| // Protocol Buffers - Google's data interchange format |
| // Copyright 2013 Google Inc. All rights reserved. |
| // https://developers.google.com/protocol-buffers/ |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| package com.google.protobuf.nano; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| /** |
| * Utility class for maps support. |
| */ |
| public final class MapFactories { |
| public static interface MapFactory { |
| <K, V> Map<K, V> forMap(Map<K, V> oldMap); |
| } |
| |
| // NOTE(liujisi): The factory setter is temporarily marked as package private. |
| // The way to provide customized implementations of maps for different |
| // platforms are still under discussion. Mark it as private to avoid exposing |
| // the API in proto3 alpha release. |
| /* public */ static void setMapFactory(MapFactory newMapFactory) { |
| mapFactory = newMapFactory; |
| } |
| |
| public static MapFactory getMapFactory() { |
| return mapFactory; |
| } |
| |
| private static class DefaultMapFactory implements MapFactory { |
| public <K, V> Map<K, V> forMap(Map<K, V> oldMap) { |
| if (oldMap == null) { |
| return new HashMap<K, V>(); |
| } |
| return oldMap; |
| } |
| } |
| private static volatile MapFactory mapFactory = new DefaultMapFactory(); |
| |
| private MapFactories() {} |
| } |