javolution.util.internal.map.FastMapImpl Maven / Gradle / Ivy
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/*
* Javolution - Java(TM) Solution for Real-Time and Embedded Systems
* Copyright (C) 2012 - Javolution (http://javolution.org/)
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software is
* freely granted, provided that this notice is preserved.
*/
package javolution.util.internal.map;
import java.util.Iterator;
import java.util.NoSuchElementException;
import javolution.util.function.Equality;
import javolution.util.service.MapService;
/**
* The default {@link javolution.util.FastMap FastMap} implementation
* based on {@link FractalMapImpl fractal maps}.
* This implementation ensures that no more than 3/4 of the map capacity is
* ever wasted.
*/
public class FastMapImpl extends MapView {
private static final long serialVersionUID = 0x600L; // Version.
transient MapEntryImpl firstEntry = null;
transient FractalMapImpl fractal = new FractalMapImpl();
transient MapEntryImpl freeEntry = new MapEntryImpl();
final Equality keyComparator;
transient MapEntryImpl lastEntry = null;
transient int size;
final Equality valueComparator;
public FastMapImpl(Equality keyComparator,
final Equality valueComparator) {
super(null); // Root.
this.keyComparator = keyComparator;
this.valueComparator = valueComparator;
}
@Override
public void clear() {
firstEntry = null;
lastEntry = null;
fractal = new FractalMapImpl();
size = 0;
}
@Override
public FastMapImpl clone() { // Makes a copy.
FastMapImpl copy = new FastMapImpl(keyComparator(),
valueComparator());
copy.putAll(this);
return copy;
}
@SuppressWarnings("unchecked")
@Override
public boolean containsKey(Object key) {
return fractal.getEntry(key, keyComparator.hashCodeOf((K) key)) != null;
}
@SuppressWarnings("unchecked")
@Override
public V get(Object key) {
MapEntryImpl entry = fractal.getEntry(key,
keyComparator.hashCodeOf((K) key));
if (entry == null) return null;
return entry.value;
}
@Override
public Iterator> iterator() {
return new Iterator>() {
MapEntryImpl current;
MapEntryImpl next = firstEntry;
@Override
public boolean hasNext() {
return (next != null);
}
@Override
public java.util.Map.Entry next() {
if (next == null) throw new NoSuchElementException();
current = next;
next = next.next;
return current;
}
@Override
public void remove() {
if (current == null) throw new IllegalStateException();
fractal.removeEntry(current.key, current.hash);
detachEntry(current); // Entry is not referenced anymore and will be gc.
size--;
}
};
}
@Override
public Equality keyComparator() {
return keyComparator;
}
@SuppressWarnings("unchecked")
@Override
public V put(K key, V value) {
int hash = keyComparator.hashCodeOf(key);
MapEntryImpl tmp = fractal.addEntry(freeEntry, key, hash);
if (tmp == freeEntry) { // New entry.
freeEntry = new MapEntryImpl();
attachEntry(tmp);
size++;
tmp.value = value;
return null;
} else { // Existing entry.
V oldValue = (V) tmp.value;
tmp.value = value;
return oldValue;
}
}
@SuppressWarnings("unchecked")
@Override
public V putIfAbsent(K key, V value) {
int hash = keyComparator.hashCodeOf(key);
MapEntryImpl tmp = fractal.addEntry(freeEntry, key, hash);
if (tmp == freeEntry) { // New entry.
freeEntry = new MapEntryImpl();
attachEntry(tmp);
size++;
tmp.value = value;
return null;
} else { // Existing entry.
return (V) tmp.value;
}
}
@SuppressWarnings("unchecked")
@Override
public V remove(Object key) {
MapEntryImpl entry = fractal.removeEntry(key,
keyComparator.hashCodeOf((K) key));
if (entry == null) return null;
detachEntry(entry); // Entry is not referenced anymore and will be gc.
size--;
return entry.value;
}
@SuppressWarnings("unchecked")
@Override
public boolean remove(Object key, Object value) {
int hash = keyComparator.hashCodeOf((K) key);
MapEntryImpl entry = fractal.getEntry(key, hash);
if (entry == null) return false;
if (!valueComparator.areEqual((V) entry.value, (V) value)) return false;
fractal.removeEntry(key, hash);
detachEntry(entry); // Entry is not referenced anymore and will be gc.
size--;
return true;
}
@SuppressWarnings("unchecked")
@Override
public V replace(K key, V value) {
MapEntryImpl entry = fractal.getEntry(key,
keyComparator.hashCodeOf(key));
if (entry == null) return null;
V oldValue = entry.value;
entry.value = value;
return oldValue;
}
@SuppressWarnings("unchecked")
@Override
public boolean replace(K key, V oldValue, V newValue) {
MapEntryImpl entry = fractal.getEntry(key,
keyComparator.hashCodeOf(key));
if (entry == null) return false;
if (!valueComparator.areEqual(entry.value, oldValue)) return false;
entry.value = newValue;
return true;
}
@Override
public int size() {
return size;
}
@SuppressWarnings("unchecked")
@Override
public MapService[] split(int n) {
return new MapService[] { this }; // No splitting supported yet.
}
@Override
public Equality valueComparator() {
return valueComparator;
}
private void attachEntry(MapEntryImpl entry) {
if (lastEntry != null) {
lastEntry.next = entry;
entry.previous = lastEntry;
}
lastEntry = entry;
if (firstEntry == null) {
firstEntry = entry;
}
}
private void detachEntry(MapEntryImpl entry) {
if (entry == firstEntry) {
firstEntry = entry.next;
}
if (entry == lastEntry) {
lastEntry = entry.previous;
}
MapEntryImpl previous = entry.previous;
MapEntryImpl next = entry.next;
if (previous != null) {
previous.next = next;
}
if (next != null) {
next.previous = previous;
}
}
/** For serialization support */
@SuppressWarnings("unchecked")
private void readObject(java.io.ObjectInputStream s)
throws java.io.IOException, ClassNotFoundException {
s.defaultReadObject(); // Deserialize comparator.
fractal = new FractalMapImpl();
freeEntry = new MapEntryImpl();
int n = s.readInt();
for (int i = 0; i < n; i++) {
put((K) s.readObject(), (V) s.readObject());
}
}
/** For serialization support */
private void writeObject(java.io.ObjectOutputStream s)
throws java.io.IOException {
s.defaultWriteObject(); // Serialize comparators.
s.writeInt(size);
Iterator> it = iterator();
while (it.hasNext()) {
Entry e = it.next();
s.writeObject(e.getKey());
s.writeObject(e.getValue());
}
}
}