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 org.apache.bookkeeper.test;
  
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicLong;
  import java.util.function.BiConsumer;
  import org.apache.bookkeeper.stats.Counter;
  import org.apache.bookkeeper.stats.Gauge;
  import org.apache.bookkeeper.stats.OpStatsData;
  import org.apache.bookkeeper.stats.OpStatsLogger;
  import org.apache.bookkeeper.stats.StatsLogger;
  import org.apache.bookkeeper.stats.StatsProvider;
  import org.apache.commons.configuration2.Configuration;
  import org.apache.commons.lang3.StringUtils;
  
  /**
   * Simple in-memory stat provider for use in unit tests.
   */
  public class TestStatsProvider implements StatsProvider {
      /**
       * In-memory counter.
       */
      public class TestCounter implements Counter {
          private AtomicLong val = new AtomicLong(0);
          private AtomicLong max = new AtomicLong(0);
  
          @Override
          public void clear() {
              val.set(0);
          }
  
          @Override
          public void inc() {
              updateMax(val.incrementAndGet());
          }
  
          @Override
          public void dec() {
              val.decrementAndGet();
          }
  
          @Override
          public void addCount(long delta) {
              updateMax(val.addAndGet(delta));
          }
  
          @Override
          public void addLatency(long eventLatency, TimeUnit unit) {
              long valueMillis = unit.toMillis(eventLatency);
              updateMax(val.addAndGet(valueMillis));
          }
  
          @Override
          public Long get() {
              return val.get();
          }
  
          private void updateMax(long newVal) {
              while (true) {
                  long curMax = max.get();
                  if (curMax > newVal) {
                      break;
                  }
                  if (max.compareAndSet(curMax, newVal)) {
                      break;
                  }
              }
          }
  
          public Long getMax() {
              return max.get();
          }
      }
  
      /**
       * In-memory StatsLogger.
       */
      public class TestOpStatsLogger implements OpStatsLogger {
          private long successCount;
          private long successValue;
  
          private long failureCount;
          private long failureValue;
  
          TestOpStatsLogger() {
              clear();
          }
  
          @Override
          public void registerFailedEvent(long eventLatency, TimeUnit unit) {
              registerFailedValue(TimeUnit.NANOSECONDS.convert(eventLatency, unit));
          }
  
          @Override
          public void registerSuccessfulEvent(long eventLatency, TimeUnit unit) {
              registerSuccessfulValue(TimeUnit.NANOSECONDS.convert(eventLatency, unit));
          }
  
          @Override
          public synchronized void registerSuccessfulValue(long value) {
              successCount++;
              successValue += value;
          }
  
          @Override
          public synchronized void registerFailedValue(long value) {
              failureCount++;
              failureValue += value;
          }
  
          @Override
          public OpStatsData toOpStatsData() {
              // Not supported at this time
              return null;
          }
  
          @Override
          public synchronized void clear() {
              successCount = 0;
              successValue = 0;
              failureCount = 0;
              failureValue = 0;
          }
  
          public synchronized double getSuccessAverage() {
              if (successCount == 0) {
                  return 0;
              }
              return successValue / (double) successCount;
          }
  
          public synchronized long getSuccessCount() {
              return successCount;
          }
  
          public synchronized long getFailureCount() {
              return failureCount;
          }
      }
  
      /**
       * In-memory Logger.
       */
      public class TestStatsLogger implements StatsLogger {
          private String path;
  
          TestStatsLogger(String path) {
              this.path = path;
          }
  
          private String getSubPath(String name) {
              if (path.isEmpty()) {
                  return name;
              } else {
                  return path + "." + name;
              }
          }
  
          @Override
          public OpStatsLogger getOpStatsLogger(String name) {
              return TestStatsProvider.this.getOrCreateOpStatsLogger(getSubPath(name));
          }
  
          @Override
          public Counter getCounter(String name) {
              return TestStatsProvider.this.getOrCreateCounter(getSubPath(name));
          }
  
          public Gauge<? extends Number> getGauge(String name) {
              return gaugeMap.get(getSubPath(name));
          }
  
          @Override
          public <T extends Number> void registerGauge(String name, Gauge<T> gauge) {
              TestStatsProvider.this.registerGauge(getSubPath(name), gauge);
          }
  
          @Override
          public <T extends Number> void unregisterGauge(String name, Gauge<T> gauge) {
              TestStatsProvider.this.unregisterGauge(getSubPath(name), gauge);
          }
  
          @Override
          public StatsLogger scope(String name) {
              return new TestStatsLogger(getSubPath(name));
          }
  
          @Override
          public void removeScope(String name, StatsLogger statsLogger) {}
  
          @Override
          public OpStatsLogger getThreadScopedOpStatsLogger(String name) {
              return getOpStatsLogger(name);
          }
  
          @Override
          public Counter getThreadScopedCounter(String name) {
              return getCounter(name);
          }
      }
  
      @Override
      public void start(Configuration conf) {
      }
  
      @Override
      public void stop() {
      }
  
      private Map<String, TestOpStatsLogger> opStatLoggerMap = new ConcurrentHashMap<>();
      private Map<String, TestCounter> counterMap = new ConcurrentHashMap<>();
      private Map<String, Gauge<? extends Number>> gaugeMap = new ConcurrentHashMap<>();
  
      @Override
      public TestStatsLogger getStatsLogger(String scope) {
          return new TestStatsLogger(scope);
      }
  
      public TestOpStatsLogger getOpStatsLogger(String path) {
          return opStatLoggerMap.get(path);
      }
  
      public TestCounter getCounter(String path) {
          return counterMap.get(path);
      }
  
      public Gauge<? extends Number> getGauge(String path) {
          return gaugeMap.get(path);
      }
  
      public void forEachOpStatLogger(BiConsumer<String, TestOpStatsLogger> f) {
          for (Map.Entry<String, TestOpStatsLogger> entry : opStatLoggerMap.entrySet()) {
              f.accept(entry.getKey(), entry.getValue());
          }
      }
  
      public void clear() {
          for (TestOpStatsLogger logger : opStatLoggerMap.values()) {
              logger.clear();
          }
          for (TestCounter counter : counterMap.values()) {
              counter.clear();
          }
      }
  
      private TestOpStatsLogger getOrCreateOpStatsLogger(String path) {
          return opStatLoggerMap.computeIfAbsent(
                  path,
                  (String s) -> new TestOpStatsLogger());
      }
  
      private TestCounter getOrCreateCounter(String path) {
          return counterMap.computeIfAbsent(
                  path,
                  (String s) -> new TestCounter());
      }
  
      private <T extends Number> void registerGauge(String name, Gauge<T> gauge) {
          gaugeMap.put(name, gauge);
      }
  
      private <T extends Number> void unregisterGauge(String name, Gauge<T> gauge) {
          gaugeMap.remove(name, gauge);
      }
  
      @Override
      public String getStatsName(String... statsComponents) {
          if (statsComponents.length == 0) {
              return "";
          } else if (statsComponents[0].isEmpty()) {
              return StringUtils.join(statsComponents, '.', 1, statsComponents.length);
          } else {
              return StringUtils.join(statsComponents, '.');
          }
      }
  }
  