// Copyright (C) 2016 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;
import static com.google.gerrit.server.notedb.ReviewerStateInternal.REVIEWER;
import static java.util.stream.Collectors.toList;
import com.google.common.base.Strings;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.gerrit.common.data.LabelType;
import com.google.gerrit.extensions.registration.DynamicMap;
import com.google.gerrit.reviewdb.client.Account;
import com.google.gerrit.reviewdb.client.PatchSetApproval;
import com.google.gerrit.reviewdb.server.ReviewDb;
import com.google.gerrit.server.account.AccountDirectory.FillOptions;
import com.google.gerrit.server.account.AccountLoader;
import com.google.gerrit.server.change.ReviewerSuggestion;
import com.google.gerrit.server.change.SuggestReviewers;
import com.google.gerrit.server.change.SuggestedReviewer;
import com.google.gerrit.server.config.GerritServerConfig;
import com.google.gerrit.server.git.WorkQueue;
import com.google.gerrit.server.index.change.ChangeField;
import com.google.gerrit.server.notedb.ChangeNotes;
import com.google.gerrit.server.project.ProjectControl;
import com.google.gerrit.server.query.Predicate;
import com.google.gerrit.server.query.QueryParseException;
import com.google.gerrit.server.query.change.ChangeData;
import com.google.gerrit.server.query.change.ChangeQueryBuilder;
import com.google.gerrit.server.query.change.InternalChangeQuery;
import com.google.gwtorm.server.OrmException;
import com.google.inject.Inject;
import com.google.inject.Provider;
import java.util.ArrayList;
import java.util.Collections;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.stream.Stream;
import org.apache.commons.lang.mutable.MutableDouble;
import org.eclipse.jgit.lib.Config;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class ReviewerRecommender {
private static final Logger log = LoggerFactory.getLogger(ReviewerRecommender.class);
private static final double BASE_REVIEWER_WEIGHT = 10;
private static final double BASE_OWNER_WEIGHT = 1;
private static final double BASE_COMMENT_WEIGHT = 0.5;
private static final double[] WEIGHTS =
new double[] {
BASE_REVIEWER_WEIGHT, BASE_OWNER_WEIGHT, BASE_COMMENT_WEIGHT,
};
private static final long PLUGIN_QUERY_TIMEOUT = 500; //ms
private final ChangeQueryBuilder changeQueryBuilder;
private final Config config;
private final DynamicMap<ReviewerSuggestion> reviewerSuggestionPluginMap;
private final InternalChangeQuery internalChangeQuery;
private final WorkQueue workQueue;
private final Provider<ReviewDb> dbProvider;
private final ApprovalsUtil approvalsUtil;
@Inject
ReviewerRecommender(
ChangeQueryBuilder changeQueryBuilder,
DynamicMap<ReviewerSuggestion> reviewerSuggestionPluginMap,
InternalChangeQuery internalChangeQuery,
WorkQueue workQueue,
Provider<ReviewDb> dbProvider,
ApprovalsUtil approvalsUtil,
@GerritServerConfig Config config) {
Set<FillOptions> fillOptions = EnumSet.of(FillOptions.SECONDARY_EMAILS);
fillOptions.addAll(AccountLoader.DETAILED_OPTIONS);
this.changeQueryBuilder = changeQueryBuilder;
this.config = config;
this.internalChangeQuery = internalChangeQuery;
this.reviewerSuggestionPluginMap = reviewerSuggestionPluginMap;
this.workQueue = workQueue;
this.dbProvider = dbProvider;
this.approvalsUtil = approvalsUtil;
}
public List<Account.Id> suggestReviewers(
ChangeNotes changeNotes,
SuggestReviewers suggestReviewers,
ProjectControl projectControl,
List<Account.Id> candidateList)
throws OrmException {
String query = suggestReviewers.getQuery();
double baseWeight = config.getInt("addReviewer", "baseWeight", 1);
Map<Account.Id, MutableDouble> reviewerScores;
if (Strings.isNullOrEmpty(query)) {
reviewerScores = baseRankingForEmptyQuery(baseWeight);
} else {
reviewerScores = baseRankingForCandidateList(candidateList, projectControl, baseWeight);
}
// Send the query along with a candidate list to all plugins and merge the
// results. Plugins don't necessarily need to use the candidates list, they
// can also return non-candidate account ids.
List<Callable<Set<SuggestedReviewer>>> tasks =
new ArrayList<>(reviewerSuggestionPluginMap.plugins().size());
List<Double> weights = new ArrayList<>(reviewerSuggestionPluginMap.plugins().size());
for (DynamicMap.Entry<ReviewerSuggestion> plugin : reviewerSuggestionPluginMap) {
tasks.add(
() ->
plugin
.getProvider()
.get()
.suggestReviewers(
projectControl.getProject().getNameKey(),
changeNotes.getChangeId(),
query,
reviewerScores.keySet()));
String pluginWeight =
config.getString(
"addReviewer", plugin.getPluginName() + "-" + plugin.getExportName(), "weight");
if (Strings.isNullOrEmpty(pluginWeight)) {
pluginWeight = "1";
}
try {
weights.add(Double.parseDouble(pluginWeight));
} catch (NumberFormatException e) {
log.error(
"Exception while parsing weight for "
+ plugin.getPluginName()
+ "-"
+ plugin.getExportName(),
e);
weights.add(1d);
}
}
try {
List<Future<Set<SuggestedReviewer>>> futures =
workQueue.getDefaultQueue().invokeAll(tasks, PLUGIN_QUERY_TIMEOUT, TimeUnit.MILLISECONDS);
Iterator<Double> weightIterator = weights.iterator();
for (Future<Set<SuggestedReviewer>> f : futures) {
double weight = weightIterator.next();
for (SuggestedReviewer s : f.get()) {
if (reviewerScores.containsKey(s.account)) {
reviewerScores.get(s.account).add(s.score * weight);
} else {
reviewerScores.put(s.account, new MutableDouble(s.score * weight));
}
}
}
} catch (ExecutionException | InterruptedException e) {
log.error("Exception while suggesting reviewers", e);
return ImmutableList.of();
}
if (changeNotes != null) {
// Remove change owner
reviewerScores.remove(changeNotes.getChange().getOwner());
// Remove existing reviewers
reviewerScores
.keySet()
.removeAll(approvalsUtil.getReviewers(dbProvider.get(), changeNotes).byState(REVIEWER));
}
// Sort results
Stream<Entry<Account.Id, MutableDouble>> sorted =
reviewerScores
.entrySet()
.stream()
.sorted(Collections.reverseOrder(Map.Entry.comparingByValue()));
List<Account.Id> sortedSuggestions = sorted.map(Map.Entry::getKey).collect(toList());
return sortedSuggestions;
}
private Map<Account.Id, MutableDouble> baseRankingForEmptyQuery(double baseWeight)
throws OrmException {
// Get the user's last 25 changes, check approvals
try {
List<ChangeData> result =
internalChangeQuery
.setLimit(25)
.setRequestedFields(ImmutableSet.of(ChangeField.REVIEWER.getName()))
.query(changeQueryBuilder.owner("self"));
Map<Account.Id, MutableDouble> suggestions = new HashMap<>();
for (ChangeData cd : result) {
for (PatchSetApproval approval : cd.currentApprovals()) {
Account.Id id = approval.getAccountId();
if (suggestions.containsKey(id)) {
suggestions.get(id).add(baseWeight);
} else {
suggestions.put(id, new MutableDouble(baseWeight));
}
}
}
return suggestions;
} catch (QueryParseException e) {
// Unhandled, because owner:self will never provoke a QueryParseException
log.error("Exception while suggesting reviewers", e);
return ImmutableMap.of();
}
}
private Map<Account.Id, MutableDouble> baseRankingForCandidateList(
List<Account.Id> candidates, ProjectControl projectControl, double baseWeight)
throws OrmException {
// Get each reviewer's activity based on number of applied labels
// (weighted 10d), number of comments (weighted 0.5d) and number of owned
// changes (weighted 1d).
Map<Account.Id, MutableDouble> reviewers = new LinkedHashMap<>();
if (candidates.size() == 0) {
return reviewers;
}
List<Predicate<ChangeData>> predicates = new ArrayList<>();
for (Account.Id id : candidates) {
try {
Predicate<ChangeData> projectQuery =
changeQueryBuilder.project(projectControl.getProject().getName());
// Get all labels for this project and create a compound OR query to
// fetch all changes where users have applied one of these labels
List<LabelType> labelTypes = projectControl.getLabelTypes().getLabelTypes();
List<Predicate<ChangeData>> labelPredicates = new ArrayList<>(labelTypes.size());
for (LabelType type : labelTypes) {
labelPredicates.add(changeQueryBuilder.label(type.getName() + ",user=" + id));
}
Predicate<ChangeData> reviewerQuery =
Predicate.and(projectQuery, Predicate.or(labelPredicates));
Predicate<ChangeData> ownerQuery =
Predicate.and(projectQuery, changeQueryBuilder.owner(id.toString()));
Predicate<ChangeData> commentedByQuery =
Predicate.and(projectQuery, changeQueryBuilder.commentby(id.toString()));
predicates.add(reviewerQuery);
predicates.add(ownerQuery);
predicates.add(commentedByQuery);
reviewers.put(id, new MutableDouble());
} catch (QueryParseException e) {
// Unhandled: If an exception is thrown, we won't increase the
// candidates's score
log.error("Exception while suggesting reviewers", e);
}
}
List<List<ChangeData>> result =
internalChangeQuery.setLimit(25).setRequestedFields(ImmutableSet.of()).query(predicates);
Iterator<List<ChangeData>> queryResultIterator = result.iterator();
Iterator<Account.Id> reviewersIterator = reviewers.keySet().iterator();
int i = 0;
Account.Id currentId = null;
while (queryResultIterator.hasNext()) {
List<ChangeData> currentResult = queryResultIterator.next();
if (i % WEIGHTS.length == 0) {
currentId = reviewersIterator.next();
}
reviewers.get(currentId).add(WEIGHTS[i % WEIGHTS.length] * baseWeight * currentResult.size());
i++;
}
return reviewers;
}
}