--- jsr166/src/main/java/util/Vector.java 2005/11/26 03:12:10 1.2 +++ jsr166/src/main/java/util/Vector.java 2018/05/05 18:29:53 1.50 @@ -1,63 +1,91 @@ /* - * %W% %E% + * Copyright (c) 1994, 2018, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * - * Copyright 2005 Sun Microsystems, Inc. All rights reserved. - * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. + * 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 + * particular file as subject to the "Classpath" exception as provided + * by Oracle in the LICENSE file that accompanied this code. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. */ package java.util; -import java.util.*; // for javadoc (till 6280605 is fixed) + +import java.io.IOException; +import java.io.ObjectInputStream; +import java.io.StreamCorruptedException; +import java.util.function.Consumer; +import java.util.function.Predicate; +import java.util.function.UnaryOperator; /** - * The Vector class implements a growable array of + * The {@code Vector} class implements a growable array of * objects. Like an array, it contains components that can be * accessed using an integer index. However, the size of a - * Vector can grow or shrink as needed to accommodate - * adding and removing items after the Vector has been created.

+ * {@code Vector} can grow or shrink as needed to accommodate + * adding and removing items after the {@code Vector} has been created. * - * Each vector tries to optimize storage management by maintaining a - * capacity and a capacityIncrement. The - * capacity is always at least as large as the vector + *

Each vector tries to optimize storage management by maintaining a + * {@code capacity} and a {@code capacityIncrement}. The + * {@code capacity} is always at least as large as the vector * size; it is usually larger because as components are added to the * vector, the vector's storage increases in chunks the size of - * capacityIncrement. An application can increase the + * {@code capacityIncrement}. An application can increase the * capacity of a vector before inserting a large number of - * components; this reduces the amount of incremental reallocation.

- * - * As of the Java 2 platform v1.2, this class has been retrofitted to - * implement List, so that it becomes a part of Java's collection framework. - * Unlike the new collection implementations, Vector is synchronized.

+ * components; this reduces the amount of incremental reallocation. * - * The Iterators returned by Vector's iterator and listIterator - * methods are fail-fast: if the Vector is structurally modified - * at any time after the Iterator is created, in any way except through the - * Iterator's own remove or add methods, the Iterator will throw a - * ConcurrentModificationException. Thus, in the face of concurrent - * modification, the Iterator fails quickly and cleanly, rather than risking - * arbitrary, non-deterministic behavior at an undetermined time in the future. - * The Enumerations returned by Vector's elements method are not - * fail-fast. + *

+ * The iterators returned by this class's {@link #iterator() iterator} and + * {@link #listIterator(int) listIterator} methods are fail-fast: + * if the vector is structurally modified at any time after the iterator is + * created, in any way except through the iterator's own + * {@link ListIterator#remove() remove} or + * {@link ListIterator#add(Object) add} methods, the iterator will throw a + * {@link ConcurrentModificationException}. Thus, in the face of + * concurrent modification, the iterator fails quickly and cleanly, rather + * than risking arbitrary, non-deterministic behavior at an undetermined + * time in the future. The {@link Enumeration Enumerations} returned by + * the {@link #elements() elements} method are not fail-fast; if the + * Vector is structurally modified at any time after the enumeration is + * created then the results of enumerating are undefined. * *

Note that the fail-fast behavior of an iterator cannot be guaranteed * as it is, generally speaking, impossible to make any hard guarantees in the * presence of unsynchronized concurrent modification. Fail-fast iterators - * throw ConcurrentModificationException on a best-effort basis. + * throw {@code ConcurrentModificationException} on a best-effort basis. * Therefore, it would be wrong to write a program that depended on this * exception for its correctness: the fail-fast behavior of iterators - * should be used only to detect bugs.

+ * should be used only to detect bugs. + * + *

As of the Java 2 platform v1.2, this class was retrofitted to + * implement the {@link List} interface, making it a member of the + * + * Java Collections Framework. Unlike the new collection + * implementations, {@code Vector} is synchronized. If a thread-safe + * implementation is not needed, it is recommended to use {@link + * ArrayList} in place of {@code Vector}. * - * This class is a member of the - * - * Java Collections Framework. + * @param Type of component elements * * @author Lee Boynton * @author Jonathan Payne - * @version %I%, %G% * @see Collection - * @see List - * @see ArrayList * @see LinkedList - * @since JDK1.0 + * @since 1.0 */ public class Vector extends AbstractList @@ -66,18 +94,18 @@ public class Vector /** * The array buffer into which the components of the vector are * stored. The capacity of the vector is the length of this array buffer, - * and is at least large enough to contain all the vector's elements.

+ * and is at least large enough to contain all the vector's elements. * - * Any array elements following the last element in the Vector are null. + *

Any array elements following the last element in the Vector are null. * * @serial */ protected Object[] elementData; /** - * The number of valid components in this Vector object. - * Components elementData[0] through - * elementData[elementCount-1] are the actual items. + * The number of valid components in this {@code Vector} object. + * Components {@code elementData[0]} through + * {@code elementData[elementCount-1]} are the actual items. * * @serial */ @@ -103,16 +131,16 @@ public class Vector * @param initialCapacity the initial capacity of the vector * @param capacityIncrement the amount by which the capacity is * increased when the vector overflows - * @exception IllegalArgumentException if the specified initial capacity - * is negative + * @throws IllegalArgumentException if the specified initial capacity + * is negative */ public Vector(int initialCapacity, int capacityIncrement) { - super(); + super(); if (initialCapacity < 0) throw new IllegalArgumentException("Illegal Capacity: "+ initialCapacity); - this.elementData = new Object[initialCapacity]; - this.capacityIncrement = capacityIncrement; + this.elementData = new Object[initialCapacity]; + this.capacityIncrement = capacityIncrement; } /** @@ -120,20 +148,20 @@ public class Vector * with its capacity increment equal to zero. * * @param initialCapacity the initial capacity of the vector - * @exception IllegalArgumentException if the specified initial capacity - * is negative + * @throws IllegalArgumentException if the specified initial capacity + * is negative */ public Vector(int initialCapacity) { - this(initialCapacity, 0); + this(initialCapacity, 0); } /** * Constructs an empty vector so that its internal data array - * has size 10 and its standard capacity increment is + * has size {@code 10} and its standard capacity increment is * zero. */ public Vector() { - this(10); + this(10); } /** @@ -147,19 +175,18 @@ public class Vector * @since 1.2 */ public Vector(Collection c) { - Object[] a = c.toArray(); - elementCount = a.length; - // If c.toArray incorrectly doesn't return Object[], copy it. - if (a.getClass() == Object[].class) - elementData = a; - else - elementData = Arrays.copyOf(a, a.length, Object[].class); + elementData = c.toArray(); + elementCount = elementData.length; + // defend against c.toArray (incorrectly) not returning Object[] + // (see e.g. https://bugs.openjdk.java.net/browse/JDK-6260652) + if (elementData.getClass() != Object[].class) + elementData = Arrays.copyOf(elementData, elementCount, Object[].class); } /** * Copies the components of this vector into the specified array. - * The item at index k in this vector is copied into - * component k of anArray. + * The item at index {@code k} in this vector is copied into + * component {@code k} of {@code anArray}. * * @param anArray the array into which the components get copied * @throws NullPointerException if the given array is null @@ -170,23 +197,23 @@ public class Vector * @see #toArray(Object[]) */ public synchronized void copyInto(Object[] anArray) { - System.arraycopy(elementData, 0, anArray, 0, elementCount); + System.arraycopy(elementData, 0, anArray, 0, elementCount); } /** * Trims the capacity of this vector to be the vector's current * size. If the capacity of this vector is larger than its current * size, then the capacity is changed to equal the size by replacing - * its internal data array, kept in the field elementData, + * its internal data array, kept in the field {@code elementData}, * with a smaller one. An application can use this operation to * minimize the storage of a vector. */ public synchronized void trimToSize() { - modCount++; - int oldCapacity = elementData.length; - if (elementCount < oldCapacity) { + modCount++; + int oldCapacity = elementData.length; + if (elementCount < oldCapacity) { elementData = Arrays.copyOf(elementData, elementCount); - } + } } /** @@ -195,73 +222,108 @@ public class Vector * the minimum capacity argument. * *

If the current capacity of this vector is less than - * minCapacity, then its capacity is increased by replacing its - * internal data array, kept in the field elementData, with a + * {@code minCapacity}, then its capacity is increased by replacing its + * internal data array, kept in the field {@code elementData}, with a * larger one. The size of the new data array will be the old size plus - * capacityIncrement, unless the value of - * capacityIncrement is less than or equal to zero, in which case + * {@code capacityIncrement}, unless the value of + * {@code capacityIncrement} is less than or equal to zero, in which case * the new capacity will be twice the old capacity; but if this new size - * is still smaller than minCapacity, then the new capacity will - * be minCapacity. + * is still smaller than {@code minCapacity}, then the new capacity will + * be {@code minCapacity}. * * @param minCapacity the desired minimum capacity */ public synchronized void ensureCapacity(int minCapacity) { - modCount++; - ensureCapacityHelper(minCapacity); + if (minCapacity > 0) { + modCount++; + if (minCapacity > elementData.length) + 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)); + } + + private Object[] grow() { + return grow(elementCount + 1); } /** - * This implements the unsynchronized semantics of ensureCapacity. - * Synchronized methods in this class can internally call this - * method for ensuring capacity without incurring the cost of an - * extra synchronization. - * - * @see java.util.Vector#ensureCapacity(int) - */ - private void ensureCapacityHelper(int minCapacity) { - int oldCapacity = elementData.length; - if (minCapacity > oldCapacity) { - Object[] oldData = elementData; - int newCapacity = (capacityIncrement > 0) ? - (oldCapacity + capacityIncrement) : (oldCapacity * 2); - if (newCapacity < minCapacity) { - newCapacity = minCapacity; - } - elementData = Arrays.copyOf(elementData, newCapacity); - } + * Returns a capacity at least as large as the given minimum capacity. + * 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 + ((capacityIncrement > 0) ? + capacityIncrement : oldCapacity); + if (newCapacity - minCapacity <= 0) { + 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; } /** * Sets the size of this vector. If the new size is greater than the - * current size, new null items are added to the end of + * current size, new {@code null} items are added to the end of * the vector. If the new size is less than the current size, all - * components at index newSize and greater are discarded. + * components at index {@code newSize} and greater are discarded. * - * @param newSize the new size of this vector - * @throws ArrayIndexOutOfBoundsException if new size is negative + * @param newSize the new size of this vector + * @throws ArrayIndexOutOfBoundsException if the new size is negative */ public synchronized void setSize(int newSize) { - modCount++; - if (newSize > elementCount) { - ensureCapacityHelper(newSize); - } else { - for (int i = newSize ; i < elementCount ; i++) { - elementData[i] = null; - } - } - elementCount = newSize; + modCount++; + if (newSize > elementData.length) + grow(newSize); + final Object[] es = elementData; + for (int to = elementCount, i = newSize; i < to; i++) + es[i] = null; + elementCount = newSize; } /** * Returns the current capacity of this vector. * * @return the current capacity (the length of its internal - * data array, kept in the field elementData + * data array, kept in the field {@code elementData} * of this vector) */ public synchronized int capacity() { - return elementData.length; + return elementData.length; } /** @@ -270,67 +332,68 @@ public class Vector * @return the number of components in this vector */ public synchronized int size() { - return elementCount; + return elementCount; } /** * Tests if this vector has no components. * - * @return true if and only if this vector has + * @return {@code true} if and only if this vector has * no components, that is, its size is zero; - * false otherwise. + * {@code false} otherwise. */ public synchronized boolean isEmpty() { - return elementCount == 0; + return elementCount == 0; } /** * Returns an enumeration of the components of this vector. The - * returned Enumeration object will generate all items in - * this vector. The first item generated is the item at index 0, - * then the item at index 1, and so on. + * returned {@code Enumeration} object will generate all items in + * this vector. The first item generated is the item at index {@code 0}, + * then the item at index {@code 1}, and so on. If the vector is + * structurally modified while enumerating over the elements then the + * results of enumerating are undefined. * * @return an enumeration of the components of this vector - * @see Enumeration * @see Iterator */ public Enumeration elements() { - return new Enumeration() { - int count = 0; + return new Enumeration() { + int count = 0; - public boolean hasMoreElements() { - return count < elementCount; - } - - public E nextElement() { - synchronized (Vector.this) { - if (count < elementCount) { - return (E)elementData[count++]; - } - } - throw new NoSuchElementException("Vector Enumeration"); - } - }; + public boolean hasMoreElements() { + return count < elementCount; + } + + public E nextElement() { + synchronized (Vector.this) { + if (count < elementCount) { + return elementData(count++); + } + } + throw new NoSuchElementException("Vector Enumeration"); + } + }; } /** - * Returns true if this vector contains the specified element. - * More formally, returns true if and only if this vector - * contains at least one element e such that - * (o==null ? e==null : o.equals(e)). + * Returns {@code true} if this vector contains the specified element. + * More formally, returns {@code true} if and only if this vector + * contains at least one element {@code e} such that + * {@code Objects.equals(o, e)}. * * @param o element whose presence in this vector is to be tested - * @return true if this vector contains the specified element + * @return {@code true} if this vector contains the specified element */ public boolean contains(Object o) { - return indexOf(o, 0) >= 0; + return indexOf(o, 0) >= 0; } /** * Returns the index of the first occurrence of the specified element * in this vector, or -1 if this vector does not contain the element. - * More formally, returns the lowest index i such that - * (o==null ? get(i)==null : o.equals(get(i))), + * More formally, returns the lowest index {@code i} such that + * {@code Objects.equals(o, get(i))}, * or -1 if there is no such index. * * @param o element to search for @@ -338,43 +401,43 @@ public class Vector * this vector, or -1 if this vector does not contain the element */ public int indexOf(Object o) { - return indexOf(o, 0); + return indexOf(o, 0); } /** * Returns the index of the first occurrence of the specified element in - * this vector, searching forwards from index, or returns -1 if + * this vector, searching forwards from {@code index}, or returns -1 if * the element is not found. - * More formally, returns the lowest index i such that - * (i >= index && (o==null ? get(i)==null : o.equals(get(i)))), + * More formally, returns the lowest index {@code i} such that + * {@code (i >= index && Objects.equals(o, get(i)))}, * or -1 if there is no such index. * * @param o element to search for * @param index index to start searching from * @return the index of the first occurrence of the element in - * this vector at position index or later in the vector; - * -1 if the element is not found. + * this vector at position {@code index} or later in the vector; + * {@code -1} if the element is not found. * @throws IndexOutOfBoundsException if the specified index is negative * @see Object#equals(Object) */ public synchronized int indexOf(Object o, int index) { - if (o == null) { - for (int i = index ; i < elementCount ; i++) - if (elementData[i]==null) - return i; - } else { - for (int i = index ; i < elementCount ; i++) - if (o.equals(elementData[i])) - return i; - } - return -1; + if (o == null) { + for (int i = index ; i < elementCount ; i++) + if (elementData[i]==null) + return i; + } else { + for (int i = index ; i < elementCount ; i++) + if (o.equals(elementData[i])) + return i; + } + return -1; } /** * Returns the index of the last occurrence of the specified element * in this vector, or -1 if this vector does not contain the element. - * More formally, returns the highest index i such that - * (o==null ? get(i)==null : o.equals(get(i))), + * More formally, returns the highest index {@code i} such that + * {@code Objects.equals(o, get(i))}, * or -1 if there is no such index. * * @param o element to search for @@ -382,21 +445,21 @@ public class Vector * this vector, or -1 if this vector does not contain the element */ public synchronized int lastIndexOf(Object o) { - return lastIndexOf(o, elementCount-1); + return lastIndexOf(o, elementCount-1); } /** * Returns the index of the last occurrence of the specified element in - * this vector, searching backwards from index, or returns -1 if + * this vector, searching backwards from {@code index}, or returns -1 if * the element is not found. - * More formally, returns the highest index i such that - * (i <= index && (o==null ? get(i)==null : o.equals(get(i)))), + * More formally, returns the highest index {@code i} such that + * {@code (i <= index && Objects.equals(o, get(i)))}, * or -1 if there is no such index. * * @param o element to search for * @param index index to start searching backwards from * @return the index of the last occurrence of the element at position - * less than or equal to index in this vector; + * less than or equal to {@code index} in this vector; * -1 if the element is not found. * @throws IndexOutOfBoundsException if the specified index is greater * than or equal to the current size of this vector @@ -405,185 +468,184 @@ public class Vector if (index >= elementCount) throw new IndexOutOfBoundsException(index + " >= "+ elementCount); - if (o == null) { - for (int i = index; i >= 0; i--) - if (elementData[i]==null) - return i; - } else { - for (int i = index; i >= 0; i--) - if (o.equals(elementData[i])) - return i; - } - return -1; + if (o == null) { + for (int i = index; i >= 0; i--) + if (elementData[i]==null) + return i; + } else { + for (int i = index; i >= 0; i--) + if (o.equals(elementData[i])) + return i; + } + return -1; } /** - * Returns the component at the specified index.

+ * Returns the component at the specified index. * - * This method is identical in functionality to the get method - * (which is part of the List interface). + *

This method is identical in functionality to the {@link #get(int)} + * method (which is part of the {@link List} interface). * * @param index an index into this vector * @return the component at the specified index - * @exception ArrayIndexOutOfBoundsException if the index - * is negative or not less than the current size of this - * Vector object. - * @see #get(int) - * @see List + * @throws ArrayIndexOutOfBoundsException if the index is out of range + * ({@code index < 0 || index >= size()}) */ public synchronized E elementAt(int index) { - if (index >= elementCount) { - throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); - } + if (index >= elementCount) { + throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); + } - return (E)elementData[index]; + return elementData(index); } /** - * Returns the first component (the item at index 0) of + * Returns the first component (the item at index {@code 0}) of * this vector. * * @return the first component of this vector - * @exception NoSuchElementException if this vector has no components + * @throws NoSuchElementException if this vector has no components */ public synchronized E firstElement() { - if (elementCount == 0) { - throw new NoSuchElementException(); - } - return (E)elementData[0]; + if (elementCount == 0) { + throw new NoSuchElementException(); + } + return elementData(0); } /** * Returns the last component of the vector. * * @return the last component of the vector, i.e., the component at index - * size() - 1. - * @exception NoSuchElementException if this vector is empty + * {@code size() - 1} + * @throws NoSuchElementException if this vector is empty */ public synchronized E lastElement() { - if (elementCount == 0) { - throw new NoSuchElementException(); - } - return (E)elementData[elementCount - 1]; + if (elementCount == 0) { + throw new NoSuchElementException(); + } + return elementData(elementCount - 1); } /** - * Sets the component at the specified index of this + * Sets the component at the specified {@code index} of this * vector to be the specified object. The previous component at that - * position is discarded.

+ * position is discarded. * - * The index must be a value greater than or equal to 0 - * and less than the current size of the vector.

+ *

The index must be a value greater than or equal to {@code 0} + * and less than the current size of the vector. * - * This method is identical in functionality to the set method - * (which is part of the List interface). Note that the set method reverses - * the order of the parameters, to more closely match array usage. Note - * also that the set method returns the old value that was stored at the - * specified position. + *

This method is identical in functionality to the + * {@link #set(int, Object) set(int, E)} + * method (which is part of the {@link List} interface). Note that the + * {@code set} method reverses the order of the parameters, to more closely + * match array usage. Note also that the {@code set} method returns the + * old value that was stored at the specified position. * * @param obj what the component is to be set to * @param index the specified index - * @exception ArrayIndexOutOfBoundsException if the index was invalid - * @see #size() - * @see List - * @see #set(int, java.lang.Object) + * @throws ArrayIndexOutOfBoundsException if the index is out of range + * ({@code index < 0 || index >= size()}) */ public synchronized void setElementAt(E obj, int index) { - if (index >= elementCount) { - throw new ArrayIndexOutOfBoundsException(index + " >= " + - elementCount); - } - elementData[index] = obj; + if (index >= elementCount) { + throw new ArrayIndexOutOfBoundsException(index + " >= " + + elementCount); + } + elementData[index] = obj; } /** * Deletes the component at the specified index. Each component in * this vector with an index greater or equal to the specified - * index is shifted downward to have an index one + * {@code index} is shifted downward to have an index one * smaller than the value it had previously. The size of this vector - * is decreased by 1.

+ * is decreased by {@code 1}. * - * The index must be a value greater than or equal to 0 - * and less than the current size of the vector.

+ *

The index must be a value greater than or equal to {@code 0} + * and less than the current size of the vector. * - * This method is identical in functionality to the remove method - * (which is part of the List interface). Note that the remove method - * returns the old value that was stored at the specified position. + *

This method is identical in functionality to the {@link #remove(int)} + * method (which is part of the {@link List} interface). Note that the + * {@code remove} method returns the old value that was stored at the + * specified position. * * @param index the index of the object to remove - * @exception ArrayIndexOutOfBoundsException if the index was invalid - * @see #size() - * @see #remove(int) - * @see List + * @throws ArrayIndexOutOfBoundsException if the index is out of range + * ({@code index < 0 || index >= size()}) */ public synchronized void removeElementAt(int index) { - modCount++; - if (index >= elementCount) { - throw new ArrayIndexOutOfBoundsException(index + " >= " + - elementCount); - } - else if (index < 0) { - throw new ArrayIndexOutOfBoundsException(index); - } - int j = elementCount - index - 1; - if (j > 0) { - System.arraycopy(elementData, index + 1, elementData, index, j); - } - elementCount--; - elementData[elementCount] = null; /* to let gc do its work */ + if (index >= elementCount) { + throw new ArrayIndexOutOfBoundsException(index + " >= " + + elementCount); + } + else if (index < 0) { + throw new ArrayIndexOutOfBoundsException(index); + } + int j = elementCount - index - 1; + if (j > 0) { + System.arraycopy(elementData, index + 1, elementData, index, j); + } + modCount++; + elementCount--; + elementData[elementCount] = null; /* to let gc do its work */ + // checkInvariants(); } /** * Inserts the specified object as a component in this vector at the - * specified index. Each component in this vector with - * an index greater or equal to the specified index is + * specified {@code index}. Each component in this vector with + * an index greater or equal to the specified {@code index} is * shifted upward to have an index one greater than the value it had - * previously.

+ * previously. * - * The index must be a value greater than or equal to 0 + *

The index must be a value greater than or equal to {@code 0} * and less than or equal to the current size of the vector. (If the * index is equal to the current size of the vector, the new element - * is appended to the Vector.)

+ * is appended to the Vector.) * - * This method is identical in functionality to the add(Object, int) method - * (which is part of the List interface). Note that the add method reverses - * the order of the parameters, to more closely match array usage. + *

This method is identical in functionality to the + * {@link #add(int, Object) add(int, E)} + * method (which is part of the {@link List} interface). Note that the + * {@code add} method reverses the order of the parameters, to more closely + * match array usage. * * @param obj the component to insert * @param index where to insert the new component - * @exception ArrayIndexOutOfBoundsException if the index was invalid - * @see #size() - * @see #add(int, Object) - * @see List + * @throws ArrayIndexOutOfBoundsException if the index is out of range + * ({@code index < 0 || index > size()}) */ public synchronized void insertElementAt(E obj, int index) { - modCount++; - if (index > elementCount) { - throw new ArrayIndexOutOfBoundsException(index - + " > " + elementCount); - } - ensureCapacityHelper(elementCount + 1); - System.arraycopy(elementData, index, elementData, index + 1, elementCount - index); - elementData[index] = obj; - elementCount++; + if (index > elementCount) { + throw new ArrayIndexOutOfBoundsException(index + + " > " + elementCount); + } + modCount++; + final int s = elementCount; + Object[] elementData = this.elementData; + if (s == elementData.length) + elementData = grow(); + System.arraycopy(elementData, index, + elementData, index + 1, + s - index); + elementData[index] = obj; + elementCount = s + 1; } /** * Adds the specified component to the end of this vector, * increasing its size by one. The capacity of this vector is - * increased if its size becomes greater than its capacity.

+ * increased if its size becomes greater than its capacity. * - * This method is identical in functionality to the add(Object) method - * (which is part of the List interface). + *

This method is identical in functionality to the + * {@link #add(Object) add(E)} + * method (which is part of the {@link List} interface). * * @param obj the component to be added - * @see #add(Object) - * @see List */ public synchronized void addElement(E obj) { - modCount++; - ensureCapacityHelper(elementCount + 1); - elementData[elementCount++] = obj; + modCount++; + add(obj, elementData, elementCount); } /** @@ -591,62 +653,57 @@ public class Vector * from this vector. If the object is found in this vector, each * component in the vector with an index greater or equal to the * object's index is shifted downward to have an index one smaller - * than the value it had previously.

+ * than the value it had previously. * - * This method is identical in functionality to the remove(Object) - * method (which is part of the List interface). + *

This method is identical in functionality to the + * {@link #remove(Object)} method (which is part of the + * {@link List} interface). * * @param obj the component to be removed - * @return true if the argument was a component of this - * vector; false otherwise. - * @see List#remove(Object) - * @see List + * @return {@code true} if the argument was a component of this + * vector; {@code false} otherwise. */ public synchronized boolean removeElement(Object obj) { - modCount++; - int i = indexOf(obj); - if (i >= 0) { - removeElementAt(i); - return true; - } - return false; + modCount++; + int i = indexOf(obj); + if (i >= 0) { + removeElementAt(i); + return true; + } + return false; } /** - * Removes all components from this vector and sets its size to zero.

+ * Removes all components from this vector and sets its size to zero. * - * This method is identical in functionality to the clear method - * (which is part of the List interface). - * - * @see #clear - * @see List + *

This method is identical in functionality to the {@link #clear} + * method (which is part of the {@link List} interface). */ public synchronized void removeAllElements() { + final Object[] es = elementData; + for (int to = elementCount, i = elementCount = 0; i < to; i++) + es[i] = null; modCount++; - // Let gc do its work - for (int i = 0; i < elementCount; i++) - elementData[i] = null; - - elementCount = 0; } /** * Returns a clone of this vector. The copy will contain a * reference to a clone of the internal data array, not a reference - * to the original internal data array of this Vector object. + * to the original internal data array of this {@code Vector} object. * * @return a clone of this vector */ public synchronized Object clone() { - try { - Vector v = (Vector) super.clone(); - v.elementData = Arrays.copyOf(elementData, elementCount); - v.modCount = 0; - return v; - } catch (CloneNotSupportedException e) { - // this shouldn't happen, since we are Cloneable - throw new InternalError(); - } + try { + @SuppressWarnings("unchecked") + Vector v = (Vector) super.clone(); + v.elementData = Arrays.copyOf(elementData, elementCount); + v.modCount = 0; + return v; + } catch (CloneNotSupportedException e) { + // this shouldn't happen, since we are Cloneable + throw new InternalError(e); + } } /** @@ -664,29 +721,33 @@ public class Vector * correct order; the runtime type of the returned array is that of the * specified array. If the Vector fits in the specified array, it is * returned therein. Otherwise, a new array is allocated with the runtime - * type of the specified array and the size of this Vector.

+ * type of the specified array and the size of this Vector. * - * If the Vector fits in the specified array with room to spare + *

If the Vector fits in the specified array with room to spare * (i.e., the array has more elements than the Vector), * the element in the array immediately following the end of the * Vector is set to null. (This is useful in determining the length * of the Vector only if the caller knows that the Vector * does not contain any null elements.) * + * @param type of array elements. The same type as {@code } or a + * supertype of {@code }. * @param a the array into which the elements of the Vector are to - * be stored, if it is big enough; otherwise, a new array of the - * same runtime type is allocated for this purpose. + * be stored, if it is big enough; otherwise, a new array of the + * same runtime type is allocated for this purpose. * @return an array containing the elements of the Vector - * @exception ArrayStoreException the runtime type of a is not a supertype - * of the runtime type of every element in this Vector + * @throws ArrayStoreException if the runtime type of a, {@code }, is not + * a supertype of the runtime type, {@code }, of every element in this + * Vector * @throws NullPointerException if the given array is null * @since 1.2 */ + @SuppressWarnings("unchecked") public synchronized T[] toArray(T[] a) { if (a.length < elementCount) return (T[]) Arrays.copyOf(elementData, elementCount, a.getClass()); - System.arraycopy(elementData, 0, a, 0, elementCount); + System.arraycopy(elementData, 0, a, 0, elementCount); if (a.length > elementCount) a[elementCount] = null; @@ -696,20 +757,30 @@ public class Vector // Positional Access Operations + @SuppressWarnings("unchecked") + E elementData(int index) { + return (E) elementData[index]; + } + + @SuppressWarnings("unchecked") + static E elementAt(Object[] es, int index) { + return (E) es[index]; + } + /** * Returns the element at the specified position in this Vector. * * @param index index of the element to return * @return object at the specified index - * @exception ArrayIndexOutOfBoundsException index is out of range (index - * < 0 || index >= size()) + * @throws ArrayIndexOutOfBoundsException if the index is out of range + * ({@code index < 0 || index >= size()}) * @since 1.2 */ public synchronized E get(int index) { - if (index >= elementCount) - throw new ArrayIndexOutOfBoundsException(index); + if (index >= elementCount) + throw new ArrayIndexOutOfBoundsException(index); - return (E)elementData[index]; + return elementData(index); } /** @@ -719,30 +790,42 @@ public class Vector * @param index index of the element to replace * @param element element to be stored at the specified position * @return the element previously at the specified position - * @exception ArrayIndexOutOfBoundsException index out of range - * (index < 0 || index >= size()) + * @throws ArrayIndexOutOfBoundsException if the index is out of range + * ({@code index < 0 || index >= size()}) * @since 1.2 */ public synchronized E set(int index, E element) { - if (index >= elementCount) - throw new ArrayIndexOutOfBoundsException(index); + if (index >= elementCount) + throw new ArrayIndexOutOfBoundsException(index); - Object oldValue = elementData[index]; - elementData[index] = element; - return (E)oldValue; + E oldValue = elementData(index); + elementData[index] = element; + return oldValue; + } + + /** + * This helper method split out from add(E) to keep method + * bytecode size under 35 (the -XX:MaxInlineSize default value), + * which helps when add(E) is called in a C1-compiled loop. + */ + private void add(E e, Object[] elementData, int s) { + if (s == elementData.length) + elementData = grow(); + elementData[s] = e; + elementCount = s + 1; + // checkInvariants(); } /** * Appends the specified element to the end of this Vector. * * @param e element to be appended to this Vector - * @return true (as specified by {@link Collection#add}) + * @return {@code true} (as specified by {@link Collection#add}) * @since 1.2 */ public synchronized boolean add(E e) { - modCount++; - ensureCapacityHelper(elementCount + 1); - elementData[elementCount++] = e; + modCount++; + add(e, elementData, elementCount); return true; } @@ -750,7 +833,7 @@ public class Vector * Removes the first occurrence of the specified element in this Vector * If the Vector does not contain the element, it is unchanged. More * formally, removes the element with the lowest index i such that - * (o==null ? get(i)==null : o.equals(get(i))) (if such + * {@code Objects.equals(o, get(i))} (if such * an element exists). * * @param o element to be removed from this Vector, if present @@ -768,8 +851,8 @@ public class Vector * * @param index index at which the specified element is to be inserted * @param element element to be inserted - * @exception ArrayIndexOutOfBoundsException index is out of range - * (index < 0 || index > size()) + * @throws ArrayIndexOutOfBoundsException if the index is out of range + * ({@code index < 0 || index > size()}) * @since 1.2 */ public void add(int index, E element) { @@ -781,25 +864,26 @@ public class Vector * Shifts any subsequent elements to the left (subtracts one from their * indices). Returns the element that was removed from the Vector. * - * @exception ArrayIndexOutOfBoundsException index out of range (index - * < 0 || index >= size()) * @param index the index of the element to be removed * @return element that was removed + * @throws ArrayIndexOutOfBoundsException if the index is out of range + * ({@code index < 0 || index >= size()}) * @since 1.2 */ public synchronized E remove(int index) { - modCount++; - if (index >= elementCount) - throw new ArrayIndexOutOfBoundsException(index); - Object oldValue = elementData[index]; - - int numMoved = elementCount - index - 1; - if (numMoved > 0) - System.arraycopy(elementData, index+1, elementData, index, - numMoved); - elementData[--elementCount] = null; // Let gc do its work + modCount++; + if (index >= elementCount) + throw new ArrayIndexOutOfBoundsException(index); + E oldValue = elementData(index); - return (E)oldValue; + int numMoved = elementCount - index - 1; + if (numMoved > 0) + System.arraycopy(elementData, index+1, elementData, index, + numMoved); + elementData[--elementCount] = null; // Let gc do its work + + // checkInvariants(); + return oldValue; } /** @@ -821,7 +905,7 @@ public class Vector * @param c a collection whose elements will be tested for containment * in this Vector * @return true if this Vector contains all of the elements in the - * specified collection + * specified collection * @throws NullPointerException if the specified collection is null */ public synchronized boolean containsAll(Collection c) { @@ -837,18 +921,26 @@ public class Vector * specified Collection is this Vector, and this Vector is nonempty.) * * @param c elements to be inserted into this Vector - * @return true if this Vector changed as a result of the call + * @return {@code true} if this Vector changed as a result of the call * @throws NullPointerException if the specified collection is null * @since 1.2 */ - public synchronized boolean addAll(Collection c) { - modCount++; + public boolean addAll(Collection c) { Object[] a = c.toArray(); + modCount++; int numNew = a.length; - ensureCapacityHelper(elementCount + numNew); - System.arraycopy(a, 0, elementData, elementCount, numNew); - elementCount += numNew; - return numNew != 0; + if (numNew == 0) + return false; + synchronized (this) { + Object[] elementData = this.elementData; + final int s = elementCount; + if (numNew > elementData.length - s) + elementData = grow(s + numNew); + System.arraycopy(a, 0, elementData, s, numNew); + elementCount = s + numNew; + // checkInvariants(); + return true; + } } /** @@ -859,14 +951,18 @@ public class Vector * @return true if this Vector changed as a result of the call * @throws ClassCastException if the types of one or more elements * in this vector are incompatible with the specified - * collection (optional) + * collection + * (optional) * @throws NullPointerException if this vector contains one or more null * elements and the specified collection does not support null - * elements (optional), or if the specified collection is null + * elements + * (optional), + * or if the specified collection is null * @since 1.2 */ - public synchronized boolean removeAll(Collection c) { - return super.removeAll(c); + public boolean removeAll(Collection c) { + Objects.requireNonNull(c); + return bulkRemove(e -> c.contains(e)); } /** @@ -879,14 +975,76 @@ public class Vector * @return true if this Vector changed as a result of the call * @throws ClassCastException if the types of one or more elements * in this vector are incompatible with the specified - * collection (optional) + * collection + * (optional) * @throws NullPointerException if this vector contains one or more null * elements and the specified collection does not support null - * elements (optional), or if the specified collection is null + * elements + * (optional), + * or if the specified collection is null * @since 1.2 */ - public synchronized boolean retainAll(Collection c) { - return super.retainAll(c); + public boolean retainAll(Collection c) { + Objects.requireNonNull(c); + return bulkRemove(e -> !c.contains(e)); + } + + /** + * @throws NullPointerException {@inheritDoc} + */ + @Override + public boolean removeIf(Predicate filter) { + Objects.requireNonNull(filter); + return bulkRemove(filter); + } + + // A tiny bit set implementation + + private static long[] nBits(int n) { + return new long[((n - 1) >> 6) + 1]; + } + private static void setBit(long[] bits, int i) { + bits[i >> 6] |= 1L << i; + } + private static boolean isClear(long[] bits, int i) { + return (bits[i >> 6] & (1L << i)) == 0; + } + + private synchronized boolean bulkRemove(Predicate filter) { + int expectedModCount = modCount; + final Object[] es = elementData; + final int end = elementCount; + int i; + // Optimize for initial run of survivors + for (i = 0; i < end && !filter.test(elementAt(es, i)); i++) + ; + // Tolerate predicates that reentrantly access the collection for + // read (but writers still get CME), so traverse once to find + // elements to delete, a second pass to physically expunge. + if (i < end) { + final int beg = i; + final long[] deathRow = nBits(end - beg); + deathRow[0] = 1L; // set bit 0 + for (i = beg + 1; i < end; i++) + if (filter.test(elementAt(es, i))) + setBit(deathRow, i - beg); + if (modCount != expectedModCount) + throw new ConcurrentModificationException(); + modCount++; + int w = beg; + for (i = beg; i < end; i++) + if (isClear(deathRow, i - beg)) + es[w++] = es[i]; + for (i = elementCount = w; i < end; i++) + es[i] = null; + // checkInvariants(); + return true; + } else { + if (modCount != expectedModCount) + throw new ConcurrentModificationException(); + // checkInvariants(); + return false; + } } /** @@ -900,38 +1058,44 @@ public class Vector * @param index index at which to insert the first element from the * specified collection * @param c elements to be inserted into this Vector - * @return true if this Vector changed as a result of the call - * @exception ArrayIndexOutOfBoundsException index out of range (index - * < 0 || index > size()) + * @return {@code true} if this Vector changed as a result of the call + * @throws ArrayIndexOutOfBoundsException if the index is out of range + * ({@code index < 0 || index > size()}) * @throws NullPointerException if the specified collection is null * @since 1.2 */ public synchronized boolean addAll(int index, Collection c) { - modCount++; - if (index < 0 || index > elementCount) - throw new ArrayIndexOutOfBoundsException(index); + if (index < 0 || index > elementCount) + throw new ArrayIndexOutOfBoundsException(index); Object[] a = c.toArray(); - int numNew = a.length; - ensureCapacityHelper(elementCount + numNew); - - int numMoved = elementCount - index; - if (numMoved > 0) - System.arraycopy(elementData, index, elementData, index + numNew, - numMoved); - + modCount++; + int numNew = a.length; + if (numNew == 0) + return false; + Object[] elementData = this.elementData; + final int s = elementCount; + if (numNew > elementData.length - s) + elementData = grow(s + numNew); + + int numMoved = s - index; + if (numMoved > 0) + System.arraycopy(elementData, index, + elementData, index + numNew, + numMoved); System.arraycopy(a, 0, elementData, index, numNew); - elementCount += numNew; - return numNew != 0; + elementCount = s + numNew; + // checkInvariants(); + return true; } /** * Compares the specified Object with this Vector for equality. Returns * true if and only if the specified Object is also a List, both Lists * have the same size, and all corresponding pairs of elements in the two - * Lists are equal. (Two elements e1 and - * e2 are equal if (e1==null ? e2==null : - * e1.equals(e2)).) In other words, two Lists are defined to be + * Lists are equal. (Two elements {@code e1} and + * {@code e2} are equal if {@code Objects.equals(e1, e2)}.) + * In other words, two Lists are defined to be * equal if they contain the same elements in the same order. * * @param o the Object to be compared for equality with this Vector @@ -962,21 +1126,21 @@ public class Vector * equal, the returned List is empty.) The returned List is backed by this * List, so changes in the returned List are reflected in this List, and * vice-versa. The returned List supports all of the optional List - * operations supported by this List.

+ * operations supported by this List. * - * This method eliminates the need for explicit range operations (of - * the sort that commonly exist for arrays). Any operation that expects + *

This method eliminates the need for explicit range operations (of + * the sort that commonly exist for arrays). Any operation that expects * a List can be used as a range operation by operating on a subList view * instead of a whole List. For example, the following idiom * removes a range of elements from a List: *

-     *	    list.subList(from, to).clear();
+     *      list.subList(from, to).clear();
      * 
* Similar idioms may be constructed for indexOf and lastIndexOf, * and all of the algorithms in the Collections class can be applied to - * a subList.

+ * a subList. * - * The semantics of the List returned by this method become undefined if + *

The semantics of the List returned by this method become undefined if * the backing list (i.e., this List) is structurally modified in * any way other than via the returned List. (Structural modifications are * those that change the size of the List, or otherwise perturb it in such @@ -985,10 +1149,10 @@ public class Vector * @param fromIndex low endpoint (inclusive) of the subList * @param toIndex high endpoint (exclusive) of the subList * @return a view of the specified range within this List - * @throws IndexOutOfBoundsException endpoint index value out of range - * (fromIndex < 0 || toIndex > size) - * @throws IllegalArgumentException endpoint indices out of order - * (fromIndex > toIndex) + * @throws IndexOutOfBoundsException if an endpoint index value is out of range + * {@code (fromIndex < 0 || toIndex > size)} + * @throws IllegalArgumentException if the endpoint indices are out of order + * {@code (fromIndex > toIndex)} */ public synchronized List subList(int fromIndex, int toIndex) { return Collections.synchronizedList(super.subList(fromIndex, toIndex), @@ -996,180 +1160,360 @@ public class Vector } /** - * Removes from this List all of the elements whose index is between - * fromIndex, inclusive and toIndex, exclusive. Shifts any succeeding - * elements to the left (reduces their index). - * This call shortens the ArrayList by (toIndex - fromIndex) elements. (If - * toIndex==fromIndex, this operation has no effect.) - * - * @param fromIndex index of first element to be removed - * @param toIndex index after last element to be removed + * Removes from this list all of the elements whose index is between + * {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. + * Shifts any succeeding elements to the left (reduces their index). + * This call shortens the list by {@code (toIndex - fromIndex)} elements. + * (If {@code toIndex==fromIndex}, this operation has no effect.) */ protected synchronized void removeRange(int fromIndex, int toIndex) { - modCount++; - int numMoved = elementCount - toIndex; - System.arraycopy(elementData, toIndex, elementData, fromIndex, - numMoved); + modCount++; + shiftTailOverGap(elementData, fromIndex, toIndex); + // checkInvariants(); + } - // Let gc do its work - int newElementCount = elementCount - (toIndex-fromIndex); - while (elementCount != newElementCount) - elementData[--elementCount] = null; + /** Erases the gap from lo to hi, by sliding down following elements. */ + private void shiftTailOverGap(Object[] es, int lo, int hi) { + System.arraycopy(es, hi, es, lo, elementCount - hi); + for (int to = elementCount, i = (elementCount -= hi - lo); i < to; i++) + es[i] = null; } /** - * Save the state of the Vector instance to a stream (that - * is, serialize it). This method is present merely for synchronization. - * It just calls the default writeObject method. - */ - private synchronized void writeObject(java.io.ObjectOutputStream s) - throws java.io.IOException - { - s.defaultWriteObject(); + * Loads a {@code Vector} instance from a stream + * (that is, deserializes it). + * This method performs checks to ensure the consistency + * of the fields. + * + * @param in the stream + * @throws java.io.IOException if an I/O error occurs + * @throws ClassNotFoundException if the stream contains data + * of a non-existing class + */ + private void readObject(ObjectInputStream in) + throws IOException, ClassNotFoundException { + ObjectInputStream.GetField gfields = in.readFields(); + int count = gfields.get("elementCount", 0); + Object[] data = (Object[])gfields.get("elementData", null); + if (count < 0 || data == null || count > data.length) { + throw new StreamCorruptedException("Inconsistent vector internals"); + } + elementCount = count; + elementData = data.clone(); + } + + /** + * Saves the state of the {@code Vector} instance to a stream + * (that is, serializes it). + * This method performs synchronization to ensure the consistency + * of the serialized data. + * + * @param s the stream + * @throws java.io.IOException if an I/O error occurs + */ + private void writeObject(java.io.ObjectOutputStream s) + throws java.io.IOException { + final java.io.ObjectOutputStream.PutField fields = s.putFields(); + final Object[] data; + synchronized (this) { + fields.put("capacityIncrement", capacityIncrement); + fields.put("elementCount", elementCount); + data = elementData.clone(); + } + fields.put("elementData", data); + s.writeFields(); } /** - * Returns a list-iterator of the elements in this list (in proper + * Returns a list iterator over the elements in this list (in proper * sequence), starting at the specified position in the list. - * Obeys the general contract of List.listIterator(int).

+ * The specified index indicates the first element that would be + * returned by an initial call to {@link ListIterator#next next}. + * An initial call to {@link ListIterator#previous previous} would + * return the element with the specified index minus one. + * + *

The returned list iterator is fail-fast. * - * The list-iterator is fail-fast: if the list is structurally - * modified at any time after the Iterator is created, in any way except - * through the list-iterator's own remove or add - * methods, the list-iterator will throw a - * ConcurrentModificationException. Thus, in the face of - * concurrent modification, the iterator fails quickly and cleanly, rather - * than risking arbitrary, non-deterministic behavior at an undetermined - * time in the future. - * - * @param index index of the first element to be returned from the - * list-iterator (by a call to next) - * @return a ListIterator of the elements in this list (in proper - * sequence), starting at the specified position in the list * @throws IndexOutOfBoundsException {@inheritDoc} - * @see List#listIterator(int) */ public synchronized ListIterator listIterator(int index) { - if (index < 0 || index > elementCount) + if (index < 0 || index > elementCount) throw new IndexOutOfBoundsException("Index: "+index); - return new VectorIterator(index); + return new ListItr(index); + } + + /** + * Returns a list iterator over the elements in this list (in proper + * sequence). + * + *

The returned list iterator is fail-fast. + * + * @see #listIterator(int) + */ + public synchronized ListIterator listIterator() { + return new ListItr(0); } /** * Returns an iterator over the elements in this list in proper sequence. * + *

The returned iterator is fail-fast. + * * @return an iterator over the elements in this list in proper sequence */ public synchronized Iterator iterator() { - return new VectorIterator(0); + return new Itr(); } /** - * A streamlined version of AbstractList.Itr. + * An optimized version of AbstractList.Itr */ - final class VectorIterator implements ListIterator { - int cursor; // index of next element to return; - int lastRet; // index of last element, or -1 if no such - int expectedModCount; // to check for CME + private class Itr implements Iterator { + int cursor; // index of next element to return + int lastRet = -1; // index of last element returned; -1 if no such + int expectedModCount = modCount; + + public boolean hasNext() { + // Racy but within spec, since modifications are checked + // within or after synchronization in next/previous + return cursor != elementCount; + } + + public E next() { + synchronized (Vector.this) { + checkForComodification(); + int i = cursor; + if (i >= elementCount) + throw new NoSuchElementException(); + cursor = i + 1; + return elementData(lastRet = i); + } + } - VectorIterator(int index) { - cursor = index; + public void remove() { + if (lastRet == -1) + throw new IllegalStateException(); + synchronized (Vector.this) { + checkForComodification(); + Vector.this.remove(lastRet); + expectedModCount = modCount; + } + cursor = lastRet; lastRet = -1; - expectedModCount = modCount; - } + } - public boolean hasNext() { - // Racy but within spec and backwards-compatible - return cursor < elementCount; - } - - public boolean hasPrevious() { - return cursor > 0; - } - - public int nextIndex() { - return cursor; - } - - public int previousIndex() { - return cursor - 1; - } - - public E next() { - synchronized(Vector.this) { - if (expectedModCount == modCount) { - int i = cursor; - if (i < elementCount) { - try { - E e = (E)elementData[i]; - lastRet = i; - cursor = i + 1; - return e; - } catch (IndexOutOfBoundsException fallthrough) { - } - } + @Override + public void forEachRemaining(Consumer action) { + Objects.requireNonNull(action); + synchronized (Vector.this) { + final int size = elementCount; + int i = cursor; + if (i >= size) { + return; } - // Prefer reporting CME if applicable on failures - if (expectedModCount == modCount) - throw new NoSuchElementException(); - throw new ConcurrentModificationException(); + final Object[] es = elementData; + if (i >= es.length) + throw new ConcurrentModificationException(); + while (i < size && modCount == expectedModCount) + action.accept(elementAt(es, i++)); + // update once at end of iteration to reduce heap write traffic + cursor = i; + lastRet = i - 1; + checkForComodification(); } - } + } + + final void checkForComodification() { + if (modCount != expectedModCount) + throw new ConcurrentModificationException(); + } + } + + /** + * An optimized version of AbstractList.ListItr + */ + final class ListItr extends Itr implements ListIterator { + ListItr(int index) { + super(); + cursor = index; + } + + public boolean hasPrevious() { + return cursor != 0; + } + + public int nextIndex() { + return cursor; + } + + public int previousIndex() { + return cursor - 1; + } public E previous() { - synchronized(Vector.this) { - if (expectedModCount == modCount) { - int i = cursor - 1; - if (i < elementCount) { - try { - E e = (E)elementData[i]; - lastRet = i; - cursor = i; - return e; - } catch (IndexOutOfBoundsException fallthrough) { - } - } - } - if (expectedModCount == modCount) + synchronized (Vector.this) { + checkForComodification(); + int i = cursor - 1; + if (i < 0) throw new NoSuchElementException(); - throw new ConcurrentModificationException(); + cursor = i; + return elementData(lastRet = i); } } - public void remove() { - if (lastRet < 0) - throw new IllegalStateException(); - synchronized(Vector.this) { - if (modCount != expectedModCount) - throw new ConcurrentModificationException(); - Vector.this.remove(lastRet); - if (lastRet < cursor) - cursor--; - lastRet = -1; - expectedModCount = modCount; + public void set(E e) { + if (lastRet == -1) + throw new IllegalStateException(); + synchronized (Vector.this) { + checkForComodification(); + Vector.this.set(lastRet, e); } - } + } - public void set(E e) { - if (lastRet < 0) - throw new IllegalStateException(); - synchronized(Vector.this) { - if (modCount != expectedModCount) - throw new ConcurrentModificationException(); - Vector.this.set(lastRet, e); + public void add(E e) { + int i = cursor; + synchronized (Vector.this) { + checkForComodification(); + Vector.this.add(i, e); expectedModCount = modCount; } - } + cursor = i + 1; + lastRet = -1; + } + } + + /** + * @throws NullPointerException {@inheritDoc} + */ + @Override + public synchronized void forEach(Consumer action) { + Objects.requireNonNull(action); + final int expectedModCount = modCount; + final Object[] es = elementData; + final int size = elementCount; + for (int i = 0; modCount == expectedModCount && i < size; i++) + action.accept(elementAt(es, i)); + if (modCount != expectedModCount) + throw new ConcurrentModificationException(); + // checkInvariants(); + } - public void add(E e) { - synchronized(Vector.this) { + /** + * @throws NullPointerException {@inheritDoc} + */ + @Override + public synchronized void replaceAll(UnaryOperator operator) { + Objects.requireNonNull(operator); + final int expectedModCount = modCount; + final Object[] es = elementData; + final int size = elementCount; + for (int i = 0; modCount == expectedModCount && i < size; i++) + es[i] = operator.apply(elementAt(es, i)); + if (modCount != expectedModCount) + throw new ConcurrentModificationException(); + // checkInvariants(); + } + + @SuppressWarnings("unchecked") + @Override + public synchronized void sort(Comparator c) { + final int expectedModCount = modCount; + Arrays.sort((E[]) elementData, 0, elementCount, c); + if (modCount != expectedModCount) + throw new ConcurrentModificationException(); + modCount++; + // checkInvariants(); + } + + /** + * Creates a late-binding + * and fail-fast {@link Spliterator} over the elements in this + * list. + * + *

The {@code Spliterator} reports {@link Spliterator#SIZED}, + * {@link Spliterator#SUBSIZED}, and {@link Spliterator#ORDERED}. + * Overriding implementations should document the reporting of additional + * characteristic values. + * + * @return a {@code Spliterator} over the elements in this list + * @since 1.8 + */ + @Override + public Spliterator spliterator() { + return new VectorSpliterator(null, 0, -1, 0); + } + + /** Similar to ArrayList Spliterator */ + final class VectorSpliterator implements Spliterator { + private Object[] array; + private int index; // current index, modified on advance/split + private int fence; // -1 until used; then one past last index + private int expectedModCount; // initialized when fence set + + /** Creates new spliterator covering the given range. */ + VectorSpliterator(Object[] array, int origin, int fence, + int expectedModCount) { + this.array = array; + this.index = origin; + this.fence = fence; + this.expectedModCount = expectedModCount; + } + + private int getFence() { // initialize on first use + int hi; + if ((hi = fence) < 0) { + synchronized (Vector.this) { + array = elementData; + expectedModCount = modCount; + hi = fence = elementCount; + } + } + return hi; + } + + public Spliterator trySplit() { + int hi = getFence(), lo = index, mid = (lo + hi) >>> 1; + return (lo >= mid) ? null : + new VectorSpliterator(array, lo, index = mid, expectedModCount); + } + + @SuppressWarnings("unchecked") + public boolean tryAdvance(Consumer action) { + Objects.requireNonNull(action); + int i; + if (getFence() > (i = index)) { + index = i + 1; + action.accept((E)array[i]); if (modCount != expectedModCount) throw new ConcurrentModificationException(); - Vector.this.add(cursor++, e); - lastRet = -1; - expectedModCount = modCount; + return true; } - } + return false; + } + + @SuppressWarnings("unchecked") + public void forEachRemaining(Consumer action) { + Objects.requireNonNull(action); + final int hi = getFence(); + final Object[] a = array; + int i; + for (i = index, index = hi; i < hi; i++) + action.accept((E) a[i]); + if (modCount != expectedModCount) + throw new ConcurrentModificationException(); + } + + public long estimateSize() { + return getFence() - index; + } + + public int characteristics() { + return Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED; + } } + void checkInvariants() { + // assert elementCount >= 0; + // assert elementCount == elementData.length || elementData[elementCount] == null; + } }