org.apache.flink.runtime.util.IntArrayList Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.flink.runtime.util;
import java.util.Arrays;
import java.util.NoSuchElementException;
/**
* Minimal implementation of an array-backed list of ints
*/
public class IntArrayList {
private int size;
private int[] array;
public IntArrayList(final int capacity) {
this.size = 0;
this.array = new int[capacity];
}
public int size() {
return size;
}
public boolean add(final int number) {
grow(size+1);
array[size++] = number;
return true;
}
public int removeLast() {
if (size == 0) {
throw new NoSuchElementException();
}
--size;
return array[size];
}
public void clear() {
size = 0;
}
public boolean isEmpty() {
return size == 0;
}
private void grow(final int length) {
if(length > array.length) {
final int newLength = (int)Math.max(Math.min(2L * array.length, Integer.MAX_VALUE-8), length);
final int[] t = new int[newLength];
System.arraycopy(array, 0, t, 0, size);
array = t;
}
}
public int[] toArray() {
return Arrays.copyOf(array, size);
}
public static final IntArrayList EMPTY = new IntArrayList(0) {
@Override
public boolean add(int number) {
throw new UnsupportedOperationException();
}
@Override
public int removeLast() {
throw new UnsupportedOperationException();
};
};
}