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.Expression;
  import org.apache.skywalking.oap.server.core.analysis.metrics.annotation.MetricsFunction;
  import org.apache.skywalking.oap.server.core.query.sql.Function;
  import org.apache.skywalking.oap.server.core.storage.annotation.BanyanDB;
  import org.apache.skywalking.oap.server.core.storage.annotation.Column;
  
  @MetricsFunction(functionName = "percent")
  public abstract class PercentMetrics extends Metrics implements IntValueHolder {
      protected static final String TOTAL = "total";
      protected static final String MATCH = "match";
      protected static final String PERCENTAGE = "percentage";
  
      @Getter
      @Setter
      @Column(name = TOTAL, storageOnly = true)
      @BanyanDB.MeasureField
      private long total;
      @Getter
      @Setter
      @Column(name = PERCENTAGE, dataType = Column.ValueDataType.COMMON_VALUE, function = Function.Avg)
      @BanyanDB.MeasureField
      private int percentage;
      @Getter
      @Setter
      @Column(name = MATCH, storageOnly = true)
      private long match;
  
      @Entrance
      public final void combine(@Expression boolean isMatch) {
          if (isMatch) {
              match++;
          }
          total++;
      }
  
      @Override
      public final boolean combine(Metrics metrics) {
          total += ((PercentMetrics) metrics).total;
          match += ((PercentMetrics) metrics).match;
          return true;
      }
  
      @Override
      public void calculate() {
          percentage = (int) (match * 10000 / total);
      }
  
      @Override
      public int getValue() {
          return percentage;
      }
  }
  