/*
* Primitive Collections for Java.
* Copyright (C) 2002, 2003 S�ren Bak
*
* 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package bak.pcj.map;
import bak.pcj.DoubleCollection;
import bak.pcj.AbstractDoubleCollection;
import bak.pcj.DoubleIterator;
import bak.pcj.hash.DoubleHashFunction;
import bak.pcj.hash.DefaultDoubleHashFunction;
import bak.pcj.util.Exceptions;
import java.util.Set;
import java.util.AbstractSet;
import java.util.Iterator;
import java.io.Serializable;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
/**
* This class represents open addressing hash table based maps from
* object values to double values.
*
* @see ObjectKeyDoubleChainedHashMap
* @see java.util.Map
*
* @author Søren Bak
* @version 1.2 21-08-2003 19:41
* @since 1.1
*/
public class ObjectKeyDoubleOpenHashMap extends AbstractObjectKeyDoubleMap implements ObjectKeyDoubleMap, Cloneable, Serializable {
/** Constant indicating relative growth policy. */
private static final int GROWTH_POLICY_RELATIVE = 0;
/** Constant indicating absolute growth policy. */
private static final int GROWTH_POLICY_ABSOLUTE = 1;
/**
* The default growth policy of this map.
* @see #GROWTH_POLICY_RELATIVE
* @see #GROWTH_POLICY_ABSOLUTE
*/
private static final int DEFAULT_GROWTH_POLICY = GROWTH_POLICY_RELATIVE;
/** The default factor with which to increase the capacity of this map. */
public static final double DEFAULT_GROWTH_FACTOR = 1.0;
/** The default chunk size with which to increase the capacity of this map. */
public static final int DEFAULT_GROWTH_CHUNK = 10;
/** The default capacity of this map. */
public static final int DEFAULT_CAPACITY = 11;
/** The default load factor of this map. */
public static final double DEFAULT_LOAD_FACTOR = 0.75;
/**
* The size of this map.
* @serial
*/
private int size;
/**
* The keys of this map. Contains key values directly.
* Due to the use of a secondary hash function, the length of this
* array must be a prime.
*/
private transient Object[] keys;
/**
* The values of this map. Contains values directly.
* Due to the use of a secondary hash function, the length of this
* array must be a prime.
*/
private transient double[] values;
/** The states of each cell in the keys[] and values[]. */
private transient byte[] states;
private static final byte EMPTY = 0;
private static final byte OCCUPIED = 1;
private static final byte REMOVED = 2;
/** The number of entries in use (removed or occupied). */
private transient int used;
/**
* The growth policy of this map (0 is relative growth, 1 is absolute growth).
* @serial
*/
private int growthPolicy;
/**
* The growth factor of this map, if the growth policy is
* relative.
* @serial
*/
private double growthFactor;
/**
* The growth chunk size of this map, if the growth policy is
* absolute.
* @serial
*/
private int growthChunk;
/**
* The load factor of this map.
* @serial
*/
private double loadFactor;
/**
* The next size at which to expand the data[].
* @serial
*/
private int expandAt;
/** A set view of the keys of this map. */
private transient Set ckeys;
/** A collection view of the values of this map. */
private transient DoubleCollection cvalues;
/** Indicates whether last call to containsKey() had a corresponding value. */
private transient boolean hasLastValue;
/** Value corresponding to to the key of the last call of containsKey(). */
private transient double lastValue;
private ObjectKeyDoubleOpenHashMap(int capacity, int growthPolicy, double growthFactor, int growthChunk, double loadFactor) {
if (capacity < 0)
Exceptions.negativeArgument("capacity", String.valueOf(capacity));
if (growthFactor <= 0.0)
Exceptions.negativeOrZeroArgument("growthFactor", String.valueOf(growthFactor));
if (growthChunk <= 0)
Exceptions.negativeOrZeroArgument("growthChunk", String.valueOf(growthChunk));
if (loadFactor <= 0.0)
Exceptions.negativeOrZeroArgument("loadFactor", String.valueOf(loadFactor));
capacity = bak.pcj.hash.Primes.nextPrime(capacity);
keys = new Object[capacity];
values = new double[capacity];
this.states = new byte[capacity];
size = 0;
expandAt = (int)Math.round(loadFactor*capacity);
this.used = 0;
this.growthPolicy = growthPolicy;
this.growthFactor = growthFactor;
this.growthChunk = growthChunk;
this.loadFactor = loadFactor;
hasLastValue = false;
}
/**
* Creates a new hash map with capacity 11, a relative
* growth factor of 1.0, and a load factor of 75%.
*/
public ObjectKeyDoubleOpenHashMap() {
this(DEFAULT_CAPACITY);
}
/**
* Creates a new hash map with the same mappings as a specified map.
*
* @param map
* the map whose mappings to put into the new map.
*
* @throws NullPointerException
* if <tt>map</tt> is <tt>null</tt>.
*/
public ObjectKeyDoubleOpenHashMap(ObjectKeyDoubleMap map) {
this();
putAll(map);
}
/**
* Creates a new hash map with a specified capacity, a relative
* growth factor of 1.0, and a load factor of 75%.
*
* @param capacity
* the initial capacity of the map.
*
* @throws IllegalArgumentException
* if <tt>capacity</tt> is negative.
*/
public ObjectKeyDoubleOpenHashMap(int capacity) {
this(capacity, DEFAULT_GROWTH_POLICY, DEFAULT_GROWTH_FACTOR, DEFAULT_GROWTH_CHUNK, DEFAULT_LOAD_FACTOR);
}
/**
* Creates a new hash map with a capacity of 11, a relative
* growth factor of 1.0, and a specified load factor.
*
* @param loadFactor
* the load factor of the map.
*
* @throws IllegalArgumentException
* if <tt>capacity</tt> is negative;
* if <tt>loadFactor</tt> is not positive.
*/
public ObjectKeyDoubleOpenHashMap(double loadFactor) {
this(DEFAULT_CAPACITY, DEFAULT_GROWTH_POLICY, DEFAULT_GROWTH_FACTOR, DEFAULT_GROWTH_CHUNK, loadFactor);
}
/**
* Creates a new hash map with a specified capacity and
* load factor, and a relative growth factor of 1.0.
*
* @param capacity
* the initial capacity of the map.
*
* @param loadFactor
* the load factor of the map.
*
* @throws IllegalArgumentException
* if <tt>capacity</tt> is negative;
* if <tt>loadFactor</tt> is not positive.
*/
public ObjectKeyDoubleOpenHashMap(int capacity, double loadFactor) {
this(capacity, DEFAULT_GROWTH_POLICY, DEFAULT_GROWTH_FACTOR, DEFAULT_GROWTH_CHUNK, loadFactor);
}
/**
* Creates a new hash map with a specified capacity,
* load factor, and relative growth factor.
*
* <p>The map capacity increases to <tt>capacity()*(1+growthFactor)</tt>.
* This strategy is good for avoiding many capacity increases, but
* the amount of wasted memory is approximately the size of the map.
*
* @param capacity
* the initial capacity of the map.
*
* @param loadFactor
* the load factor of the map.
*
* @param growthFactor
* the relative amount with which to increase the
* the capacity when a capacity increase is needed.
*
* @throws IllegalArgumentException
* if <tt>capacity</tt> is negative;
* if <tt>loadFactor</tt> is not positive;
* if <tt>growthFactor</tt> is not positive.
*/
public ObjectKeyDoubleOpenHashMap(int capacity, double loadFactor, double growthFactor) {
this(capacity, GROWTH_POLICY_RELATIVE, growthFactor, DEFAULT_GROWTH_CHUNK, loadFactor);
}
/**
* Creates a new hash map with a specified capacity,
* load factor, and absolute growth factor.
*
* <p>The map capacity increases to <tt>capacity()+growthChunk</tt>.
* This strategy is good for avoiding wasting memory. However, an
* overhead is potentially introduced by frequent capacity increases.
*
* @param capacity
* the initial capacity of the map.
*
* @param loadFactor
* the load factor of the map.
*
* @param growthChunk
* the absolute amount with which to increase the
* the capacity when a capacity increase is needed.
*
* @throws IllegalArgumentException
* if <tt>capacity</tt> is negative;
* if <tt>loadFactor</tt> is not positive;
* if <tt>growthChunk</tt> is not positive.
*/
public ObjectKeyDoubleOpenHashMap(int capacity, double loadFactor, int growthChunk) {
this(capacity, GROWTH_POLICY_ABSOLUTE, DEFAULT_GROWTH_FACTOR, growthChunk, loadFactor);
}
// ---------------------------------------------------------------
// Hash table management
// ---------------------------------------------------------------
private static int hash(Object key)
{ return key == null ? 0 : key.hashCode(); }
private static boolean keyeq(Object k1, Object k2)
{ return k1 == null ? k2 == null : k1.equals(k2); }
private void ensureCapacity(int elements) {
if (elements >= expandAt) {
int newcapacity;
if (growthPolicy == GROWTH_POLICY_RELATIVE)
newcapacity = (int)(keys.length * (1.0 + growthFactor));
else
newcapacity = keys.length + growthChunk;
if (newcapacity*loadFactor < elements)
newcapacity = (int)Math.round(((double)elements/loadFactor));
newcapacity = bak.pcj.hash.Primes.nextPrime(newcapacity);
expandAt = (int)Math.round(loadFactor*newcapacity);
Object[] newkeys = new Object[newcapacity];
double[] newvalues = new double[newcapacity];
byte[] newstates = new byte[newcapacity];
used = 0;
// re-hash
for (int i = 0; i < keys.length; i++) {
if (states[i] == OCCUPIED) {
used++;
Object k = keys[i];
double v = values[i];
// first hash
int h = Math.abs(hash(k));
int n = h % newcapacity;
if (newstates[n] == OCCUPIED) {
// second hash
int c = 1 + (h % (newcapacity - 2));
for (;;) {
n -= c;
if (n < 0)
n += newcapacity;
if (newstates[n] == EMPTY)
break;
}
}
newstates[n] = OCCUPIED;
newvalues[n] = v;
newkeys[n] = k;
}
}
keys = newkeys;
values = newvalues;
states = newstates;
}
}
// ---------------------------------------------------------------
// Operations not supported by abstract implementation
// ---------------------------------------------------------------
public Set keySet() {
if (ckeys == null)
ckeys = new KeySet();
return ckeys;
}
public double lget() {
if (!hasLastValue)
Exceptions.noLastElement();
return lastValue;
}
public double put(Object key, double value) {
double result;
// first hash
int h = Math.abs(hash(key));
int i = h % keys.length;
if (states[i] == OCCUPIED) {
if (keyeq(keys[i], key)) {
double oldValue = values[i];
values[i] = value;
return oldValue;
}
// second hash
int c = 1 + (h % (keys.length - 2));
for (;;) {
i -= c;
if (i < 0)
i += keys.length;
// Empty entries are re-used
if (states[i] == EMPTY || states[i] == REMOVED)
break;
if (states[i] == OCCUPIED && keyeq(keys[i], key)) {
double oldValue = values[i];
values[i] = value;
return oldValue;
}
}
}
if (states[i] == EMPTY)
used++;
states[i] = OCCUPIED;
keys[i] = key;
values[i] = value;
size++;
ensureCapacity(used);
return MapDefaults.defaultDouble();
}
public DoubleCollection values() {
if (cvalues == null)
cvalues = new ValueCollection();
return cvalues;
}
/**
* Returns a clone of this hash map.
*
* @return a clone of this hash map.
*
* @since 1.1
*/
public Object clone() {
try {
ObjectKeyDoubleOpenHashMap c = (ObjectKeyDoubleOpenHashMap)super.clone();
c.keys = new Object[keys.length];
System.arraycopy(keys, 0, c.keys, 0, keys.length);
c.values = new double[values.length];
System.arraycopy(values, 0, c.values, 0, values.length);
c.states = new byte[states.length];
System.arraycopy(states, 0, c.states, 0, states.length);
// The views should not refer to this map's views
c.cvalues = null;
c.ckeys = null;
return c;
} catch (CloneNotSupportedException e) {
Exceptions.cloning(); return null;
}
}
public ObjectKeyDoubleMapIterator entries() {
return new ObjectKeyDoubleMapIterator() {
int nextEntry = nextEntry(0);
int lastEntry = -1;
int nextEntry(int index) {
while (index < keys.length && states[index] != OCCUPIED)
index++;
return index;
}
public boolean hasNext() {
return nextEntry < keys.length;
}
public void next() {
if (!hasNext())
Exceptions.endOfIterator();
lastEntry = nextEntry;
nextEntry = nextEntry(nextEntry+1);
}
public void remove() {
if (lastEntry == -1)
Exceptions.noElementToRemove();
states[lastEntry] = REMOVED;
size--;
lastEntry = -1;
}
public Object getKey() {
if (lastEntry == -1)
Exceptions.noElementToGet();
return keys[lastEntry];
}
public double getValue() {
if (lastEntry == -1)
Exceptions.noElementToGet();
return values[lastEntry];
}
};
}
private class KeySet extends AbstractSet {
public void clear()
{ ObjectKeyDoubleOpenHashMap.this.clear(); }
public boolean contains(Object v) {
return containsKey(v);
}
public Iterator iterator() {
return new Iterator() {
int nextEntry = nextEntry(0);
int lastEntry = -1;
int nextEntry(int index) {
while (index < keys.length && states[index] != OCCUPIED)
index++;
return index;
}
public boolean hasNext() {
return nextEntry < keys.length;
}
public Object next() {
if (!hasNext())
Exceptions.endOfIterator();
lastEntry = nextEntry;
nextEntry = nextEntry(nextEntry+1);
return keys[lastEntry];
}
public void remove() {
if (lastEntry == -1)
Exceptions.noElementToRemove();
states[lastEntry] = REMOVED;
keys[lastEntry] = null; // GC
size--;
lastEntry = -1;
}
};
}
public boolean remove(Object v) {
boolean result = containsKey(v);
if (result)
ObjectKeyDoubleOpenHashMap.this.remove(v);
return result;
}
public int size()
{ return size; }
}
private class ValueCollection extends AbstractDoubleCollection {
public void clear()
{ ObjectKeyDoubleOpenHashMap.this.clear(); }
public boolean contains(double v) {
return containsValue(v);
}
public DoubleIterator iterator() {
return new DoubleIterator() {
int nextEntry = nextEntry(0);
int lastEntry = -1;
int nextEntry(int index) {
while (index < keys.length && states[index] != OCCUPIED)
index++;
return index;
}
public boolean hasNext() {
return nextEntry < keys.length;
}
public double next() {
if (!hasNext())
Exceptions.endOfIterator();
lastEntry = nextEntry;
nextEntry = nextEntry(nextEntry+1);
return values[lastEntry];
}
public void remove() {
if (lastEntry == -1)
Exceptions.noElementToRemove();
states[lastEntry] = REMOVED;
size--;
lastEntry = -1;
}
};
}
public int size()
{ return size; }
}
// ---------------------------------------------------------------
// Operations overwritten for efficiency
// ---------------------------------------------------------------
public void clear() {
java.util.Arrays.fill(states, EMPTY);
java.util.Arrays.fill(keys, null); // GC
size = 0;
used = 0;
}
public boolean containsKey(Object key) {
int h = Math.abs(hash(key));
int i = h % keys.length;
if (states[i] != EMPTY) {
if (states[i] == OCCUPIED && keyeq(keys[i], key)) {
hasLastValue = true;
lastValue = values[i];
return true;
}
// second hash
int c = 1 + (h % (keys.length - 2));
for (;;) {
i -= c;
if (i < 0)
i += keys.length;
if (states[i] == EMPTY) {
hasLastValue = false;
return false;
}
if (states[i] == OCCUPIED && keyeq(keys[i], key)) {
hasLastValue = true;
lastValue = values[i];
return true;
}
}
}
hasLastValue = false;
return false;
}
public boolean containsValue(double value) {
for (int i = 0; i < states.length; i++)
if (states[i] == OCCUPIED && values[i] == value)
return true;
return false;
}
public double get(Object key) {
int h = Math.abs(hash(key));
int i = h % keys.length;
if (states[i] != EMPTY) {
if (states[i] == OCCUPIED && keyeq(keys[i], key))
return values[i];
// second hash
int c = 1 + (h % (keys.length - 2));
for (;;) {
i -= c;
if (i < 0)
i += keys.length;
if (states[i] == EMPTY)
return MapDefaults.defaultDouble();
if (states[i] == OCCUPIED && keyeq(keys[i], key))
return values[i];
}
}
return MapDefaults.defaultDouble();
}
public boolean isEmpty()
{ return size == 0; }
public double remove(Object key) {
int h = Math.abs(hash(key));
int i = h % keys.length;
if (states[i] != EMPTY) {
if (states[i] == OCCUPIED && keyeq(keys[i], key)) {
double oldValue = values[i];
states[i] = REMOVED;
keys[i] = null; // GC
size--;
return oldValue;
}
// second hash
int c = 1 + (h % (keys.length - 2));
for (;;) {
i -= c;
if (i < 0)
i += keys.length;
if (states[i] == EMPTY) {
return MapDefaults.defaultDouble();
}
if (states[i] == OCCUPIED && keyeq(keys[i], key)) {
double oldValue = values[i];
states[i] = REMOVED;
keys[i] = null; // GC
size--;
return oldValue;
}
}
}
return MapDefaults.defaultDouble();
}
public int size()
{ return size; }
public double tget(Object key) {
int h = Math.abs(hash(key));
int i = h % keys.length;
if (states[i] != EMPTY) {
if (states[i] == OCCUPIED && keyeq(keys[i], key))
return values[i];
// second hash
int c = 1 + (h % (keys.length - 2));
for (;;) {
i -= c;
if (i < 0)
i += keys.length;
if (states[i] == EMPTY)
Exceptions.noSuchMapping(key);
if (states[i] == OCCUPIED && keyeq(keys[i], key))
return values[i];
}
}
Exceptions.noSuchMapping(key); throw new RuntimeException();
}
// ---------------------------------------------------------------
// Serialization
// ---------------------------------------------------------------
/**
* @serialData Default fields; the capacity of the
* map (<tt>int</tt>); the maps's entries
* (<tt>double</tt>, <tt><S></tt>).
*/
private void writeObject(ObjectOutputStream s) throws IOException {
s.defaultWriteObject();
s.writeInt(keys.length);
ObjectKeyDoubleMapIterator i = entries();
while (i.hasNext()) {
i.next();
s.writeObject(i.getKey());
s.writeDouble(i.getValue());
}
}
private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {
s.defaultReadObject();
keys = new Object[s.readInt()];
states = new byte[keys.length];
values = new double[keys.length];
used = size;
for (int n = 0; n < size; n++) {
Object key = s.readObject();
double value = s.readDouble();
// first hash
int h = Math.abs(hash(key));
int i = h % keys.length;
if (states[i] != EMPTY) {
// second hash
int c = 1 + (h % (keys.length - 2));
for (;;) {
i -= c;
if (i < 0)
i += keys.length;
if (states[i] == EMPTY)
break;
}
}
states[i] = OCCUPIED;
keys[i] = key;
values[i] = value;
}
}
}