Initial implementation of group index in Lucene

Same as for the account index there is no open/closed split.

Change-Id: Iff98ecab6e8eb07a49b915c4b97bab77f9809d84
Signed-off-by: Edwin Kempin <ekempin@google.com>

gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneGroupIndex.java

@@ -0,0 +1,198 @@
+// Copyright (C) 2017 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.lucene;
+
+import static com.google.gerrit.server.index.group.GroupField.UUID;
+
+import com.google.gerrit.reviewdb.client.AccountGroup;
+import com.google.gerrit.server.account.GroupCache;
+import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.gerrit.server.config.SitePaths;
+import com.google.gerrit.server.index.IndexUtils;
+import com.google.gerrit.server.index.QueryOptions;
+import com.google.gerrit.server.index.Schema;
+import com.google.gerrit.server.index.group.GroupIndex;
+import com.google.gerrit.server.query.DataSource;
+import com.google.gerrit.server.query.Predicate;
+import com.google.gerrit.server.query.QueryParseException;
+import com.google.gwtorm.server.OrmException;
+import com.google.gwtorm.server.ResultSet;
+import com.google.inject.Inject;
+import com.google.inject.assistedinject.Assisted;
+
+import org.apache.lucene.document.Document;
+import org.apache.lucene.index.Term;
+import org.apache.lucene.search.IndexSearcher;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.search.ScoreDoc;
+import org.apache.lucene.search.SearcherFactory;
+import org.apache.lucene.search.Sort;
+import org.apache.lucene.search.SortField;
+import org.apache.lucene.search.TopFieldDocs;
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.FSDirectory;
+import org.apache.lucene.store.RAMDirectory;
+import org.eclipse.jgit.lib.Config;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+import java.util.concurrent.ExecutionException;
+
+public class LuceneGroupIndex extends
+    AbstractLuceneIndex<AccountGroup.UUID, AccountGroup> implements GroupIndex {
+  private static final Logger log =
+      LoggerFactory.getLogger(LuceneGroupIndex.class);
+
+  private static final String GROUPS = "groups";
+
+  private static final String UUID_SORT_FIELD = sortFieldName(UUID);
+
+  private static Term idTerm(AccountGroup group) {
+    return idTerm(group.getGroupUUID());
+  }
+
+  private static Term idTerm(AccountGroup.UUID uuid) {
+    return QueryBuilder.stringTerm(UUID.getName(), uuid.get());
+  }
+
+  private final GerritIndexWriterConfig indexWriterConfig;
+  private final QueryBuilder<AccountGroup> queryBuilder;
+  private final GroupCache groupCache;
+
+  private static Directory dir(Schema<AccountGroup> schema, Config cfg,
+      SitePaths sitePaths) throws IOException {
+    if (LuceneIndexModule.isInMemoryTest(cfg)) {
+      return new RAMDirectory();
+    }
+    Path indexDir =
+        LuceneVersionManager.getDir(sitePaths, GROUPS + "_", schema);
+    return FSDirectory.open(indexDir);
+  }
+
+  @Inject
+  LuceneGroupIndex(
+      @GerritServerConfig Config cfg,
+      SitePaths sitePaths,
+      GroupCache groupCache,
+      @Assisted Schema<AccountGroup> schema) throws IOException {
+    super(schema, sitePaths, dir(schema, cfg, sitePaths), GROUPS, null,
+        new GerritIndexWriterConfig(cfg, GROUPS), new SearcherFactory());
+    this.groupCache = groupCache;
+
+    indexWriterConfig =
+        new GerritIndexWriterConfig(cfg, GROUPS);
+    queryBuilder = new QueryBuilder<>(schema, indexWriterConfig.getAnalyzer());
+  }
+
+  @Override
+  public void replace(AccountGroup group) throws IOException {
+    try {
+      // No parts of FillArgs are currently required, just use null.
+      replace(idTerm(group), toDocument(group, null)).get();
+    } catch (ExecutionException | InterruptedException e) {
+      throw new IOException(e);
+    }
+  }
+
+  @Override
+  public void delete(AccountGroup.UUID key) throws IOException {
+    try {
+      delete(idTerm(key)).get();
+    } catch (ExecutionException | InterruptedException e) {
+      throw new IOException(e);
+    }
+  }
+
+  @Override
+  public DataSource<AccountGroup> getSource(Predicate<AccountGroup> p,
+      QueryOptions opts) throws QueryParseException {
+    return new QuerySource(opts, queryBuilder.toQuery(p),
+        new Sort(new SortField(UUID_SORT_FIELD, SortField.Type.STRING, false)));
+  }
+
+  private class QuerySource implements DataSource<AccountGroup> {
+    private final QueryOptions opts;
+    private final Query query;
+    private final Sort sort;
+
+    private QuerySource(QueryOptions opts, Query query, Sort sort) {
+      this.opts = opts;
+      this.query = query;
+      this.sort = sort;
+    }
+
+    @Override
+    public int getCardinality() {
+      return 10;
+    }
+
+    @Override
+    public ResultSet<AccountGroup> read() throws OrmException {
+      IndexSearcher searcher = null;
+      try {
+        searcher = acquire();
+        int realLimit = opts.start() + opts.limit();
+        TopFieldDocs docs = searcher.search(query, realLimit, sort);
+        List<AccountGroup> result = new ArrayList<>(docs.scoreDocs.length);
+        for (int i = opts.start(); i < docs.scoreDocs.length; i++) {
+          ScoreDoc sd = docs.scoreDocs[i];
+          Document doc = searcher.doc(sd.doc, IndexUtils.groupFields(opts));
+          result.add(toAccountGroup(doc));
+        }
+        final List<AccountGroup> r = Collections.unmodifiableList(result);
+        return new ResultSet<AccountGroup>() {
+          @Override
+          public Iterator<AccountGroup> iterator() {
+            return r.iterator();
+          }
+
+          @Override
+          public List<AccountGroup> toList() {
+            return r;
+          }
+
+          @Override
+          public void close() {
+            // Do nothing.
+          }
+        };
+      } catch (IOException e) {
+        throw new OrmException(e);
+      } finally {
+        if (searcher != null) {
+          try {
+            release(searcher);
+          } catch (IOException e) {
+            log.warn("cannot release Lucene searcher", e);
+          }
+        }
+      }
+    }
+  }
+
+  private AccountGroup toAccountGroup(Document doc) {
+    AccountGroup.UUID uuid =
+        new AccountGroup.UUID(doc.getField(UUID.getName()).stringValue());
+    // Use the GroupCache rather than depending on any stored fields in the
+    // document (of which there shouldn't be any).
+    return groupCache.get(uuid);
+  }
+}

gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneIndexModule.java

@@ -22,6 +22,7 @@ import com.google.gerrit.server.index.IndexModule;
 import com.google.gerrit.server.index.SingleVersionModule;
 import com.google.gerrit.server.index.account.AccountIndex;
 import com.google.gerrit.server.index.change.ChangeIndex;
+import com.google.gerrit.server.index.group.GroupIndex;
 import com.google.inject.Provides;
 import com.google.inject.Singleton;
 import com.google.inject.assistedinject.FactoryModuleBuilder;
@@ -59,14 +60,18 @@ public class LuceneIndexModule extends LifecycleModule {
 
   @Override
   protected void configure() {
+    install(
+        new FactoryModuleBuilder()
+            .implement(AccountIndex.class, LuceneAccountIndex.class)
+            .build(AccountIndex.Factory.class));
     install(
         new FactoryModuleBuilder()
             .implement(ChangeIndex.class, LuceneChangeIndex.class)
             .build(ChangeIndex.Factory.class));
     install(
         new FactoryModuleBuilder()
-            .implement(AccountIndex.class, LuceneAccountIndex.class)
-            .build(AccountIndex.Factory.class));
+            .implement(GroupIndex.class, LuceneGroupIndex.class)
+            .build(GroupIndex.Factory.class));
 
     install(new IndexModule(threads));
     if (singleVersions == null) {

gerrit-lucene/src/main/java/com/google/gerrit/lucene/QueryBuilder.java

@@ -15,6 +15,7 @@
 package com.google.gerrit.lucene;
 
 import static com.google.common.base.Preconditions.checkArgument;
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.apache.lucene.search.BooleanClause.Occur.MUST;
 import static org.apache.lucene.search.BooleanClause.Occur.MUST_NOT;
 import static org.apache.lucene.search.BooleanClause.Occur.SHOULD;
@@ -54,6 +55,12 @@ public class QueryBuilder<V> {
     return new Term(name, builder.get());
   }
 
+  static Term stringTerm(String name, String value) {
+    BytesRefBuilder builder = new BytesRefBuilder();
+    builder.append(value.getBytes(UTF_8), 0, value.length());
+    return new Term(name, builder.get());
+  }
+
   private final Schema<V> schema;
   private final org.apache.lucene.util.QueryBuilder queryBuilder;