Line data    Source code

       1             : // Copyright (C) 2016 The Android Open Source Project
       2             : //
       3             : // Licensed under the Apache License, Version 2.0 (the "License");
       4             : // you may not use this file except in compliance with the License.
       5             : // You may obtain a copy of the License at
       6             : //
       7             : // http://www.apache.org/licenses/LICENSE-2.0
       8             : //
       9             : // Unless required by applicable law or agreed to in writing, software
      10             : // distributed under the License is distributed on an "AS IS" BASIS,
      11             : // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             : // See the License for the specific language governing permissions and
      13             : // limitations under the License.
      14             : 
      15             : package com.google.gerrit.server.change;
      16             : 
      17             : import com.google.common.base.Throwables;
      18             : import com.google.common.cache.Cache;
      19             : import com.google.common.collect.ImmutableList;
      20             : import com.google.common.collect.Sets;
      21             : import com.google.common.flogger.FluentLogger;
      22             : import com.google.common.primitives.Ints;
      23             : import com.google.gerrit.entities.Change;
      24             : import com.google.gerrit.entities.Project;
      25             : import com.google.gerrit.exceptions.StorageException;
      26             : import com.google.gerrit.extensions.restapi.Url;
      27             : import com.google.gerrit.git.ObjectIds;
      28             : import com.google.gerrit.index.IndexConfig;
      29             : import com.google.gerrit.metrics.Counter1;
      30             : import com.google.gerrit.metrics.Description;
      31             : import com.google.gerrit.metrics.Field;
      32             : import com.google.gerrit.metrics.MetricMaker;
      33             : import com.google.gerrit.server.cache.CacheModule;
      34             : import com.google.gerrit.server.logging.Metadata;
      35             : import com.google.gerrit.server.notedb.ChangeNotes;
      36             : import com.google.gerrit.server.project.NoSuchChangeException;
      37             : import com.google.gerrit.server.query.change.ChangeData;
      38             : import com.google.gerrit.server.query.change.InternalChangeQuery;
      39             : import com.google.inject.Inject;
      40             : import com.google.inject.Module;
      41             : import com.google.inject.Provider;
      42             : import com.google.inject.Singleton;
      43             : import com.google.inject.name.Named;
      44             : import java.util.ArrayList;
      45             : import java.util.Collections;
      46             : import java.util.List;
      47             : import java.util.Optional;
      48             : import java.util.Set;
      49             : import org.eclipse.jgit.errors.RepositoryNotFoundException;
      50             : 
      51             : @Singleton
      52             : public class ChangeFinder {
      53         152 :   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
      54             : 
      55             :   private static final String CACHE_NAME = "changeid_project";
      56             : 
      57             :   public static Module module() {
      58         152 :     return new CacheModule() {
      59             :       @Override
      60             :       protected void configure() {
      61         152 :         cache(CACHE_NAME, Change.Id.class, String.class).maximumWeight(1024);
      62         152 :       }
      63             :     };
      64             :   }
      65             : 
      66          90 :   public enum ChangeIdType {
      67          90 :     ALL,
      68          90 :     TRIPLET,
      69          90 :     NUMERIC_ID,
      70          90 :     I_HASH,
      71          90 :     PROJECT_NUMERIC_ID,
      72          90 :     COMMIT_HASH
      73             :   }
      74             : 
      75             :   private final IndexConfig indexConfig;
      76             :   private final Cache<Change.Id, String> changeIdProjectCache;
      77             :   private final Provider<InternalChangeQuery> queryProvider;
      78             :   private final ChangeNotes.Factory changeNotesFactory;
      79             :   private final Counter1<ChangeIdType> changeIdCounter;
      80             : 
      81             :   @Inject
      82             :   ChangeFinder(
      83             :       IndexConfig indexConfig,
      84             :       @Named(CACHE_NAME) Cache<Change.Id, String> changeIdProjectCache,
      85             :       Provider<InternalChangeQuery> queryProvider,
      86             :       ChangeNotes.Factory changeNotesFactory,
      87         149 :       MetricMaker metricMaker) {
      88         149 :     this.indexConfig = indexConfig;
      89         149 :     this.changeIdProjectCache = changeIdProjectCache;
      90         149 :     this.queryProvider = queryProvider;
      91         149 :     this.changeNotesFactory = changeNotesFactory;
      92         149 :     this.changeIdCounter =
      93         149 :         metricMaker.newCounter(
      94             :             "http/server/rest_api/change_id_type",
      95             :             new Description("Total number of API calls per identifier type.")
      96         149 :                 .setRate()
      97         149 :                 .setUnit("requests"),
      98         149 :             Field.ofEnum(ChangeIdType.class, "change_id_type", Metadata.Builder::changeIdType)
      99         149 :                 .description("The type of the change identifier.")
     100         149 :                 .build());
     101         149 :   }
     102             : 
     103             :   public Optional<ChangeNotes> findOne(String id) {
     104             :     // Limit the maximum number of results to just 2 items for saving CPU cycles
     105             :     // in reading change-notes.
     106          15 :     List<ChangeNotes> ctls = find(id, 2);
     107          15 :     if (ctls.size() != 1) {
     108           1 :       return Optional.empty();
     109             :     }
     110          15 :     return Optional.of(ctls.get(0));
     111             :   }
     112             : 
     113             :   /**
     114             :    * Find changes matching the given identifier.
     115             :    *
     116             :    * @param id change identifier.
     117             :    * @return possibly-empty list of notes for all matching changes; may or may not be visible.
     118             :    */
     119             :   public List<ChangeNotes> find(String id) {
     120          11 :     return find(id, 0);
     121             :   }
     122             : 
     123             :   /**
     124             :    * Find at most N changes matching the given identifier.
     125             :    *
     126             :    * @param id change identifier.
     127             :    * @param queryLimit maximum number of changes to be returned
     128             :    * @return possibly-empty list of notes for all matching changes; may or may not be visible.
     129             :    */
     130             :   public List<ChangeNotes> find(String id, int queryLimit) {
     131          90 :     if (id.isEmpty()) {
     132           0 :       return Collections.emptyList();
     133             :     }
     134             : 
     135          90 :     int z = id.lastIndexOf('~');
     136          90 :     int y = id.lastIndexOf('~', z - 1);
     137          90 :     if (y < 0 && z > 0) {
     138             :       // Try project~numericChangeId
     139           3 :       Integer n = Ints.tryParse(id.substring(z + 1));
     140           3 :       if (n != null) {
     141           3 :         changeIdCounter.increment(ChangeIdType.PROJECT_NUMERIC_ID);
     142           3 :         return fromProjectNumber(id.substring(0, z), n.intValue());
     143             :       }
     144             :     }
     145             : 
     146          90 :     if (y < 0 && z < 0) {
     147             :       // Try numeric changeId
     148          90 :       Integer n = Ints.tryParse(id);
     149          90 :       if (n != null) {
     150          55 :         changeIdCounter.increment(ChangeIdType.NUMERIC_ID);
     151          55 :         return find(Change.id(n));
     152             :       }
     153             :     }
     154             : 
     155             :     // Use the index to search for changes, but don't return any stored fields,
     156             :     // to force rereading in case the index is stale.
     157          80 :     InternalChangeQuery query = queryProvider.get().noFields();
     158          80 :     if (queryLimit > 0) {
     159          80 :       query.setLimit(queryLimit);
     160             :     }
     161             : 
     162             :     // Try commit hash
     163          80 :     if (id.matches("^([0-9a-fA-F]{" + ObjectIds.ABBREV_STR_LEN + "," + ObjectIds.STR_LEN + "})$")) {
     164           2 :       changeIdCounter.increment(ChangeIdType.COMMIT_HASH);
     165           2 :       return asChangeNotes(query.byCommit(id));
     166             :     }
     167             : 
     168          79 :     if (y > 0 && z > 0) {
     169             :       // Try change triplet (project~branch~Ihash...)
     170          18 :       Optional<ChangeTriplet> triplet = ChangeTriplet.parse(id, y, z);
     171          18 :       if (triplet.isPresent()) {
     172          18 :         ChangeTriplet t = triplet.get();
     173          18 :         changeIdCounter.increment(ChangeIdType.TRIPLET);
     174          18 :         return asChangeNotes(query.byBranchKey(t.branch(), t.id()));
     175             :       }
     176             :     }
     177             : 
     178             :     // Try isolated Ihash... format ("Change-Id: Ihash").
     179          79 :     List<ChangeNotes> notes = asChangeNotes(query.byKeyPrefix(id));
     180          79 :     if (!notes.isEmpty()) {
     181          79 :       changeIdCounter.increment(ChangeIdType.I_HASH);
     182             :     }
     183          79 :     return notes;
     184             :   }
     185             : 
     186             :   private List<ChangeNotes> fromProjectNumber(String project, int changeNumber) {
     187          45 :     Change.Id cId = Change.id(changeNumber);
     188             :     try {
     189          45 :       return ImmutableList.of(
     190          45 :           changeNotesFactory.createChecked(Project.NameKey.parse(project), cId));
     191           1 :     } catch (NoSuchChangeException e) {
     192           1 :       return Collections.emptyList();
     193           1 :     } catch (StorageException e) {
     194             :       // Distinguish between a RepositoryNotFoundException (project argument invalid) and
     195             :       // other StorageExceptions (failure in the persistence layer).
     196           1 :       if (Throwables.getRootCause(e) instanceof RepositoryNotFoundException) {
     197           1 :         return Collections.emptyList();
     198             :       }
     199           0 :       throw e;
     200             :     }
     201             :   }
     202             : 
     203             :   public Optional<ChangeNotes> findOne(Change.Id id) {
     204          10 :     List<ChangeNotes> notes = find(id);
     205          10 :     if (notes.size() != 1) {
     206           1 :       return Optional.empty();
     207             :     }
     208          10 :     return Optional.of(notes.get(0));
     209             :   }
     210             : 
     211             :   public List<ChangeNotes> find(Change.Id id) {
     212          65 :     String project = changeIdProjectCache.getIfPresent(id);
     213          65 :     if (project != null) {
     214          45 :       return fromProjectNumber(project, id.get());
     215             :     }
     216             : 
     217             :     // Use the index to search for changes, but don't return any stored fields,
     218             :     // to force rereading in case the index is stale.
     219          65 :     InternalChangeQuery query = queryProvider.get().noFields();
     220          65 :     List<ChangeData> r = query.byLegacyChangeId(id);
     221          65 :     if (r.size() == 1) {
     222          65 :       changeIdProjectCache.put(id, Url.encode(r.get(0).project().get()));
     223             :     }
     224          65 :     return asChangeNotes(r);
     225             :   }
     226             : 
     227             :   private List<ChangeNotes> asChangeNotes(List<ChangeData> cds) {
     228          91 :     List<ChangeNotes> notes = new ArrayList<>(cds.size());
     229          91 :     if (!indexConfig.separateChangeSubIndexes()) {
     230           0 :       for (ChangeData cd : cds) {
     231             :         try {
     232           0 :           notes.add(cd.notes());
     233           0 :         } catch (NoSuchChangeException e) {
     234           0 :           logger.atWarning().log("Change %s seen in index, but missing in NoteDb", e.getMessage());
     235           0 :         }
     236           0 :       }
     237           0 :       return notes;
     238             :     }
     239             : 
     240             :     // If an index implementation uses separate non-atomic subindexes, it's possible to temporarily
     241             :     // observe a change as present in both subindexes, if this search is concurrent with a write.
     242             :     // Dedup to avoid confusing the caller. We can choose an arbitrary ChangeData instance because
     243             :     // the index results have no stored fields, so the data is already reloaded. (It's also possible
     244             :     // that a change might appear in zero subindexes, but there's nothing we can do here to help
     245             :     // this case.)
     246          91 :     Set<Change.Id> seen = Sets.newHashSetWithExpectedSize(cds.size());
     247          91 :     for (ChangeData cd : cds) {
     248          91 :       if (seen.add(cd.getId())) {
     249             :         try {
     250          91 :           notes.add(cd.notes());
     251           0 :         } catch (NoSuchChangeException e) {
     252           0 :           logger.atWarning().log("Change %s seen in index, but missing in NoteDb", e.getMessage());
     253          91 :         }
     254             :       }
     255          91 :     }
     256          91 :     return notes;
     257             :   }
     258             : }