--- jsr166/src/main/java/util/ArrayList.java 2018/01/26 06:09:23 1.56 +++ jsr166/src/main/java/util/ArrayList.java 2020/01/10 21:32:08 1.70 @@ -1,5 +1,5 @@ /* - * Copyright (c) 1997, 2017, 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 @@ -28,7 +28,8 @@ package java.util; import java.util.function.Consumer; import java.util.function.Predicate; import java.util.function.UnaryOperator; -import jdk.internal.misc.SharedSecrets; +// OPENJDK import jdk.internal.access.SharedSecrets; +import jdk.internal.util.ArraysSupport; /** * Resizable-array implementation of the {@code List} interface. Implements @@ -92,7 +93,7 @@ import jdk.internal.misc.SharedSecrets; * should be used only to detect bugs. * *

This class is a member of the - * + * * Java Collections Framework. * * @param the type of elements in this list @@ -108,6 +109,7 @@ import jdk.internal.misc.SharedSecrets; public class ArrayList extends AbstractList implements List, RandomAccess, Cloneable, java.io.Serializable { + // OPENJDK @java.io.Serial private static final long serialVersionUID = 8683452581122892189L; /** @@ -219,14 +221,6 @@ public class ArrayList extends Abstra } /** - * 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. * @@ -234,8 +228,15 @@ public class ArrayList extends Abstra * @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.newLength(oldCapacity, + minCapacity - oldCapacity, /* minimum growth */ + oldCapacity >> 1 /* preferred growth */); + return elementData = Arrays.copyOf(elementData, newCapacity); + } else { + return elementData = new Object[Math.max(DEFAULT_CAPACITY, minCapacity)]; + } } private Object[] grow() { @@ -243,39 +244,6 @@ public class ArrayList extends Abstra } /** - * 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 @@ -314,14 +282,23 @@ public class ArrayList extends Abstra * or -1 if there is no such index. */ public int indexOf(Object o) { + return indexOfRange(o, 0, size); + } + + int indexOfRange(Object o, int start, int end) { + Object[] es = elementData; if (o == null) { - for (int i = 0; i < size; i++) - if (elementData[i]==null) + for (int i = start; i < end; i++) { + if (es[i] == null) { return i; + } + } } else { - for (int i = 0; i < size; i++) - if (o.equals(elementData[i])) + for (int i = start; i < end; i++) { + if (o.equals(es[i])) { return i; + } + } } return -1; } @@ -334,14 +311,23 @@ public class ArrayList extends Abstra * or -1 if there is no such index. */ public int lastIndexOf(Object o) { + return lastIndexOfRange(o, 0, size); + } + + int lastIndexOfRange(Object o, int start, int end) { + Object[] es = elementData; if (o == null) { - for (int i = size-1; i >= 0; i--) - if (elementData[i]==null) + for (int i = end - 1; i >= start; i--) { + if (es[i] == null) { return i; + } + } } else { - for (int i = size-1; i >= 0; i--) - if (o.equals(elementData[i])) + for (int i = end - 1; i >= start; i--) { + if (o.equals(es[i])) { return i; + } + } } return -1; } @@ -526,6 +512,93 @@ public class ArrayList extends Abstra } /** + * {@inheritDoc} + */ + public boolean equals(Object o) { + if (o == this) { + return true; + } + + if (!(o instanceof List)) { + return false; + } + + final int expectedModCount = modCount; + // ArrayList can be subclassed and given arbitrary behavior, but we can + // still deal with the common case where o is ArrayList precisely + boolean equal = (o.getClass() == ArrayList.class) + ? equalsArrayList((ArrayList) o) + : equalsRange((List) o, 0, size); + + checkForComodification(expectedModCount); + return equal; + } + + boolean equalsRange(List other, int from, int to) { + final Object[] es = elementData; + if (to > es.length) { + throw new ConcurrentModificationException(); + } + var oit = other.iterator(); + for (; from < to; from++) { + if (!oit.hasNext() || !Objects.equals(es[from], oit.next())) { + return false; + } + } + return !oit.hasNext(); + } + + private boolean equalsArrayList(ArrayList other) { + final int otherModCount = other.modCount; + final int s = size; + boolean equal; + if (equal = (s == other.size)) { + final Object[] otherEs = other.elementData; + final Object[] es = elementData; + if (s > es.length || s > otherEs.length) { + throw new ConcurrentModificationException(); + } + for (int i = 0; i < s; i++) { + if (!Objects.equals(es[i], otherEs[i])) { + equal = false; + break; + } + } + } + other.checkForComodification(otherModCount); + return equal; + } + + private void checkForComodification(final int expectedModCount) { + if (modCount != expectedModCount) { + throw new ConcurrentModificationException(); + } + } + + /** + * {@inheritDoc} + */ + public int hashCode() { + int expectedModCount = modCount; + int hash = hashCodeRange(0, size); + checkForComodification(expectedModCount); + return hash; + } + + int hashCodeRange(int from, int to) { + final Object[] es = elementData; + if (to > es.length) { + throw new ConcurrentModificationException(); + } + int hashCode = 1; + for (int i = from; i < to; i++) { + Object e = es[i]; + hashCode = 31 * hashCode + (e == null ? 0 : e.hashCode()); + } + return hashCode; + } + + /** * Removes the first occurrence of the specified element from this list, * if it is present. If the list does not contain the element, it is * unchanged. More formally, removes the element with the lowest index @@ -783,6 +856,7 @@ public class ArrayList extends Abstra * instance is emitted (int), followed by all of its elements * (each an {@code Object}) in the proper order. */ + // OPENJDK @java.io.Serial private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException { // Write out element count, and any hidden stuff @@ -810,6 +884,7 @@ public class ArrayList extends Abstra * could not be found * @throws java.io.IOException if an I/O error occurs */ + // OPENJDK @java.io.Serial private void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException { @@ -821,7 +896,7 @@ public class ArrayList extends Abstra if (size > 0) { // like clone(), allocate array based upon size not capacity - SharedSecrets.getJavaObjectInputStreamAccess().checkArray(s, Object[].class, size); + jsr166.Platform.checkArray(s, Object[].class, size); Object[] elements = new Object[size]; // Read in all elements in the proper order. @@ -1064,7 +1139,7 @@ public class ArrayList extends Abstra this.parent = parent; this.offset = parent.offset + fromIndex; this.size = toIndex - fromIndex; - this.modCount = root.modCount; + this.modCount = parent.modCount; } public E set(int index, E element) { @@ -1122,6 +1197,10 @@ public class ArrayList extends Abstra return true; } + public void replaceAll(UnaryOperator operator) { + root.replaceAllRange(operator, offset, offset + size); + } + public boolean removeAll(Collection c) { return batchRemove(c, false); } @@ -1166,6 +1245,42 @@ public class ArrayList extends Abstra return a; } + public boolean equals(Object o) { + if (o == this) { + return true; + } + + if (!(o instanceof List)) { + return false; + } + + boolean equal = root.equalsRange((List)o, offset, offset + size); + checkForComodification(); + return equal; + } + + public int hashCode() { + int hash = root.hashCodeRange(offset, offset + size); + checkForComodification(); + return hash; + } + + public int indexOf(Object o) { + int index = root.indexOfRange(o, offset, offset + size); + checkForComodification(); + return index >= 0 ? index - offset : -1; + } + + public int lastIndexOf(Object o) { + int index = root.lastIndexOfRange(o, offset, offset + size); + checkForComodification(); + return index >= 0 ? index - offset : -1; + } + + public boolean contains(Object o) { + return indexOf(o) >= 0; + } + public Iterator iterator() { return listIterator(); } @@ -1177,7 +1292,7 @@ public class ArrayList extends Abstra return new ListIterator() { int cursor = index; int lastRet = -1; - int expectedModCount = root.modCount; + int expectedModCount = SubList.this.modCount; public boolean hasNext() { return cursor != SubList.this.size; @@ -1221,7 +1336,7 @@ public class ArrayList extends Abstra final Object[] es = root.elementData; if (offset + i >= es.length) throw new ConcurrentModificationException(); - for (; i < size && modCount == expectedModCount; i++) + for (; i < size && root.modCount == expectedModCount; i++) action.accept(elementAt(es, offset + i)); // update once at end to reduce heap write traffic cursor = i; @@ -1247,7 +1362,7 @@ public class ArrayList extends Abstra SubList.this.remove(lastRet); cursor = lastRet; lastRet = -1; - expectedModCount = root.modCount; + expectedModCount = SubList.this.modCount; } catch (IndexOutOfBoundsException ex) { throw new ConcurrentModificationException(); } @@ -1273,7 +1388,7 @@ public class ArrayList extends Abstra SubList.this.add(i, e); cursor = i + 1; lastRet = -1; - expectedModCount = root.modCount; + expectedModCount = SubList.this.modCount; } catch (IndexOutOfBoundsException ex) { throw new ConcurrentModificationException(); } @@ -1591,15 +1706,19 @@ public class ArrayList extends Abstra @Override public void replaceAll(UnaryOperator operator) { + replaceAllRange(operator, 0, size); + // TODO(8203662): remove increment of modCount from ... + modCount++; + } + + private void replaceAllRange(UnaryOperator operator, int i, int end) { Objects.requireNonNull(operator); final int expectedModCount = modCount; final Object[] es = elementData; - final int size = this.size; - for (int i = 0; modCount == expectedModCount && i < size; i++) + for (; modCount == expectedModCount && i < end; i++) es[i] = operator.apply(elementAt(es, i)); if (modCount != expectedModCount) throw new ConcurrentModificationException(); - modCount++; // checkInvariants(); }