| // 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.Collection; |
| 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; |
| |
| public class BidirectionalManyToOneMap<K, V> { |
| |
| private final Map<K, V> backing = new IdentityHashMap<>(); |
| private final Map<V, Set<K>> inverse = new IdentityHashMap<>(); |
| |
| public void forEach(BiConsumer<Set<K>, V> consumer) { |
| inverse.forEach((value, keys) -> consumer.accept(keys, value)); |
| } |
| |
| public V getOrDefault(K key, V value) { |
| return backing.getOrDefault(key, value); |
| } |
| |
| public Map<K, V> getForwardMap() { |
| return backing; |
| } |
| |
| public Set<K> keySet() { |
| return backing.keySet(); |
| } |
| |
| public boolean hasKey(K key) { |
| return backing.containsKey(key); |
| } |
| |
| public boolean hasValue(V value) { |
| return inverse.containsKey(value); |
| } |
| |
| public Set<K> getKeys(V value) { |
| return inverse.getOrDefault(value, Collections.emptySet()); |
| } |
| |
| public boolean isEmpty() { |
| return backing.isEmpty(); |
| } |
| |
| public void 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); |
| } |
| } |
| } |
| |
| public void put(K key, V value) { |
| remove(key); |
| backing.put(key, value); |
| inverse.computeIfAbsent(value, ignore -> new LinkedHashSet<>()).add(key); |
| } |
| |
| public Collection<V> values() { |
| return backing.values(); |
| } |
| } |