javolution.util.internal.map.SharedMapImpl 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.Map;
import javolution.util.function.Equality;
import javolution.util.internal.collection.ReadWriteLockImpl;
import javolution.util.service.MapService;
/**
* A shared view over a map.
*/
public class SharedMapImpl extends MapView {
/** Thread-Safe Iterator. */
private class IteratorImpl implements Iterator> {
private Entry next;
private final Iterator> targetIterator;
public IteratorImpl() {
lock.readLock.lock();
try {
targetIterator = cloneTarget().entrySet().iterator(); // Copy.
} finally {
lock.readLock.unlock();
}
}
@Override
public boolean hasNext() {
return targetIterator.hasNext();
}
@Override
public Entry next() {
next = targetIterator.next();
return next;
}
@Override
public void remove() {
if (next == null) throw new IllegalStateException();
SharedMapImpl.this.remove(next.getKey());
next = null;
}
}
private static final long serialVersionUID = 0x600L; // Version.
protected ReadWriteLockImpl lock;
protected transient Thread updatingThread; // The thread executing an update.
public SharedMapImpl(MapService target) {
this(target, new ReadWriteLockImpl());
}
public SharedMapImpl(MapService target, ReadWriteLockImpl lock) {
super(target);
this.lock = lock;
}
@Override
public void clear() {
lock.writeLock.lock();
try {
target().clear();
} finally {
lock.writeLock.unlock();
}
}
@Override
public boolean containsKey(Object key) {
lock.readLock.lock();
try {
return target().containsKey(key);
} finally {
lock.readLock.unlock();
}
}
@Override
public boolean containsValue(Object value) {
lock.readLock.lock();
try {
return target().containsValue(value);
} finally {
lock.readLock.unlock();
}
}
@Override
public V get(Object key) {
lock.readLock.lock();
try {
return target().get(key);
} finally {
lock.readLock.unlock();
}
}
@Override
public boolean isEmpty() {
lock.readLock.lock();
try {
return target().isEmpty();
} finally {
lock.readLock.unlock();
}
}
@Override
public Iterator> iterator() {
return new IteratorImpl();
}
@Override
public Equality keyComparator() {
return target().keyComparator();
}
@Override
public V put(K key, V value) {
lock.writeLock.lock();
try {
return target().put(key, value);
} finally {
lock.writeLock.unlock();
}
}
@Override
public void putAll(Map m) {
lock.writeLock.lock();
try {
target().putAll(m);
} finally {
lock.writeLock.unlock();
}
}
@Override
public V putIfAbsent(K key, V value) {
lock.writeLock.lock();
try {
return target().putIfAbsent(key, value);
} finally {
lock.writeLock.unlock();
}
}
@Override
public V remove(Object key) {
lock.writeLock.lock();
try {
return target().remove(key);
} finally {
lock.writeLock.unlock();
}
}
@Override
public boolean remove(Object key, Object value) {
lock.writeLock.lock();
try {
return target().remove(key, value);
} finally {
lock.writeLock.unlock();
}
}
@Override
public V replace(K key, V value) {
lock.writeLock.lock();
try {
return target().replace(key, value);
} finally {
lock.writeLock.unlock();
}
}
@Override
public boolean replace(K key, V oldValue, V newValue) {
lock.writeLock.lock();
try {
return target().replace(key, oldValue, newValue);
} finally {
lock.writeLock.unlock();
}
}
@Override
public int size() {
lock.readLock.lock();
try {
return target().size();
} finally {
lock.readLock.unlock();
}
}
@SuppressWarnings("unchecked")
@Override
public MapService[] split(int n) {
MapService[] tmp;
lock.readLock.lock();
try {
tmp = target().split(n);
} finally {
lock.readLock.unlock();
}
MapService[] result = new MapService[tmp.length];
for (int i = 0; i < tmp.length; i++) {
result[i] = new SharedMapImpl(tmp[i], lock); // Same lock.
}
return result;
}
@Override
public MapService threadSafe() {
return this;
}
@Override
public Equality valueComparator() {
return target().valueComparator();
}
/** Returns a clone copy of target. */
protected MapService cloneTarget() {
try {
return target().clone();
} catch (CloneNotSupportedException e) {
throw new Error("Cannot happen since target is Cloneable.");
}
}
}