gnu.trove.set.hash.THashSet Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of core Show documentation
Show all versions of core Show documentation
High performance collections for Java
The newest version!
///////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2001, Eric D. Friedman All Rights Reserved.
// Copyright (c) 2009, Rob Eden All Rights Reserved.
// Copyright (c) 2009, Jeff Randall All Rights Reserved.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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 for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
///////////////////////////////////////////////////////////////////////////////
package gnu.trove.set.hash;
import gnu.trove.impl.hash.TObjectHash;
import gnu.trove.impl.HashFunctions;
import gnu.trove.procedure.TObjectProcedure;
import gnu.trove.procedure.array.ToObjectArrayProceedure;
import gnu.trove.iterator.hash.TObjectHashIterator;
import java.io.*;
import java.util.Collection;
import java.util.Iterator;
import java.util.Set;
import java.util.Arrays;
import java.lang.reflect.Array;
/**
* An implementation of the Set interface that uses an
* open-addressed hash table to store its contents.
*
* @author Eric D. Friedman
* @author Rob Eden
* @author Jeff Randall
* @version $Id: THashSet.java,v 1.1.2.8 2010/03/02 04:09:50 robeden Exp $
*/
public class THashSet extends TObjectHash
implements Set, Iterable, Externalizable {
static final long serialVersionUID = 1L;
/**
* Creates a new THashSet instance with the default
* capacity and load factor.
*/
public THashSet() {
super();
}
/**
* Creates a new THashSet instance with a prime
* capacity equal to or greater than initialCapacity and
* with the default load factor.
*
* @param initialCapacity an int value
*/
public THashSet(int initialCapacity) {
super(initialCapacity);
}
/**
* Creates a new THashSet instance with a prime
* capacity equal to or greater than initialCapacity and
* with the specified load factor.
*
* @param initialCapacity an int value
* @param loadFactor a float value
*/
public THashSet(int initialCapacity, float loadFactor) {
super(initialCapacity, loadFactor);
}
/**
* Creates a new THashSet instance containing the
* elements of collection.
*
* @param collection a Collection value
*/
public THashSet(Collection collection) {
this(collection.size());
addAll(collection);
}
/**
* Inserts a value into the set.
*
* @param obj an Object value
* @return true if the set was modified by the add operation
*/
public boolean add(E obj) {
int index = insertKey(obj);
if (index < 0) {
return false; // already present in set, nothing to add
}
postInsertHook(consumeFreeSlot);
return true; // yes, we added something
}
@SuppressWarnings({"SimplifiableIfStatement"})
public boolean equals(Object other) {
if (!(other instanceof Set)) {
return false;
}
Set that = (Set) other;
if (that.size() != this.size()) {
return false;
}
return containsAll(that);
}
public int hashCode() {
HashProcedure p = new HashProcedure();
forEach(p);
return p.getHashCode();
}
private final class HashProcedure implements TObjectProcedure {
private int h = 0;
public int getHashCode() {
return h;
}
public final boolean execute(E key) {
h += HashFunctions.hash(key);
return true;
}
}
/**
* Expands the set to accommodate new values.
*
* @param newCapacity an int value
*/
@SuppressWarnings({"unchecked"})
protected void rehash(int newCapacity) {
int oldCapacity = _set.length;
int oldSize = size();
Object oldSet[] = _set;
_set = new Object[newCapacity];
Arrays.fill(_set, FREE);
int count = 0;
for (int i = oldCapacity; i-- > 0;) {
E o = (E) oldSet[i];
if (o != FREE && o != REMOVED) {
int index = insertKey(o);
if (index < 0) { // everyone pays for this because some people can't RTFM
throwObjectContractViolation(_set[(-index - 1)], o, size(), oldSize, oldSet);
}
//
count++;
}
}
// Last check: size before and after should be the same
reportPotentialConcurrentMod(size(), oldSize);
}
/**
* Returns a new array containing the objects in the set.
*
* @return an Object[] value
*/
@SuppressWarnings({"unchecked"})
public Object[] toArray() {
Object[] result = new Object[size()];
forEach(new ToObjectArrayProceedure(result));
return result;
}
/**
* Returns a typed array of the objects in the set.
*
* @param a an Object[] value
* @return an Object[] value
*/
@SuppressWarnings({"unchecked"})
public T[] toArray(T[] a) {
int size = size();
if (a.length < size) {
a = (T[]) Array.newInstance(a.getClass().getComponentType(), size);
}
forEach(new ToObjectArrayProceedure(a));
// If this collection fits in the specified array with room to
// spare (i.e., the array has more elements than this
// collection), the element in the array immediately following
// the end of the collection is set to null. This is useful in
// determining the length of this collection only if the
// caller knows that this collection does not contain any null
// elements.)
if (a.length > size) {
a[size] = null;
}
return a;
}
/**
* Empties the set.
*/
public void clear() {
super.clear();
Arrays.fill(_set, 0, _set.length, FREE);
}
/**
* Removes obj from the set.
*
* @param obj an Object value
* @return true if the set was modified by the remove operation.
*/
@SuppressWarnings({"unchecked"})
public boolean remove(Object obj) {
int index = index(obj);
if (index >= 0) {
removeAt(index);
return true;
}
return false;
}
/**
* Creates an iterator over the values of the set. The iterator
* supports element deletion.
*
* @return an Iterator value
*/
@SuppressWarnings({"unchecked"})
public TObjectHashIterator iterator() {
return new TObjectHashIterator(this);
}
/**
* Tests the set to determine if all of the elements in
* collection are present.
*
* @param collection a Collection value
* @return true if all elements were present in the set.
*/
@SuppressWarnings("ForLoopReplaceableByForEach")
public boolean containsAll(Collection collection) {
for (Iterator i = collection.iterator(); i.hasNext();) {
if (!contains(i.next())) {
return false;
}
}
return true;
}
/**
* Adds all of the elements in collection to the set.
*
* @param collection a Collection value
* @return true if the set was modified by the add all operation.
*/
public boolean addAll(Collection collection) {
boolean changed = false;
int size = collection.size();
ensureCapacity(size);
Iterator it = collection.iterator();
while (size-- > 0) {
if (add(it.next())) {
changed = true;
}
}
return changed;
}
/**
* Removes all of the elements in collection from the set.
*
* @param collection a Collection value
* @return true if the set was modified by the remove all operation.
*/
public boolean removeAll(Collection collection) {
boolean changed = false;
int size = collection.size();
Iterator it;
it = collection.iterator();
while (size-- > 0) {
if (remove(it.next())) {
changed = true;
}
}
return changed;
}
/**
* Removes any values in the set which are not contained in
* collection.
*
* @param collection a Collection value
* @return true if the set was modified by the retain all operation
*/
@SuppressWarnings({"SuspiciousMethodCalls"})
public boolean retainAll(Collection collection) {
boolean changed = false;
int size = size();
Iterator it = iterator();
while (size-- > 0) {
if (!collection.contains(it.next())) {
it.remove();
changed = true;
}
}
return changed;
}
public String toString() {
final StringBuilder buf = new StringBuilder("{");
forEach(new TObjectProcedure() {
private boolean first = true;
public boolean execute(Object value) {
if (first) {
first = false;
} else {
buf.append(", ");
}
buf.append(value);
return true;
}
});
buf.append("}");
return buf.toString();
}
public void writeExternal(ObjectOutput out) throws IOException {
// VERSION
out.writeByte(1);
// NOTE: Super was not written in version 0
super.writeExternal(out);
// NUMBER OF ENTRIES
out.writeInt(_size);
// ENTRIES
writeEntries(out);
}
protected void writeEntries(ObjectOutput out) throws IOException {
for (int i = _set.length; i-- > 0;) {
if (_set[i] != REMOVED && _set[i] != FREE) {
out.writeObject(_set[i]);
}
}
}
@SuppressWarnings({"unchecked"})
public void readExternal(ObjectInput in)
throws IOException, ClassNotFoundException {
// VERSION
byte version = in.readByte();
// NOTE: super was not written in version 0
if (version != 0) {
super.readExternal(in);
}
// NUMBER OF ENTRIES
int size = in.readInt();
setUp(size);
// ENTRIES
while (size-- > 0) {
E val = (E) in.readObject();
add(val);
}
}
} // THashSet
© 2015 - 2024 Weber Informatics LLC | Privacy Policy