Add a separate queue for non-interactive users

A new internal user group, "Non-Interactive Users" is added. members
of this group are not expected to perform interactive operations on
the gerrit web frontend.

However, sometimes such a user may need a separate thread pool in
order to prevent it from grabbing threads from the interactive users.

This change introduces a second thread pool, which separates
operations from the non-interactive users from the interactive ones.
This ensures that the interactive users can keep working when
resources are tight.

Change-Id: I16334dd84ec50e1a6ca894e635c8beea9bd42115

gerrit-server/src/main/java/com/google/gerrit/server/CurrentUser.java

@@ -59,6 +59,11 @@ public abstract class CurrentUser {
   /** Set of changes starred by this user. */
   public abstract Set<Change.Id> getStarredChanges();
 
+  /** Is the user a non-interactive user? */
+  public boolean isBatchUser() {
+    return getEffectiveGroups().contains(authConfig.getBatchUsersGroup());
+  }
+
   @Deprecated
   public final boolean isAdministrator() {
     return getEffectiveGroups().contains(authConfig.getAdministratorsGroup());

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

@@ -46,6 +46,7 @@ public class AuthConfig {
   private final AccountGroup.Id administratorGroup;
   private final Set<AccountGroup.Id> anonymousGroups;
   private final Set<AccountGroup.Id> registeredGroups;
+  private final AccountGroup.Id batchUsersGroup;
 
   private final boolean allowGoogleAccountUpgrade;
 
@@ -65,6 +66,7 @@ public class AuthConfig {
     registeredGroups = Collections.unmodifiableSet(r);
     anonymousGroups = Collections.singleton(s.anonymousGroupId);
     administratorGroup = s.adminGroupId;
+    batchUsersGroup = s.batchUsersGroupId;
 
     if (authType == AuthType.OPENID) {
       allowGoogleAccountUpgrade =
@@ -117,6 +119,11 @@ public class AuthConfig {
     return administratorGroup;
   }
 
+  /** Identity of the group whose service is degraded to lower priority. */
+  public AccountGroup.Id getBatchUsersGroup() {
+    return batchUsersGroup;
+  }
+
   /** Groups that all users, including anonymous users, belong to. */
   public Set<AccountGroup.Id> getAnonymousGroups() {
     return anonymousGroups;

gerrit-server/src/main/java/com/google/gerrit/server/schema/SchemaCreator.java

@@ -140,11 +140,22 @@ public class SchemaCreator {
     c.accountGroupNames().insert(
         Collections.singleton(new AccountGroupName(registered)));
 
+    final AccountGroup batchUsers =
+      new AccountGroup(new AccountGroup.NameKey("Non-Interactive Users"),
+          new AccountGroup.Id(c.nextAccountGroupId()));
+    batchUsers.setDescription("Users who perform batch actions on Gerrit");
+    batchUsers.setOwnerGroupId(admin.getId());
+    batchUsers.setType(AccountGroup.Type.INTERNAL);
+    c.accountGroups().insert(Collections.singleton(batchUsers));
+    c.accountGroupNames().insert(
+        Collections.singleton(new AccountGroupName(batchUsers)));
+
     final SystemConfig s = SystemConfig.create();
     s.registerEmailPrivateKey = SignedToken.generateRandomKey();
     s.adminGroupId = admin.getId();
     s.anonymousGroupId = anonymous.getId();
     s.registeredGroupId = registered.getId();
+    s.batchUsersGroupId = batchUsers.getId();
     s.wildProjectName = DEFAULT_WILD_NAME;
     try {
       s.sitePath = site_path.getCanonicalPath();

gerrit-server/src/main/java/com/google/gerrit/server/schema/SchemaVersion.java

@@ -32,7 +32,7 @@ import java.util.List;
 /** A version of the database schema. */
 public abstract class SchemaVersion {
   /** The current schema version. */
-  private static final Class<? extends SchemaVersion> C = Schema_32.class;
+  private static final Class<? extends SchemaVersion> C = Schema_33.class;
 
   public static class Module extends AbstractModule {
     @Override

gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_33.java

@@ -0,0 +1,49 @@
+// Copyright (C) 2010 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.schema;
+
+import com.google.gerrit.reviewdb.AccountGroup;
+import com.google.gerrit.reviewdb.AccountGroupName;
+import com.google.gerrit.reviewdb.ReviewDb;
+import com.google.gerrit.reviewdb.SystemConfig;
+import com.google.gwtorm.client.OrmException;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+
+import java.util.Collections;
+
+public class Schema_33 extends SchemaVersion {
+  @Inject
+  Schema_33(Provider<Schema_32> prior) {
+    super(prior);
+  }
+
+  @Override
+  protected void migrateData(ReviewDb db, UpdateUI ui) throws OrmException {
+    SystemConfig config = db.systemConfig().all().toList().get(0);
+    final AccountGroup batchUsers =
+      new AccountGroup(new AccountGroup.NameKey("Non-Interactive Users"),
+          new AccountGroup.Id(db.nextAccountGroupId()));
+    batchUsers.setDescription("Users who perform batch actions on Gerrit");
+    batchUsers.setOwnerGroupId(config.adminGroupId);
+    batchUsers.setType(AccountGroup.Type.INTERNAL);
+    db.accountGroups().insert(Collections.singleton(batchUsers));
+    db.accountGroupNames().insert(
+        Collections.singleton(new AccountGroupName(batchUsers)));
+
+    config.batchUsersGroupId = batchUsers.getId();
+    db.systemConfig().update(Collections.singleton(config));
+  }
+}