Move REST endpoints to singleton scope

The majority of REST endpoints don't maintain state and don't need to be
created each time they are used. Exceptions are endpoints with @Option
annotation and therefore must stay in default scope.

Change-Id: Ia2ac8cfccf41966daa48334cedcb7a20101474d2

gerrit-server/src/main/java/com/google/gerrit/server/access/AccessCollection.java

@@ -22,7 +22,9 @@ import com.google.gerrit.extensions.restapi.RestView;
 import com.google.gerrit.extensions.restapi.TopLevelResource;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class AccessCollection implements
     RestCollection<TopLevelResource, AccessResource> {
   private final Provider<ListAccess> list;

gerrit-server/src/main/java/com/google/gerrit/server/account/AccountsCollection.java

@@ -30,7 +30,9 @@ import com.google.gerrit.server.IdentifiedUser;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class AccountsCollection implements
     RestCollection<TopLevelResource, AccountResource>,
     AcceptsCreate<TopLevelResource>{

gerrit-server/src/main/java/com/google/gerrit/server/account/AddSshKey.java

@@ -35,11 +35,13 @@ import com.google.gwtorm.server.OrmException;
 import com.google.gwtorm.server.ResultSet;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Collections;
 
+@Singleton
 public class AddSshKey implements RestModifyView<AccountResource, Input> {
   public static class Input {
     public RawInput raw;

gerrit-server/src/main/java/com/google/gerrit/server/account/Capabilities.java

@@ -25,7 +25,9 @@ import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.account.AccountResource.Capability;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 class Capabilities implements
     ChildCollection<AccountResource, AccountResource.Capability> {
   private final Provider<CurrentUser> self;

gerrit-server/src/main/java/com/google/gerrit/server/account/DeleteActive.java

@@ -25,10 +25,12 @@ import com.google.gerrit.server.account.DeleteActive.Input;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 
 @RequiresCapability(GlobalCapability.ADMINISTRATE_SERVER)
+@Singleton
 public class DeleteActive implements RestModifyView<AccountResource, Input> {
   public static class Input {
   }

gerrit-server/src/main/java/com/google/gerrit/server/account/DeleteEmail.java

@@ -29,7 +29,9 @@ import com.google.gerrit.server.account.DeleteEmail.Input;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class DeleteEmail implements RestModifyView<AccountResource.Email, Input> {
   public static class Input {
   }

gerrit-server/src/main/java/com/google/gerrit/server/account/DeleteSshKey.java

@@ -22,9 +22,11 @@ import com.google.gerrit.server.ssh.SshKeyCache;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 
+@Singleton
 public class DeleteSshKey implements
     RestModifyView<AccountResource.SshKey, Input> {
   public static class Input {

gerrit-server/src/main/java/com/google/gerrit/server/account/Emails.java

@@ -25,7 +25,9 @@ import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.account.AccountResource.Email;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class Emails implements
     ChildCollection<AccountResource, AccountResource.Email>,
     AcceptsCreate<AccountResource> {

gerrit-server/src/main/java/com/google/gerrit/server/account/GetAccount.java

@@ -17,7 +17,9 @@ package com.google.gerrit.server.account;
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetAccount implements RestReadView<AccountResource> {
   private final AccountInfo.Loader.Factory infoFactory;
 

gerrit-server/src/main/java/com/google/gerrit/server/account/GetActive.java

@@ -17,7 +17,9 @@ package com.google.gerrit.server.account;
 import com.google.gerrit.extensions.restapi.BinaryResult;
 import com.google.gerrit.extensions.restapi.Response;
 import com.google.gerrit.extensions.restapi.RestReadView;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetActive implements RestReadView<AccountResource> {
   @Override
   public Object apply(AccountResource rsrc) {

gerrit-server/src/main/java/com/google/gerrit/server/account/GetAvatarChangeUrl.java

@@ -20,7 +20,9 @@ import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.avatar.AvatarProvider;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetAvatarChangeUrl implements RestReadView<AccountResource> {
   private final DynamicItem<AvatarProvider> avatarProvider;
 

gerrit-server/src/main/java/com/google/gerrit/server/account/GetCapabilities.java

@@ -48,6 +48,7 @@ import com.google.gerrit.server.git.QueueProvider;
 import com.google.gson.reflect.TypeToken;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.kohsuke.args4j.Option;
 
@@ -178,6 +179,7 @@ class GetCapabilities implements RestReadView<AccountResource> {
     }
   }
 
+  @Singleton
   static class CheckOne implements RestReadView<AccountResource.Capability> {
     @Override
     public BinaryResult apply(Capability resource) {

gerrit-server/src/main/java/com/google/gerrit/server/account/GetDiffPreferences.java

@@ -25,7 +25,9 @@ import com.google.gerrit.server.CurrentUser;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetDiffPreferences implements RestReadView<AccountResource> {
   private final Provider<CurrentUser> self;
   private final Provider<ReviewDb> db;

gerrit-server/src/main/java/com/google/gerrit/server/account/GetEmail.java

@@ -16,7 +16,9 @@ package com.google.gerrit.server.account;
 
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.account.GetEmails.EmailInfo;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetEmail implements RestReadView<AccountResource.Email> {
   @Override
   public EmailInfo apply(AccountResource.Email rsrc) {

gerrit-server/src/main/java/com/google/gerrit/server/account/GetGroups.java

@@ -24,9 +24,11 @@ import com.google.gerrit.server.group.GroupJson;
 import com.google.gerrit.server.group.GroupJson.GroupInfo;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
 import java.util.List;
 
+@Singleton
 public class GetGroups implements RestReadView<AccountResource> {
   private final GroupControl.Factory groupControlFactory;
   private final GroupJson json;

gerrit-server/src/main/java/com/google/gerrit/server/account/GetHttpPassword.java

@@ -20,7 +20,9 @@ import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.CurrentUser;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetHttpPassword implements RestReadView<AccountResource> {
 
   private final Provider<CurrentUser> self;

gerrit-server/src/main/java/com/google/gerrit/server/account/GetName.java

@@ -16,7 +16,9 @@ package com.google.gerrit.server.account;
 
 import com.google.common.base.Strings;
 import com.google.gerrit.extensions.restapi.RestReadView;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetName implements RestReadView<AccountResource> {
   @Override
   public String apply(AccountResource rsrc) {

gerrit-server/src/main/java/com/google/gerrit/server/account/GetPreferences.java

@@ -35,6 +35,7 @@ import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;
@@ -46,6 +47,7 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 
+@Singleton
 public class GetPreferences implements RestReadView<AccountResource> {
   private static final Logger log = LoggerFactory.getLogger(GetPreferences.class);
 

gerrit-server/src/main/java/com/google/gerrit/server/account/GetSshKey.java

@@ -17,7 +17,9 @@ package com.google.gerrit.server.account;
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.account.AccountResource.SshKey;
 import com.google.gerrit.server.account.GetSshKeys.SshKeyInfo;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetSshKey implements RestReadView<AccountResource.SshKey> {
 
   @Override

gerrit-server/src/main/java/com/google/gerrit/server/account/GetUsername.java

@@ -20,7 +20,9 @@ import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.CurrentUser;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetUsername implements RestReadView<AccountResource> {
 
   private final Provider<CurrentUser> self;

gerrit-server/src/main/java/com/google/gerrit/server/account/PutAccount.java

@@ -17,7 +17,9 @@ package com.google.gerrit.server.account;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.extensions.restapi.RestModifyView;
 import com.google.gerrit.server.account.CreateAccount.Input;
+import com.google.inject.Singleton;
 
+@Singleton
 public class PutAccount implements RestModifyView<AccountResource, Input> {
   @Override
   public Object apply(AccountResource resource, Input input)

gerrit-server/src/main/java/com/google/gerrit/server/account/PutActive.java

@@ -25,10 +25,12 @@ import com.google.gerrit.server.account.PutActive.Input;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 
 @RequiresCapability(GlobalCapability.ADMINISTRATE_SERVER)
+@Singleton
 public class PutActive implements RestModifyView<AccountResource, Input> {
   public static class Input {
   }

gerrit-server/src/main/java/com/google/gerrit/server/account/PutEmail.java

@@ -18,7 +18,9 @@ import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.extensions.restapi.Response;
 import com.google.gerrit.extensions.restapi.RestModifyView;
 import com.google.gerrit.server.account.CreateEmail.Input;
+import com.google.inject.Singleton;
 
+@Singleton
 public class PutEmail implements RestModifyView<AccountResource.Email, Input> {
   @Override
   public Response<?> apply(AccountResource.Email rsrc, Input input)

gerrit-server/src/main/java/com/google/gerrit/server/account/PutHttpPassword.java

@@ -30,6 +30,7 @@ import com.google.gerrit.server.account.PutHttpPassword.Input;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.apache.commons.codec.binary.Base64;
 
@@ -37,6 +38,7 @@ import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
 import java.util.Collections;
 
+@Singleton
 public class PutHttpPassword implements RestModifyView<AccountResource, Input> {
   public static class Input {
     public String httpPassword;

gerrit-server/src/main/java/com/google/gerrit/server/account/PutName.java

@@ -34,9 +34,11 @@ import com.google.gerrit.server.auth.ldap.LdapRealm;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 
+@Singleton
 public class PutName implements RestModifyView<AccountResource, Input> {
   public static class Input {
     @DefaultInput

gerrit-server/src/main/java/com/google/gerrit/server/account/PutPreferred.java

@@ -26,9 +26,11 @@ import com.google.gerrit.server.account.PutPreferred.Input;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 
+@Singleton
 public class PutPreferred implements
     RestModifyView<AccountResource.Email, Input> {
   static class Input {

gerrit-server/src/main/java/com/google/gerrit/server/account/SetDiffPreferences.java

@@ -27,9 +27,11 @@ import com.google.gerrit.server.account.SetDiffPreferences.Input;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 
+@Singleton
 public class SetDiffPreferences implements RestModifyView<AccountResource, Input> {
   static class Input {
     Short context;
@@ -54,10 +56,10 @@ public class SetDiffPreferences implements RestModifyView<AccountResource, Input
   }
 
   private final Provider<CurrentUser> self;
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
 
   @Inject
-  SetDiffPreferences(Provider<CurrentUser> self, ReviewDb db) {
+  SetDiffPreferences(Provider<CurrentUser> self, Provider<ReviewDb> db) {
     this.self = self;
     this.db = db;
   }
@@ -76,9 +78,9 @@ public class SetDiffPreferences implements RestModifyView<AccountResource, Input
     Account.Id accountId = rsrc.getUser().getAccountId();
     AccountDiffPreference p;
 
-    db.accounts().beginTransaction(accountId);
+    db.get().accounts().beginTransaction(accountId);
     try {
-      p = db.accountDiffPreferences().get(accountId);
+      p = db.get().accountDiffPreferences().get(accountId);
       if (p == null) {
         p = new AccountDiffPreference(accountId);
       }
@@ -141,10 +143,10 @@ public class SetDiffPreferences implements RestModifyView<AccountResource, Input
         p.setHideEmptyPane(input.hideEmptyPane);
       }
 
-      db.accountDiffPreferences().upsert(Collections.singleton(p));
+      db.get().accountDiffPreferences().upsert(Collections.singleton(p));
-      db.commit();
+      db.get().commit();
     } finally {
-      db.rollback();
+      db.get().rollback();
     }
     return DiffPreferencesInfo.parse(p);
   }

gerrit-server/src/main/java/com/google/gerrit/server/account/SetPreferences.java

@@ -41,6 +41,7 @@ import com.google.gerrit.server.git.MetaDataUpdate;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;
@@ -49,6 +50,7 @@ import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
 
+@Singleton
 public class SetPreferences implements RestModifyView<AccountResource, Input> {
   public static class Input {
     public Short changesPerPage;
@@ -72,13 +74,14 @@ public class SetPreferences implements RestModifyView<AccountResource, Input> {
 
   private final Provider<CurrentUser> self;
   private final AccountCache cache;
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
   private final MetaDataUpdate.User metaDataUpdateFactory;
   private final AllUsersName allUsersName;
 
   @Inject
-  SetPreferences(Provider<CurrentUser> self, AccountCache cache, ReviewDb db,
+  SetPreferences(Provider<CurrentUser> self, AccountCache cache,
-      MetaDataUpdate.User metaDataUpdateFactory, AllUsersName allUsersName) {
+      Provider<ReviewDb> db, MetaDataUpdate.User metaDataUpdateFactory,
+      AllUsersName allUsersName) {
     this.self = self;
     this.cache = cache;
     this.db = db;
@@ -102,9 +105,9 @@ public class SetPreferences implements RestModifyView<AccountResource, Input> {
     AccountGeneralPreferences p;
     VersionedAccountPreferences versionedPrefs;
     MetaDataUpdate md = metaDataUpdateFactory.create(allUsersName);
-    db.accounts().beginTransaction(accountId);
+    db.get().accounts().beginTransaction(accountId);
     try {
-      Account a = db.accounts().get(accountId);
+      Account a = db.get().accounts().get(accountId);
       if (a == null) {
         throw new ResourceNotFoundException();
       }
@@ -167,8 +170,8 @@ public class SetPreferences implements RestModifyView<AccountResource, Input> {
         p.setChangeScreen(i.changeScreen);
       }
 
-      db.accounts().update(Collections.singleton(a));
+      db.get().accounts().update(Collections.singleton(a));
-      db.commit();
+      db.get().commit();
       storeMyMenus(versionedPrefs, i.my);
       versionedPrefs.commit(md);
       cache.evict(accountId);
@@ -177,7 +180,7 @@ public class SetPreferences implements RestModifyView<AccountResource, Input> {
           md.getRepository());
     } finally {
       md.close();
-      db.rollback();
+      db.get().rollback();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/account/SshKeys.java

@@ -26,7 +26,9 @@ import com.google.gerrit.server.IdentifiedUser;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class SshKeys implements
     ChildCollection<AccountResource, AccountResource.SshKey> {
   private final DynamicMap<RestView<AccountResource.SshKey>> views;

gerrit-server/src/main/java/com/google/gerrit/server/account/StarredChanges.java

@@ -38,12 +38,14 @@ import com.google.gwtorm.server.OrmDuplicateKeyException;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.Collections;
 
+@Singleton
 public class StarredChanges implements
     ChildCollection<AccountResource, AccountResource.StarredChange>,
     AcceptsCreate<AccountResource> {
@@ -112,6 +114,7 @@ public class StarredChanges implements
     }
   }
 
+  @Singleton
   public static class Create implements RestModifyView<AccountResource, EmptyInput> {
     private final Provider<CurrentUser> self;
     private final Provider<ReviewDb> dbProvider;
@@ -146,6 +149,7 @@ public class StarredChanges implements
     }
   }
 
+  @Singleton
   static class Put implements
       RestModifyView<AccountResource.StarredChange, EmptyInput> {
     private final Provider<CurrentUser> self;
@@ -165,6 +169,7 @@ public class StarredChanges implements
     }
   }
 
+  @Singleton
   public static class Delete implements
       RestModifyView<AccountResource.StarredChange, EmptyInput> {
     private final Provider<CurrentUser> self;

gerrit-server/src/main/java/com/google/gerrit/server/api/GerritApiImpl.java

@@ -20,7 +20,9 @@ import com.google.gerrit.extensions.api.changes.Changes;
 import com.google.gerrit.extensions.api.projects.Projects;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 class GerritApiImpl extends GerritApi.NotImplemented implements GerritApi {
   private final Provider<Accounts> accounts;
   private final Provider<Changes> changes;

gerrit-server/src/main/java/com/google/gerrit/server/api/accounts/AccountsImpl.java

@@ -27,7 +27,9 @@ import com.google.gerrit.server.account.AccountsCollection;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class AccountsImpl extends Accounts.NotImplemented implements Accounts {
   private final AccountsCollection accounts;
   private final AccountApiImpl.Factory api;

gerrit-server/src/main/java/com/google/gerrit/server/api/changes/ChangesImpl.java

@@ -38,10 +38,12 @@ import com.google.gerrit.server.query.change.QueryChanges;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.io.IOException;
 import java.util.List;
 
+@Singleton
 class ChangesImpl implements Changes {
   private final ChangesCollection changes;
   private final ChangeApiImpl.Factory api;

gerrit-server/src/main/java/com/google/gerrit/server/api/projects/ProjectsImpl.java

@@ -24,10 +24,12 @@ import com.google.gerrit.server.project.ListProjects;
 import com.google.gerrit.server.project.ProjectsCollection;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.io.IOException;
 import java.util.List;
 
+@Singleton
 class ProjectsImpl extends Projects.NotImplemented implements Projects {
   private final ProjectsCollection projects;
   private final ProjectApiImpl.Factory api;

gerrit-server/src/main/java/com/google/gerrit/server/change/ChangesCollection.java

@@ -32,10 +32,12 @@ import com.google.gerrit.server.query.change.QueryChanges;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 import java.util.List;
 
+@Singleton
 public class ChangesCollection implements
     RestCollection<TopLevelResource, ChangeResource>,
     AcceptsPost<TopLevelResource> {

gerrit-server/src/main/java/com/google/gerrit/server/change/CherryPickChange.java

@@ -22,6 +22,7 @@ import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.ChangeUtil;
+import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.events.CommitReceivedEvent;
@@ -39,6 +40,8 @@ import com.google.gerrit.server.ssh.NoSshInfo;
 import com.google.gerrit.server.util.TimeUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
@@ -57,30 +60,34 @@ import org.eclipse.jgit.util.ChangeIdUtil;
 
 import java.io.IOException;
 import java.util.List;
+import java.util.TimeZone;
 
+@Singleton
 public class CherryPickChange {
 
   private static final FooterKey CHANGE_ID = new FooterKey("Change-Id");
 
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
   private final GitRepositoryManager gitManager;
-  private final PersonIdent myIdent;
+  private final TimeZone serverTimeZone;
-  private final IdentifiedUser currentUser;
+  private final Provider<CurrentUser> currentUser;
   private final CommitValidators.Factory commitValidatorsFactory;
   private final ChangeInserter.Factory changeInserterFactory;
   private final PatchSetInserter.Factory patchSetInserterFactory;
   final MergeUtil.Factory mergeUtilFactory;
 
   @Inject
-  CherryPickChange(final ReviewDb db, @GerritPersonIdent final PersonIdent myIdent,
+  CherryPickChange(final Provider<ReviewDb> db,
-      final GitRepositoryManager gitManager, final IdentifiedUser currentUser,
+      @GerritPersonIdent final PersonIdent myIdent,
+      final GitRepositoryManager gitManager,
+      final Provider<CurrentUser> currentUser,
       final CommitValidators.Factory commitValidatorsFactory,
       final ChangeInserter.Factory changeInserterFactory,
       final PatchSetInserter.Factory patchSetInserterFactory,
       final MergeUtil.Factory mergeUtilFactory) {
     this.db = db;
     this.gitManager = gitManager;
-    this.myIdent = myIdent;
+    this.serverTimeZone = myIdent.getTimeZone();
     this.currentUser = currentUser;
     this.commitValidatorsFactory = commitValidatorsFactory;
     this.changeInserterFactory = changeInserterFactory;
@@ -96,7 +103,7 @@ public class CherryPickChange {
       InvalidChangeOperationException, MergeException {
 
     final Change.Id changeId = patchSetId.getParentKey();
-    final PatchSet patch = db.patchSets().get(patchSetId);
+    final PatchSet patch = db.get().patchSets().get(patchSetId);
     if (patch == null) {
       throw new NoSuchChangeException(changeId);
     }
@@ -105,7 +112,8 @@ public class CherryPickChange {
           "Cherry Pick: Destination branch cannot be null or empty");
     }
 
-    Project.NameKey project = db.changes().get(changeId).getProject();
+    Project.NameKey project = db.get().changes().get(changeId).getProject();
+    IdentifiedUser identifiedUser = (IdentifiedUser) currentUser.get();
     final Repository git;
     try {
       git = gitManager.openRepository(project);
@@ -128,13 +136,13 @@ public class CherryPickChange {
             revWalk.parseCommit(ObjectId.fromString(patch.getRevision().get()));
 
         PersonIdent committerIdent =
-            currentUser.newCommitterIdent(myIdent.getWhen(),
+            identifiedUser.newCommitterIdent(TimeUtil.nowTs(),
-                myIdent.getTimeZone());
+                serverTimeZone);
 
         final ObjectId computedChangeId =
             ChangeIdUtil
                 .computeChangeId(commitToCherryPick.getTree(), mergeTip,
-                    commitToCherryPick.getAuthorIdent(), myIdent, message);
+                    commitToCherryPick.getAuthorIdent(), committerIdent, message);
         String commitMessage =
             ChangeIdUtil.insertId(message, computedChangeId).trim() + '\n';
 
@@ -163,9 +171,9 @@ public class CherryPickChange {
         }
 
         List<Change> destChanges =
-            db.changes()
+            db.get().changes()
                 .byBranchKey(
-                    new Branch.NameKey(db.changes().get(changeId).getProject(),
+                    new Branch.NameKey(db.get().changes().get(changeId).getProject(),
                         destRef.getName()), changeKey).toList();
 
         if (destChanges.size() > 1) {
@@ -176,12 +184,12 @@ public class CherryPickChange {
           // The change key exists on the destination branch. The cherry pick
           // will be added as a new patch set.
           return insertPatchSet(git, revWalk, destChanges.get(0), patchSetId,
-              cherryPickCommit, refControl, currentUser);
+              cherryPickCommit, refControl, identifiedUser);
         } else {
           // Change key not found on destination branch. We can create a new
           // change.
           return createNewChange(git, revWalk, changeKey, project, patchSetId, destRef,
-              cherryPickCommit, refControl);
+              cherryPickCommit, refControl, identifiedUser);
         }
       } finally {
         revWalk.release();
@@ -193,7 +201,7 @@ public class CherryPickChange {
 
   private Change.Id insertPatchSet(Repository git, RevWalk revWalk, Change change,
       PatchSet.Id patchSetId, RevCommit cherryPickCommit,
-      RefControl refControl, IdentifiedUser uploader)
+      RefControl refControl, IdentifiedUser identifiedUser)
       throws InvalidChangeOperationException, IOException, OrmException,
       NoSuchChangeException {
     final ChangeControl changeControl =
@@ -201,11 +209,11 @@ public class CherryPickChange {
     final PatchSetInserter inserter = patchSetInserterFactory
         .create(git, revWalk, changeControl, cherryPickCommit);
     final PatchSet.Id newPatchSetId = inserter.getPatchSetId();
-    final PatchSet current = db.patchSets().get(change.currentPatchSetId());
+    PatchSet current = db.get().patchSets().get(change.currentPatchSetId());
     inserter
       .setMessage("Uploaded patch set " + newPatchSetId.get() + ".")
       .setDraft(current.isDraft())
-      .setUploader(uploader.getAccountId())
+      .setUploader(identifiedUser.getAccountId())
       .setCopyLabels(true)
       .insert();
     return change.getId();
@@ -213,11 +221,12 @@ public class CherryPickChange {
 
   private Change.Id createNewChange(Repository git, RevWalk revWalk,
       Change.Key changeKey, Project.NameKey project, PatchSet.Id patchSetId,
-      Ref destRef, RevCommit cherryPickCommit, RefControl refControl)
+      Ref destRef, RevCommit cherryPickCommit, RefControl refControl,
+      IdentifiedUser identifiedUser)
       throws OrmException, InvalidChangeOperationException, IOException {
     Change change =
-        new Change(changeKey, new Change.Id(db.nextChangeId()),
+        new Change(changeKey, new Change.Id(db.get().nextChangeId()),
-            currentUser.getAccountId(), new Branch.NameKey(project,
+            identifiedUser.getAccountId(), new Branch.NameKey(project,
                 destRef.getName()), TimeUtil.nowTs());
     ChangeInserter ins =
         changeInserterFactory.create(refControl, change, cherryPickCommit);
@@ -229,7 +238,7 @@ public class CherryPickChange {
         new CommitReceivedEvent(new ReceiveCommand(ObjectId.zeroId(),
             cherryPickCommit.getId(), newPatchSet.getRefName()), refControl
             .getProjectControl().getProject(), refControl.getRefName(),
-            cherryPickCommit, currentUser);
+            cherryPickCommit, identifiedUser);
 
     try {
       commitValidators.validateForGerritCommits(commitReceivedEvent);
@@ -247,18 +256,20 @@ public class CherryPickChange {
           change.getDest().getParentKey().get(), ru.getResult()));
     }
 
-    ins.setMessage(buildChangeMessage(patchSetId, change, cherryPickCommit))
+    ins.setMessage(buildChangeMessage(patchSetId, change, cherryPickCommit,
+        identifiedUser))
         .insert();
 
     return change.getId();
   }
 
   private ChangeMessage buildChangeMessage(PatchSet.Id patchSetId, Change dest,
-      RevCommit cherryPickCommit) throws OrmException {
+      RevCommit cherryPickCommit, IdentifiedUser identifiedUser)
+      throws OrmException {
     ChangeMessage cmsg = new ChangeMessage(
         new ChangeMessage.Key(
-            patchSetId.getParentKey(), ChangeUtil.messageUUID(db)),
+            patchSetId.getParentKey(), ChangeUtil.messageUUID(db.get())),
-        currentUser.getAccountId(), TimeUtil.nowTs(), patchSetId);
+            identifiedUser.getAccountId(), TimeUtil.nowTs(), patchSetId);
     String destBranchName = dest.getDest().get();
     StringBuilder msgBuf = new StringBuilder("Patch Set ")
         .append(patchSetId.get())

gerrit-server/src/main/java/com/google/gerrit/server/change/Comments.java

@@ -24,7 +24,9 @@ import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 class Comments implements ChildCollection<RevisionResource, CommentResource> {
   private final DynamicMap<RestView<CommentResource>> views;
   private final Provider<ListComments> list;

gerrit-server/src/main/java/com/google/gerrit/server/change/CreateChange.java

@@ -47,6 +47,7 @@ import com.google.gerrit.server.util.TimeUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.lib.CommitBuilder;
 import org.eclipse.jgit.lib.Constants;
@@ -67,6 +68,7 @@ import java.sql.Timestamp;
 import java.util.List;
 import java.util.TimeZone;
 
+@Singleton
 public class CreateChange implements
     RestModifyView<TopLevelResource, ChangeInfo> {
 

gerrit-server/src/main/java/com/google/gerrit/server/change/CreateDraft.java

@@ -29,9 +29,11 @@ import com.google.gerrit.server.util.TimeUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 
+@Singleton
 class CreateDraft implements RestModifyView<RevisionResource, Input> {
   private final Provider<ReviewDb> db;
 

gerrit-server/src/main/java/com/google/gerrit/server/change/DeleteDraft.java

@@ -21,9 +21,11 @@ import com.google.gerrit.server.change.DeleteDraft.Input;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 
+@Singleton
 class DeleteDraft implements RestModifyView<DraftResource, Input> {
   static class Input {
   }

gerrit-server/src/main/java/com/google/gerrit/server/change/DeleteReviewer.java

@@ -37,11 +37,13 @@ import com.google.gerrit.server.util.TimeUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
 
+@Singleton
 public class DeleteReviewer implements RestModifyView<ReviewerResource, Input> {
   public static class Input {
   }

gerrit-server/src/main/java/com/google/gerrit/server/change/Drafts.java

@@ -26,7 +26,9 @@ import com.google.gerrit.server.CurrentUser;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 class Drafts implements ChildCollection<RevisionResource, DraftResource> {
   private final DynamicMap<RestView<DraftResource>> views;
   private final Provider<CurrentUser> user;

gerrit-server/src/main/java/com/google/gerrit/server/change/GetComment.java

@@ -18,7 +18,9 @@ import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.account.AccountInfo;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
+@Singleton
 class GetComment implements RestReadView<CommentResource> {
 
   private final AccountInfo.Loader.Factory accountLoaderFactory;

gerrit-server/src/main/java/com/google/gerrit/server/change/GetCommit.java

@@ -22,9 +22,11 @@ import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.patch.PatchSetInfoNotAvailableException;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
 import java.util.concurrent.TimeUnit;
 
+@Singleton
 public class GetCommit implements RestReadView<RevisionResource> {
   private final ChangeJson json;
 

gerrit-server/src/main/java/com/google/gerrit/server/change/GetContent.java

@@ -20,6 +20,7 @@ import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.lib.ObjectLoader;
 import org.eclipse.jgit.lib.Repository;
@@ -30,6 +31,7 @@ import org.eclipse.jgit.treewalk.TreeWalk;
 import java.io.IOException;
 import java.io.OutputStream;
 
+@Singleton
 public class GetContent implements RestReadView<FileResource> {
   private final GitRepositoryManager repoManager;
 

gerrit-server/src/main/java/com/google/gerrit/server/change/GetDraft.java

@@ -15,7 +15,9 @@
 package com.google.gerrit.server.change;
 
 import com.google.gerrit.extensions.restapi.RestReadView;
+import com.google.inject.Singleton;
 
+@Singleton
 class GetDraft implements RestReadView<DraftResource> {
   @Override
   public CommentInfo apply(DraftResource rsrc) {

gerrit-server/src/main/java/com/google/gerrit/server/change/GetRelated.java

@@ -34,6 +34,7 @@ import com.google.gwtorm.server.OrmException;
 import com.google.gwtorm.server.ResultSet;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.RepositoryNotFoundException;
@@ -57,6 +58,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
+@Singleton
 public class GetRelated implements RestReadView<RevisionResource> {
   private static final Logger log = LoggerFactory.getLogger(GetRelated.class);
 

gerrit-server/src/main/java/com/google/gerrit/server/change/GetReview.java

@@ -20,7 +20,9 @@ import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.change.ChangeJson.ChangeInfo;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetReview implements RestReadView<RevisionResource> {
   private final GetChange delegate;
 

gerrit-server/src/main/java/com/google/gerrit/server/change/GetReviewer.java

@@ -18,9 +18,11 @@ import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.change.ReviewerJson.ReviewerInfo;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
 import java.util.List;
 
+@Singleton
 public class GetReviewer implements RestReadView<ReviewerResource> {
   private final ReviewerJson json;
 

gerrit-server/src/main/java/com/google/gerrit/server/change/GetTopic.java

@@ -16,7 +16,9 @@ package com.google.gerrit.server.change;
 
 import com.google.common.base.Strings;
 import com.google.gerrit.extensions.restapi.RestReadView;
+import com.google.inject.Singleton;
 
+@Singleton
 class GetTopic implements RestReadView<ChangeResource> {
   @Override
   public String apply(ChangeResource rsrc) {

gerrit-server/src/main/java/com/google/gerrit/server/change/IncludedIn.java

@@ -24,6 +24,7 @@ import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.project.ChangeControl;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Provider;
 
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
@@ -37,11 +38,11 @@ import java.util.Collection;
 
 class IncludedIn implements RestReadView<ChangeResource> {
 
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
   private final GitRepositoryManager repoManager;
 
   @Inject
-  IncludedIn(ReviewDb db, GitRepositoryManager repoManager) {
+  IncludedIn(Provider<ReviewDb> db, GitRepositoryManager repoManager) {
     this.db = db;
     this.repoManager = repoManager;
   }
@@ -51,7 +52,7 @@ class IncludedIn implements RestReadView<ChangeResource> {
       ResourceConflictException, OrmException, IOException {
     ChangeControl ctl = rsrc.getControl();
     PatchSet ps =
-        db.patchSets().get(ctl.getChange().currentPatchSetId());
+        db.get().patchSets().get(ctl.getChange().currentPatchSetId());
     Repository r =
         repoManager.openRepository(ctl.getProject().getNameKey());
     try {

gerrit-server/src/main/java/com/google/gerrit/server/change/Index.java

@@ -23,10 +23,12 @@ import com.google.gerrit.server.change.Index.Input;
 import com.google.gerrit.server.index.ChangeIndexer;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.io.IOException;
 
 @RequiresCapability(GlobalCapability.ADMINISTRATE_SERVER)
+@Singleton
 public class Index implements RestModifyView<ChangeResource, Input> {
   public static class Input {
   }

gerrit-server/src/main/java/com/google/gerrit/server/change/PostReviewers.java

@@ -36,6 +36,7 @@ import com.google.gerrit.reviewdb.client.PatchSetApproval;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.ApprovalsUtil;
 import com.google.gerrit.server.ChangeUtil;
+import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.account.AccountCache;
 import com.google.gerrit.server.account.AccountInfo;
@@ -54,6 +55,7 @@ import com.google.gerrit.server.project.NoSuchProjectException;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.lib.Config;
 import org.slf4j.Logger;
@@ -65,6 +67,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
+@Singleton
 public class PostReviewers implements RestModifyView<ChangeResource, AddReviewerInput> {
   private static final Logger log = LoggerFactory
       .getLogger(PostReviewers.class);
@@ -81,7 +84,7 @@ public class PostReviewers implements RestModifyView<ChangeResource, AddReviewer
   private final AccountInfo.Loader.Factory accountLoaderFactory;
   private final Provider<ReviewDb> dbProvider;
   private final ChangeUpdate.Factory updateFactory;
-  private final IdentifiedUser currentUser;
+  private final Provider<CurrentUser> currentUser;
   private final IdentifiedUser.GenericFactory identifiedUserFactory;
   private final Config cfg;
   private final ChangeHooks hooks;
@@ -99,7 +102,7 @@ public class PostReviewers implements RestModifyView<ChangeResource, AddReviewer
       AccountInfo.Loader.Factory accountLoaderFactory,
       Provider<ReviewDb> db,
       ChangeUpdate.Factory updateFactory,
-      IdentifiedUser currentUser,
+      Provider<CurrentUser> currentUser,
       IdentifiedUser.GenericFactory identifiedUserFactory,
       @GerritServerConfig Config cfg,
       ChangeHooks hooks,
@@ -268,15 +271,16 @@ public class PostReviewers implements RestModifyView<ChangeResource, AddReviewer
     //
     // The user knows they added themselves, don't bother emailing them.
     List<Account.Id> toMail = Lists.newArrayListWithCapacity(added.size());
+    IdentifiedUser identifiedUser = (IdentifiedUser) currentUser.get();
     for (PatchSetApproval psa : added) {
-      if (!psa.getAccountId().equals(currentUser.getAccountId())) {
+      if (!psa.getAccountId().equals(identifiedUser.getAccountId())) {
         toMail.add(psa.getAccountId());
       }
     }
     if (!toMail.isEmpty()) {
       try {
         AddReviewerSender cm = addReviewerSenderFactory.create(change);
-        cm.setFrom(currentUser.getAccountId());
+        cm.setFrom(identifiedUser.getAccountId());
         cm.addReviewers(toMail);
         cm.send();
       } catch (Exception err) {

gerrit-server/src/main/java/com/google/gerrit/server/change/PutDraft.java

@@ -29,10 +29,12 @@ import com.google.gerrit.server.util.TimeUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.sql.Timestamp;
 import java.util.Collections;
 
+@Singleton
 class PutDraft implements RestModifyView<DraftResource, Input> {
   static class Input {
     String kind;

gerrit-server/src/main/java/com/google/gerrit/server/change/Reviewed.java

@@ -22,6 +22,7 @@ import com.google.gwtorm.server.OrmDuplicateKeyException;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 
@@ -29,6 +30,7 @@ class Reviewed {
   static class Input {
   }
 
+  @Singleton
   static class PutReviewed implements RestModifyView<FileResource, Input> {
     private final Provider<ReviewDb> dbProvider;
 
@@ -57,6 +59,7 @@ class Reviewed {
     }
   }
 
+  @Singleton
   static class DeleteReviewed implements RestModifyView<FileResource, Input> {
     private final Provider<ReviewDb> dbProvider;
 

gerrit-server/src/main/java/com/google/gerrit/server/change/ReviewerJson.java

@@ -35,12 +35,14 @@ import com.google.gerrit.server.query.change.ChangeData;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
 
+@Singleton
 public class ReviewerJson {
   private final Provider<ReviewDb> db;
   private final ChangeData.Factory changeDataFactory;

gerrit-server/src/main/java/com/google/gerrit/server/change/Reviewers.java

@@ -28,9 +28,11 @@ import com.google.gerrit.server.account.AccountsCollection;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collection;
 
+@Singleton
 public class Reviewers implements
     ChildCollection<ChangeResource, ReviewerResource> {
   private final DynamicMap<RestView<ReviewerResource>> views;

gerrit-server/src/main/java/com/google/gerrit/server/change/Revisions.java

@@ -27,10 +27,12 @@ import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 import java.util.List;
 
+@Singleton
 public class Revisions implements ChildCollection<ChangeResource, RevisionResource> {
   private final DynamicMap<RestView<RevisionResource>> views;
   private final Provider<ReviewDb> dbProvider;

gerrit-server/src/main/java/com/google/gerrit/server/change/TestSubmitRule.java

@@ -37,6 +37,7 @@ import com.google.gerrit.server.project.SubmitRuleEvaluator;
 import com.google.gerrit.server.query.change.ChangeData;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Provider;
 
 import com.googlecode.prolog_cafe.lang.Term;
 
@@ -57,7 +58,7 @@ public class TestSubmitRule implements RestModifyView<RevisionResource, Input> {
     public Filters filters;
   }
 
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
   private final ChangeData.Factory changeDataFactory;
   private final RulesCache rules;
   private final AccountInfo.Loader.Factory accountInfoFactory;
@@ -66,7 +67,7 @@ public class TestSubmitRule implements RestModifyView<RevisionResource, Input> {
   private Filters filters = Filters.RUN;
 
   @Inject
-  TestSubmitRule(ReviewDb db,
+  TestSubmitRule(Provider<ReviewDb> db,
       ChangeData.Factory changeDataFactory,
       RulesCache rules,
       AccountInfo.Loader.Factory infoFactory) {
@@ -88,12 +89,12 @@ public class TestSubmitRule implements RestModifyView<RevisionResource, Input> {
     input.filters = Objects.firstNonNull(input.filters, filters);
 
     SubmitRuleEvaluator evaluator = new SubmitRuleEvaluator(
-        db,
+        db.get(),
         rsrc.getPatchSet(),
         rsrc.getControl().getProjectControl(),
         rsrc.getControl(),
         rsrc.getChange(),
-        changeDataFactory.create(db, rsrc.getChange()),
+        changeDataFactory.create(db.get(), rsrc.getChange()),
         false,
         "locate_submit_rule", "can_submit",
         "locate_submit_filter", "filter_submit_results",

gerrit-server/src/main/java/com/google/gerrit/server/change/TestSubmitType.java

@@ -30,6 +30,7 @@ import com.google.gerrit.server.project.RuleEvalException;
 import com.google.gerrit.server.project.SubmitRuleEvaluator;
 import com.google.gerrit.server.query.change.ChangeData;
 import com.google.inject.Inject;
+import com.google.inject.Provider;
 
 import com.googlecode.prolog_cafe.lang.SymbolTerm;
 import com.googlecode.prolog_cafe.lang.Term;
@@ -40,7 +41,7 @@ import java.io.ByteArrayInputStream;
 import java.util.List;
 
 public class TestSubmitType implements RestModifyView<RevisionResource, Input> {
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
   private final ChangeData.Factory changeDataFactory;
   private final RulesCache rules;
 
@@ -48,7 +49,7 @@ public class TestSubmitType implements RestModifyView<RevisionResource, Input> {
   private Filters filters = Filters.RUN;
 
   @Inject
-  TestSubmitType(ReviewDb db,
+  TestSubmitType(Provider<ReviewDb> db,
       ChangeData.Factory changeDataFactory,
       RulesCache rules) {
     this.db = db;
@@ -68,12 +69,12 @@ public class TestSubmitType implements RestModifyView<RevisionResource, Input> {
     input.filters = Objects.firstNonNull(input.filters, filters);
 
     SubmitRuleEvaluator evaluator = new SubmitRuleEvaluator(
-        db,
+        db.get(),
         rsrc.getPatchSet(),
         rsrc.getControl().getProjectControl(),
         rsrc.getControl(),
         rsrc.getChange(),
-        changeDataFactory.create(db, rsrc.getChange()),
+        changeDataFactory.create(db.get(), rsrc.getChange()),
         false,
         "locate_submit_type", "get_submit_type",
         "locate_submit_type_filter", "filter_submit_type_results",

gerrit-server/src/main/java/com/google/gerrit/server/changedetail/RebaseChange.java

@@ -14,8 +14,6 @@
 
 package com.google.gerrit.server.changedetail;
 
-import static com.google.gerrit.server.change.PatchSetInserter.ValidatePolicy;
-
 import com.google.gerrit.common.errors.EmailException;
 import com.google.gerrit.reviewdb.client.Branch;
 import com.google.gerrit.reviewdb.client.Change;
@@ -29,6 +27,7 @@ import com.google.gerrit.server.ChangeUtil;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.change.PatchSetInserter;
+import com.google.gerrit.server.change.PatchSetInserter.ValidatePolicy;
 import com.google.gerrit.server.change.RevisionResource;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.git.MergeUtil;
@@ -38,6 +37,8 @@ import com.google.gerrit.server.project.NoSuchChangeException;
 import com.google.gerrit.server.util.TimeUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.errors.RepositoryNotFoundException;
 import org.eclipse.jgit.lib.CommitBuilder;
@@ -52,18 +53,20 @@ import org.eclipse.jgit.revwalk.RevWalk;
 
 import java.io.IOException;
 import java.util.List;
+import java.util.TimeZone;
 
+@Singleton
 public class RebaseChange {
   private final ChangeControl.GenericFactory changeControlFactory;
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
   private final GitRepositoryManager gitManager;
-  private final PersonIdent myIdent;
+  private final TimeZone serverTimeZone;
   private final MergeUtil.Factory mergeUtilFactory;
   private final PatchSetInserter.Factory patchSetInserterFactory;
 
   @Inject
   RebaseChange(final ChangeControl.GenericFactory changeControlFactory,
-      final ReviewDb db,
+      final Provider<ReviewDb> db,
       @GerritPersonIdent final PersonIdent myIdent,
       final GitRepositoryManager gitManager,
       final MergeUtil.Factory mergeUtilFactory,
@@ -71,7 +74,7 @@ public class RebaseChange {
     this.changeControlFactory = changeControlFactory;
     this.db = db;
     this.gitManager = gitManager;
-    this.myIdent = myIdent;
+    this.serverTimeZone = myIdent.getTimeZone();
     this.mergeUtilFactory = mergeUtilFactory;
     this.patchSetInserterFactory = patchSetInserterFactory;
   }
@@ -122,14 +125,14 @@ public class RebaseChange {
       rw = new RevWalk(git);
       inserter = git.newObjectInserter();
 
-      final String baseRev = findBaseRevision(patchSetId, db,
+      final String baseRev = findBaseRevision(patchSetId, db.get(),
           change.getDest(), git, null, null, null);
       final RevCommit baseCommit =
           rw.parseCommit(ObjectId.fromString(baseRev));
 
       PersonIdent committerIdent =
-          uploader.newCommitterIdent(myIdent.getWhen(),
+          uploader.newCommitterIdent(TimeUtil.nowTs(),
-              myIdent.getTimeZone());
+              serverTimeZone);
 
       rebase(git, rw, inserter, patchSetId, change,
           uploader, baseCommit, mergeUtilFactory.create(
@@ -282,7 +285,7 @@ public class RebaseChange {
     if (!change.currentPatchSetId().equals(patchSetId)) {
       throw new InvalidChangeOperationException("patch set is not current");
     }
-    final PatchSet originalPatchSet = db.patchSets().get(patchSetId);
+    final PatchSet originalPatchSet = db.get().patchSets().get(patchSetId);
 
     final RevCommit rebasedCommit;
     ObjectId oldId = ObjectId.fromString(originalPatchSet.getRevision().get());
@@ -305,8 +308,9 @@ public class RebaseChange {
 
     final PatchSet.Id newPatchSetId = patchSetInserter.getPatchSetId();
     final ChangeMessage cmsg = new ChangeMessage(
-        new ChangeMessage.Key(change.getId(), ChangeUtil.messageUUID(db)),
+        new ChangeMessage.Key(change.getId(),
-        uploader.getAccountId(), TimeUtil.nowTs(), patchSetId);
+            ChangeUtil.messageUUID(db.get())), uploader.getAccountId(),
+            TimeUtil.nowTs(), patchSetId);
 
     cmsg.setMessage("Patch Set " + newPatchSetId.get()
         + ": Patch Set " + patchSetId.get() + " was rebased");
@@ -315,7 +319,7 @@ public class RebaseChange {
         .setMessage(cmsg)
         .insert();
 
-    return db.patchSets().get(newChange.currentPatchSetId());
+    return db.get().patchSets().get(newChange.currentPatchSetId());
   }
 
   /**
@@ -375,7 +379,7 @@ public class RebaseChange {
     try {
       findBaseRevision(
           r.getPatchSet().getId(),
-          db,
+          db.get(),
           r.getChange().getDest(),
           git,
           null,

gerrit-server/src/main/java/com/google/gerrit/server/config/CapabilitiesCollection.java

@@ -21,7 +21,9 @@ import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
 import com.google.gerrit.extensions.restapi.RestView;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class CapabilitiesCollection implements
     ChildCollection<ConfigResource, CapabilityResource> {
   private final DynamicMap<RestView<CapabilityResource>> views;

gerrit-server/src/main/java/com/google/gerrit/server/config/GetPreferences.java

@@ -19,12 +19,14 @@ import com.google.gerrit.server.account.GetPreferences.PreferenceInfo;
 import com.google.gerrit.server.account.VersionedAccountPreferences;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Repository;
 
 import java.io.IOException;
 
+@Singleton
 public class GetPreferences implements RestReadView<ConfigResource> {
   private final AllUsersName allUsersName;
   private final GitRepositoryManager gitMgr;

gerrit-server/src/main/java/com/google/gerrit/server/config/GetVersion.java

@@ -17,7 +17,9 @@ package com.google.gerrit.server.config;
 import com.google.gerrit.common.Version;
 import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
 import com.google.gerrit.extensions.restapi.RestReadView;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetVersion implements RestReadView<ConfigResource> {
   @Override
   public String apply(ConfigResource resource) throws ResourceNotFoundException {

gerrit-server/src/main/java/com/google/gerrit/server/config/SetPreferences.java

@@ -23,12 +23,14 @@ import com.google.gerrit.server.account.SetPreferences.Input;
 import com.google.gerrit.server.account.VersionedAccountPreferences;
 import com.google.gerrit.server.git.MetaDataUpdate;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.errors.ConfigInvalidException;
 
 import java.io.IOException;
 
 @RequiresCapability(GlobalCapability.ADMINISTRATE_SERVER)
+@Singleton
 public class SetPreferences implements RestModifyView<ConfigResource, Input> {
   private final MetaDataUpdate.User metaDataUpdateFactory;
   private final AllUsersName allUsersName;

gerrit-server/src/main/java/com/google/gerrit/server/config/TopMenuCollection.java

@@ -21,7 +21,9 @@ import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
 import com.google.gerrit.extensions.restapi.RestView;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 class TopMenuCollection implements
     ChildCollection<ConfigResource, TopMenuResource> {
   private final DynamicMap<RestView<TopMenuResource>> views;

gerrit-server/src/main/java/com/google/gerrit/server/group/AddIncludedGroups.java

@@ -38,10 +38,12 @@ import com.google.gerrit.server.util.TimeUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.List;
 import java.util.Map;
 
+@Singleton
 public class AddIncludedGroups implements RestModifyView<GroupResource, Input> {
   public static class Input {
     @DefaultInput
@@ -71,13 +73,13 @@ public class AddIncludedGroups implements RestModifyView<GroupResource, Input> {
 
   private final Provider<GroupsCollection> groupsCollection;
   private final GroupIncludeCache groupIncludeCache;
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
   private final GroupJson json;
 
   @Inject
   public AddIncludedGroups(Provider<GroupsCollection> groupsCollection,
       GroupIncludeCache groupIncludeCache,
-      ReviewDb db, GroupJson json) {
+      Provider<ReviewDb> db, GroupJson json) {
     this.groupsCollection = groupsCollection;
     this.groupIncludeCache = groupIncludeCache;
     this.db = db;
@@ -111,7 +113,7 @@ public class AddIncludedGroups implements RestModifyView<GroupResource, Input> {
         AccountGroupById.Key agiKey =
             new AccountGroupById.Key(group.getId(),
                 d.getGroupUUID());
-        AccountGroupById agi = db.accountGroupById().get(agiKey);
+        AccountGroupById agi = db.get().accountGroupById().get(agiKey);
         if (agi == null) {
           agi = new AccountGroupById(agiKey);
           newIncludedGroups.put(d.getGroupUUID(), agi);
@@ -123,8 +125,8 @@ public class AddIncludedGroups implements RestModifyView<GroupResource, Input> {
     }
 
     if (!newIncludedGroups.isEmpty()) {
-      db.accountGroupByIdAud().insert(newIncludedGroupsAudits);
+      db.get().accountGroupByIdAud().insert(newIncludedGroupsAudits);
-      db.accountGroupById().insert(newIncludedGroups.values());
+      db.get().accountGroupById().insert(newIncludedGroups.values());
       for (AccountGroupById agi : newIncludedGroups.values()) {
         groupIncludeCache.evictMemberIn(agi.getIncludeUUID());
       }
@@ -134,6 +136,7 @@ public class AddIncludedGroups implements RestModifyView<GroupResource, Input> {
     return result;
   }
 
+  @Singleton
   static class PutIncludedGroup implements RestModifyView<GroupResource, PutIncludedGroup.Input> {
     static class Input {
     }
@@ -160,6 +163,7 @@ public class AddIncludedGroups implements RestModifyView<GroupResource, Input> {
     }
   }
 
+  @Singleton
   static class UpdateIncludedGroup implements RestModifyView<IncludedGroupResource, PutIncludedGroup.Input> {
     static class Input {
     }

gerrit-server/src/main/java/com/google/gerrit/server/group/AddMembers.java

@@ -43,10 +43,12 @@ import com.google.gerrit.server.util.TimeUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.List;
 import java.util.Map;
 
+@Singleton
 public class AddMembers implements RestModifyView<GroupResource, Input> {
   public static class Input {
     @DefaultInput
@@ -79,7 +81,7 @@ public class AddMembers implements RestModifyView<GroupResource, Input> {
   private final AccountResolver accountResolver;
   private final AccountCache accountCache;
   private final AccountInfo.Loader.Factory infoFactory;
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
 
   @Inject
   AddMembers(AccountManager accountManager,
@@ -88,7 +90,7 @@ public class AddMembers implements RestModifyView<GroupResource, Input> {
       AccountResolver accountResolver,
       AccountCache accountCache,
       AccountInfo.Loader.Factory infoFactory,
-      ReviewDb db) {
+      Provider<ReviewDb> db) {
     this.accountManager = accountManager;
     this.authType = authConfig.getAuthType();
     this.accounts = accounts;
@@ -129,7 +131,7 @@ public class AddMembers implements RestModifyView<GroupResource, Input> {
       if (!newAccountGroupMembers.containsKey(a.getId())) {
         AccountGroupMember.Key key =
             new AccountGroupMember.Key(a.getId(), internalGroup.getId());
-        AccountGroupMember m = db.accountGroupMembers().get(key);
+        AccountGroupMember m = db.get().accountGroupMembers().get(key);
         if (m == null) {
           m = new AccountGroupMember(key);
           newAccountGroupMembers.put(m.getAccountId(), m);
@@ -140,8 +142,8 @@ public class AddMembers implements RestModifyView<GroupResource, Input> {
       result.add(loader.get(a.getId()));
     }
 
-    db.accountGroupMembersAudit().insert(newAccountGroupMemberAudits);
+    db.get().accountGroupMembersAudit().insert(newAccountGroupMemberAudits);
-    db.accountGroupMembers().insert(newAccountGroupMembers.values());
+    db.get().accountGroupMembers().insert(newAccountGroupMembers.values());
     for (AccountGroupMember m : newAccountGroupMembers.values()) {
       accountCache.evict(m.getAccountId());
     }
@@ -213,6 +215,7 @@ public class AddMembers implements RestModifyView<GroupResource, Input> {
     }
   }
 
+  @Singleton
   static class UpdateMember implements RestModifyView<MemberResource, PutMember.Input> {
     static class Input {
     }

gerrit-server/src/main/java/com/google/gerrit/server/group/DeleteIncludedGroups.java

@@ -37,19 +37,22 @@ import com.google.gerrit.server.util.TimeUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.List;
 import java.util.Map;
 
+@Singleton
 public class DeleteIncludedGroups implements RestModifyView<GroupResource, Input> {
   private final Provider<GroupsCollection> groupsCollection;
   private final GroupIncludeCache groupIncludeCache;
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
   private final Provider<CurrentUser> self;
 
   @Inject
   DeleteIncludedGroups(Provider<GroupsCollection> groupsCollection,
-      GroupIncludeCache groupIncludeCache, ReviewDb db,
+      GroupIncludeCache groupIncludeCache,
+      Provider<ReviewDb> db,
       Provider<CurrentUser> self) {
     this.groupsCollection = groupsCollection;
     this.groupIncludeCache = groupIncludeCache;
@@ -86,7 +89,7 @@ public class DeleteIncludedGroups implements RestModifyView<GroupResource, Input
 
     if (!toRemove.isEmpty()) {
       writeAudits(toRemove);
-      db.accountGroupById().delete(toRemove);
+      db.get().accountGroupById().delete(toRemove);
       for (final AccountGroupById g : toRemove) {
         groupIncludeCache.evictMemberIn(g.getIncludeUUID());
       }
@@ -100,7 +103,7 @@ public class DeleteIncludedGroups implements RestModifyView<GroupResource, Input
       final AccountGroup.Id groupId) throws OrmException {
     final Map<AccountGroup.UUID, AccountGroupById> groups =
         Maps.newHashMap();
-    for (final AccountGroupById g : db.accountGroupById().byGroup(groupId)) {
+    for (AccountGroupById g : db.get().accountGroupById().byGroup(groupId)) {
       groups.put(g.getIncludeUUID(), g);
     }
     return groups;
@@ -112,7 +115,7 @@ public class DeleteIncludedGroups implements RestModifyView<GroupResource, Input
     final List<AccountGroupByIdAud> auditUpdates = Lists.newLinkedList();
     for (final AccountGroupById g : toBeRemoved) {
       AccountGroupByIdAud audit = null;
-      for (AccountGroupByIdAud a : db
+      for (AccountGroupByIdAud a : db.get()
           .accountGroupByIdAud().byGroupInclude(g.getGroupId(),
               g.getIncludeUUID())) {
         if (a.isActive()) {
@@ -126,9 +129,10 @@ public class DeleteIncludedGroups implements RestModifyView<GroupResource, Input
         auditUpdates.add(audit);
       }
     }
-    db.accountGroupByIdAud().update(auditUpdates);
+    db.get().accountGroupByIdAud().update(auditUpdates);
   }
 
+  @Singleton
   static class DeleteIncludedGroup implements
       RestModifyView<IncludedGroupResource, DeleteIncludedGroup.Input> {
     static class Input {

gerrit-server/src/main/java/com/google/gerrit/server/group/DeleteMembers.java

@@ -36,19 +36,22 @@ import com.google.gerrit.server.util.TimeUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.List;
 import java.util.Map;
 
+@Singleton
 public class DeleteMembers implements RestModifyView<GroupResource, Input> {
   private final Provider<AccountsCollection> accounts;
   private final AccountCache accountCache;
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
   private final Provider<CurrentUser> self;
 
   @Inject
   DeleteMembers(Provider<AccountsCollection> accounts,
-      AccountCache accountCache, ReviewDb db, Provider<CurrentUser> self) {
+      AccountCache accountCache, Provider<ReviewDb> db,
+      Provider<CurrentUser> self) {
     this.accounts = accounts;
     this.accountCache = accountCache;
     this.db = db;
@@ -83,7 +86,7 @@ public class DeleteMembers implements RestModifyView<GroupResource, Input> {
     }
 
     writeAudits(toRemove);
-    db.accountGroupMembers().delete(toRemove);
+    db.get().accountGroupMembers().delete(toRemove);
     for (final AccountGroupMember m : toRemove) {
       accountCache.evict(m.getAccountId());
     }
@@ -98,7 +101,7 @@ public class DeleteMembers implements RestModifyView<GroupResource, Input> {
     final List<AccountGroupMemberAudit> auditInserts = Lists.newLinkedList();
     for (final AccountGroupMember m : toBeRemoved) {
       AccountGroupMemberAudit audit = null;
-      for (AccountGroupMemberAudit a : db.accountGroupMembersAudit()
+      for (AccountGroupMemberAudit a : db.get().accountGroupMembersAudit()
           .byGroupAccount(m.getAccountGroupId(), m.getAccountId())) {
         if (a.isActive()) {
           audit = a;
@@ -115,19 +118,21 @@ public class DeleteMembers implements RestModifyView<GroupResource, Input> {
         auditInserts.add(audit);
       }
     }
-    db.accountGroupMembersAudit().update(auditUpdates);
+    db.get().accountGroupMembersAudit().update(auditUpdates);
-    db.accountGroupMembersAudit().insert(auditInserts);
+    db.get().accountGroupMembersAudit().insert(auditInserts);
   }
 
   private Map<Account.Id, AccountGroupMember> getMembers(
       final AccountGroup.Id groupId) throws OrmException {
     final Map<Account.Id, AccountGroupMember> members = Maps.newHashMap();
-    for (final AccountGroupMember m : db.accountGroupMembers().byGroup(groupId)) {
+    for (final AccountGroupMember m : db.get().accountGroupMembers()
+        .byGroup(groupId)) {
       members.put(m.getAccountId(), m);
     }
     return members;
   }
 
+  @Singleton
   static class DeleteMember implements RestModifyView<MemberResource, DeleteMember.Input> {
     static class Input {
     }

gerrit-server/src/main/java/com/google/gerrit/server/group/GetDescription.java

@@ -18,7 +18,9 @@ import com.google.common.base.Strings;
 import com.google.gerrit.extensions.restapi.MethodNotAllowedException;
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.reviewdb.client.AccountGroup;
+import com.google.inject.Singleton;
 
+@Singleton
 class GetDescription implements RestReadView<GroupResource> {
   @Override
   public String apply(GroupResource resource) throws MethodNotAllowedException {

gerrit-server/src/main/java/com/google/gerrit/server/group/GetDetail.java

@@ -19,7 +19,9 @@ import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.group.GroupJson.GroupInfo;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetDetail implements RestReadView<GroupResource> {
   private final GroupJson json;
 

gerrit-server/src/main/java/com/google/gerrit/server/group/GetGroup.java

@@ -18,7 +18,9 @@ import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.group.GroupJson.GroupInfo;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
+@Singleton
 class GetGroup implements RestReadView<GroupResource> {
   private final GroupJson json;
 

gerrit-server/src/main/java/com/google/gerrit/server/group/GetIncludedGroup.java

@@ -18,7 +18,9 @@ import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.group.GroupJson.GroupInfo;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetIncludedGroup implements RestReadView<IncludedGroupResource>  {
   private final GroupJson json;
 

gerrit-server/src/main/java/com/google/gerrit/server/group/GetMember.java

@@ -18,7 +18,9 @@ import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.account.AccountInfo;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetMember implements RestReadView<MemberResource> {
   private final AccountInfo.Loader.Factory infoFactory;
 

gerrit-server/src/main/java/com/google/gerrit/server/group/GetName.java

@@ -15,7 +15,9 @@
 package com.google.gerrit.server.group;
 
 import com.google.gerrit.extensions.restapi.RestReadView;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetName implements RestReadView<GroupResource> {
 
   @Override

gerrit-server/src/main/java/com/google/gerrit/server/group/GetOptions.java

@@ -15,7 +15,9 @@
 package com.google.gerrit.server.group;
 
 import com.google.gerrit.extensions.restapi.RestReadView;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetOptions implements RestReadView<GroupResource> {
 
   @Override

gerrit-server/src/main/java/com/google/gerrit/server/group/GetOwner.java

@@ -23,7 +23,9 @@ import com.google.gerrit.server.account.GroupControl;
 import com.google.gerrit.server.group.GroupJson.GroupInfo;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetOwner implements RestReadView<GroupResource> {
 
   private final GroupControl.Factory controlFactory;

gerrit-server/src/main/java/com/google/gerrit/server/group/GroupsCollection.java

@@ -35,7 +35,9 @@ import com.google.gerrit.server.account.GroupBackends;
 import com.google.gerrit.server.account.GroupControl;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GroupsCollection implements
     RestCollection<TopLevelResource, GroupResource>,
     AcceptsCreate<TopLevelResource> {

gerrit-server/src/main/java/com/google/gerrit/server/group/IncludedGroupsCollection.java

@@ -31,7 +31,9 @@ import com.google.gerrit.server.group.AddIncludedGroups.PutIncludedGroup;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class IncludedGroupsCollection implements
     ChildCollection<GroupResource, IncludedGroupResource>,
     AcceptsCreate<GroupResource> {

gerrit-server/src/main/java/com/google/gerrit/server/group/ListIncludedGroups.java

@@ -27,6 +27,7 @@ import com.google.gerrit.server.group.GroupJson.GroupInfo;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.slf4j.Logger;
 
@@ -34,6 +35,7 @@ import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 
+@Singleton
 public class ListIncludedGroups implements RestReadView<GroupResource> {
   private static final Logger log = org.slf4j.LoggerFactory.getLogger(ListIncludedGroups.class);
 

gerrit-server/src/main/java/com/google/gerrit/server/group/MembersCollection.java

@@ -31,7 +31,9 @@ import com.google.gerrit.server.group.AddMembers.PutMember;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class MembersCollection implements
     ChildCollection<GroupResource, MemberResource>,
     AcceptsCreate<GroupResource> {

gerrit-server/src/main/java/com/google/gerrit/server/group/PutDescription.java

@@ -27,9 +27,12 @@ import com.google.gerrit.server.account.GroupCache;
 import com.google.gerrit.server.group.PutDescription.Input;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 
+@Singleton
 public class PutDescription implements RestModifyView<GroupResource, Input> {
   public static class Input {
     @DefaultInput
@@ -37,10 +40,10 @@ public class PutDescription implements RestModifyView<GroupResource, Input> {
   }
 
   private final GroupCache groupCache;
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
 
   @Inject
-  PutDescription(GroupCache groupCache, ReviewDb db) {
+  PutDescription(GroupCache groupCache, Provider<ReviewDb> db) {
     this.groupCache = groupCache;
     this.db = db;
   }
@@ -59,14 +62,14 @@ public class PutDescription implements RestModifyView<GroupResource, Input> {
       throw new AuthException("Not group owner");
     }
 
-    AccountGroup group = db.accountGroups().get(
+    AccountGroup group = db.get().accountGroups().get(
         resource.toAccountGroup().getId());
     if (group == null) {
       throw new ResourceNotFoundException();
     }
 
     group.setDescription(Strings.emptyToNull(input.description));
-    db.accountGroups().update(Collections.singleton(group));
+    db.get().accountGroups().update(Collections.singleton(group));
     groupCache.evict(group);
 
     return Strings.isNullOrEmpty(input.description)

gerrit-server/src/main/java/com/google/gerrit/server/group/PutGroup.java

@@ -18,7 +18,9 @@ import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.extensions.restapi.Response;
 import com.google.gerrit.extensions.restapi.RestModifyView;
 import com.google.gerrit.server.group.CreateGroup.Input;
+import com.google.inject.Singleton;
 
+@Singleton
 public class PutGroup implements RestModifyView<GroupResource, Input> {
   @Override
   public Response<?> apply(GroupResource resource, Input input)

gerrit-server/src/main/java/com/google/gerrit/server/group/PutName.java

@@ -29,7 +29,9 @@ import com.google.gerrit.server.account.PerformRenameGroup;
 import com.google.gerrit.server.group.PutName.Input;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
+@Singleton
 public class PutName implements RestModifyView<GroupResource, Input> {
   public static class Input {
     @DefaultInput

gerrit-server/src/main/java/com/google/gerrit/server/group/PutOptions.java

@@ -25,19 +25,22 @@ import com.google.gerrit.server.account.GroupCache;
 import com.google.gerrit.server.group.PutOptions.Input;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 
+@Singleton
 public class PutOptions implements RestModifyView<GroupResource, Input> {
   public static class Input {
     public Boolean visibleToAll;
   }
 
   private final GroupCache groupCache;
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
 
   @Inject
-  PutOptions(GroupCache groupCache, ReviewDb db) {
+  PutOptions(GroupCache groupCache, Provider<ReviewDb> db) {
     this.groupCache = groupCache;
     this.db = db;
   }
@@ -59,14 +62,14 @@ public class PutOptions implements RestModifyView<GroupResource, Input> {
       input.visibleToAll = false;
     }
 
-    AccountGroup group = db.accountGroups().get(
+    AccountGroup group = db.get().accountGroups().get(
         resource.toAccountGroup().getId());
     if (group == null) {
       throw new ResourceNotFoundException();
     }
 
     group.setVisibleToAll(input.visibleToAll);
-    db.accountGroups().update(Collections.singleton(group));
+    db.get().accountGroups().update(Collections.singleton(group));
     groupCache.evict(group);
 
     return new GroupOptionsInfo(group);

gerrit-server/src/main/java/com/google/gerrit/server/group/PutOwner.java

@@ -31,9 +31,11 @@ import com.google.gerrit.server.group.PutOwner.Input;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.util.Collections;
 
+@Singleton
 public class PutOwner implements RestModifyView<GroupResource, Input> {
   public static class Input {
     @DefaultInput
@@ -42,12 +44,12 @@ public class PutOwner implements RestModifyView<GroupResource, Input> {
 
   private final Provider<GroupsCollection> groupsCollection;
   private final GroupCache groupCache;
-  private final ReviewDb db;
+  private final Provider<ReviewDb> db;
   private final GroupJson json;
 
   @Inject
   PutOwner(Provider<GroupsCollection> groupsCollection, GroupCache groupCache,
-      ReviewDb db, GroupJson json) {
+      Provider<ReviewDb> db, GroupJson json) {
     this.groupsCollection = groupsCollection;
     this.groupCache = groupCache;
     this.db = db;
@@ -70,7 +72,7 @@ public class PutOwner implements RestModifyView<GroupResource, Input> {
       throw new BadRequestException("owner is required");
     }
 
-    group = db.accountGroups().get(group.getId());
+    group = db.get().accountGroups().get(group.getId());
     if (group == null) {
       throw new ResourceNotFoundException();
     }
@@ -78,7 +80,7 @@ public class PutOwner implements RestModifyView<GroupResource, Input> {
     GroupDescription.Basic owner = groupsCollection.get().parse(input.owner);
     if (!group.getOwnerGroupUUID().equals(owner.getGroupUUID())) {
       group.setOwnerGroupUUID(owner.getGroupUUID());
-      db.accountGroups().update(Collections.singleton(group));
+      db.get().accountGroups().update(Collections.singleton(group));
       groupCache.evict(group);
     }
     return json.format(owner);

gerrit-server/src/main/java/com/google/gerrit/server/plugins/DisablePlugin.java

@@ -22,8 +22,10 @@ import com.google.gerrit.extensions.restapi.RestModifyView;
 import com.google.gerrit.server.plugins.DisablePlugin.Input;
 import com.google.gerrit.server.plugins.ListPlugins.PluginInfo;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
 @RequiresCapability(GlobalCapability.ADMINISTRATE_SERVER)
+@Singleton
 class DisablePlugin implements RestModifyView<PluginResource, Input> {
   static class Input {
   }

gerrit-server/src/main/java/com/google/gerrit/server/plugins/EnablePlugin.java

@@ -23,11 +23,13 @@ import com.google.gerrit.extensions.restapi.RestModifyView;
 import com.google.gerrit.server.plugins.EnablePlugin.Input;
 import com.google.gerrit.server.plugins.ListPlugins.PluginInfo;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
 import java.io.PrintWriter;
 import java.io.StringWriter;
 
 @RequiresCapability(GlobalCapability.ADMINISTRATE_SERVER)
+@Singleton
 class EnablePlugin implements RestModifyView<PluginResource, Input> {
   static class Input {
   }

gerrit-server/src/main/java/com/google/gerrit/server/plugins/GetStatus.java

@@ -16,7 +16,9 @@ package com.google.gerrit.server.plugins;
 
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.plugins.ListPlugins.PluginInfo;
+import com.google.inject.Singleton;
 
+@Singleton
 class GetStatus implements RestReadView<PluginResource> {
   @Override
   public PluginInfo apply(PluginResource resource) {

gerrit-server/src/main/java/com/google/gerrit/server/plugins/PluginsCollection.java

@@ -24,7 +24,9 @@ import com.google.gerrit.extensions.restapi.RestView;
 import com.google.gerrit.extensions.restapi.TopLevelResource;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class PluginsCollection implements
     RestCollection<TopLevelResource, PluginResource>,
     AcceptsCreate<TopLevelResource> {

gerrit-server/src/main/java/com/google/gerrit/server/plugins/ReloadPlugin.java

@@ -22,11 +22,13 @@ import com.google.gerrit.extensions.restapi.RestModifyView;
 import com.google.gerrit.server.plugins.ListPlugins.PluginInfo;
 import com.google.gerrit.server.plugins.ReloadPlugin.Input;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
 import java.io.PrintWriter;
 import java.io.StringWriter;
 
 @RequiresCapability(GlobalCapability.ADMINISTRATE_SERVER)
+@Singleton
 class ReloadPlugin implements RestModifyView<PluginResource, Input> {
   static class Input {
   }

gerrit-server/src/main/java/com/google/gerrit/server/project/BranchesCollection.java

@@ -23,12 +23,14 @@ import com.google.gerrit.extensions.restapi.RestView;
 import com.google.gerrit.server.project.ListBranches.BranchInfo;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.lib.Constants;
 
 import java.io.IOException;
 import java.util.List;
 
+@Singleton
 public class BranchesCollection implements
     ChildCollection<ProjectResource, BranchResource>,
     AcceptsCreate<ProjectResource> {

gerrit-server/src/main/java/com/google/gerrit/server/project/ChildProjectsCollection.java

@@ -23,9 +23,11 @@ import com.google.gerrit.extensions.restapi.RestView;
 import com.google.gerrit.extensions.restapi.TopLevelResource;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.io.IOException;
 
+@Singleton
 public class ChildProjectsCollection implements
     ChildCollection<ProjectResource, ChildProjectResource> {
   private final Provider<ListChildProjects> list;

gerrit-server/src/main/java/com/google/gerrit/server/project/DashboardsCollection.java

@@ -37,6 +37,7 @@ import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gson.annotations.SerializedName;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.errors.AmbiguousObjectException;
 import org.eclipse.jgit.errors.ConfigInvalidException;
@@ -51,9 +52,10 @@ import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.util.List;
 
+@Singleton
 class DashboardsCollection implements
     ChildCollection<ProjectResource, DashboardResource>,
-    AcceptsCreate<ProjectResource>{
+    AcceptsCreate<ProjectResource> {
   private final GitRepositoryManager gitManager;
   private final DynamicMap<RestView<DashboardResource>> views;
   private final Provider<ListDashboards> list;

gerrit-server/src/main/java/com/google/gerrit/server/project/DeleteBranch.java

@@ -27,6 +27,7 @@ import com.google.gerrit.server.project.DeleteBranch.Input;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import org.eclipse.jgit.lib.RefUpdate;
 import org.eclipse.jgit.lib.Repository;
@@ -35,6 +36,7 @@ import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 
+@Singleton
 public class DeleteBranch implements RestModifyView<BranchResource, Input>{
   private static final Logger log = LoggerFactory.getLogger(DeleteBranch.class);
 

gerrit-server/src/main/java/com/google/gerrit/server/project/DeleteDashboard.java

@@ -25,9 +25,11 @@ import com.google.gerrit.server.project.DashboardsCollection.DashboardInfo;
 import com.google.gerrit.server.project.DeleteDashboard.Input;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
 import java.io.IOException;
 
+@Singleton
 class DeleteDashboard implements RestModifyView<DashboardResource, Input> {
   static class Input {
     String commitMessage;

gerrit-server/src/main/java/com/google/gerrit/server/project/FilesCollection.java

@@ -21,7 +21,9 @@ import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
 import com.google.gerrit.extensions.restapi.RestView;
 import com.google.gerrit.server.project.BranchResource;
 import com.google.inject.Inject;
+import com.google.inject.Singleton;
 
+@Singleton
 public class FilesCollection implements
     ChildCollection<BranchResource, FileResource> {
   private final DynamicMap<RestView<FileResource>> views;

gerrit-server/src/main/java/com/google/gerrit/server/project/GetBranch.java

@@ -16,7 +16,9 @@ package com.google.gerrit.server.project;
 
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.project.ListBranches.BranchInfo;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetBranch implements RestReadView<BranchResource> {
 
   @Override

gerrit-server/src/main/java/com/google/gerrit/server/project/GetConfig.java

@@ -24,7 +24,9 @@ import com.google.gerrit.server.config.ProjectConfigEntry;
 import com.google.gerrit.server.git.TransferConfig;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import com.google.inject.Singleton;
 
+@Singleton
 public class GetConfig implements RestReadView<ProjectResource> {
 
   private final TransferConfig config;