Initial implementation of account index in Lucene

This is much simpler than changes, since we don't have so many stored
fields to deal with, and there is no open/closed split.
LuceneAccountIndex is a very straightforward implementation of
AbstractLuceneIndex; there is probably even more that can be factored
out when it comes time to add yet more indexes.

Change-Id: I530003a36152b4330b9e91a7a777eabcf2aeb361

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

@@ -0,0 +1,199 @@
+// 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.lucene;
+
+import static com.google.gerrit.server.index.account.AccountField.ID;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Sets;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.server.account.AccountCache;
+import com.google.gerrit.server.account.AccountState;
+import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.gerrit.server.config.SitePaths;
+import com.google.gerrit.server.index.QueryOptions;
+import com.google.gerrit.server.index.Schema;
+import com.google.gerrit.server.index.account.AccountIndex;
+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.List;
+import java.util.Set;
+import java.util.concurrent.ExecutionException;
+
+public class LuceneAccountIndex
+    extends AbstractLuceneIndex<Account.Id, AccountState>
+    implements AccountIndex {
+  private static final Logger log =
+      LoggerFactory.getLogger(LuceneAccountIndex.class);
+
+  private static final String ACCOUNTS = "accounts";
+
+  private static final String ID_SORT_FIELD = sortFieldName(ID);
+
+  private static Term idTerm(AccountState as) {
+    return idTerm(as.getAccount().getId());
+  }
+
+  private static Term idTerm(Account.Id id) {
+    return QueryBuilder.intTerm(ID.getName(), id.get());
+  }
+
+  private final GerritIndexWriterConfig indexWriterConfig;
+  private final QueryBuilder<AccountState> queryBuilder;
+  private final AccountCache accountCache;
+
+  private static Directory dir(Schema<AccountState> schema, Config cfg,
+      SitePaths sitePaths) throws IOException {
+    if (LuceneIndexModule.isInMemoryTest(cfg)) {
+      return new RAMDirectory();
+    }
+    Path indexDir =
+        LuceneVersionManager.getDir(sitePaths, ACCOUNTS + "_", schema);
+    return FSDirectory.open(indexDir);
+  }
+
+  @Inject
+  LuceneAccountIndex(
+      @GerritServerConfig Config cfg,
+      SitePaths sitePaths,
+      AccountCache accountCache,
+      @Assisted Schema<AccountState> schema) throws IOException {
+    super(schema, sitePaths, dir(schema, cfg, sitePaths), ACCOUNTS, null,
+        new GerritIndexWriterConfig(cfg, ACCOUNTS), new SearcherFactory());
+    this.accountCache = accountCache;
+
+    indexWriterConfig =
+        new GerritIndexWriterConfig(cfg, ACCOUNTS);
+    queryBuilder = new QueryBuilder<>(schema, indexWriterConfig.getAnalyzer());
+  }
+
+  @Override
+  public void replace(AccountState as) throws IOException {
+    try {
+      // No parts of FillArgs are currently required, just use null.
+      replace(idTerm(as), toDocument(as, null)).get();
+    } catch (ExecutionException | InterruptedException e) {
+      throw new IOException(e);
+    }
+  }
+
+  @Override
+  public void delete(Account.Id key) throws IOException {
+    try {
+      delete(idTerm(key)).get();
+    } catch (ExecutionException | InterruptedException e) {
+      throw new IOException(e);
+    }
+  }
+
+  @Override
+  public DataSource<AccountState> getSource(Predicate<AccountState> p,
+      QueryOptions opts) throws QueryParseException {
+    return new QuerySource(
+        opts,
+        queryBuilder.toQuery(p),
+        new Sort(
+            new SortField(ID_SORT_FIELD, SortField.Type.LONG, true)));
+  }
+
+  private class QuerySource implements DataSource<AccountState> {
+    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() {
+      // TODO(dborowitz): In contrast to the comment in
+      // LuceneChangeIndex.QuerySource#getCardinality, at this point I actually
+      // think we might just want to remove getCardinality.
+      return 10;
+    }
+
+    @Override
+    public ResultSet<AccountState> read() throws OrmException {
+      IndexSearcher searcher = null;
+      try {
+        searcher = acquire();
+        int realLimit = opts.start() + opts.limit();
+        TopFieldDocs docs = searcher.search(query, realLimit, sort);
+        List<AccountState> 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, fields(opts));
+          result.add(toAccountState(doc));
+        }
+      } catch (IOException e) {
+        throw new OrmException(e);
+      } finally {
+        if (searcher != null) {
+          try {
+            release(searcher);
+          } catch (IOException e) {
+            log.warn("cannot release Lucene searcher", e);
+          }
+        }
+      }
+      return null;
+    }
+  }
+
+  private Set<String> fields(QueryOptions opts) {
+    Set<String> fs = opts.fields();
+    return fs.contains(ID.getName())
+        ? fs
+        : Sets.union(fs, ImmutableSet.of(ID.getName()));
+  }
+
+  private AccountState toAccountState(Document doc) {
+    Account.Id id =
+        new Account.Id(doc.getField(ID.getName()).numericValue().intValue());
+    // Use the AccountCache rather than depending on any stored fields in the
+    // document (of which there shouldn't be any. The most expensive part to
+    // compute anyway is the effective group IDs, and we don't have a good way
+    // to reindex when those change.
+    return accountCache.get(id);
+  }
+}

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

@@ -23,6 +23,7 @@ import com.google.gerrit.server.index.IndexConfig;
 import com.google.gerrit.server.index.IndexDefinition;
 import com.google.gerrit.server.index.IndexModule;
 import com.google.gerrit.server.index.Schema;
+import com.google.gerrit.server.index.account.AccountIndex;
 import com.google.gerrit.server.index.change.ChangeIndex;
 import com.google.inject.Inject;
 import com.google.inject.Provides;
@@ -74,6 +75,10 @@ public class LuceneIndexModule extends LifecycleModule {
         new FactoryModuleBuilder()
             .implement(ChangeIndex.class, LuceneChangeIndex.class)
             .build(ChangeIndex.Factory.class));
+    install(
+        new FactoryModuleBuilder()
+            .implement(AccountIndex.class, LuceneAccountIndex.class)
+            .build(AccountIndex.Factory.class));
 
     install(new IndexModule(threads));
     if (singleVersions == null) {

gerrit-server/src/main/java/com/google/gerrit/server/index/DummyIndexModule.java

@@ -14,6 +14,8 @@
 
 package com.google.gerrit.server.index;
 
+import com.google.gerrit.server.account.AccountState;
+import com.google.gerrit.server.index.account.AccountIndex;
 import com.google.gerrit.server.index.change.ChangeIndex;
 import com.google.gerrit.server.index.change.DummyChangeIndex;
 import com.google.gerrit.server.query.change.ChangeData;
@@ -27,11 +29,19 @@ public class DummyIndexModule extends AbstractModule {
     }
   }
 
+  private static class DummyAccountIndexFactory implements AccountIndex.Factory {
+    @Override
+    public AccountIndex create(Schema<AccountState> schema) {
+      throw new UnsupportedOperationException();
+    }
+  }
+
   @Override
   protected void configure() {
     install(new IndexModule(1));
     bind(IndexConfig.class).toInstance(IndexConfig.createDefault());
     bind(Index.class).toInstance(new DummyChangeIndex());
+    bind(AccountIndex.Factory.class).toInstance(new DummyAccountIndexFactory());
     bind(ChangeIndex.Factory.class).toInstance(new DummyChangeIndexFactory());
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/index/IndexModule.java

@@ -26,6 +26,8 @@ import com.google.common.util.concurrent.MoreExecutors;
 import com.google.gerrit.lifecycle.LifecycleModule;
 import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.git.WorkQueue;
+import com.google.gerrit.server.index.account.AccountIndexDefinition;
+import com.google.gerrit.server.index.account.AccountSchemaDefinitions;
 import com.google.gerrit.server.index.change.ChangeIndexCollection;
 import com.google.gerrit.server.index.change.ChangeIndexDefinition;
 import com.google.gerrit.server.index.change.ChangeIndexer;
@@ -55,6 +57,7 @@ public class IndexModule extends LifecycleModule {
 
   public static final ImmutableCollection<SchemaDefinitions<?>> ALL_SCHEMA_DEFS =
       ImmutableList.<SchemaDefinitions<?>> of(
+          AccountSchemaDefinitions.INSTANCE,
           ChangeSchemaDefinitions.INSTANCE);
 
   /** Type of secondary index. */
@@ -91,9 +94,12 @@ public class IndexModule extends LifecycleModule {
 
   @Provides
   Collection<IndexDefinition<?, ?, ?>> getIndexDefinitions(
+      AccountIndexDefinition accounts,
       ChangeIndexDefinition changes) {
     Collection<IndexDefinition<?, ?, ?>> result =
-        ImmutableList.<IndexDefinition<?, ?, ?>> of(changes);
+        ImmutableList.<IndexDefinition<?, ?, ?>> of(
+            accounts,
+            changes);
     Set<String> expected = FluentIterable.from(ALL_SCHEMA_DEFS)
         .transform(new Function<SchemaDefinitions<?>, String>() {
           @Override