java/com/google/gerrit/server/restapi/change/ReviewerRecommender.java - gerrit - Git at Google

 // 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.restapi.change;

 import static java.util.stream.Collectors.toList;

 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
 import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.entities.Account;
 import com.google.gerrit.extensions.client.ReviewerState;
 import com.google.gerrit.index.query.QueryParseException;
 import com.google.gerrit.server.FanOutExecutor;
 import com.google.gerrit.server.account.AccountCache;
 import com.google.gerrit.server.account.AccountState;
 import com.google.gerrit.server.approval.ApprovalsUtil;
 import com.google.gerrit.server.change.ReviewerSuggestion;
 import com.google.gerrit.server.change.SuggestedReviewer;
 import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.index.change.ChangeField;
 import com.google.gerrit.server.notedb.ChangeNotes;
 import com.google.gerrit.server.notedb.ReviewerStateInternal;
 import com.google.gerrit.server.plugincontext.PluginMapContext;
 import com.google.gerrit.server.project.ProjectState;
 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.inject.Inject;
 import com.google.inject.Provider;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Stream;
 import org.apache.commons.lang3.mutable.MutableDouble;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;

 public class ReviewerRecommender {
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();

   private static final long PLUGIN_QUERY_TIMEOUT = 500; // ms

   private final ChangeQueryBuilder changeQueryBuilder;
   private final Config config;
   private final PluginMapContext<ReviewerSuggestion> reviewerSuggestionPluginMap;
   private final Provider<InternalChangeQuery> queryProvider;
   private final ExecutorService executor;
   private final ApprovalsUtil approvalsUtil;
   private final AccountCache accountCache;

   @Inject
   ReviewerRecommender(
       ChangeQueryBuilder changeQueryBuilder,
       PluginMapContext<ReviewerSuggestion> reviewerSuggestionPluginMap,
       Provider<InternalChangeQuery> queryProvider,
       @FanOutExecutor ExecutorService executor,
       ApprovalsUtil approvalsUtil,
       @GerritServerConfig Config config,
       AccountCache accountCache) {
     this.changeQueryBuilder = changeQueryBuilder;
     this.config = config;
     this.queryProvider = queryProvider;
     this.reviewerSuggestionPluginMap = reviewerSuggestionPluginMap;
     this.executor = executor;
     this.approvalsUtil = approvalsUtil;
     this.accountCache = accountCache;
   }

   public List<Account.Id> suggestReviewers(
       ReviewerState reviewerState,
       @Nullable ChangeNotes changeNotes,
       SuggestReviewers suggestReviewers,
       ProjectState projectState,
       List<Account.Id> candidateList)
       throws IOException, ConfigInvalidException {
     logger.atFine().log("Candidates %s", candidateList);

     String query = suggestReviewers.getQuery();
     logger.atFine().log("query: %s", query);

     double baseWeight = config.getInt("addReviewer", "baseWeight", 1);
     logger.atFine().log("base weight: %s", baseWeight);

     Map<Account.Id, MutableDouble> reviewerScores = baseRanking(baseWeight, query, candidateList);
     logger.atFine().log("Base reviewer scores: %s", reviewerScores);

     // 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());

     reviewerSuggestionPluginMap.runEach(
         extension -> {
           tasks.add(
               () ->
                   extension
                       .get()
                       .suggestReviewers(
                           projectState.getNameKey(),
                           changeNotes != null ? changeNotes.getChangeId() : null,
                           query,
                           reviewerScores.keySet()));
           String key = extension.getPluginName() + "-" + extension.getExportName();
           String pluginWeight = config.getString("addReviewer", key, "weight");
           if (Strings.isNullOrEmpty(pluginWeight)) {
             pluginWeight = "1";
           }
           logger.atFine().log("weight for %s: %s", key, pluginWeight);
           try {
             weights.add(Double.parseDouble(pluginWeight));
           } catch (NumberFormatException e) {
             logger.atSevere().withCause(e).log("Exception while parsing weight for %s", key);
             weights.add(1d);
           }
         });

     try {
       List<Future<Set<SuggestedReviewer>>> futures =
           executor.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));
           }
         }
       }
       logger.atFine().log("Reviewer scores: %s", reviewerScores);
     } catch (ExecutionException | InterruptedException e) {
       logger.atSevere().withCause(e).log("Exception while suggesting reviewers");
       return ImmutableList.of();
     }

     if (changeNotes != null) {
       // Remove change owner
       if (reviewerScores.remove(changeNotes.getChange().getOwner()) != null) {
         logger.atFine().log("Remove change owner %s", changeNotes.getChange().getOwner());
       }

       // Remove existing reviewers
       approvalsUtil
           .getReviewers(changeNotes)
           .byState(ReviewerStateInternal.fromReviewerState(reviewerState))
           .forEach(
               r -> {
                 if (reviewerScores.remove(r) != null) {
                   logger.atFine().log("Remove existing reviewer %s", r);
                 }
               });
     }

     // Sort results
     Stream<Map.Entry<Account.Id, MutableDouble>> sorted =
         reviewerScores.entrySet().stream()
             .sorted(Map.Entry.comparingByValue(Collections.reverseOrder()));
     List<Account.Id> sortedSuggestions = sorted.map(Map.Entry::getKey).collect(toList());
     logger.atFine().log("Sorted suggestions: %s", sortedSuggestions);
     return sortedSuggestions;
   }

   /**
    * @param baseWeight The weight applied to the ordering of the reviewers.
    * @param query Query to match. For example, it can try to match all users that start with "Ab".
    * @param candidateList The list of candidates based on the query. If query is empty, this list is
    *     also empty.
    * @return Map of account ids that match the query and their appropriate ranking (the better the
    *     ranking, the better it is to suggest them as reviewers).
    * @throws IOException Can't find owner="self" account.
    * @throws ConfigInvalidException Can't find owner="self" account.
    */
   private Map<Account.Id, MutableDouble> baseRanking(
       double baseWeight, String query, List<Account.Id> candidateList)
       throws IOException, ConfigInvalidException {
     int numberOfRelevantChanges = config.getInt("suggest", "relevantChanges", 50);
     // Get the user's last numberOfRelevantChanges changes, check reviewers
     try {
       List<ChangeData> result =
           queryProvider
               .get()
               .setLimit(numberOfRelevantChanges)
               .setRequestedFields(ChangeField.REVIEWER)
               .query(changeQueryBuilder.owner("self"));
       Map<Account.Id, MutableDouble> suggestions = new LinkedHashMap<>();
       // Put those candidates at the bottom of the list
       candidateList.stream().forEach(id -> suggestions.put(id, new MutableDouble(0)));

       for (ChangeData cd : result) {
         for (Account.Id reviewer : cd.reviewers().all()) {
           if (accountMatchesQuery(reviewer, query)) {
             suggestions
                 .computeIfAbsent(reviewer, (ignored) -> new MutableDouble(0))
                 .add(baseWeight);
           }
         }
       }
       return suggestions;
     } catch (QueryParseException e) {
       // Unhandled, because owner:self will never provoke a QueryParseException
       logger.atSevere().withCause(e).log("Exception while suggesting reviewers");
       return new HashMap<>();
     }
   }

   private boolean accountMatchesQuery(Account.Id id, String query) {
     Optional<Account> account = accountCache.get(id).map(AccountState::account);
     if (account.isPresent() && account.get().isActive()) {
       if (Strings.isNullOrEmpty(query)
           || (account.get().fullName() != null && account.get().fullName().startsWith(query))
           || (account.get().preferredEmail() != null
               && account.get().preferredEmail().startsWith(query))) {
         return true;
       }
     }
     return false;
   }
 }
	// 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.restapi.change;

	import static java.util.stream.Collectors.toList;

	import com.google.common.base.Strings;
	import com.google.common.collect.ImmutableList;
	import com.google.common.flogger.FluentLogger;
	import com.google.gerrit.common.Nullable;
	import com.google.gerrit.entities.Account;
	import com.google.gerrit.extensions.client.ReviewerState;
	import com.google.gerrit.index.query.QueryParseException;
	import com.google.gerrit.server.FanOutExecutor;
	import com.google.gerrit.server.account.AccountCache;
	import com.google.gerrit.server.account.AccountState;
	import com.google.gerrit.server.approval.ApprovalsUtil;
	import com.google.gerrit.server.change.ReviewerSuggestion;
	import com.google.gerrit.server.change.SuggestedReviewer;
	import com.google.gerrit.server.config.GerritServerConfig;
	import com.google.gerrit.server.index.change.ChangeField;
	import com.google.gerrit.server.notedb.ChangeNotes;
	import com.google.gerrit.server.notedb.ReviewerStateInternal;
	import com.google.gerrit.server.plugincontext.PluginMapContext;
	import com.google.gerrit.server.project.ProjectState;
	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.inject.Inject;
	import com.google.inject.Provider;
	import java.io.IOException;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.LinkedHashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Optional;
	import java.util.Set;
	import java.util.concurrent.Callable;
	import java.util.concurrent.ExecutionException;
	import java.util.concurrent.ExecutorService;
	import java.util.concurrent.Future;
	import java.util.concurrent.TimeUnit;
	import java.util.stream.Stream;
	import org.apache.commons.lang3.mutable.MutableDouble;
	import org.eclipse.jgit.errors.ConfigInvalidException;
	import org.eclipse.jgit.lib.Config;

	public class ReviewerRecommender {
	private static final FluentLogger logger = FluentLogger.forEnclosingClass();

	private static final long PLUGIN_QUERY_TIMEOUT = 500; // ms

	private final ChangeQueryBuilder changeQueryBuilder;
	private final Config config;
	private final PluginMapContext<ReviewerSuggestion> reviewerSuggestionPluginMap;
	private final Provider<InternalChangeQuery> queryProvider;
	private final ExecutorService executor;
	private final ApprovalsUtil approvalsUtil;
	private final AccountCache accountCache;

	@Inject
	ReviewerRecommender(
	ChangeQueryBuilder changeQueryBuilder,
	PluginMapContext<ReviewerSuggestion> reviewerSuggestionPluginMap,
	Provider<InternalChangeQuery> queryProvider,
	@FanOutExecutor ExecutorService executor,
	ApprovalsUtil approvalsUtil,
	@GerritServerConfig Config config,
	AccountCache accountCache) {
	this.changeQueryBuilder = changeQueryBuilder;
	this.config = config;
	this.queryProvider = queryProvider;
	this.reviewerSuggestionPluginMap = reviewerSuggestionPluginMap;
	this.executor = executor;
	this.approvalsUtil = approvalsUtil;
	this.accountCache = accountCache;
	}

	public List<Account.Id> suggestReviewers(
	ReviewerState reviewerState,
	@Nullable ChangeNotes changeNotes,
	SuggestReviewers suggestReviewers,
	ProjectState projectState,
	List<Account.Id> candidateList)
	throws IOException, ConfigInvalidException {
	logger.atFine().log("Candidates %s", candidateList);

	String query = suggestReviewers.getQuery();
	logger.atFine().log("query: %s", query);

	double baseWeight = config.getInt("addReviewer", "baseWeight", 1);
	logger.atFine().log("base weight: %s", baseWeight);

	Map<Account.Id, MutableDouble> reviewerScores = baseRanking(baseWeight, query, candidateList);
	logger.atFine().log("Base reviewer scores: %s", reviewerScores);

	// 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());

	reviewerSuggestionPluginMap.runEach(
	extension -> {
	tasks.add(
	() ->
	extension
	.get()
	.suggestReviewers(
	projectState.getNameKey(),
	changeNotes != null ? changeNotes.getChangeId() : null,
	query,
	reviewerScores.keySet()));
	String key = extension.getPluginName() + "-" + extension.getExportName();
	String pluginWeight = config.getString("addReviewer", key, "weight");
	if (Strings.isNullOrEmpty(pluginWeight)) {
	pluginWeight = "1";
	}
	logger.atFine().log("weight for %s: %s", key, pluginWeight);
	try {
	weights.add(Double.parseDouble(pluginWeight));
	} catch (NumberFormatException e) {
	logger.atSevere().withCause(e).log("Exception while parsing weight for %s", key);
	weights.add(1d);
	}
	});

	try {
	List<Future<Set<SuggestedReviewer>>> futures =
	executor.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));
	}
	}
	}
	logger.atFine().log("Reviewer scores: %s", reviewerScores);
	} catch (ExecutionException \| InterruptedException e) {
	logger.atSevere().withCause(e).log("Exception while suggesting reviewers");
	return ImmutableList.of();
	}

	if (changeNotes != null) {
	// Remove change owner
	if (reviewerScores.remove(changeNotes.getChange().getOwner()) != null) {
	logger.atFine().log("Remove change owner %s", changeNotes.getChange().getOwner());
	}

	// Remove existing reviewers
	approvalsUtil
	.getReviewers(changeNotes)
	.byState(ReviewerStateInternal.fromReviewerState(reviewerState))
	.forEach(
	r -> {
	if (reviewerScores.remove(r) != null) {
	logger.atFine().log("Remove existing reviewer %s", r);
	}
	});
	}

	// Sort results
	Stream<Map.Entry<Account.Id, MutableDouble>> sorted =
	reviewerScores.entrySet().stream()
	.sorted(Map.Entry.comparingByValue(Collections.reverseOrder()));
	List<Account.Id> sortedSuggestions = sorted.map(Map.Entry::getKey).collect(toList());
	logger.atFine().log("Sorted suggestions: %s", sortedSuggestions);
	return sortedSuggestions;
	}

	/**
	* @param baseWeight The weight applied to the ordering of the reviewers.
	* @param query Query to match. For example, it can try to match all users that start with "Ab".
	* @param candidateList The list of candidates based on the query. If query is empty, this list is
	* also empty.
	* @return Map of account ids that match the query and their appropriate ranking (the better the
	* ranking, the better it is to suggest them as reviewers).
	* @throws IOException Can't find owner="self" account.
	* @throws ConfigInvalidException Can't find owner="self" account.
	*/
	private Map<Account.Id, MutableDouble> baseRanking(
	double baseWeight, String query, List<Account.Id> candidateList)
	throws IOException, ConfigInvalidException {
	int numberOfRelevantChanges = config.getInt("suggest", "relevantChanges", 50);
	// Get the user's last numberOfRelevantChanges changes, check reviewers
	try {
	List<ChangeData> result =
	queryProvider
	.get()
	.setLimit(numberOfRelevantChanges)
	.setRequestedFields(ChangeField.REVIEWER)
	.query(changeQueryBuilder.owner("self"));
	Map<Account.Id, MutableDouble> suggestions = new LinkedHashMap<>();
	// Put those candidates at the bottom of the list
	candidateList.stream().forEach(id -> suggestions.put(id, new MutableDouble(0)));

	for (ChangeData cd : result) {
	for (Account.Id reviewer : cd.reviewers().all()) {
	if (accountMatchesQuery(reviewer, query)) {
	suggestions
	.computeIfAbsent(reviewer, (ignored) -> new MutableDouble(0))
	.add(baseWeight);
	}
	}
	}
	return suggestions;
	} catch (QueryParseException e) {
	// Unhandled, because owner:self will never provoke a QueryParseException
	logger.atSevere().withCause(e).log("Exception while suggesting reviewers");
	return new HashMap<>();
	}
	}

	private boolean accountMatchesQuery(Account.Id id, String query) {
	Optional<Account> account = accountCache.get(id).map(AccountState::account);
	if (account.isPresent() && account.get().isActive()) {
	if (Strings.isNullOrEmpty(query)
	\|\| (account.get().fullName() != null && account.get().fullName().startsWith(query))
	\|\| (account.get().preferredEmail() != null
	&& account.get().preferredEmail().startsWith(query))) {
	return true;
	}
	}
	return false;
	}
	}