content: /*
   * 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 com.datastax.oss.driver.internal.metrics.micrometer;
  
  import com.datastax.oss.driver.api.core.config.DefaultDriverOption;
  import com.datastax.oss.driver.api.core.config.DriverExecutionProfile;
  import com.datastax.oss.driver.api.core.config.DriverOption;
  import com.datastax.oss.driver.internal.core.context.InternalDriverContext;
  import com.datastax.oss.driver.internal.core.metrics.AbstractMetricUpdater;
  import com.datastax.oss.driver.internal.core.metrics.MetricId;
  import edu.umd.cs.findbugs.annotations.Nullable;
  import io.micrometer.core.instrument.Counter;
  import io.micrometer.core.instrument.DistributionSummary;
  import io.micrometer.core.instrument.Gauge;
  import io.micrometer.core.instrument.Meter;
  import io.micrometer.core.instrument.MeterRegistry;
  import io.micrometer.core.instrument.Tag;
  import io.micrometer.core.instrument.Timer;
  import java.util.List;
  import java.util.Set;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  import java.util.concurrent.TimeUnit;
  import java.util.function.Supplier;
  import net.jcip.annotations.ThreadSafe;
  
  @ThreadSafe
  public abstract class MicrometerMetricUpdater<MetricT> extends AbstractMetricUpdater<MetricT> {
  
    protected final MeterRegistry registry;
  
    protected final ConcurrentMap<MetricT, Meter> metrics = new ConcurrentHashMap<>();
  
    protected MicrometerMetricUpdater(
        InternalDriverContext context, Set<MetricT> enabledMetrics, MeterRegistry registry) {
      super(context, enabledMetrics);
      this.registry = registry;
    }
  
    @Override
    public void incrementCounter(MetricT metric, @Nullable String profileName, long amount) {
      if (isEnabled(metric, profileName)) {
        getOrCreateCounterFor(metric).increment(amount);
      }
    }
  
    @Override
    public void updateHistogram(MetricT metric, @Nullable String profileName, long value) {
      if (isEnabled(metric, profileName)) {
        getOrCreateDistributionSummaryFor(metric).record(value);
      }
    }
  
    @Override
    public void markMeter(MetricT metric, @Nullable String profileName, long amount) {
      if (isEnabled(metric, profileName)) {
        // There is no meter type in Micrometer, so use a counter
        getOrCreateCounterFor(metric).increment(amount);
      }
    }
  
    @Override
    public void updateTimer(
        MetricT metric, @Nullable String profileName, long duration, TimeUnit unit) {
      if (isEnabled(metric, profileName)) {
        getOrCreateTimerFor(metric).record(duration, unit);
      }
    }
  
    @Override
    public void clearMetrics() {
      for (Meter metric : metrics.values()) {
        registry.remove(metric);
      }
      metrics.clear();
    }
  
    protected abstract MetricId getMetricId(MetricT metric);
  
    protected void initializeGauge(
        MetricT metric, DriverExecutionProfile profile, Supplier<Number> supplier) {
      if (isEnabled(metric, profile.getName())) {
        metrics.computeIfAbsent(
            metric,
            m -> {
              MetricId id = getMetricId(m);
              Iterable<Tag> tags = MicrometerTags.toMicrometerTags(id.getTags());
              return Gauge.builder(id.getName(), supplier).tags(tags).register(registry);
            });
      }
    }
  
    protected void initializeCounter(MetricT metric, DriverExecutionProfile profile) {
      if (isEnabled(metric, profile.getName())) {
        getOrCreateCounterFor(metric);
      }
    }
  
    protected void initializeTimer(MetricT metric, DriverExecutionProfile profile) {
      if (isEnabled(metric, profile.getName())) {
        getOrCreateTimerFor(metric);
      }
    }
  
    protected Counter getOrCreateCounterFor(MetricT metric) {
      return (Counter)
          metrics.computeIfAbsent(
              metric,
              m -> {
                MetricId id = getMetricId(m);
                Iterable<Tag> tags = MicrometerTags.toMicrometerTags(id.getTags());
                return Counter.builder(id.getName()).tags(tags).register(registry);
              });
    }
  
    protected DistributionSummary getOrCreateDistributionSummaryFor(MetricT metric) {
      return (DistributionSummary)
          metrics.computeIfAbsent(
              metric,
              m -> {
                MetricId id = getMetricId(m);
                Iterable<Tag> tags = MicrometerTags.toMicrometerTags(id.getTags());
                DistributionSummary.Builder builder =
                    DistributionSummary.builder(id.getName()).tags(tags);
                builder = configureDistributionSummary(builder, metric, id);
                return builder.register(registry);
              });
    }
  
    protected Timer getOrCreateTimerFor(MetricT metric) {
      return (Timer)
          metrics.computeIfAbsent(
              metric,
              m -> {
                MetricId id = getMetricId(m);
                Iterable<Tag> tags = MicrometerTags.toMicrometerTags(id.getTags());
                Timer.Builder builder = Timer.builder(id.getName()).tags(tags);
                builder = configureTimer(builder, metric, id);
                return builder.register(registry);
              });
    }
  
    protected Timer.Builder configureTimer(Timer.Builder builder, MetricT metric, MetricId id) {
      DriverExecutionProfile profile = context.getConfig().getDefaultProfile();
      if (profile.getBoolean(DefaultDriverOption.METRICS_GENERATE_AGGREGABLE_HISTOGRAMS)) {
        builder.publishPercentileHistogram();
      }
      return builder;
    }
  
    @SuppressWarnings("unused")
    protected DistributionSummary.Builder configureDistributionSummary(
        DistributionSummary.Builder builder, MetricT metric, MetricId id) {
      DriverExecutionProfile profile = context.getConfig().getDefaultProfile();
      if (profile.getBoolean(DefaultDriverOption.METRICS_GENERATE_AGGREGABLE_HISTOGRAMS)) {
        builder.publishPercentileHistogram();
      }
      return builder;
    }
  
    static double[] toDoubleArray(List<Double> doubleList) {
      return doubleList.stream().mapToDouble(Double::doubleValue).toArray();
    }
  
    static void configurePercentilesPublishIfDefined(
        Timer.Builder builder, DriverExecutionProfile profile, DriverOption driverOption) {
      if (profile.isDefined(driverOption)) {
        builder.publishPercentiles(toDoubleArray(profile.getDoubleList(driverOption)));
      }
    }
  }
  