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/*
* Copyright (C) 2002-2022 Sebastiano Vigna
*
* 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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* 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.
*/
package it.unimi.dsi.fastutil.objects;
import java.util.Map;
import java.util.function.Consumer;
import it.unimi.dsi.fastutil.objects.Object2ObjectMap.FastEntrySet;
/** A class providing static methods and objects that do useful things with type-specific maps.
*
* @see java.util.Collections
*/
public final class Object2ObjectMaps {
private Object2ObjectMaps() {}
/** Returns an iterator that will be {@linkplain FastEntrySet fast}, if possible, on the {@linkplain Map#entrySet() entry set} of the provided {@code map}.
* @param map a map from which we will try to extract a (fast) iterator on the entry set.
* @return an iterator on the entry set of the given map that will be fast, if possible.
* @since 8.0.0
*/
@SuppressWarnings("unchecked")
public static ObjectIterator > fastIterator(Object2ObjectMap map) {
final ObjectSet > entries = map.object2ObjectEntrySet();
return entries instanceof Object2ObjectMap.FastEntrySet ? ((Object2ObjectMap.FastEntrySet ) entries).fastIterator() : entries.iterator();
}
/** Iterates {@linkplain FastEntrySet#fastForEach(Consumer) quickly}, if possible, on the {@linkplain Map#entrySet() entry set} of the provided {@code map}.
* @param map a map on which we will try to iterate {@linkplain FastEntrySet#fastForEach(Consumer) quickly}.
* @param consumer the consumer that will be passed to {@link FastEntrySet#fastForEach(Consumer)}, if possible, or to {@link Iterable#forEach(Consumer)}.
* @since 8.1.0
*/
@SuppressWarnings("unchecked")
public static void fastForEach(Object2ObjectMap map, final Consumer > consumer) {
final ObjectSet > entries = map.object2ObjectEntrySet();
if (entries instanceof Object2ObjectMap.FastEntrySet) ((Object2ObjectMap.FastEntrySet ) entries).fastForEach(consumer);
else entries.forEach(consumer);
}
/** Returns an iterable yielding an iterator that will be {@linkplain FastEntrySet fast}, if possible, on the {@linkplain Map#entrySet() entry set} of the provided {@code map}.
* @param map a map from which we will try to extract an iterable yielding a (fast) iterator on the entry set.
* @return an iterable yielding an iterator on the entry set of the given map that will be
* fast, if possible.
* @since 8.0.0
*/
@SuppressWarnings("unchecked")
public static ObjectIterable > fastIterable(Object2ObjectMap map) {
final ObjectSet > entries = map.object2ObjectEntrySet();
return entries instanceof Object2ObjectMap.FastEntrySet ? new ObjectIterable >() {
@Override
public ObjectIterator > iterator() { return ((Object2ObjectMap.FastEntrySet )entries).fastIterator(); }
@Override
public ObjectSpliterator > spliterator() { return entries.spliterator(); }
@Override
public void forEach(final Consumer > consumer) { ((Object2ObjectMap.FastEntrySet )entries).fastForEach(consumer); }
} : entries;
}
/** An immutable class representing an empty type-specific map.
*
* This class may be useful to implement your own in case you subclass
* a type-specific map.
*/
public static class EmptyMap extends Object2ObjectFunctions.EmptyFunction implements Object2ObjectMap , java.io.Serializable, Cloneable {
private static final long serialVersionUID = -7046029254386353129L;
protected EmptyMap() {}
@Override
public boolean containsValue(final Object v) { return false; }
@Override
public V getOrDefault(final Object key, final V defaultValue) { return defaultValue; }
@Override
public void putAll(final Map m) { throw new UnsupportedOperationException(); }
@Override
public ObjectSet > object2ObjectEntrySet() { return ObjectSets.EMPTY_SET; }
@SuppressWarnings("unchecked")
@Override
public ObjectSet keySet() { return ObjectSets.EMPTY_SET; }
@SuppressWarnings("unchecked")
@Override
public ObjectCollection values() { return ObjectSets.EMPTY_SET; }
@Override
public void forEach(final java.util.function.BiConsumer consumer) { }
@Override
public Object clone() { return EMPTY_MAP; }
@Override
public boolean isEmpty() { return true; }
@Override
public int hashCode() { return 0; }
@Override
public boolean equals(final Object o) {
if (! (o instanceof Map)) return false;
return ((Map)o).isEmpty();
}
@Override
public String toString() { return "{}"; }
}
/** An empty type-specific map (immutable). It is serializable and cloneable.
*/
@SuppressWarnings("rawtypes")
public static final EmptyMap EMPTY_MAP = new EmptyMap();
/** Returns an empty map (immutable). It is serializable and cloneable.
*
* This method provides a typesafe access to {@link #EMPTY_MAP}.
* @return an empty map (immutable).
*/
@SuppressWarnings("unchecked")
public static Object2ObjectMap emptyMap() {
return EMPTY_MAP;
}
/** An immutable class representing a type-specific singleton map.
*
* This class may be useful to implement your own in case you subclass
* a type-specific map.
*/
public static class Singleton extends Object2ObjectFunctions.Singleton implements Object2ObjectMap , java.io.Serializable, Cloneable {
private static final long serialVersionUID = -7046029254386353129L;
protected transient ObjectSet > entries;
protected transient ObjectSet keys;
protected transient ObjectCollection values;
protected Singleton(final K key, final V value) {
super(key, value);
}
@Override
public boolean containsValue(final Object v) { return java.util.Objects.equals(value, v); }
@Override
public void putAll(final Map m) { throw new UnsupportedOperationException(); }
@Override
public ObjectSet > object2ObjectEntrySet() { if (entries == null) entries = ObjectSets.singleton(new AbstractObject2ObjectMap.BasicEntry <>(key, value)); return entries; }
/** {@inheritDoc} */
@Override
@SuppressWarnings({ "rawtypes", "unchecked" })
public ObjectSet> entrySet() { return (ObjectSet)object2ObjectEntrySet(); }
@Override
public ObjectSet keySet() { if (keys == null) keys = ObjectSets.singleton(key); return keys; }
@Override
public ObjectCollection values() { if (values == null) values = ObjectSets.singleton(value); return values; }
@Override
public boolean isEmpty() { return false; }
@Override
public int hashCode() { return ( (key) == null ? 0 : (key).hashCode() ) ^ ( (value) == null ? 0 : (value).hashCode() ); }
@Override
public boolean equals(final Object o) {
if (o == this) return true;
if (! (o instanceof Map)) return false;
Map m = (Map)o;
if (m.size() != 1) return false;
return m.entrySet().iterator().next().equals(entrySet().iterator().next());
}
@Override
public String toString() { return "{" + key + "=>" + value + "}"; }
}
/** Returns a type-specific immutable map containing only the specified pair. The returned map is serializable and cloneable.
*
* Note that albeit the returned map is immutable, its default return value may be changed.
*
* @param key the only key of the returned map.
* @param value the only value of the returned map.
* @return a type-specific immutable map containing just the pair {@code <key,value>}.
*/
public static Object2ObjectMap singleton(final K key, V value) { return new Singleton <>(key, value); }
/** A synchronized wrapper class for maps. */
public static class SynchronizedMap extends Object2ObjectFunctions.SynchronizedFunction implements Object2ObjectMap , java.io.Serializable {
private static final long serialVersionUID = -7046029254386353129L;
protected final Object2ObjectMap map;
protected transient ObjectSet > entries;
protected transient ObjectSet keys;
protected transient ObjectCollection values;
protected SynchronizedMap(final Object2ObjectMap m, final Object sync) {
super(m, sync);
this.map = m;
}
protected SynchronizedMap(final Object2ObjectMap m) {
super(m);
this.map = m;
}
@Override
public boolean containsValue(final Object v) { synchronized(sync) { return map.containsValue(v); } }
@Override
public void putAll(final Map m) { synchronized(sync) { map.putAll(m); } }
@Override
public ObjectSet > object2ObjectEntrySet() { synchronized(sync) { if (entries == null) entries = ObjectSets.synchronize(map.object2ObjectEntrySet(), sync); return entries; } }
/** {@inheritDoc} */
@Override
@SuppressWarnings({ "unchecked", "rawtypes" })
public ObjectSet> entrySet() { return (ObjectSet)object2ObjectEntrySet(); }
@Override
public ObjectSet keySet() {
synchronized(sync) { if (keys == null) keys = ObjectSets.synchronize(map.keySet(), sync); return keys; }
}
@Override
public ObjectCollection values() {
synchronized(sync) { if (values == null) values = ObjectCollections.synchronize(map.values(), sync); return values; }
}
@Override
public boolean isEmpty() { synchronized(sync) { return map.isEmpty(); } }
@Override
public int hashCode() { synchronized(sync) { return map.hashCode(); } }
@Override
public boolean equals(final Object o) {
if (o == this) return true;
synchronized(sync) { return map.equals(o); }
}
private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException {
synchronized(sync) { s.defaultWriteObject(); }
}
// Defaultable methods
@Override
public V getOrDefault(final Object key, final V defaultValue) { synchronized(sync) { return map.getOrDefault(key, defaultValue); } }
@Override
public void forEach(final java.util.function.BiConsumer action) { synchronized (sync) { map.forEach(action); } }
@Override
public void replaceAll(final java.util.function.BiFunction function) { synchronized (sync) { map.replaceAll(function); } }
@Override
public V putIfAbsent(final K key, final V value) { synchronized(sync) { return map.putIfAbsent(key, value); } }
@Override
public boolean remove(final Object key, final Object value) { synchronized(sync) { return map.remove(key, value); } }
@Override
public V replace(final K key, final V value) { synchronized(sync) { return map.replace(key, value); } }
@Override
public boolean replace(final K key, final V oldValue, final V newValue) { synchronized(sync) { return map.replace(key, oldValue, newValue); } }
@Override
public V computeIfPresent(final K key, final java.util.function.BiFunction remappingFunction) {
synchronized (sync) { return map.computeIfPresent(key, remappingFunction); }
}
@Override
public V compute(final K key, final java.util.function.BiFunction remappingFunction) {
synchronized (sync) { return map.compute(key, remappingFunction); }
}
@Override
public V merge(final K key, final V value, final java.util.function.BiFunction remappingFunction) {
synchronized (sync) { return map.merge(key, value, remappingFunction); }
}
}
/** Returns a synchronized type-specific map backed by the given type-specific map.
*
* @param m the map to be wrapped in a synchronized map.
* @return a synchronized view of the specified map.
* @see java.util.Collections#synchronizedMap(Map)
*/
public static Object2ObjectMap synchronize(final Object2ObjectMap m) { return new SynchronizedMap <>(m); }
/** Returns a synchronized type-specific map backed by the given type-specific map, using an assigned object to synchronize.
*
* @param m the map to be wrapped in a synchronized map.
* @param sync an object that will be used to synchronize the access to the map.
* @return a synchronized view of the specified map.
* @see java.util.Collections#synchronizedMap(Map)
*/
public static Object2ObjectMap synchronize(final Object2ObjectMap m, final Object sync) { return new SynchronizedMap <>(m, sync); }
/** An unmodifiable wrapper class for maps. */
public static class UnmodifiableMap extends Object2ObjectFunctions.UnmodifiableFunction implements Object2ObjectMap , java.io.Serializable {
private static final long serialVersionUID = -7046029254386353129L;
protected final Object2ObjectMap map;
protected transient ObjectSet > entries;
protected transient ObjectSet keys;
protected transient ObjectCollection values;
protected UnmodifiableMap(final Object2ObjectMap m) {
super(m);
this.map = m;
}
@Override
public boolean containsValue(final Object v) { return map.containsValue(v); }
@Override
public void putAll(final Map m) { throw new UnsupportedOperationException(); }
@SuppressWarnings({ "unchecked", "rawtypes" })
@Override
public ObjectSet > object2ObjectEntrySet() { if (entries == null) entries = ObjectSets.unmodifiable((ObjectSet)map.object2ObjectEntrySet()); return entries; }
/** {@inheritDoc} */
@SuppressWarnings({ "unchecked", "rawtypes" })
@Override
public ObjectSet> entrySet() { return (ObjectSet)object2ObjectEntrySet(); }
@Override
public ObjectSet keySet() { if (keys == null) keys = ObjectSets.unmodifiable(map.keySet()); return keys; }
@Override
public ObjectCollection values() { if (values == null) values = ObjectCollections.unmodifiable(map.values()); return values; }
@Override
public boolean isEmpty() { return map.isEmpty(); }
@Override
public int hashCode() { return map.hashCode(); }
@Override
public boolean equals(final Object o) {
if (o == this) return true;
return map.equals(o);
}
// Defaultable methods
@Override
@SuppressWarnings("unchecked")
public V getOrDefault(final Object key, final V defaultValue) { return ((Object2ObjectMap )map).getOrDefault(key, defaultValue); }
@Override
public void forEach(final java.util.function.BiConsumer action) { map.forEach(action); }
@Override
public void replaceAll(final java.util.function.BiFunction function) { throw new UnsupportedOperationException(); }
@Override
public V putIfAbsent(final K key, final V value) { throw new UnsupportedOperationException(); }
@Override
public boolean remove(final Object key, final Object value) { throw new UnsupportedOperationException(); }
@Override
public V replace(final K key, final V value) { throw new UnsupportedOperationException(); }
@Override
public boolean replace(final K key, final V oldValue, final V newValue) { throw new UnsupportedOperationException(); }
@Override
public V computeIfPresent(final K key, final java.util.function.BiFunction remappingFunction) { throw new UnsupportedOperationException(); }
@Override
public V compute(final K key, final java.util.function.BiFunction remappingFunction) { throw new UnsupportedOperationException(); }
@Override
public V merge(final K key, final V value, final java.util.function.BiFunction remappingFunction) { throw new UnsupportedOperationException(); }
}
/** Returns an unmodifiable type-specific map backed by the given type-specific map.
*
* @param m the map to be wrapped in an unmodifiable map.
* @return an unmodifiable view of the specified map.
* @see java.util.Collections#unmodifiableMap(Map)
*/
public static Object2ObjectMap unmodifiable(final Object2ObjectMap m) { return new UnmodifiableMap <>(m); }
}