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quiver/lib/src/cache/map_cache.dart

-// Copyright 2013 Google Inc. All Rights Reserved.
-//
-// 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.
-
-part of quiver.cache;
-
-/**
- * A [Cache] that's backed by a [Map].
- */
-class MapCache<K, V> implements Cache<K, V> {
-  final Map<K, V> _map;
-
-  /**
-   * Creates a new [MapCache], optionally using [map] as the backing [Map].
-   */
-  MapCache({Map<K, V> map}) : _map = map != null ? map : new HashMap<K, V>();
-
-  /**
-   * Creates a new [MapCache], using [LruMap] as the backing [Map].
-   * Optionally specify [maximumSize].
-   */
-  factory MapCache.lru({int maximumSize}) {
-    return new MapCache<K, V>(map: new LruMap(maximumSize: maximumSize));
-  }
-
-  Future<V> get(K key, {Loader<K> ifAbsent}) {
-    if (!_map.containsKey(key) && ifAbsent != null) {
-      var valOrFuture = ifAbsent(key);
-      if (valOrFuture is Future) {
-        return valOrFuture.then((v) {
-          _map[key] = v;
-          return v;
-        });
-      } else {
-        _map[key] = valOrFuture;
-        return new Future.value(valOrFuture);
-      }
-    }
-    return new Future.value(_map[key]);
-  }
-
-  Future set(K key, V value) {
-    _map[key] = value;
-    return new Future.value();
-  }
-
-  Future invalidate(K key) {
-    _map.remove(key);
-    return new Future.value();
-  }
-}