| // 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.common.data; |
| |
| import com.google.gerrit.reviewdb.client.AccountGroup; |
| |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| /** In-memory table of {@link GroupInfo}, indexed by {@code AccountGroup.Id}. */ |
| public class GroupInfoCache { |
| private static final GroupInfoCache EMPTY; |
| static { |
| EMPTY = new GroupInfoCache(); |
| EMPTY.groups = Collections.emptyMap(); |
| } |
| |
| /** Obtain an empty cache singleton. */ |
| public static GroupInfoCache empty() { |
| return EMPTY; |
| } |
| |
| protected Map<AccountGroup.UUID, GroupInfo> groups; |
| |
| protected GroupInfoCache() { |
| } |
| |
| public GroupInfoCache(final Iterable<GroupInfo> list) { |
| groups = new HashMap<>(); |
| for (final GroupInfo gi : list) { |
| groups.put(gi.getId(), gi); |
| } |
| } |
| |
| /** |
| * Lookup the group summary |
| * <p> |
| * The return value can take on one of three forms: |
| * <ul> |
| * <li>{@code null}, if {@code id == null}.</li> |
| * <li>a valid info block, if {@code id} was loaded.</li> |
| * <li>an anonymous info block, if {@code id} was not loaded.</li> |
| * </ul> |
| * |
| * @param uuid the id desired. |
| * @return info block for the group. |
| */ |
| public GroupInfo get(final AccountGroup.UUID uuid) { |
| if (uuid == null) { |
| return null; |
| } |
| |
| GroupInfo r = groups.get(uuid); |
| if (r == null) { |
| r = new GroupInfo(uuid); |
| groups.put(uuid, r); |
| } |
| return r; |
| } |
| |
| /** Merge the information from another cache into this one. */ |
| public void merge(final GroupInfoCache other) { |
| assert this != EMPTY; |
| groups.putAll(other.groups); |
| } |
| } |