| // Copyright (C) 2014 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 com.google.gerrit.server.change; |
| |
| import com.google.common.base.Predicate; |
| import com.google.common.cache.CacheBuilder; |
| import com.google.common.cache.CacheLoader; |
| import com.google.common.cache.LoadingCache; |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.Iterables; |
| import com.google.gerrit.reviewdb.client.Account; |
| import com.google.gerrit.reviewdb.server.ReviewDb; |
| import com.google.inject.Inject; |
| import com.google.inject.Provider; |
| import com.google.inject.Singleton; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.TimeUnit; |
| /** |
| * The suggest oracle may be called many times in rapid succession during the |
| * course of one operation. |
| * It would be easy to have a simple {@code Cache<Boolean, List<Account>>} |
| * with a short expiration time of 30s. |
| * Cache only has a single key we're just using Cache for the expiration behavior. |
| */ |
| @Singleton |
| public class ReviewerSuggestionCache { |
| private static final Logger log = LoggerFactory |
| .getLogger(ReviewerSuggestionCache.class); |
| private final LoadingCache<Boolean, List<Account>> cache; |
| |
| @Inject |
| ReviewerSuggestionCache(final Provider<ReviewDb> dbProvider) { |
| this.cache = |
| CacheBuilder.newBuilder().maximumSize(1) |
| .expireAfterWrite(30, TimeUnit.SECONDS) |
| .build(new CacheLoader<Boolean, List<Account>>() { |
| @Override |
| public List<Account> load(Boolean key) throws Exception { |
| return ImmutableList.copyOf(Iterables.filter( |
| dbProvider.get().accounts().all(), |
| new Predicate<Account>() { |
| @Override |
| public boolean apply(Account in) { |
| return in.isActive(); |
| } |
| })); |
| } |
| }); |
| } |
| |
| List<Account> get() { |
| try { |
| return cache.get(true); |
| } catch (ExecutionException e) { |
| log.warn("Cannot fetch reviewers from cache", e); |
| return Collections.emptyList(); |
| } |
| } |
| } |