/*
* Primitive Collections for Java.
* Copyright (C) 2002 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.CharCollection;
import bak.pcj.AbstractCharCollection;
import bak.pcj.ByteIterator;
import bak.pcj.CharIterator;
import bak.pcj.AbstractByteCollection;
import bak.pcj.set.AbstractByteSet;
import bak.pcj.set.ByteSet;
import bak.pcj.hash.ByteHashFunction;
import bak.pcj.hash.DefaultByteHashFunction;
import bak.pcj.util.Exceptions;
import java.io.Serializable;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
/**
* This class represents chained hash table based maps from
* byte values to char values.
*
* @see ByteKeyCharOpenHashMap
* @see java.util.Map
*
* @author Søren Bak
* @version 1.4 21-08-2003 19:48
* @since 1.0
*/
public class ByteKeyCharChainedHashMap extends AbstractByteKeyCharMap implements ByteKeyCharMap, 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 hash function used to hash keys in this map.
* @serial
*/
private ByteHashFunction keyhash;
/**
* The size of this map.
* @serial
*/
private int size;
/** The hash table backing up this map. Contains linked entry values. */
private transient Entry[] data;
/**
* 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 ByteSet keys;
/** A collection view of the values of this map. */
private transient CharCollection values;
/** Indicates whether last call to containsKey() had a corresponding value. */
private transient boolean hasLastValue;
/** Value corresponding to the key of the last call of containsKey(). */
private transient char lastValue;
private ByteKeyCharChainedHashMap(ByteHashFunction keyhash, int capacity, int growthPolicy, double growthFactor, int growthChunk, double loadFactor) {
if (keyhash == null)
Exceptions.nullArgument("hash function");
if (capacity < 0)
Exceptions.negativeArgument("capacity", String.valueOf(capacity));
if (growthFactor < 0.0)
Exceptions.negativeArgument("growthFactor", String.valueOf(growthFactor));
if (growthChunk < 0)
Exceptions.negativeArgument("growthChunk", String.valueOf(growthChunk));
if (loadFactor <= 0.0)
Exceptions.negativeOrZeroArgument("loadFactor", String.valueOf(loadFactor));
this.keyhash = keyhash;
data = new Entry[capacity];
size = 0;
expandAt = (int)Math.round(loadFactor*capacity);
this.growthPolicy = growthPolicy;
this.growthFactor = growthFactor;
this.growthChunk = growthChunk;
this.loadFactor = loadFactor;
hasLastValue = false;
}
private ByteKeyCharChainedHashMap(int capacity, int growthPolicy, double growthFactor, int growthChunk, double loadFactor) {
this(DefaultByteHashFunction.INSTANCE, capacity, growthPolicy, growthFactor, growthChunk, loadFactor);
}
/**
* Creates a new hash map with capacity 11, a relative
* growth factor of 1.0, and a load factor of 75%.
*/
public ByteKeyCharChainedHashMap() {
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 ByteKeyCharChainedHashMap(ByteKeyCharMap 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 ByteKeyCharChainedHashMap(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.
*/
public ByteKeyCharChainedHashMap(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 ByteKeyCharChainedHashMap(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 ByteKeyCharChainedHashMap(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 ByteKeyCharChainedHashMap(int capacity, double loadFactor, int growthChunk) {
this(capacity, GROWTH_POLICY_ABSOLUTE, DEFAULT_GROWTH_FACTOR, growthChunk, loadFactor);
}
// ---------------------------------------------------------------
// Constructors with hash function argument
// ---------------------------------------------------------------
/**
* Creates a new hash map with capacity 11, a relative
* growth factor of 1.0, and a load factor of 75%.
*
* @param keyhash
* the hash function to use when hashing keys.
*
* @throws NullPointerException
* if <tt>keyhash</tt> is <tt>null</tt>.
*/
public ByteKeyCharChainedHashMap(ByteHashFunction keyhash) {
this(keyhash, DEFAULT_CAPACITY, DEFAULT_GROWTH_POLICY, DEFAULT_GROWTH_FACTOR, DEFAULT_GROWTH_CHUNK, DEFAULT_LOAD_FACTOR);
}
/**
* Creates a new hash map with a specified capacity, a relative
* growth factor of 1.0, and a load factor of 75%.
*
* @param keyhash
* the hash function to use when hashing keys.
*
* @param capacity
* the initial capacity of the map.
*
* @throws IllegalArgumentException
* if <tt>capacity</tt> is negative.
*
* @throws NullPointerException
* if <tt>keyhash</tt> is <tt>null</tt>.
*/
public ByteKeyCharChainedHashMap(ByteHashFunction keyhash, int capacity) {
this(keyhash, 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 keyhash
* the hash function to use when hashing keys.
*
* @param loadFactor
* the load factor of the map.
*
* @throws IllegalArgumentException
* if <tt>capacity</tt> is negative.
*
* @throws NullPointerException
* if <tt>keyhash</tt> is <tt>null</tt>.
*/
public ByteKeyCharChainedHashMap(ByteHashFunction keyhash, double loadFactor) {
this(keyhash, 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 keyhash
* the hash function to use when hashing keys.
*
* @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.
*
* @throws NullPointerException
* if <tt>keyhash</tt> is <tt>null</tt>.
*/
public ByteKeyCharChainedHashMap(ByteHashFunction keyhash, int capacity, double loadFactor) {
this(keyhash, 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 keyhash
* the hash function to use when hashing keys.
*
* @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.
*
* @throws NullPointerException
* if <tt>keyhash</tt> is <tt>null</tt>.
*/
public ByteKeyCharChainedHashMap(ByteHashFunction keyhash, int capacity, double loadFactor, double growthFactor) {
this(keyhash, 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 keyhash
* the hash function to use when hashing keys.
*
* @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;
*
* @throws NullPointerException
* if <tt>keyhash</tt> is <tt>null</tt>.
*/
public ByteKeyCharChainedHashMap(ByteHashFunction keyhash, int capacity, double loadFactor, int growthChunk) {
this(keyhash, capacity, GROWTH_POLICY_ABSOLUTE, DEFAULT_GROWTH_FACTOR, growthChunk, loadFactor);
}
// ---------------------------------------------------------------
// Hash table management
// ---------------------------------------------------------------
private void ensureCapacity(int elements) {
if (elements >= expandAt) {
int newcapacity;
if (growthPolicy == GROWTH_POLICY_RELATIVE)
newcapacity = (int)(data.length * (1.0 + growthFactor));
else
newcapacity = data.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);
Entry[] newdata = new Entry[newcapacity];
// re-hash
for (int i = 0; i < data.length; i++) {
Entry e = data[i];
while (e != null) {
int index = Math.abs(keyhash.hash(e.key)) % newdata.length;
Entry next = e.next;
e.next = newdata[index];
newdata[index] = e;
e = next;
}
}
data = newdata;
}
}
private Entry addList(Entry list, Entry v) {
v.next = list;
return v;
}
private Entry removeList(Entry list, Entry e) {
if (list == e) {
list = e.next;
e.next = null;
return list;
}
Entry listStart = list;
while (list.next != e)
list = list.next;
list.next = e.next;
e.next = null;
return listStart;
}
private Entry searchList(Entry list, byte key) {
while (list != null) {
if (list.key == key)
return list;
list = list.next;
}
return null;
}
private Entry getEntry(byte key) {
int index = Math.abs(keyhash.hash(key)) % data.length;
return searchList(data[index], key);
}
// ---------------------------------------------------------------
// Operations not supported by abstract implementation
// ---------------------------------------------------------------
public ByteSet keySet() {
if (keys == null)
keys = new KeySet();
return keys;
}
public char lget() {
if (!hasLastValue)
Exceptions.noLastElement();
return lastValue;
}
public char put(byte key, char value) {
char result;
int index = Math.abs(keyhash.hash(key)) % data.length;
Entry e = searchList(data[index], key);
if (e == null) {
result = MapDefaults.defaultChar();
e = new Entry(key, value);
e.next = data[index];
data[index] = e;
// Capacity is increased after insertion in order to
// avoid recalculation of index
ensureCapacity(size+1);
size++;
} else {
result = e.value;
e.value = value;
}
return result;
}
public CharCollection values() {
if (values == null)
values = new ValueCollection();
return values;
}
/**
* Returns a clone of this hash map.
*
* @return a clone of this hash map.
*
* @since 1.1
*/
public Object clone() {
try {
ByteKeyCharChainedHashMap c = (ByteKeyCharChainedHashMap)super.clone();
c.data = new Entry[data.length];
for (int i = 0; i < data.length; i++)
c.data[i] = cloneList(data[i]);
// The views should not refer to this map's views
c.values = null;
c.keys = null;
return c;
} catch (CloneNotSupportedException e) {
Exceptions.cloning(); return null;
}
}
private Entry cloneList(Entry e) {
if (e == null)
return null;
Entry ne = new Entry(e.getKey(), e.getValue());
ne.next = cloneList(e.next);
return ne;
}
private static class Entry {
byte key;
char value;
Entry next;
Entry(byte key, char value) {
this.key = key;
this.value = value;
}
public byte getKey()
{ return key; }
public char getValue()
{ return value; }
public boolean equals(Object obj) {
if (!(obj instanceof Entry))
return false;
Entry e = (Entry)obj;
return e.getKey() == key && e.getValue() == value;
}
}
public ByteKeyCharMapIterator entries() {
return new ByteKeyCharMapIterator() {
Entry currEntry = null;
int nextList = nextList(0);
Entry nextEntry = nextList == -1 ? null : data[nextList];
int nextList(int index) {
while (index < data.length && data[index] == null)
index++;
return index < data.length ? index : -1;
}
public boolean hasNext() {
return nextEntry != null;
}
public void next() {
if (nextEntry == null)
Exceptions.endOfIterator();
currEntry = nextEntry;
// Find next
nextEntry = nextEntry.next;
if (nextEntry == null) {
nextList = nextList(nextList+1);
if (nextList != -1)
nextEntry = data[nextList];
}
}
public byte getKey() {
if (currEntry == null)
Exceptions.noElementToGet();
return currEntry.getKey();
}
public char getValue() {
if (currEntry == null)
Exceptions.noElementToGet();
return currEntry.getValue();
}
public void remove() {
if (currEntry == null)
Exceptions.noElementToRemove();
ByteKeyCharChainedHashMap.this.remove(currEntry.getKey());
currEntry = null;
}
};
}
private class KeySet extends AbstractByteSet {
public void clear()
{ ByteKeyCharChainedHashMap.this.clear(); }
public boolean contains(byte v) {
return getEntry(v) != null;
}
public ByteIterator iterator() {
return new ByteIterator() {
Entry currEntry = null;
int nextList = nextList(0);
Entry nextEntry = nextList == -1 ? null : data[nextList];
int nextList(int index) {
while (index < data.length && data[index] == null)
index++;
return index < data.length ? index : -1;
}
public boolean hasNext() {
return nextEntry != null;
}
public byte next() {
if (nextEntry == null)
Exceptions.endOfIterator();
currEntry = nextEntry;
// Find next
nextEntry = nextEntry.next;
if (nextEntry == null) {
nextList = nextList(nextList+1);
if (nextList != -1)
nextEntry = data[nextList];
}
return currEntry.key;
}
public void remove() {
if (currEntry == null)
Exceptions.noElementToRemove();
ByteKeyCharChainedHashMap.this.remove(currEntry.getKey());
currEntry = null;
}
};
}
public boolean remove(byte v) {
boolean result = containsKey(v);
if (result)
ByteKeyCharChainedHashMap.this.remove(v);
return result;
}
public int size()
{ return size; }
}
private class ValueCollection extends AbstractCharCollection {
public void clear()
{ ByteKeyCharChainedHashMap.this.clear(); }
public boolean contains(char v) {
return containsValue(v);
}
public CharIterator iterator() {
return new CharIterator() {
Entry currEntry = null;
int nextList = nextList(0);
Entry nextEntry = nextList == -1 ? null : data[nextList];
int nextList(int index) {
while (index < data.length && data[index] == null)
index++;
return index < data.length ? index : -1;
}
public boolean hasNext() {
return nextEntry != null;
}
public char next() {
if (nextEntry == null)
Exceptions.endOfIterator();
currEntry = nextEntry;
// Find next
nextEntry = nextEntry.next;
if (nextEntry == null) {
nextList = nextList(nextList+1);
if (nextList != -1)
nextEntry = data[nextList];
}
return currEntry.value;
}
public void remove() {
if (currEntry == null)
Exceptions.noElementToRemove();
ByteKeyCharChainedHashMap.this.remove(currEntry.getKey());
currEntry = null;
}
};
}
public int size()
{ return size; }
}
// ---------------------------------------------------------------
// Operations overwritten for efficiency
// ---------------------------------------------------------------
public void clear() {
java.util.Arrays.fill(data, null);
size = 0;
}
public boolean containsKey(byte key) {
Entry e = getEntry(key);
if (e == null)
hasLastValue = false;
else {
hasLastValue = true;
lastValue = e.value;
}
return hasLastValue;
}
public boolean containsValue(char value) {
for (int i = 0; i < data.length; i++) {
Entry e = data[i];
while (e != null) {
if (e.value == value)
return true;
e = e.next;
}
}
return false;
}
public char get(byte key) {
int index = Math.abs(keyhash.hash(key)) % data.length;
Entry e = searchList(data[index], key);
return e != null ? e.value : MapDefaults.defaultChar();
}
public boolean isEmpty()
{ return size == 0; }
public char remove(byte key) {
int index = Math.abs(keyhash.hash(key)) % data.length;
Entry e = searchList(data[index], key);
char value;
if (e != null) {
// This can be improved to one iteration
data[index] = removeList(data[index], e);
value = e.value;
size--;
} else
value = MapDefaults.defaultChar();
return value;
}
public int size()
{ return size; }
public char tget(byte key) {
int index = Math.abs(keyhash.hash(key)) % data.length;
Entry e = searchList(data[index], key);
if (e == null)
Exceptions.noSuchMapping(String.valueOf(key));
return e.value;
}
// ---------------------------------------------------------------
// Serialization
// ---------------------------------------------------------------
/**
* @serialData Default fields; the capacity of the
* map (<tt>int</tt>); the maps's entries
* (<tt>byte</tt>, <tt>char</tt>).
*
* @since 1.1
*/
private void writeObject(ObjectOutputStream s) throws IOException {
s.defaultWriteObject();
s.writeInt(data.length);
ByteKeyCharMapIterator i = entries();
while (i.hasNext()) {
i.next();
s.writeByte(i.getKey());
s.writeChar(i.getValue());
}
}
/**
* @since 1.1
*/
private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {
s.defaultReadObject();
data = new Entry[s.readInt()];
for (int i = 0; i < size; i++) {
byte key = s.readByte();
char value = s.readChar();
int index = Math.abs(keyhash.hash(key)) % data.length;
Entry e = new Entry(key, value);
e.next = data[index];
data[index] = e;
}
}
}