1   /*
2    * Copyright 2018 LINE Corporation
3    *
4    * LINE Corporation licenses this file to you under the Apache License,
5    * version 2.0 (the "License"); you may not use this file except in compliance
6    * with the License. You may obtain a copy of the License at:
7    *
8    *   https://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13   * License for the specific language governing permissions and limitations
14   * under the License.
15   */
16  
17  package com.linecorp.centraldogma.server.internal.storage.repository.cache;
18  
19  import static com.google.common.base.MoreObjects.firstNonNull;
20  import static java.util.Objects.requireNonNull;
21  
22  import java.util.Objects;
23  import java.util.concurrent.CompletableFuture;
24  
25  import com.google.common.base.MoreObjects.ToStringHelper;
26  
27  import com.linecorp.armeria.common.util.Exceptions;
28  import com.linecorp.centraldogma.common.EntryNotFoundException;
29  import com.linecorp.centraldogma.common.Revision;
30  import com.linecorp.centraldogma.server.internal.storage.repository.CacheableCall;
31  import com.linecorp.centraldogma.server.storage.repository.Repository;
32  
33  final class CacheableFindLatestRevCall extends CacheableCall<Revision> {
34  
35      static final Revision EMPTY = new Revision(Integer.MIN_VALUE);
36      static final Revision ENTRY_NOT_FOUND = new Revision(Integer.MIN_VALUE);
37  
38      private final Revision lastKnownRevision;
39      private final Revision headRevision;
40      private final String pathPattern;
41      private final boolean errorOnEntryNotFound;
42      private final int hashCode;
43  
44      CacheableFindLatestRevCall(Repository repo, Revision lastKnownRevision, Revision headRevision,
45                                 String pathPattern, boolean errorOnEntryNotFound) {
46          super(repo);
47  
48          this.lastKnownRevision = requireNonNull(lastKnownRevision, "lastKnownRevision");
49          this.headRevision = requireNonNull(headRevision, "headRevision");
50          this.pathPattern = requireNonNull(pathPattern, "pathPattern");
51          this.errorOnEntryNotFound = errorOnEntryNotFound;
52  
53          hashCode = Objects.hash(lastKnownRevision, headRevision, pathPattern, errorOnEntryNotFound) +
54                     System.identityHashCode(repo);
55  
56          assert !lastKnownRevision.isRelative();
57      }
58  
59      @Override
60      protected int weigh(Revision value) {
61          return pathPattern.length();
62      }
63  
64      @Override
65      public CompletableFuture<Revision> execute() {
66          return repo().findLatestRevision(lastKnownRevision, pathPattern, errorOnEntryNotFound)
67                       .handle((revision, cause) -> {
68                           if (cause != null) {
69                               cause = Exceptions.peel(cause);
70                               if (cause instanceof EntryNotFoundException) {
71                                   return ENTRY_NOT_FOUND;
72                               }
73                               return Exceptions.throwUnsafely(cause);
74                           }
75                           return firstNonNull(revision, EMPTY);
76                       });
77      }
78  
79      @Override
80      public int hashCode() {
81          return hashCode;
82      }
83  
84      @Override
85      public boolean equals(Object o) {
86          if (!super.equals(o)) {
87              return false;
88          }
89  
90          final CacheableFindLatestRevCall that = (CacheableFindLatestRevCall) o;
91          return lastKnownRevision.equals(that.lastKnownRevision) &&
92                 headRevision.equals(that.headRevision) &&
93                 pathPattern.equals(that.pathPattern) &&
94                 errorOnEntryNotFound == that.errorOnEntryNotFound;
95      }
96  
97      @Override
98      protected void toString(ToStringHelper helper) {
99          helper.add("lastKnownRevision", lastKnownRevision)
100               .add("headRevision", headRevision)
101               .add("pathPattern", pathPattern)
102               .add("errorOnEntryNotFound", errorOnEntryNotFound);
103     }
104 }