Function hook

packages/effect/src/internal/metric.ts:132–151

(extraTags: ReadonlyArray<MetricLabel.MetricLabel>)

  const hookCache = new WeakMap<ReadonlyArray<MetricLabel.MetricLabel>, MetricHook.MetricHook<any, any>>()

  const hook = (extraTags: ReadonlyArray<MetricLabel.MetricLabel>): MetricHook.MetricHook<
    MetricKeyType.MetricKeyType.InType<Type>,
    MetricKeyType.MetricKeyType.OutType<Type>
  > => {
    if (extraTags.length === 0) {
      if (untaggedHook !== undefined) {
        return untaggedHook
      }
      untaggedHook = globalMetricRegistry.get(key)
      return untaggedHook
    }

    let hook = hookCache.get(extraTags)
    if (hook !== undefined) {
      return hook
    }
    hook = globalMetricRegistry.get(metricKey.taggedWithLabels(key, extraTags))
    hookCache.set(extraTags, hook)
    return hook
  }

  return make(
    key.keyType,