diff options
Diffstat (limited to 'kamon-core/src/main/scala/kamon/metric/instrument/Gauge.scala')
-rw-r--r-- | kamon-core/src/main/scala/kamon/metric/instrument/Gauge.scala | 120 |
1 files changed, 0 insertions, 120 deletions
diff --git a/kamon-core/src/main/scala/kamon/metric/instrument/Gauge.scala b/kamon-core/src/main/scala/kamon/metric/instrument/Gauge.scala deleted file mode 100644 index 39571d3d..00000000 --- a/kamon-core/src/main/scala/kamon/metric/instrument/Gauge.scala +++ /dev/null @@ -1,120 +0,0 @@ -/* - * ========================================================================================= - * Copyright © 2013-2015 the kamon project <http://kamon.io/> - * - * Licensed 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 kamon.metric.instrument - -import java.util.concurrent.atomic.{AtomicLong, AtomicLongFieldUpdater, AtomicReference} - -import akka.actor.Cancellable -import kamon.metric.instrument.Gauge.CurrentValueCollector -import kamon.metric.instrument.Histogram.DynamicRange - -import scala.concurrent.duration.FiniteDuration - -trait Gauge extends Instrument { - type SnapshotType = Histogram.Snapshot - - def record(value: Long): Unit - def record(value: Long, count: Long): Unit - def refreshValue(): Unit -} - -object Gauge { - - def apply(dynamicRange: DynamicRange, refreshInterval: FiniteDuration, scheduler: RefreshScheduler, valueCollector: CurrentValueCollector): Gauge = { - val underlyingHistogram = Histogram(dynamicRange) - val gauge = new HistogramBackedGauge(underlyingHistogram, valueCollector) - val refreshValuesSchedule = scheduler.schedule(refreshInterval, () ⇒ { - gauge.refreshValue() - }) - - gauge.automaticValueCollectorSchedule.set(refreshValuesSchedule) - gauge - } - - def create(dynamicRange: DynamicRange, refreshInterval: FiniteDuration, scheduler: RefreshScheduler, valueCollector: CurrentValueCollector): Gauge = - apply(dynamicRange, refreshInterval, scheduler, valueCollector) - - trait CurrentValueCollector { - def currentValue: Long - } - - implicit def functionZeroAsCurrentValueCollector(f: () ⇒ Long): CurrentValueCollector = new CurrentValueCollector { - def currentValue: Long = f.apply() - } - - implicit def callByNameLongAsCurrentValueCollector(f: ⇒ Long): CurrentValueCollector = new CurrentValueCollector { - def currentValue: Long = f - } -} - -/** - * Helper for cases in which a gauge shouldn't store the current value of a observed value but the difference between - * the current observed value and the previously observed value. Should only be used if the observed value is always - * increasing or staying steady, but is never able to decrease. - * - * Note: The first time a value is collected, this wrapper will always return zero, afterwards, the difference between - * the current value and the last value will be returned. - */ -class DifferentialValueCollector(wrappedValueCollector: CurrentValueCollector) extends CurrentValueCollector { - @volatile private var _readAtLeastOnce = false - private val _lastObservedValue = new AtomicLong(0) - - def currentValue: Long = { - if (_readAtLeastOnce) { - val wrappedCurrent = wrappedValueCollector.currentValue - val diff = wrappedCurrent - _lastObservedValue.getAndSet(wrappedCurrent) - - if (diff >= 0) diff else 0L - - } else { - _lastObservedValue.set(wrappedValueCollector.currentValue) - _readAtLeastOnce = true - 0L - } - - } -} - -object DifferentialValueCollector { - def apply(wrappedValueCollector: CurrentValueCollector): CurrentValueCollector = - new DifferentialValueCollector(wrappedValueCollector) - - def apply(wrappedValueCollector: ⇒ Long): CurrentValueCollector = - new DifferentialValueCollector(new CurrentValueCollector { - def currentValue: Long = wrappedValueCollector - }) -} - -class HistogramBackedGauge(underlyingHistogram: Histogram, currentValueCollector: Gauge.CurrentValueCollector) extends Gauge { - private[kamon] val automaticValueCollectorSchedule = new AtomicReference[Cancellable]() - - def record(value: Long): Unit = underlyingHistogram.record(value) - - def record(value: Long, count: Long): Unit = underlyingHistogram.record(value, count) - - def collect(context: CollectionContext): Histogram.Snapshot = underlyingHistogram.collect(context) - - def cleanup: Unit = { - if (automaticValueCollectorSchedule.get() != null) - automaticValueCollectorSchedule.get().cancel() - } - - def refreshValue(): Unit = - underlyingHistogram.record(currentValueCollector.currentValue) - -} - |