com.google.gerrit.server.account.GroupsSnapshotReader Maven / Gradle / Ivy
// Copyright (C) 2020 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.account;
import com.google.auto.value.AutoValue;
import com.google.common.collect.ImmutableList;
import com.google.common.hash.Hashing;
import com.google.gerrit.entities.RefNames;
import com.google.gerrit.server.config.AllUsersName;
import com.google.gerrit.server.git.GitRepositoryManager;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import java.io.IOException;
import java.nio.ByteBuffer;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
/**
* This class is used to compute a compound key that represents the state of the internal groups in
* NoteDb.
*/
@Singleton
public class GroupsSnapshotReader {
private final GitRepositoryManager repoManager;
private final AllUsersName allUsersName;
@Inject
GroupsSnapshotReader(GitRepositoryManager repoManager, AllUsersName allUsersName) {
this.repoManager = repoManager;
this.allUsersName = allUsersName;
}
@AutoValue
public abstract static class Snapshot {
/**
* 128-bit hash of all group ref {@link com.google.gerrit.git.ObjectIds}. To be used as cache
* key.
*/
public abstract String hash();
/** Snapshot of the state of all relevant NoteDb group refs. */
public abstract ImmutableList groupsRefs();
public static Snapshot create(String hash, ImmutableList groupsRefs) {
return new AutoValue_GroupsSnapshotReader_Snapshot(hash, groupsRefs);
}
}
/** Retrieves a snapshot key of all internal groups refs from NoteDb. */
public Snapshot getSnapshot() throws IOException {
try (Repository repo = repoManager.openRepository(allUsersName)) {
ImmutableList groupsRefs =
ImmutableList.copyOf(repo.getRefDatabase().getRefsByPrefix(RefNames.REFS_GROUPS));
ByteBuffer buf = ByteBuffer.allocate(groupsRefs.size() * Constants.OBJECT_ID_LENGTH);
for (Ref groupRef : groupsRefs) {
groupRef.getObjectId().copyRawTo(buf);
}
String hash = Hashing.murmur3_128().hashBytes(buf.array()).toString();
return Snapshot.create(hash, groupsRefs);
}
}
}