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Diffstat (limited to 'jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/HashBag.java')
-rw-r--r--jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/HashBag.java842
1 files changed, 0 insertions, 842 deletions
diff --git a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/HashBag.java b/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/HashBag.java
deleted file mode 100644
index 45dba9a781..0000000000
--- a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/HashBag.java
+++ /dev/null
@@ -1,842 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2005, 2007 Oracle. All rights reserved.
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Public License v1.0, which accompanies this distribution
- * and is available at http://www.eclipse.org/legal/epl-v10.html.
- *
- * Contributors:
- * Oracle - initial API and implementation
- ******************************************************************************/
-package org.eclipse.jpt.utility.internal;
-
-import java.io.Serializable;
-import java.util.AbstractCollection;
-import java.util.Collection;
-import java.util.ConcurrentModificationException;
-import java.util.Iterator;
-import java.util.NoSuchElementException;
-
-/**
- * This class implements the <code>Bag</code> interface, backed by a
- * hash table. It makes no guarantees as to the iteration order of
- * the bag's elements; in particular, it does not guarantee that the order
- * will remain constant over time. This class permits the <code>null</code>
- * element.
- * <p>
- * This class offers constant time performance for the basic operations
- * (<code>add</code>, <code>remove</code>, <code>contains</code> and
- * <code>size</code>), assuming the hash function disperses the elements
- * properly among the buckets. Iterating over this bag requires time
- * proportional to the sum of the bag's size (the number of elements) plus the
- * "capacity" of the backing hash table (the number of buckets). Thus, it is
- * important not to set the initial capacity too high (or the load factor too
- * low) if iteration performance is important.
- * <p>
- * <b>Note that this implementation is not synchronized.</b> If multiple
- * threads access a bag concurrently, and at least one of the threads modifies
- * the bag, it <i>must</i> be synchronized externally. This is typically
- * accomplished by synchronizing on some object that naturally encapsulates
- * the bag. If no such object exists, the bag should be "wrapped" using the
- * <code>Collections.synchronizedCollection</code> method. This is
- * best done at creation time, to prevent accidental unsynchronized access
- * to the bag:
- * <pre>
- * Collection c = Collections.synchronizedCollection(new HashBag(...));
- * </pre>
- * <p>
- * The iterators returned by this class's <code>iterator</code> method are
- * <i>fail-fast</i>: if the bag is modified at any time after the iterator is
- * created, in any way except through the iterator's own <code>remove</code>
- * method, the iterator throws a <code>ConcurrentModificationException</code>.
- * 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.
- *
- * @see Collections#synchronizedCollection(Collection)
- */
-
-public class HashBag<E> extends AbstractCollection<E>
- implements Bag<E>, Cloneable, Serializable {
-
- /** The hash table. */
- transient Entry<E>[] table;
-
- /** The total number of entries in the bag. */
- transient int count = 0;
-
- /** The number of unique entries in the bag. */
- transient int uniqueCount = 0;
-
- /**
- * The hash table is rehashed when its size exceeds this threshold. (The
- * value of this field is (int)(capacity * loadFactor).)
- *
- * @serial
- */
- private int threshold;
-
- /**
- * The load factor for the hash table.
- *
- * @serial
- */
- private float loadFactor;
-
- /**
- * The number of times this bag has been structurally modified.
- * Structural modifications are those that change the number of entries in
- * the bag or otherwise modify its internal structure (e.g. rehash).
- * This field is used to make iterators on this bag fail-fast.
- *
- * @see java.util.ConcurrentModificationException
- */
- transient int modCount = 0;
-
- /**
- * Constructs a new, empty bag with the
- * default capacity, which is 11, and load factor, which is 0.75.
- */
- public HashBag() {
- this(11, 0.75f);
- }
-
- /**
- * Constructs a new, empty bag with the specified initial capacity
- * and default load factor, which is 0.75.
- *
- * @param initialCapacity the initial capacity of the backing map.
- * @throws IllegalArgumentException if the initial capacity is less
- * than zero.
- */
- public HashBag(int initialCapacity) {
- this(initialCapacity, 0.75f);
- }
-
- /**
- * Constructs a new, empty bag with
- * the specified initial capacity and the specified load factor.
- *
- * @param initialCapacity the initial capacity of the backing map.
- * @param loadFactor the load factor of the backing map.
- * @throws IllegalArgumentException if the initial capacity is less
- * than zero, or if the load factor is nonpositive.
- */
- public HashBag(int initialCapacity, float loadFactor) {
- if (initialCapacity < 0) {
- throw new IllegalArgumentException("Illegal Initial Capacity: " + initialCapacity);
- }
- if (loadFactor <= 0 || Float.isNaN(loadFactor)) {
- throw new IllegalArgumentException("Illegal Load factor: " + loadFactor);
- }
- if (initialCapacity == 0) {
- initialCapacity = 1;
- }
- this.loadFactor = loadFactor;
- this.table = this.buildTable(initialCapacity);
- this.threshold = (int) (initialCapacity * loadFactor);
- }
-
- /**
- * Constructs a new bag containing the elements in the specified
- * collection. The capacity of the bag is
- * twice the size of the specified collection or 11 (whichever is
- * greater), and the default load factor, which is 0.75, is used.
- *
- * @param c the collection whose elements are to be placed into this bag.
- */
- public HashBag(Collection<? extends E> c) {
- this(Math.max(2*c.size(), 11));
- this.addAll(c);
- }
-
- /**
- * This implementation simply returns the maintained count.
- */
- @Override
- public int size() {
- return this.count;
- }
-
- /**
- * This implementation simply compares the maintained count to zero.
- */
- @Override
- public boolean isEmpty() {
- return this.count == 0;
- }
-
- /**
- * This implementation searches for the object in the hash table by calculating
- * the object's hash code and examining the entries in the corresponding hash
- * table bucket.
- */
- @Override
- public boolean contains(Object o) {
- Entry<E>[] tab = this.table;
- if (o == null) {
- for (Entry<E> e = tab[0]; e != null; e = e.next) {
- if (e.object == null) {
- return true;
- }
- }
- } else {
- int hash = o.hashCode();
- int index = (hash & 0x7FFFFFFF) % tab.length;
- for (Entry<E> e = tab[index]; e != null; e = e.next) {
- if ((e.hash == hash) && o.equals(e.object)) {
- return true;
- }
- }
- }
- return false;
- }
-
- public int count(Object o) {
- Entry<E>[] tab = this.table;
- if (o == null) {
- for (Entry<E> e = tab[0]; e != null; e = e.next) {
- if (e.object == null) {
- return e.count;
- }
- }
- } else {
- int hash = o.hashCode();
- int index = (hash & 0x7FFFFFFF) % tab.length;
- for (Entry<E> e = tab[index]; e != null; e = e.next) {
- if ((e.hash == hash) && o.equals(e.object)) {
- return e.count;
- }
- }
- }
- return 0;
- }
-
- /**
- * Rehashes the contents of this bag into a new hash table
- * with a larger capacity. This method is called when the
- * number of different elements in this map exceeds its
- * capacity and load factor.
- */
- private void rehash() {
- Entry<E>[] oldMap = this.table;
- int oldCapacity = oldMap.length;
-
- int newCapacity = oldCapacity * 2 + 1;
- Entry<E>[] newTable = this.buildTable(newCapacity);
-
- this.modCount++;
- this.threshold = (int) (newCapacity * this.loadFactor);
- this.table = newTable;
-
- for (int i = oldCapacity; i-- > 0; ) {
- for (Entry<E> old = oldMap[i]; old != null; ) {
- Entry<E> e = old;
- old = old.next;
-
- int index = (e.hash & 0x7FFFFFFF) % newCapacity;
- e.next = newTable[index];
- newTable[index] = e;
- }
- }
- }
-
- @SuppressWarnings("unchecked")
- private Entry<E>[] buildTable(int capacity) {
- return new Entry[capacity];
- }
-
- @SuppressWarnings("unchecked")
- private <T> Entry<E> buildEntry(int hash, Object o, Entry<T> next) {
- return new Entry(hash, o, next);
- }
-
- @SuppressWarnings("unchecked")
- private <T> Entry<E> buildEntry(int hash, Object o, int cnt, Entry<T> next) {
- return new Entry(hash, o, cnt, next);
- }
-
- /**
- * This implementation searches for the object in the hash table by calculating
- * the object's hash code and examining the entries in the corresponding hash
- * table bucket.
- */
- @Override
- public boolean add(E o) {
- this.modCount++;
- Entry<E>[] tab = this.table;
- int hash = 0;
- int index = 0;
-
- // if the object is already in the bag, simply bump its count
- if (o == null) {
- for (Entry<E> e = tab[0]; e != null; e = e.next) {
- if (e.object == null) {
- e.count++;
- this.count++;
- return true;
- }
- }
- } else {
- hash = o.hashCode();
- index = (hash & 0x7FFFFFFF) % tab.length;
- for (Entry<E> e = tab[index]; e != null; e = e.next) {
- if ((e.hash == hash) && o.equals(e.object)) {
- e.count++;
- this.count++;
- return true;
- }
- }
- }
-
- // rehash the table if the threshold is exceeded
- if (this.uniqueCount >= this.threshold) {
- this.rehash();
- tab = this.table;
- index = (hash & 0x7FFFFFFF) % tab.length;
- }
-
- // create the new entry and put it in the table
- Entry<E> e = this.buildEntry(hash, o, tab[index]);
- tab[index] = e;
- this.count++;
- this.uniqueCount++;
- return true;
- }
-
- /**
- * This implementation searches for the object in the hash table by calculating
- * the object's hash code and examining the entries in the corresponding hash
- * table bucket.
- */
- public boolean add(E o, int cnt) {
- if (cnt <= 0) {
- return false;
- }
- this.modCount++;
- Entry<E>[] tab = this.table;
- int hash = 0;
- int index = 0;
-
- // if the object is already in the bag, simply bump its count
- if (o == null) {
- for (Entry<E> e = tab[0]; e != null; e = e.next) {
- if (e.object == null) {
- e.count += cnt;
- this.count += cnt;
- return true;
- }
- }
- } else {
- hash = o.hashCode();
- index = (hash & 0x7FFFFFFF) % tab.length;
- for (Entry<E> e = tab[index]; e != null; e = e.next) {
- if ((e.hash == hash) && o.equals(e.object)) {
- e.count += cnt;
- this.count += cnt;
- return true;
- }
- }
- }
-
- // rehash the table if the threshold is exceeded
- if (this.uniqueCount >= this.threshold) {
- this.rehash();
- tab = this.table;
- index = (hash & 0x7FFFFFFF) % tab.length;
- }
-
- // create the new entry and put it in the table
- Entry<E> e = this.buildEntry(hash, o, cnt, tab[index]);
- tab[index] = e;
- this.count += cnt;
- this.uniqueCount++;
- return true;
- }
-
- /**
- * This implementation searches for the object in the hash table by calculating
- * the object's hash code and examining the entries in the corresponding hash
- * table bucket.
- */
- @Override
- public boolean remove(Object o) {
- Entry<E>[] tab = this.table;
- if (o == null) {
- for (Entry<E> e = tab[0], prev = null; e != null; prev = e, e = e.next) {
- if (e.object == null) {
- this.modCount++;
- e.count--;
- // if we are removing the last one, remove the entry from the table
- if (e.count == 0) {
- if (prev == null) {
- tab[0] = e.next;
- } else {
- prev.next = e.next;
- }
- this.uniqueCount--;
- }
- this.count--;
- return true;
- }
- }
- } else {
- int hash = o.hashCode();
- int index = (hash & 0x7FFFFFFF) % tab.length;
- for (Entry<E> e = tab[index], prev = null; e != null; prev = e, e = e.next) {
- if ((e.hash == hash) && o.equals(e.object)) {
- this.modCount++;
- e.count--;
- // if we are removing the last one, remove the entry from the table
- if (e.count == 0) {
- if (prev == null) {
- tab[index] = e.next;
- } else {
- prev.next = e.next;
- }
- this.uniqueCount--;
- }
- this.count--;
- return true;
- }
- }
- }
-
- return false;
- }
-
- /**
- * This implementation searches for the object in the hash table by calculating
- * the object's hash code and examining the entries in the corresponding hash
- * table bucket.
- */
- public boolean remove(Object o, int cnt) {
- if (cnt <= 0) {
- return false;
- }
- Entry<E>[] tab = this.table;
- if (o == null) {
- for (Entry<E> e = tab[0], prev = null; e != null; prev = e, e = e.next) {
- if (e.object == null) {
- this.modCount++;
- int cnt2 = (cnt < e.count) ? cnt : e.count;
- e.count -= cnt2;
- // if we are removing the last element(s), remove the entry from the table
- if (e.count == 0) {
- if (prev == null) {
- tab[0] = e.next;
- } else {
- prev.next = e.next;
- }
- this.uniqueCount--;
- }
- this.count -= cnt2;
- return true;
- }
- }
- } else {
- int hash = o.hashCode();
- int index = (hash & 0x7FFFFFFF) % tab.length;
- for (Entry<E> e = tab[index], prev = null; e != null; prev = e, e = e.next) {
- if ((e.hash == hash) && o.equals(e.object)) {
- this.modCount++;
- int cnt2 = (cnt < e.count) ? cnt : e.count;
- e.count -= cnt2;
- // if we are removing the last element(s), remove the entry from the table
- if (e.count == 0) {
- if (prev == null) {
- tab[index] = e.next;
- } else {
- prev.next = e.next;
- }
- this.uniqueCount--;
- }
- this.count -= cnt2;
- return true;
- }
- }
- }
-
- return false;
- }
-
- /**
- * This implementation simply clears out all of the hash table buckets.
- */
- @Override
- public void clear() {
- Entry<E>[] tab = this.table;
- this.modCount++;
- for (int i = tab.length; --i >= 0; ) {
- tab[i] = null;
- }
- this.count = 0;
- this.uniqueCount = 0;
- }
-
- /**
- * Returns a shallow copy of this bag: the elements
- * themselves are not cloned.
- *
- * @return a shallow copy of this bag.
- */
- @Override
- public HashBag<E> clone() {
- try {
- @SuppressWarnings("unchecked")
- HashBag<E> clone = (HashBag<E>) super.clone();
- clone.table = this.buildTable(this.table.length);
- for (int i = this.table.length; i-- > 0; ) {
- clone.table[i] = (this.table[i] == null)
- ? null : (Entry<E>) this.table[i].clone();
- }
- clone.modCount = 0;
- return clone;
- } catch (CloneNotSupportedException e) {
- throw new InternalError();
- }
- }
-
- /**
- * Hash table collision list entry.
- */
- private static class Entry<E> {
- int hash;
- E object;
- int count;
- Entry<E> next;
-
- Entry(int hash, E object, Entry<E> next) {
- this(hash, object, 1, next);
- }
-
- Entry(int hash, E object, int count, Entry<E> next) {
- this.hash = hash;
- this.object = object;
- this.count = count;
- this.next = next;
- }
-
- /**
- * Cascade the clone to all the entries in the same bucket.
- */
- @Override
- @SuppressWarnings("unchecked")
- protected Entry<E> clone() {
- return new Entry(this.hash, this.object, this.count,
- (this.next == null ? null : this.next.clone()));
- }
-
- @Override
- public String toString() {
- return this.object + "=>" + this.count;
- }
- }
-
- @Override
- @SuppressWarnings("unchecked")
- public Iterator<E> iterator() {
- if (this.count == 0) {
- return EMPTY_ITERATOR;
- }
- return new HashIterator();
- }
-
- @SuppressWarnings("unchecked")
- public Iterator<E> uniqueIterator() {
- if (this.count == 0) {
- return EMPTY_ITERATOR;
- }
- return new UniqueIterator();
- }
-
- /**
- * Empty iterator that does just about nothing.
- */
- @SuppressWarnings("unchecked")
- private static final Iterator EMPTY_ITERATOR = new EmptyIterator();
-
- @SuppressWarnings("unchecked")
- private static class EmptyIterator implements Iterator {
-
- EmptyIterator() {
- super();
- }
-
- public boolean hasNext() {
- return false;
- }
-
- public Object next() {
- throw new NoSuchElementException();
- }
-
- public void remove() {
- throw new IllegalStateException();
- }
- }
-
- private class HashIterator implements Iterator<E> {
- Entry<E>[] localTable = HashBag.this.table;
- int index = this.localTable.length; // start at the end of the table
- Entry<E> nextEntry = null;
- int nextEntryCount = 0;
- Entry<E> lastReturnedEntry = null;
-
- /**
- * The modCount value that the iterator believes that the backing
- * bag should have. If this expectation is violated, the iterator
- * has detected a concurrent modification.
- */
- private int expectedModCount = HashBag.this.modCount;
-
- HashIterator() {
- super();
- }
-
- public boolean hasNext() {
- Entry<E> e = this.nextEntry;
- int i = this.index;
- Entry<E>[] tab = this.localTable;
- // Use locals for faster loop iteration
- while ((e == null) && (i > 0)) {
- e = tab[--i]; // move backwards through the table
- }
- this.nextEntry = e;
- this.index = i;
- return e != null;
- }
-
- public E next() {
- if (HashBag.this.modCount != this.expectedModCount) {
- throw new ConcurrentModificationException();
- }
- Entry<E> et = this.nextEntry;
- int i = this.index;
- Entry<E>[] tab = this.localTable;
- // Use locals for faster loop iteration
- while ((et == null) && (i > 0)) {
- et = tab[--i]; // move backwards through the table
- }
- this.nextEntry = et;
- this.index = i;
- if (et == null) {
- throw new NoSuchElementException();
- }
- Entry<E> e = this.lastReturnedEntry = this.nextEntry;
- this.nextEntryCount++;
- if (this.nextEntryCount == e.count) {
- this.nextEntry = e.next;
- this.nextEntryCount = 0;
- }
- return e.object;
- }
-
- public void remove() {
- if (this.lastReturnedEntry == null) {
- throw new IllegalStateException();
- }
- if (HashBag.this.modCount != this.expectedModCount) {
- throw new ConcurrentModificationException();
- }
- Entry<E>[] tab = this.localTable;
- int slot = (this.lastReturnedEntry.hash & 0x7FFFFFFF) % tab.length;
- for (Entry<E> e = tab[slot], prev = null; e != null; prev = e, e = e.next) {
- if (e == this.lastReturnedEntry) {
- HashBag.this.modCount++;
- this.expectedModCount++;
- e.count--;
- if (e.count == 0) {
- // if we are removing the last one, remove the entry from the table
- if (prev == null) {
- tab[slot] = e.next;
- } else {
- prev.next = e.next;
- }
- HashBag.this.uniqueCount--;
- } else {
- // slide back the count to account for the just-removed element
- this.nextEntryCount--;
- }
- HashBag.this.count--;
- this.lastReturnedEntry = null; // it cannot be removed again
- return;
- }
- }
- throw new ConcurrentModificationException();
- }
-
- }
-
-
- private class UniqueIterator implements Iterator<E> {
- Entry<E>[] localTable = HashBag.this.table;
- int index = this.localTable.length; // start at the end of the table
- Entry<E> nextEntry = null;
- Entry<E> lastReturnedEntry = null;
-
- /**
- * The modCount value that the iterator believes that the backing
- * bag should have. If this expectation is violated, the iterator
- * has detected a concurrent modification.
- */
- private int expectedModCount = HashBag.this.modCount;
-
- UniqueIterator() {
- super();
- }
-
- public boolean hasNext() {
- Entry<E> e = this.nextEntry;
- int i = this.index;
- Entry<E>[] tab = this.localTable;
- // Use locals for faster loop iteration
- while ((e == null) && (i > 0)) {
- e = tab[--i]; // move backwards through the table
- }
- this.nextEntry = e;
- this.index = i;
- return e != null;
- }
-
- public E next() {
- if (HashBag.this.modCount != this.expectedModCount) {
- throw new ConcurrentModificationException();
- }
- Entry<E> et = this.nextEntry;
- int i = this.index;
- Entry<E>[] tab = this.localTable;
- // Use locals for faster loop iteration
- while ((et == null) && (i > 0)) {
- et = tab[--i]; // move backwards through the table
- }
- this.nextEntry = et;
- this.index = i;
- if (et == null) {
- throw new NoSuchElementException();
- }
- Entry<E> e = this.lastReturnedEntry = this.nextEntry;
- this.nextEntry = e.next;
- return e.object;
- }
-
- public void remove() {
- if (this.lastReturnedEntry == null) {
- throw new IllegalStateException();
- }
- if (HashBag.this.modCount != this.expectedModCount) {
- throw new ConcurrentModificationException();
- }
- Entry<E>[] tab = this.localTable;
- int slot = (this.lastReturnedEntry.hash & 0x7FFFFFFF) % tab.length;
- for (Entry<E> e = tab[slot], prev = null; e != null; prev = e, e = e.next) {
- if (e == this.lastReturnedEntry) {
- HashBag.this.modCount++;
- this.expectedModCount++;
- // remove the entry from the table
- if (prev == null) {
- tab[slot] = e.next;
- } else {
- prev.next = e.next;
- }
- HashBag.this.uniqueCount--;
- HashBag.this.count -= this.lastReturnedEntry.count;
- this.lastReturnedEntry = null; // it cannot be removed again
- return;
- }
- }
- throw new ConcurrentModificationException();
- }
-
- }
-
-
- @Override
- public boolean equals(Object o) {
- if (o == this) {
- return true;
- }
- if ( ! (o instanceof Bag)) {
- return false;
- }
- @SuppressWarnings("unchecked")
- Bag<E> b = (Bag<E>) o;
- if (b.size() != this.size()) {
- return false;
- }
- Bag<E> clone = this.clone();
- for (E e : b) {
- if ( ! clone.remove(e)) {
- return false;
- }
- }
- return clone.isEmpty();
- }
-
- @Override
- public int hashCode() {
- int h = 0;
- for (Iterator<E> stream = this.iterator(); stream.hasNext(); ) {
- Object next = stream.next();
- if (next != null) {
- h += next.hashCode();
- }
- }
- return h;
- }
-
- /**
- * Save the state of this bag to a stream (i.e. serialize it).
- *
- * @serialData Emit the capacity of the bag (int),
- * followed by the number of unique elements in the bag (int),
- * followed by all of the bag's elements (each an Object) and
- * their counts (each an int), in no particular order.
- */
- private synchronized void writeObject(java.io.ObjectOutputStream s)
- throws java.io.IOException {
- // write out the threshold, load factor, and any hidden stuff
- s.defaultWriteObject();
-
- // write out number of buckets
- s.writeInt(this.table.length);
-
- // write out number of unique elements
- s.writeInt(this.uniqueCount);
-
- Entry<E>[] tab = this.table;
- // write out elements and counts (alternating)
- for (Entry<E> entry : tab) {
- while (entry != null) {
- s.writeObject(entry.object);
- s.writeInt(entry.count);
- entry = entry.next;
- }
- }
- }
-
- private static final long serialVersionUID = 1L;
-
- /**
- * Reconstitute the bag from a stream (i.e. deserialize it).
- */
- private synchronized void readObject(java.io.ObjectInputStream s)
- throws java.io.IOException, ClassNotFoundException {
- // read in the threshold, loadfactor, and any hidden stuff
- s.defaultReadObject();
-
- // read in number of buckets and allocate the bucket array
- this.table = this.buildTable(s.readInt());
-
- // read in number of unique elements
- int unique = s.readInt();
-
- // read the elements and counts, and put the elements in the bag
- for (int i = 0; i < unique; i++) {
- @SuppressWarnings("unchecked")
- E element = (E) s.readObject();
- int elementCount = s.readInt();
- this.add(element, elementCount);
- }
- }
-
-}

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