blob: 043158b662b5a4fa89baf60742885994a2ad29fa [file] [log] [blame] [edit]
// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
Map<Key, dynamic> _cache = <Key, dynamic>{};
const int _maxSize = 10;
T cache<T>(Key key, T getter()) {
T result = _cache[key];
if (result != null) {
_cache.remove(key);
} else {
if (_cache.length == _maxSize)
_cache.remove(_cache.keys.first);
result = getter();
assert(result is! Function);
}
_cache[key] = result;
return result;
}
abstract class Key {
Key(this._value);
final dynamic _value;
@override
bool operator ==(Object other) {
if (identical(this, other))
return true;
if (runtimeType != other.runtimeType)
return false;
return other is Key
&& other._value == _value;
}
@override
int get hashCode => runtimeType.hashCode ^ _value.hashCode;
@override
String toString() => '$runtimeType($_value)';
}