diff options
Diffstat (limited to 'kamon-core/src/legacy-main/scala/kamon/trace/Sampler.scala')
-rw-r--r-- | kamon-core/src/legacy-main/scala/kamon/trace/Sampler.scala | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/kamon-core/src/legacy-main/scala/kamon/trace/Sampler.scala b/kamon-core/src/legacy-main/scala/kamon/trace/Sampler.scala new file mode 100644 index 00000000..234c67bb --- /dev/null +++ b/kamon-core/src/legacy-main/scala/kamon/trace/Sampler.scala @@ -0,0 +1,101 @@ +/* + * ========================================================================================= + * Copyright © 2013-2014 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.trace + +import java.net.InetAddress +import java.util.concurrent.atomic.AtomicLong +import kamon.util.{NanoTimestamp, NanoInterval, Sequencer} +import scala.concurrent.forkjoin.ThreadLocalRandom + +import scala.util.Try + +trait Sampler { + def shouldTrace: Boolean + def shouldReport(traceElapsedTime: NanoInterval): Boolean +} + +object NoSampling extends Sampler { + def shouldTrace: Boolean = false + def shouldReport(traceElapsedTime: NanoInterval): Boolean = false +} + +object SampleAll extends Sampler { + def shouldTrace: Boolean = true + def shouldReport(traceElapsedTime: NanoInterval): Boolean = true +} + +class RandomSampler(chance: Int) extends Sampler { + require(chance > 0, "kamon.trace.random-sampler.chance cannot be <= 0") + require(chance <= 100, "kamon.trace.random-sampler.chance cannot be > 100") + + def shouldTrace: Boolean = ThreadLocalRandom.current().nextInt(100) <= chance + def shouldReport(traceElapsedTime: NanoInterval): Boolean = true +} + +class OrderedSampler(interval: Int) extends Sampler { + import OrderedSampler._ + + require(interval > 0, "kamon.trace.ordered-sampler.sample-interval cannot be <= 0") + assume(interval isPowerOfTwo, "kamon.trace.ordered-sampler.sample-interval must be power of two") + + private val sequencer = Sequencer() + + def shouldTrace: Boolean = (sequencer.next() fastMod interval) == 0 + def shouldReport(traceElapsedTime: NanoInterval): Boolean = true +} + +object OrderedSampler { + implicit class EnhancedInt(i: Int) { + def isPowerOfTwo = (i & (i - 1)) == 0 + } + + implicit class EnhancedLong(dividend: Long) { + def fastMod(divisor: Int) = dividend & (divisor - 1) + } +} + +class ThresholdSampler(thresholdInNanoseconds: NanoInterval) extends Sampler { + require(thresholdInNanoseconds.nanos > 0, "kamon.trace.threshold-sampler.minimum-elapsed-time cannot be <= 0") + + def shouldTrace: Boolean = true + def shouldReport(traceElapsedTime: NanoInterval): Boolean = traceElapsedTime >= thresholdInNanoseconds +} + +class ClockSampler(pauseInNanoseconds: NanoInterval) extends Sampler { + require(pauseInNanoseconds.nanos > 0, "kamon.trace.clock-sampler.pause cannot be <= 0") + + private val timer: AtomicLong = new AtomicLong(0L) + + def shouldTrace: Boolean = { + val now = NanoTimestamp.now.nanos + val lastTimer = timer.get() + if ((lastTimer + pauseInNanoseconds.nanos) < now) + timer.compareAndSet(lastTimer, now) + else + false + } + def shouldReport(traceElapsedTime: NanoInterval): Boolean = true +} + +class DefaultTokenGenerator extends Function0[String] { + private val _hostnamePrefix = Try(InetAddress.getLocalHost.getHostName).getOrElse("unknown-localhost") + private val _tokenCounter = new AtomicLong + + def apply(): String = { + _hostnamePrefix + "-" + String.valueOf(_tokenCounter.incrementAndGet()) + } +}
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