| // Copyright (c) 2020, the R8 project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| package com.android.tools.r8.utils.collections; |
| |
| import java.util.Collections; |
| import java.util.IdentityHashMap; |
| import java.util.LinkedHashSet; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.function.BiConsumer; |
| import java.util.function.Consumer; |
| |
| public class BidirectionalManyToOneHashMap<K, V> implements MutableBidirectionalManyToOneMap<K, V> { |
| |
| private final Map<K, V> backing; |
| private final Map<V, Set<K>> inverse; |
| |
| public BidirectionalManyToOneHashMap() { |
| this(new IdentityHashMap<>(), new IdentityHashMap<>()); |
| } |
| |
| private BidirectionalManyToOneHashMap(Map<K, V> backing, Map<V, Set<K>> inverse) { |
| this.backing = backing; |
| this.inverse = inverse; |
| } |
| |
| @Override |
| public void clear() { |
| backing.clear(); |
| inverse.clear(); |
| } |
| |
| @Override |
| public boolean containsKey(K key) { |
| return backing.containsKey(key); |
| } |
| |
| @Override |
| public boolean containsValue(V value) { |
| return inverse.containsKey(value); |
| } |
| |
| @Override |
| public void forEach(BiConsumer<? super K, ? super V> consumer) { |
| backing.forEach(consumer); |
| } |
| |
| @Override |
| public void forEachKey(Consumer<? super K> consumer) { |
| backing.keySet().forEach(consumer); |
| } |
| |
| @Override |
| public void forEachManyToOneMapping(BiConsumer<? super Set<K>, V> consumer) { |
| inverse.forEach((value, keys) -> consumer.accept(keys, value)); |
| } |
| |
| @Override |
| public V get(Object key) { |
| return backing.get(key); |
| } |
| |
| @Override |
| public V getOrDefault(Object key, V value) { |
| return backing.getOrDefault(key, value); |
| } |
| |
| @Override |
| public Map<K, V> getForwardMap() { |
| return backing; |
| } |
| |
| @Override |
| public Set<K> keySet() { |
| return backing.keySet(); |
| } |
| |
| @Override |
| public Set<K> getKeys(V value) { |
| return inverse.getOrDefault(value, Collections.emptySet()); |
| } |
| |
| @Override |
| public Set<V> getValues(K key) { |
| V value = get(key); |
| return value != null ? Collections.singleton(value) : Collections.emptySet(); |
| } |
| |
| @Override |
| public boolean isEmpty() { |
| return backing.isEmpty(); |
| } |
| |
| @Override |
| public V remove(K key) { |
| V value = backing.remove(key); |
| if (value != null) { |
| Set<K> keys = inverse.get(value); |
| keys.remove(key); |
| if (keys.isEmpty()) { |
| inverse.remove(value); |
| } |
| } |
| return value; |
| } |
| |
| @Override |
| public void removeAll(Iterable<K> keys) { |
| keys.forEach(this::remove); |
| } |
| |
| @Override |
| public Set<K> removeValue(V value) { |
| Set<K> keys = inverse.remove(value); |
| if (keys == null) { |
| return Collections.emptySet(); |
| } |
| for (K key : keys) { |
| V removedValue = backing.remove(key); |
| assert removedValue == value; |
| } |
| return keys; |
| } |
| |
| @Override |
| public void put(K key, V value) { |
| remove(key); |
| backing.put(key, value); |
| inverse.computeIfAbsent(value, ignore -> new LinkedHashSet<>()).add(key); |
| } |
| |
| @Override |
| public void put(Iterable<K> keys, V value) { |
| keys.forEach(key -> put(key, value)); |
| } |
| |
| @Override |
| public Set<V> values() { |
| return inverse.keySet(); |
| } |
| } |