io.ebeaninternal.server.profile.DTimedMetric Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of ebean Show documentation
composite of common runtime dependencies for all platforms
There is a newer version: 15.8.1
package io.ebeaninternal.server.profile;

import io.ebean.meta.MetricType;
import io.ebean.meta.MetricVisitor;
import io.ebeaninternal.metric.TimedMetric;

import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.LongAccumulator;
import java.util.concurrent.atomic.LongAdder;

/**
 * Used to collect timed execution statistics.
 * 
 * It is intended for high concurrent updates to the statistics and relatively infrequent reads.
 * 
 */
class DTimedMetric implements TimedMetric {

  private final MetricType metricType;

  private final String name;

  private final LongAdder beanCount = new LongAdder();

  private final LongAdder count = new LongAdder();

  private final LongAdder total = new LongAdder();

  private final LongAccumulator max = new LongAccumulator(Math::max, Long.MIN_VALUE);

  private final AtomicLong startTime = new AtomicLong(System.currentTimeMillis());

  DTimedMetric(MetricType metricType, String name) {
    this.metricType = metricType;
    this.name = name;
  }

  /**
   * Add a value. Usually the value is Time or Bytes etc.
   */
  @Override
  public void add(long value) {

    count.increment();
    total.add(value);
    max.accumulate(value);
  }

  @Override
  public void add(long micros, long beans) {
    add(micros);
    beanCount.add(beans);
  }

  @Override
  public boolean isEmpty() {
    return count.sum() == 0;
  }

  /**
   * Reset all the internal counters and start time.
   */
  @Override
  public void reset() {
    startTime.set(System.currentTimeMillis());
    max.reset();
    count.reset();
    total.reset();
    beanCount.reset();
  }

  @Override
  public void visit(MetricVisitor visitor) {
    DTimeMetricStats metric = collect(visitor.isReset());
    if (metric != null) {
      visitor.visitTimed(metric);
    }
  }

  @Override
  public DTimeMetricStats collect(boolean reset) {
    boolean empty = count.sum() == 0;
    if (empty) {
      if (reset) {
        startTime.set(System.currentTimeMillis());
      }
      return null;
    } else {
      return getStatistics(reset);
    }
  }

  /**
   * Return the current statistics resetting the internal values if reset is true.
   */
  private DTimeMetricStats getStatistics(boolean reset) {

    if (reset) {
      // Note these values are not guaranteed to be consistent wrt each other
      // but should be reasonably consistent (small time between count and total)
      final long beans = beanCount.sumThenReset();
      final long maxVal = max.getThenReset();
      final long totalVal = total.sumThenReset();
      final long countVal = count.sumThenReset();
      final long startTimeVal = startTime.getAndSet(System.currentTimeMillis());
      return new DTimeMetricStats(metricType, name, startTimeVal, countVal, totalVal, maxVal, beans);

    } else {
      return new DTimeMetricStats(metricType, name, startTime.get(), count.sum(), total.sum(), max.get(), beanCount.sum());
    }
  }

}