java/com/google/gerrit/server/query/change/ChangeIndexPredicate.java

// Copyright (C) 2016 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.gerrit.server.query.change;

import com.google.gerrit.index.FieldDef;
import com.google.gerrit.index.query.IndexPredicate;
import com.google.gerrit.index.query.Matchable;
import com.google.gerrit.index.query.Predicate;

public abstract class ChangeIndexPredicate extends IndexPredicate<ChangeData>
    implements Matchable<ChangeData> {
  /**
   * Returns an index predicate that matches no changes in the index.
   *
   * <p>This predicate should be used in preference to a non-index predicate (such as {@code
   * Predicate.not(Predicate.any())}), since it can be matched efficiently against the index.
   *
   * @return an index predicate matching no changes.
   */
  public static Predicate<ChangeData> none() {
    return ChangeStatusPredicate.NONE;
  }

  protected ChangeIndexPredicate(FieldDef<ChangeData, ?> def, String value) {
    super(def, value);
  }

  protected ChangeIndexPredicate(FieldDef<ChangeData, ?> def, String name, String value) {
    super(def, name, value);
  }
}