com.cedarsoftware.util.SealableNavigableMap Maven / Gradle / Ivy
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package com.cedarsoftware.util;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Comparator;
import java.util.Map;
import java.util.NavigableMap;
import java.util.NavigableSet;
import java.util.Set;
import java.util.SortedMap;
import java.util.function.Supplier;
/**
* SealableNavigableMap provides a NavigableMap or NavigableMap wrapper that can be 'sealed' and 'unsealed.'
* When sealed, the Map is mutable, when unsealed it is immutable (read-only). The view methods keySet(), entrySet(),
* values(), navigableKeySet(), descendingMap(), descendingKeySet(), subMap(), headMap(), and tailMap() return a view
* that honors the Supplier's sealed state. The sealed state can be changed as often as needed.
*
* NOTE: Please do not reformat this code as the current format makes it easy to see the overall structure.
*
* @author John DeRegnaucourt
*
* Copyright (c) Cedar Software LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* License
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
public class SealableNavigableMap implements NavigableMap {
private final NavigableMap navMap;
private final transient Supplier sealedSupplier;
/**
* Create a SealableNavigableMap. Since a Map is not supplied, this will use a ConcurrentSkipListMap internally.
* If you want a TreeMap to be used internally, use the SealableMap constructor that takes a NavigableMap and pass
* it the instance you want it to wrap.
* @param sealedSupplier {@code Supplier} that returns 'true' to indicate sealed, 'false' for mutable.
*/
public SealableNavigableMap(Supplier sealedSupplier) {
this.sealedSupplier = sealedSupplier;
this.navMap = new ConcurrentNavigableMapNullSafe<>();
}
/**
* Create a NavigableSealableMap. Since NavigableMap is not supplied, the elements from the passed in SortedMap
* will be copied to an internal ConcurrentSkipListMap. If you want to use a TreeMap for example, use the
* SealableNavigableMap constructor that takes a NavigableMap and pass it the instance you want it to wrap.
* @param map SortedMap to supply initial elements. These are copied to an internal ConcurrentSkipListMap.
* @param sealedSupplier {@code Supplier} that returns 'true' to indicate sealed, 'false' for mutable.
*/
public SealableNavigableMap(SortedMap map, Supplier sealedSupplier) {
this.sealedSupplier = sealedSupplier;
this.navMap = new ConcurrentNavigableMapNullSafe<>();
this.navMap.putAll(map);
}
/**
* Use this constructor to wrap a NavigableMap (any kind of NavigableMap) and make it a SealableNavigableMap.
* No duplicate of the Map is created and the original map is operated on directly if unsealed, or protected
* from changes if sealed.
* @param map NavigableMap instance to protect.
* @param sealedSupplier {@code Supplier} that returns 'true' to indicate sealed, 'false' for mutable.
*/
public SealableNavigableMap(NavigableMap map, Supplier sealedSupplier) {
this.sealedSupplier = sealedSupplier;
this.navMap = map;
}
private void throwIfSealed() {
if (sealedSupplier.get()) {
throw new UnsupportedOperationException("This map has been sealed and is now immutable");
}
}
// Immutable APIs
public boolean equals(Object o) { return navMap.equals(o); }
public int hashCode() { return navMap.hashCode(); }
public String toString() { return navMap.toString(); }
public boolean isEmpty() { return navMap.isEmpty(); }
public boolean containsKey(Object key) { return navMap.containsKey(key); }
public boolean containsValue(Object value) { return navMap.containsValue(value); }
public int size() { return navMap.size(); }
public V get(Object key) { return navMap.get(key); }
public Comparator comparator() { return navMap.comparator(); }
public K firstKey() { return navMap.firstKey(); }
public K lastKey() { return navMap.lastKey(); }
public Set keySet() { return new SealableSet<>(navMap.keySet(), sealedSupplier); }
public Collection values() { return new SealableList<>(new ArrayList<>(navMap.values()), sealedSupplier); }
public Set> entrySet() { return new SealableSet<>(navMap.entrySet(), sealedSupplier); }
public Map.Entry lowerEntry(K key) { return navMap.lowerEntry(key); }
public K lowerKey(K key) { return navMap.lowerKey(key); }
public Map.Entry floorEntry(K key) { return navMap.floorEntry(key); }
public K floorKey(K key) { return navMap.floorKey(key); }
public Map.Entry ceilingEntry(K key) { return navMap.ceilingEntry(key); }
public K ceilingKey(K key) { return navMap.ceilingKey(key); }
public Map.Entry higherEntry(K key) { return navMap.higherEntry(key); }
public K higherKey(K key) { return navMap.higherKey(key); }
public Map.Entry firstEntry() { return navMap.firstEntry(); }
public Map.Entry lastEntry() { return navMap.lastEntry(); }
public NavigableMap descendingMap() { return new SealableNavigableMap<>(navMap.descendingMap(), sealedSupplier); }
public NavigableSet navigableKeySet() { return new SealableNavigableSet<>(navMap.navigableKeySet(), sealedSupplier); }
public NavigableSet descendingKeySet() { return new SealableNavigableSet<>(navMap.descendingKeySet(), sealedSupplier); }
public SortedMap subMap(K fromKey, K toKey) { return subMap(fromKey, true, toKey, false); }
public NavigableMap subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
return new SealableNavigableMap<>(navMap.subMap(fromKey, fromInclusive, toKey, toInclusive), sealedSupplier);
}
public SortedMap headMap(K toKey) { return headMap(toKey, false); }
public NavigableMap headMap(K toKey, boolean inclusive) {
return new SealableNavigableMap<>(navMap.headMap(toKey, inclusive), sealedSupplier);
}
public SortedMap tailMap(K fromKey) { return tailMap(fromKey, true); }
public NavigableMap tailMap(K fromKey, boolean inclusive) {
return new SealableNavigableMap<>(navMap.tailMap(fromKey, inclusive), sealedSupplier);
}
// Mutable APIs
public Map.Entry pollFirstEntry() { throwIfSealed(); return navMap.pollFirstEntry(); }
public Map.Entry pollLastEntry() { throwIfSealed(); return navMap.pollLastEntry(); }
public V put(K key, V value) { throwIfSealed(); return navMap.put(key, value); }
public V remove(Object key) { throwIfSealed(); return navMap.remove(key); }
public void putAll(Map m) { throwIfSealed(); navMap.putAll(m); }
public void clear() { throwIfSealed(); navMap.clear(); }
}