com.github.benmanes.caffeine.cache.stats.StatsCounter Java Examples

@Test
public void recordStats_twice() {
  Supplier<StatsCounter> supplier = () -> statsCounter;
  Runnable[] tasks = {
      () -> Caffeine.newBuilder().recordStats().recordStats(),
      () -> Caffeine.newBuilder().recordStats(supplier).recordStats(),
      () -> Caffeine.newBuilder().recordStats().recordStats(supplier),
      () -> Caffeine.newBuilder().recordStats(supplier).recordStats(supplier),
  };
  for (Runnable task : tasks) {
    try {
      task.run();
      Assert.fail();
    } catch (IllegalStateException expected) {}
  }
}
 

public void testEmptySimpleStats() {
  StatsCounter counter = new ConcurrentStatsCounter();
  CacheStats stats = counter.snapshot();
  assertEquals(0, stats.requestCount());
  assertEquals(0, stats.hitCount());
  assertEquals(1.0, stats.hitRate(), 0.0);
  assertEquals(0, stats.missCount());
  assertEquals(0.0, stats.missRate(), 0.0);
  assertEquals(0, stats.loadSuccessCount());
  assertEquals(0, stats.loadFailureCount());
  assertEquals(0, stats.loadCount());
  assertEquals(0, stats.totalLoadTime());
  assertEquals(0.0, stats.averageLoadPenalty(), 0.0);
  assertEquals(0, stats.evictionCount());
}
 

public void testSingleSimpleStats() {
  StatsCounter counter = new ConcurrentStatsCounter();
  for (int i = 0; i < 11; i++) {
    counter.recordHits(1);
  }
  for (int i = 0; i < 13; i++) {
    counter.recordLoadSuccess(i);
  }
  for (int i = 0; i < 17; i++) {
    counter.recordLoadFailure(i);
  }
  for (int i = 0; i < 23; i++) {
    counter.recordMisses(1);
  }
  for (int i = 0; i < 27; i++) {
    counter.recordEviction(1, RemovalCause.SIZE);
  }
  CacheStats stats = counter.snapshot();
  int requestCount = 11 + 23;
  assertEquals(requestCount, stats.requestCount());
  assertEquals(11, stats.hitCount());
  assertEquals(11.0 / requestCount, stats.hitRate(), 0.0);
  int missCount = 23;
  assertEquals(missCount, stats.missCount());
  assertEquals(((double) missCount) / requestCount, stats.missRate(), 0.0);
  assertEquals(13, stats.loadSuccessCount());
  assertEquals(17, stats.loadFailureCount());
  assertEquals(13 + 17, stats.loadCount());
  assertEquals(214, stats.totalLoadTime());
  assertEquals(214.0 / (13 + 17), stats.averageLoadPenalty(), 0.0);
  assertEquals(27, stats.evictionCount());
}
 

public void testSimpleStatsOverflow() {
  StatsCounter counter = new ConcurrentStatsCounter();
  counter.recordLoadSuccess(Long.MAX_VALUE);
  counter.recordLoadSuccess(1);
  CacheStats stats = counter.snapshot();
  assertEquals(Long.MAX_VALUE, stats.totalLoadTime());
}
 

@Test
public void recordStats_custom() {
  Supplier<StatsCounter> supplier = () -> statsCounter;
  Caffeine<?, ?> builder = Caffeine.newBuilder().recordStats(supplier);
  builder.statsCounterSupplier.get().recordEviction(1, RemovalCause.SIZE);
  verify(statsCounter).recordEviction(1, RemovalCause.SIZE);
  builder.build();
}
 

@Override
public StatsCounter statsCounter() {
  return statsCounter;
}
 

/** Returns the {@link StatsCounter} used by this cache. */
@NonNull StatsCounter statsCounter();
 

@NonNull
Supplier<StatsCounter> getStatsCounterSupplier() {
  return (statsCounterSupplier == null)
      ? StatsCounter::disabledStatsCounter
      : statsCounterSupplier;
}
 

@Override
public StatsCounter statsCounter() {
  return StatsCounter.disabledStatsCounter();
}
 

/**
 * Enables the accumulation of {@link CacheStats} during the operation of the cache. Without this
 * {@link Cache#stats} will return zero for all statistics. Note that recording statistics
 * requires bookkeeping to be performed with each operation, and thus imposes a performance
 * penalty on cache operation. Any exception thrown by the supplied {@link StatsCounter} will be
 * suppressed and logged.
 *
 * @param statsCounterSupplier a supplier instance that returns a new {@link StatsCounter}
 * @return this {@code Caffeine} instance (for chaining)
 */
@NonNull
public Caffeine<K, V> recordStats(
    @NonNull Supplier<? extends StatsCounter> statsCounterSupplier) {
  requireState(this.statsCounterSupplier == null, "Statistics recording was already set");
  requireNonNull(statsCounterSupplier);
  this.statsCounterSupplier = () -> StatsCounter.guardedStatsCounter(statsCounterSupplier.get());
  return this;
}