| // 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. |
| |
| package com.google.enterprise.adaptor.sharepoint; |
| |
| import com.google.common.cache.CacheLoader; |
| import com.google.common.util.concurrent.ListenableFuture; |
| import com.google.common.util.concurrent.SettableFuture; |
| |
| import java.util.concurrent.Executor; |
| |
| /** |
| * An abstract CacheLoader whose reload() is asynchronous (unlike the default). |
| */ |
| abstract class AsyncCacheLoader<K, V> extends CacheLoader<K, V> { |
| protected abstract Executor executor(); |
| |
| @Override |
| public ListenableFuture<V> reload(final K key, V oldValue) { |
| final SettableFuture<V> future = SettableFuture.create(); |
| executor().execute(new Runnable() { |
| @Override |
| public void run() { |
| try { |
| future.set(load(key)); |
| } catch (Throwable t) { |
| future.setException(t); |
| } |
| } |
| }); |
| return future; |
| } |
| } |