| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * 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 android.arch.core.internal; |
| |
| import android.support.annotation.NonNull; |
| import android.support.annotation.RestrictTo; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| /** |
| * Poor's man LinkedHashMap, which supports modifications during iterations. |
| * Takes more memory that {@link SafeIterableMap} |
| * It is NOT thread safe. |
| * |
| * @param <K> Key type |
| * @param <V> Value type |
| * @hide |
| */ |
| @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP) |
| public class FastSafeIterableMap<K, V> extends SafeIterableMap<K, V> { |
| |
| private HashMap<K, Entry<K, V>> mHashMap = new HashMap<>(); |
| |
| @Override |
| protected Entry<K, V> get(K k) { |
| return mHashMap.get(k); |
| } |
| |
| @Override |
| public V putIfAbsent(@NonNull K key, @NonNull V v) { |
| Entry<K, V> current = get(key); |
| if (current != null) { |
| return current.mValue; |
| } |
| mHashMap.put(key, put(key, v)); |
| return null; |
| } |
| |
| @Override |
| public V remove(@NonNull K key) { |
| V removed = super.remove(key); |
| mHashMap.remove(key); |
| return removed; |
| } |
| |
| /** |
| * Returns {@code true} if this map contains a mapping for the specified |
| * key. |
| */ |
| public boolean contains(K key) { |
| return mHashMap.containsKey(key); |
| } |
| |
| /** |
| * Return an entry added to prior to an entry associated with the given key. |
| * |
| * @param k the key |
| */ |
| public Map.Entry<K, V> ceil(K k) { |
| if (contains(k)) { |
| return mHashMap.get(k).mPrevious; |
| } |
| return null; |
| } |
| } |