| // Copyright (C) 2011 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.git; |
| |
| import com.google.common.cache.Cache; |
| import com.google.gerrit.entities.Project; |
| import com.google.gerrit.server.cache.CacheModule; |
| import com.google.gerrit.server.cache.serialize.StringCacheSerializer; |
| import com.google.inject.Inject; |
| import com.google.inject.Module; |
| import com.google.inject.Singleton; |
| import com.google.inject.name.Named; |
| import java.util.concurrent.ExecutionException; |
| import org.eclipse.jgit.lib.ObjectId; |
| |
| @Singleton |
| public class TagCache { |
| private static final String CACHE_NAME = "git_tags"; |
| |
| public static Module module() { |
| return new CacheModule() { |
| @Override |
| protected void configure() { |
| persist(CACHE_NAME, String.class, TagSetHolder.class) |
| .version(1) |
| .keySerializer(StringCacheSerializer.INSTANCE) |
| .valueSerializer(TagSetHolder.Serializer.INSTANCE); |
| bind(TagCache.class); |
| } |
| }; |
| } |
| |
| private final Cache<String, TagSetHolder> cache; |
| |
| @Inject |
| TagCache(@Named(CACHE_NAME) Cache<String, TagSetHolder> cache) { |
| this.cache = cache; |
| } |
| |
| /** |
| * Advise the cache that a reference fast-forwarded. |
| * |
| * <p>This operation is not necessary, the cache will automatically detect changes made to |
| * references and update itself on demand. However, this method may allow the cache to update more |
| * quickly and reuse the caller's computation of the fast-forward status of a branch. |
| * |
| * @param name project the branch is contained in. |
| * @param refName the branch name. |
| * @param oldValue the old value, before the fast-forward. The cache will only update itself if it |
| * is still using this old value. |
| * @param newValue the current value, after the fast-forward. |
| */ |
| public void updateFastForward( |
| Project.NameKey name, String refName, ObjectId oldValue, ObjectId newValue) { |
| // Be really paranoid and null check everything. This method should |
| // never fail with an exception. Some of these references can be null |
| // (e.g. not all projects are cached, or the cache is not current). |
| // |
| TagSetHolder holder = cache.getIfPresent(name.get()); |
| if (holder != null) { |
| TagSet tags = holder.getTagSet(); |
| if (tags != null) { |
| if (tags.updateFastForward(refName, oldValue, newValue)) { |
| cache.put(name.get(), holder); |
| } |
| } |
| } |
| } |
| |
| public TagSetHolder get(Project.NameKey name) { |
| try { |
| return cache.get(name.get(), () -> new TagSetHolder(name)); |
| } catch (ExecutionException e) { |
| throw new IllegalStateException(e); |
| } |
| } |
| |
| void put(Project.NameKey name, TagSetHolder tags) { |
| cache.put(name.get(), tags); |
| } |
| } |