code: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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 org.apache.skywalking.oap.server.core.analysis.metrics;
  
  import lombok.Getter;
  import lombok.Setter;
  import org.apache.skywalking.oap.server.core.analysis.metrics.annotation.Entrance;
  import org.apache.skywalking.oap.server.core.analysis.metrics.annotation.MetricsFunction;
  import org.apache.skywalking.oap.server.core.analysis.metrics.annotation.SourceFrom;
  import org.apache.skywalking.oap.server.core.storage.annotation.BanyanDB;
  import org.apache.skywalking.oap.server.core.storage.annotation.Column;
  
  @MetricsFunction(functionName = "maxDouble")
  public abstract class MaxDoubleMetrics extends Metrics implements DoubleValueHolder {
  
      protected static final String VALUE = "value";
  
      @Getter
      @Setter
      @Column(name = VALUE, dataType = Column.ValueDataType.COMMON_VALUE)
      @BanyanDB.MeasureField
      private double value;
  
      @Entrance
      public final void combine(@SourceFrom double count) {
          if (count > this.value) {
              this.value = count;
          }
      }
  
      @Override
      public final boolean combine(Metrics metrics) {
          MaxDoubleMetrics maxDoubleMetrics = (MaxDoubleMetrics) metrics;
          combine(maxDoubleMetrics.value);
          return true;
      }
  
      @Override
      public void calculate() {
      }
  }
  