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src/java.base/share/classes/java/util/ArrayList.java
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rev 54801 : [mq]: 8223593-Refactor-code-for-reallocating-storage
@@ -1,7 +1,7 @@
/*
- * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
@@ -27,10 +27,11 @@
import java.util.function.Consumer;
import java.util.function.Predicate;
import java.util.function.UnaryOperator;
import jdk.internal.access.SharedSecrets;
+import jdk.internal.util.ArraysSupport;
/**
* Resizable-array implementation of the {@code List} interface. Implements
* all optional list operations, and permits all elements, including
* {@code null}. In addition to implementing the {@code List} interface,
@@ -217,67 +218,32 @@
grow(minCapacity);
}
}
/**
- * The maximum size of array to allocate (unless necessary).
- * Some VMs reserve some header words in an array.
- * Attempts to allocate larger arrays may result in
- * OutOfMemoryError: Requested array size exceeds VM limit
- */
- private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
-
- /**
* Increases the capacity to ensure that it can hold at least the
* number of elements specified by the minimum capacity argument.
*
* @param minCapacity the desired minimum capacity
* @throws OutOfMemoryError if minCapacity is less than zero
*/
private Object[] grow(int minCapacity) {
- return elementData = Arrays.copyOf(elementData,
- newCapacity(minCapacity));
+ int oldCapacity = elementData.length;
+ if (oldCapacity > 0 || elementData != DEFAULTCAPACITY_EMPTY_ELEMENTDATA) {
+ int newCapacity = ArraysSupport.newCapacity(oldCapacity,
+ minCapacity - oldCapacity, oldCapacity >> 1);
+ return elementData = Arrays.copyOf(elementData, newCapacity);
+ } else {
+ return elementData = new Object[Math.max(DEFAULT_CAPACITY, minCapacity)];
+ }
}
private Object[] grow() {
return grow(size + 1);
}
/**
- * Returns a capacity at least as large as the given minimum capacity.
- * Returns the current capacity increased by 50% if that suffices.
- * Will not return a capacity greater than MAX_ARRAY_SIZE unless
- * the given minimum capacity is greater than MAX_ARRAY_SIZE.
- *
- * @param minCapacity the desired minimum capacity
- * @throws OutOfMemoryError if minCapacity is less than zero
- */
- private int newCapacity(int minCapacity) {
- // overflow-conscious code
- int oldCapacity = elementData.length;
- int newCapacity = oldCapacity + (oldCapacity >> 1);
- if (newCapacity - minCapacity <= 0) {
- if (elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA)
- return Math.max(DEFAULT_CAPACITY, minCapacity);
- if (minCapacity < 0) // overflow
- throw new OutOfMemoryError();
- return minCapacity;
- }
- return (newCapacity - MAX_ARRAY_SIZE <= 0)
- ? newCapacity
- : hugeCapacity(minCapacity);
- }
-
- private static int hugeCapacity(int minCapacity) {
- if (minCapacity < 0) // overflow
- throw new OutOfMemoryError();
- return (minCapacity > MAX_ARRAY_SIZE)
- ? Integer.MAX_VALUE
- : MAX_ARRAY_SIZE;
- }
-
- /**
* Returns the number of elements in this list.
*
* @return the number of elements in this list
*/
public int size() {
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