org.sonar.server.health.HealthReducer Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of sonar-server Show documentation

There is a newer version: 7.2.1

/*
 * SonarQube
 * Copyright (C) 2009-2017 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.server.health;

import java.util.function.BinaryOperator;
import java.util.stream.Stream;

import static org.sonar.server.health.Health.newHealthCheckBuilder;

public enum HealthReducer implements BinaryOperator {
  INSTANCE;

  /**
   * According to Javadoc, {@link BinaryOperator} used in method
   * {@link java.util.stream.Stream#reduce(Object, BinaryOperator)} is supposed to be stateless.
   *
   * But as we are sure this {@link BinaryOperator} won't be used on a Stream with {@link Stream#parallel()}
   * feature on, we allow ourselves this optimisation.
   */
  private final Health.Builder builder = newHealthCheckBuilder();

  @Override
  public Health apply(Health left, Health right) {
    builder.clear();
    builder.setStatus(worseOf(left.getStatus(), right.getStatus()));
    left.getCauses().forEach(builder::addCause);
    right.getCauses().forEach(builder::addCause);
    return builder.build();
  }

  private static Health.Status worseOf(Health.Status left, Health.Status right) {
    if (left == right) {
      return left;
    }
    if (left.ordinal() > right.ordinal()) {
      return left;
    }
    return right;
  }
}