本文整理了Java中com.netflix.spectator.api.Utils.computeIfAbsent()方法的一些代码示例，展示了Utils.computeIfAbsent()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Utils.computeIfAbsent()方法的具体详情如下：
包路径：com.netflix.spectator.api.Utils
类名称：Utils
方法名：computeIfAbsent

Utils.computeIfAbsent介绍

[英]This method should be used instead of the ConcurrentMap#computeIfAbsent(Object,Function) call to minimize thread contention. This method does not require locking for the common case where the key exists, but potentially performs additional computation when absent.
[中]应该使用此方法，而不是ConcurrentMap#ComputeFabSent（对象、函数）调用，以最小化线程争用。对于存在密钥的常见情况，此方法不需要锁定，但在缺少密钥时可能会执行额外的计算。

代码示例

代码示例来源：origin: Netflix/spectator

/** Return the number of inflight requests associated with the given id. */
AtomicInteger inflightRequests(Id id) {
 return Utils.computeIfAbsent(inflightRequests, id, i -> new AtomicInteger());
}

代码示例来源：origin: com.netflix.spectator/spectator-ext-ipc

/** Return the number of inflight requests associated with the given id. */
AtomicInteger inflightRequests(Id id) {
 return Utils.computeIfAbsent(inflightRequests, id, i -> new AtomicInteger());
}

代码示例来源：origin: Netflix/spectator

/**
 * Return the cardinality limiter for a given key. This is used to protect the metrics
 * backend from a metrics explosion if some dimensions have a high cardinality.
 */
Function<String, String> limiterForKey(String key) {
 return Utils.computeIfAbsent(limiters, key, k -> CardinalityLimiters.mostFrequent(10));
}

代码示例来源：origin: Netflix/spectator

@Override public String apply(String s) {
 AtomicLong count = Utils.computeIfAbsent(values, s, k -> new AtomicLong(0L));
 long num = count.incrementAndGet();
 if (num >= cutoff) {
  updateCutoff();
  // cutoff may have been updated, double check it would still make the cut
  String v = limiter.apply(s);
  return num >= cutoff ? v : OTHERS;
 } else {
  return OTHERS;
 }
}

代码示例来源：origin: com.netflix.spectator/spectator-api

@Override public String apply(String s) {
 AtomicLong count = Utils.computeIfAbsent(values, s, k -> new AtomicLong(0L));
 long num = count.incrementAndGet();
 if (num >= cutoff) {
  updateCutoff();
  // cutoff may have been updated, double check it would still make the cut
  String v = limiter.apply(s);
  return num >= cutoff ? v : OTHERS;
 } else {
  return OTHERS;
 }
}

代码示例来源：origin: com.netflix.spectator/spectator-ext-ipc

/**
 * Return the cardinality limiter for a given key. This is used to protect the metrics
 * backend from a metrics explosion if some dimensions have a high cardinality.
 */
Function<String, String> limiterForKey(String key) {
 return Utils.computeIfAbsent(limiters, key, k -> CardinalityLimiters.mostFrequent(10));
}

代码示例来源：origin: Netflix/spectator

@Override public DistributionSummary distributionSummary(Id id) {
 return Utils.computeIfAbsent(distSummaries, id,
   i -> new SwapDistributionSummary(this, i, newDistributionSummary(i)));
}

代码示例来源：origin: Netflix/spectator

@Override public Gauge gauge(Id id) {
 return Utils.computeIfAbsent(gauges, id, i -> new SwapGauge(this, i, newGauge(i)));
}

代码示例来源：origin: com.netflix.spectator/spectator-api

@Override public Timer timer(Id id) {
 return Utils.computeIfAbsent(timers, id, i -> new SwapTimer(this, i, newTimer(i)));
}

代码示例来源：origin: Netflix/spectator

@Override public Counter counter(Id id) {
 return Utils.computeIfAbsent(counters, id, i -> new SwapCounter(this, i, newCounter(i)));
}

代码示例来源：origin: Netflix/spectator

@Override public Gauge maxGauge(Id id) {
 return Utils.computeIfAbsent(gauges, id, i -> new SwapGauge(this, i, newMaxGauge(i)));
}

代码示例来源：origin: Netflix/spectator

@Override public Timer timer(Id id) {
 return Utils.computeIfAbsent(timers, id, i -> new SwapTimer(this, i, newTimer(i)));
}

代码示例来源：origin: com.netflix.spectator/spectator-api

@Override public DistributionSummary distributionSummary(Id id) {
 return Utils.computeIfAbsent(distSummaries, id,
   i -> new SwapDistributionSummary(this, i, newDistributionSummary(i)));
}

代码示例来源：origin: com.netflix.spectator/spectator-api

@Override public Gauge gauge(Id id) {
 return Utils.computeIfAbsent(gauges, id, i -> new SwapGauge(this, i, newGauge(i)));
}

代码示例来源：origin: com.netflix.spectator/spectator-api

@Override public Counter counter(Id id) {
 return Utils.computeIfAbsent(counters, id, i -> new SwapCounter(this, i, newCounter(i)));
}

代码示例来源：origin: com.netflix.spectator/spectator-api

@Override public Gauge maxGauge(Id id) {
 return Utils.computeIfAbsent(gauges, id, i -> new SwapGauge(this, i, newMaxGauge(i)));
}

代码示例来源：origin: Netflix/spectator

/**
 * Provided for backwards compatibility to support the {@link Registry#register(Meter)}
 * method. Use the builder created with {@link #using(Registry)} instead.
 *
 * @deprecated This method only exists to allow for backwards compatibility and should
 * be considered an internal detail. Scheduled to be removed in 2.0.
 */
@Deprecated
public static void monitorMeter(Registry registry, Meter meter) {
 ConcurrentMap<Id, Object> state = registry.state();
 Object c = Utils.computeIfAbsent(state, meter.id(), MeterState::new);
 if (!(c instanceof MeterState)) {
  Utils.propagateTypeError(registry, meter.id(), MeterState.class, c.getClass());
 } else {
  MeterState t = (MeterState) c;
  t.add(meter);
  long delay = registry.config().gaugePollingFrequency().toMillis();
  t.schedule(registry, null, delay);
 }
}

代码示例来源：origin: com.netflix.spectator/spectator-api

/**
 * Provided for backwards compatibility to support the {@link Registry#register(Meter)}
 * method. Use the builder created with {@link #using(Registry)} instead.
 *
 * @deprecated This method only exists to allow for backwards compatibility and should
 * be considered an internal detail. Scheduled to be removed in 2.0.
 */
@Deprecated
public static void monitorMeter(Registry registry, Meter meter) {
 ConcurrentMap<Id, Object> state = registry.state();
 Object c = Utils.computeIfAbsent(state, meter.id(), MeterState::new);
 if (!(c instanceof MeterState)) {
  Utils.propagateTypeError(registry, meter.id(), MeterState.class, c.getClass());
 } else {
  MeterState t = (MeterState) c;
  t.add(meter);
  long delay = registry.config().gaugePollingFrequency().toMillis();
  t.schedule(registry, null, delay);
 }
}

代码示例来源：origin: com.netflix.spectator/spectator-api

/**
 * Create a new instance.
 *
 * @param registry
 *    Registry to use.
 * @param id
 *    Identifier for the metric being registered.
 * @return
 *    Counter instance.
 */
public static IntervalCounter get(Registry registry, Id id) {
 ConcurrentMap<Id, Object> state = registry.state();
 Object c = Utils.computeIfAbsent(state, id, i -> new IntervalCounter(registry, i));
 if (!(c instanceof IntervalCounter)) {
  Utils.propagateTypeError(registry, id, IntervalCounter.class, c.getClass());
  c = new IntervalCounter(new NoopRegistry(), id);
 }
 return (IntervalCounter) c;
}

代码示例来源：origin: Netflix/spectator

/**
 * Create a new instance.
 *
 * @param registry
 *    Registry to use.
 * @param id
 *    Identifier for the metric being registered.
 * @return
 *    Counter instance.
 */
public static IntervalCounter get(Registry registry, Id id) {
 ConcurrentMap<Id, Object> state = registry.state();
 Object c = Utils.computeIfAbsent(state, id, i -> new IntervalCounter(registry, i));
 if (!(c instanceof IntervalCounter)) {
  Utils.propagateTypeError(registry, id, IntervalCounter.class, c.getClass());
  c = new IntervalCounter(new NoopRegistry(), id);
 }
 return (IntervalCounter) c;
}