores int values with the ability to not have them boxed.
*/
public class IntArrayList extends AbstractList implements List, RandomAccess
{
/**
* The default value that will be used in place of null for an element.
*/
public static final int DEFAULT_NULL_VALUE = Integer.MIN_VALUE;
/**
* Initial capacity to which the array will be sized.
*/
@DoNotSub public static final int INITIAL_CAPACITY = 10;
private final int nullValue;
@DoNotSub private int size = 0;
private int[] elements;
/**
* Constructs a new list with the {@link #INITIAL_CAPACITY} using {@link #DEFAULT_NULL_VALUE}.
*/
public IntArrayList()
{
this(INITIAL_CAPACITY, DEFAULT_NULL_VALUE);
}
/**
* Construct a new list.
*
* @param initialCapacity for the backing array.
* @param nullValue to be used to represent a null element.
*/
public IntArrayList(
@DoNotSub final int initialCapacity,
final int nullValue)
{
this.nullValue = nullValue;
elements = new int[Math.max(initialCapacity, INITIAL_CAPACITY)];
}
/**
* Create a new list that wraps an existing arrays without copying it.
*
* @param initialElements to be wrapped.
* @param initialSize of the array to wrap.
* @param nullValue to be used to represent a null element.
*/
@SuppressWarnings("this-escape")
public IntArrayList(
final int[] initialElements,
@DoNotSub final int initialSize,
final int nullValue)
{
wrap(initialElements, initialSize);
this.nullValue = nullValue;
}
/**
* Wrap an existing array without copying it.
*
* @param initialElements to be wrapped.
* @param initialSize of the array to wrap.
* @throws IllegalArgumentException if the initialSize is less than 0 or greater than the length of the
* initial array.
*/
public void wrap(
final int[] initialElements,
final @DoNotSub int initialSize)
{
if (initialSize < 0 || initialSize > initialElements.length)
{
throw new IllegalArgumentException(
"illegal initial size " + initialSize + " for array length of " + initialElements.length);
}
elements = initialElements;
size = initialSize;
}
/**
* The value representing a null element.
*
* @return value representing a null element.
*/
public int nullValue()
{
return nullValue;
}
/**
* {@inheritDoc}
*/
@DoNotSub public int size()
{
return size;
}
/**
* The current capacity for the collection.
*
* @return the current capacity for the collection.
*/
@DoNotSub public int capacity()
{
return elements.length;
}
/**
* {@inheritDoc}
*/
public void clear()
{
size = 0;
}
/**
* Trim the underlying array to be the current size, or {@link #INITIAL_CAPACITY} if size is less.
*/
public void trimToSize()
{
if (elements.length != size && elements.length > INITIAL_CAPACITY)
{
elements = Arrays.copyOf(elements, Math.max(INITIAL_CAPACITY, size));
}
}
/**
* {@inheritDoc}
*/
public Integer get(
@DoNotSub final int index)
{
final int value = getInt(index);
return nullValue == value ? null : value;
}
/**
* Get the element at a given index without boxing.
*
* @param index to get.
* @return the unboxed element.
*/
public int getInt(
@DoNotSub final int index)
{
checkIndex(index);
return elements[index];
}
/**
* {@inheritDoc}
*/
public boolean add(final Integer element)
{
return addInt(null == element ? nullValue : element);
}
/**
* Add an element without boxing.
*
* @param element to be added.
* @return true
*/
public boolean addInt(final int element)
{
ensureCapacityPrivate(size + 1);
elements[size] = element;
size++;
return true;
}
/**
* {@inheritDoc}
*/
public void add(
@DoNotSub final int index,
final Integer element)
{
addInt(index, null == element ? nullValue : element);
}
/**
* Add an element without boxing at a given index.
*
* @param index at which the element should be added.
* @param element to be added.
*/
public void addInt(
@DoNotSub final int index,
final int element)
{
checkIndexForAdd(index);
@DoNotSub final int requiredSize = size + 1;
ensureCapacityPrivate(requiredSize);
if (index < size)
{
System.arraycopy(elements, index, elements, index + 1, size - index);
}
elements[index] = element;
size++;
}
/**
* {@inheritDoc}
*/
public Integer set(
@DoNotSub final int index,
final Integer element)
{
final int previous = setInt(index, null == element ? nullValue : element);
return nullValue == previous ? null : previous;
}
/**
* Set an element at a given index without boxing.
*
* @param index at which to set the element.
* @param element to be added.
* @return the previous element at the index.
*/
public int setInt(
@DoNotSub final int index,
final int element)
{
checkIndex(index);
final int previous = elements[index];
elements[index] = element;
return previous;
}
/**
* {@inheritDoc}
*/
public boolean contains(final Object o)
{
return containsInt(null == o ? nullValue : (int)o);
}
/**
* Does the list contain this element value.
*
* @param value of the element.
* @return true if present otherwise false.
*/
public boolean containsInt(final int value)
{
return -1 != indexOf(value);
}
/**
* Index of the first element with this value.
*
* @param value for the element.
* @return the index if found otherwise -1.
*/
public @DoNotSub int indexOf(
final int value)
{
final int[] elements = this.elements;
for (@DoNotSub int i = 0, size = this.size; i < size; i++)
{
if (value == elements[i])
{
return i;
}
}
return -1;
}
/**
* Index of the last element with this value.
*
* @param value for the element.
* @return the index if found otherwise -1.
*/
public @DoNotSub int lastIndexOf(
final int value)
{
final int[] elements = this.elements;
for (@DoNotSub int i = size - 1; i >= 0; i--)
{
if (value == elements[i])
{
return i;
}
}
return -1;
}
/**
* Appends all the elements in the specified list to the end of this list, in the order that they are stored in the
* specified list.
*
* @param list containing elements to be added to this list.
* @return {@code true} if this list changed as a result of the call.
*/
public boolean addAll(final IntArrayList list)
{
@DoNotSub final int numElements = list.size;
if (numElements > 0)
{
ensureCapacityPrivate(size + numElements);
System.arraycopy(list.elements, 0, elements, size, numElements);
size += numElements;
return true;
}
return false;
}
/**
* Inserts all the elements from the specified list to this list at the specified position. Shifts the element
* currently at that position (if any) and any subsequent elements to the right (increases their indices). The new
* elements will appear in this list in the order that they are stored in the specified list.
*
* @param index at which to insert the first element from the specified collection.
* @param list containing elements to be added to this list.
* @return {@code true} if this list changed as a result of the call.
*/
public boolean addAll(
@DoNotSub final int index,
final IntArrayList list)
{
checkIndexForAdd(index);
@DoNotSub final int numElements = list.size;
if (numElements > 0)
{
@DoNotSub final int size = this.size;
ensureCapacityPrivate(size + numElements);
final int[] elements = this.elements;
for (@DoNotSub int i = size - 1; i >= index; i--)
{
elements[i + numElements] = elements[i];
}
System.arraycopy(list.elements, 0, elements, index, numElements);
this.size += numElements;
return true;
}
return false;
}
/**
* Returns {@code true} if this list contains all the elements of the specified list.
*
* @param list to be checked for containment in this list.
* @return {@code true} if this list contains all the elements of the specified list.
*/
public boolean containsAll(final IntArrayList list)
{
final int[] listElements = list.elements;
final int listNullValue = list.nullValue;
final boolean hasNulls = contains(null);
for (@DoNotSub int i = 0, size = list.size; i < size; i++)
{
final int value = listElements[i];
if (!(containsInt(value) || hasNulls && listNullValue == value))
{
return false;
}
}
return true;
}
/**
* Retains only the elements in this list that are contained in the specified list. In other words, removes from
* this list all of its elements that are not contained in the specified list.
*
* @param list containing elements to be removed from this list.
* @return {@code true} if this list changed as a result of the call.
*/
public boolean retainAll(final IntArrayList list)
{
final int[] elements = this.elements;
@DoNotSub final int size = this.size;
if (size > 0)
{
if (list.isEmpty())
{
this.size = 0;
return true;
}
final int nullValue = this.nullValue;
final boolean listHasNulls = list.contains(null);
int[] filteredElements = null;
@DoNotSub int j = -1;
for (@DoNotSub int i = 0; i < size; i++)
{
final int value = elements[i];
if (!(list.containsInt(value) || (listHasNulls && nullValue == value)))
{
if (null == filteredElements)
{
filteredElements = Arrays.copyOf(elements, size);
j = i - 1;
}
}
else if (null != filteredElements)
{
filteredElements[++j] = value;
}
}
if (null != filteredElements)
{
this.elements = filteredElements;
this.size = j + 1;
return true;
}
}
return false;
}
/**
* Removes all of this collection's elements that are also contained in the specified list. After this call
* returns, this list will contain no elements in common with the specified list.
*
* @param list whose elements are to be removed from this list.
* @return {@code true} if this list changed as a result of the call.
*/
public boolean removeAll(final IntArrayList list)
{
final int[] elements = this.elements;
@DoNotSub final int size = this.size;
if (size > 0 && !list.isEmpty())
{
final int nullValue = this.nullValue;
final boolean listHasNulls = list.contains(null);
int[] filteredElements = null;
@DoNotSub int j = -1;
for (@DoNotSub int i = 0; i < size; i++)
{
final int value = elements[i];
if (list.containsInt(value) || (listHasNulls && nullValue == value))
{
if (null == filteredElements)
{
filteredElements = Arrays.copyOf(elements, size);
j = i - 1;
}
}
else if (null != filteredElements)
{
filteredElements[++j] = value;
}
}
if (null != filteredElements)
{
this.elements = filteredElements;
this.size = j + 1;
return true;
}
}
return false;
}
/**
* Removes all the elements of this collection that satisfy the given predicate.
*
* @param filter a predicate which returns true for elements to be removed.
* @return {@code true} if any elements were removed.
*/
public boolean removeIfInt(final IntPredicate filter)
{
requireNonNull(filter);
final int[] elements = this.elements;
@DoNotSub final int size = this.size;
if (size > 0)
{
int[] filteredElements = null;
@DoNotSub int j = -1;
for (@DoNotSub int i = 0; i < size; i++)
{
final int value = elements[i];
if (filter.test(value))
{
if (null == filteredElements)
{
filteredElements = Arrays.copyOf(elements, size);
j = i - 1;
}
}
else if (null != filteredElements)
{
filteredElements[++j] = value;
}
}
if (null != filteredElements)
{
this.elements = filteredElements;
this.size = j + 1;
return true;
}
}
return false;
}
/**
* {@inheritDoc}
*/
public boolean remove(final Object o)
{
return removeInt(null == o ? nullValue : (int)o);
}
/**
* Remove at a given index.
*
* @param index of the element to be removed.
* @return the existing value at this index.
*/
public Integer remove(
@DoNotSub final int index)
{
final int value = removeAt(index);
return nullValue == value ? null : value;
}
/**
* Remove at a given index.
*
* @param index of the element to be removed.
* @return the existing value at this index.
*/
public int removeAt(
@DoNotSub final int index)
{
checkIndex(index);
final int value = elements[index];
@DoNotSub final int moveCount = size - index - 1;
if (moveCount > 0)
{
System.arraycopy(elements, index + 1, elements, index, moveCount);
}
size--;
return value;
}
/**
* Removes element at index, but instead of copying all elements to the left,
* it replaces the item in the slot with the last item in the list. This avoids the copy
* costs at the expense of preserving list order. If index is the last element it is just removed.
*
* @param index of the element to be removed.
* @return the existing value at this index.
* @throws IndexOutOfBoundsException if index is out of bounds.
*/
public int fastUnorderedRemove(
@DoNotSub final int index)
{
checkIndex(index);
final int value = elements[index];
elements[index] = elements[--size];
return value;
}
/**
* Remove the first instance of a value if found in the list.
*
* Primitive specialization of the {@link List#remove(Object)} method.
*
* @param value to be removed.
* @return true if successful otherwise false.
*/
public boolean removeInt(final int value)
{
@DoNotSub final int index = indexOf(value);
if (-1 != index)
{
removeAt(index);
return true;
}
return false;
}
/**
* Remove the first instance of a value if found in the list and replaces it with the last item
* in the list. This saves a copy down of all items at the expense of not preserving list order.
*
* @param value to be removed.
* @return true if successful otherwise false.
*/
public boolean fastUnorderedRemoveInt(final int value)
{
@DoNotSub final int index = indexOf(value);
if (-1 != index)
{
elements[index] = elements[--size];
return true;
}
return false;
}
/**
* Push an element onto the end of the array like a stack.
*
* @param element to be pushed onto the end of the array.
*/
public void pushInt(final int element)
{
ensureCapacityPrivate(size + 1);
elements[size] = element;
size++;
}
/**
* Pop a value off the end of the array as a stack operation.
*
* @return the value at the end of the array.
* @throws NoSuchElementException if the array is empty.
*/
public int popInt()
{
if (isEmpty())
{
throw new NoSuchElementException();
}
return elements[--size];
}
/**
* For each element in order provide the int value to a {@link IntConsumer}.
*
* @param action to be taken for each element.
*/
public void forEachOrderedInt(final IntConsumer action)
{
final int[] elements = this.elements;
for (@DoNotSub int i = 0, size = this.size; i < size; i++)
{
action.accept(elements[i]);
}
}
/**
* Create a {@link IntStream} over the elements of underlying array.
*
* @return a {@link IntStream} over the elements of underlying array.
*/
public IntStream intStream()
{
return Arrays.stream(elements, 0, size);
}
/**
* Create a new array that is a copy of the elements.
*
* @return a copy of the elements.
*/
public int[] toIntArray()
{
return Arrays.copyOf(elements, size);
}
/**
* Create a new array that is a copy of the elements.
*
* @param dst destination array for the copy if it is the correct size.
* @return a copy of the elements.
*/
public int[] toIntArray(final int[] dst)
{
if (dst.length == size)
{
System.arraycopy(elements, 0, dst, 0, dst.length);
return dst;
}
else
{
return Arrays.copyOf(elements, size);
}
}
/**
* Ensure the backing array has a required capacity.
*
* @param requiredCapacity for the backing array.
*/
public void ensureCapacity(@DoNotSub final int requiredCapacity)
{
ensureCapacityPrivate(Math.max(requiredCapacity, INITIAL_CAPACITY));
}
/**
* Type-safe overload of the {@link #equals(Object)} method.
*
* @param that other list.
* @return {@code true} if lists are equal.
*/
public boolean equals(final IntArrayList that)
{
if (that == this)
{
return true;
}
boolean isEqual = false;
@DoNotSub final int size = this.size;
if (size == that.size)
{
isEqual = true;
final int[] elements = this.elements;
final int[] thatElements = that.elements;
for (@DoNotSub int i = 0; i < size; i++)
{
final int thisValue = elements[i];
final int thatValue = thatElements[i];
if (thisValue != thatValue)
{
if (thisValue != this.nullValue || thatValue != that.nullValue)
{
isEqual = false;
break;
}
}
}
}
return isEqual;
}
/**
* {@inheritDoc}
*/
public boolean equals(final Object other)
{
if (other == this)
{
return true;
}
boolean isEqual = false;
if (other instanceof IntArrayList)
{
return equals((IntArrayList)other);
}
else if (other instanceof List)
{
final List that = (List)other;
if (size == that.size())
{
isEqual = true;
@DoNotSub int i = 0;
for (final Object o : that)
{
if (null == o || o instanceof Integer)
{
final Integer thisValue = get(i++);
final Integer thatValue = (Integer)o;
if (Objects.equals(thisValue, thatValue))
{
continue;
}
}
isEqual = false;
break;
}
}
}
return isEqual;
}
/**
* {@inheritDoc}
*/
@DoNotSub public int hashCode()
{
@DoNotSub int hashCode = 1;
final int nullValue = this.nullValue;
final int[] elements = this.elements;
for (@DoNotSub int i = 0, size = this.size; i < size; i++)
{
final int value = elements[i];
hashCode = 31 * hashCode + (nullValue == value ? 0 : Integer.hashCode(value));
}
return hashCode;
}
/**
* {@inheritDoc}
*/
public void forEach(final Consumer action)
{
requireNonNull(action);
final int nullValue = this.nullValue;
final int[] elements = this.elements;
for (@DoNotSub int i = 0, size = this.size; i < size; i++)
{
final int value = elements[i];
action.accept(nullValue != value ? value : null);
}
}
/**
* Iterate over the collection without boxing.
*
* @param action to be taken for each element.
*/
public void forEachInt(final IntConsumer action)
{
requireNonNull(action);
final int[] elements = this.elements;
for (@DoNotSub int i = 0, size = this.size; i < size; i++)
{
action.accept(elements[i]);
}
}
/**
* {@inheritDoc}
*/
public String toString()
{
final StringBuilder sb = new StringBuilder();
sb.append('[');
final int nullValue = this.nullValue;
final int[] elements = this.elements;
for (@DoNotSub int i = 0, size = this.size; i < size; i++)
{
final int value = elements[i];
sb.append(value != nullValue ? value : null).append(", ");
}
if (sb.length() > 1)
{
sb.setLength(sb.length() - 2);
}
sb.append(']');
return sb.toString();
}
private void ensureCapacityPrivate(@DoNotSub final int requiredCapacity)
{
@DoNotSub final int currentCapacity = elements.length;
if (requiredCapacity > currentCapacity)
{
if (requiredCapacity > ArrayUtil.MAX_CAPACITY)
{
throw new IllegalStateException("max capacity: " + ArrayUtil.MAX_CAPACITY);
}
@DoNotSub int newCapacity = currentCapacity > INITIAL_CAPACITY ? currentCapacity : INITIAL_CAPACITY;
while (newCapacity < requiredCapacity)
{
newCapacity = newCapacity + (newCapacity >> 1);
if (newCapacity < 0 || newCapacity >= ArrayUtil.MAX_CAPACITY)
{
newCapacity = ArrayUtil.MAX_CAPACITY;
}
}
final int[] newElements = new int[newCapacity];
System.arraycopy(elements, 0, newElements, 0, currentCapacity);
elements = newElements;
}
}
private void checkIndex(@DoNotSub final int index)
{
if (index >= size || index < 0)
{
throw new IndexOutOfBoundsException("index=" + index + " size=" + size);
}
}
private void checkIndexForAdd(@DoNotSub final int index)
{
if (index > size || index < 0)
{
throw new IndexOutOfBoundsException("index=" + index + " size=" + size);
}
}
}