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/*
* =========================================================================================
* 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
/**
* A UnitOfMeasurement implementation describes the magnitude of a quantity being measured, such as Time and computer
* Memory space. Kamon uses UnitOfMeasurement implementations just as a informative companion to metrics inside entity
* recorders and might be used to scale certain kinds of measurements in metric backends.
*/
trait UnitOfMeasurement {
type U <: UnitOfMeasurement
def name: String
def label: String
def scale(toUnit: U)(value: Double): Double = value
def tryScale(toUnit: UnitOfMeasurement)(value: Double): Double =
if (canScale(toUnit)) scale(toUnit.asInstanceOf[U])(value)
else throw new IllegalArgumentException(s"Can't scale different types of units `$name` and `${toUnit.name}`")
protected def canScale(toUnit: UnitOfMeasurement): Boolean
}
object UnitOfMeasurement {
case object Unknown extends UnitOfMeasurement {
override type U = Unknown.type
val name = "unknown"
val label = "unknown"
override protected def canScale(toUnit: UnitOfMeasurement): Boolean = UnitOfMeasurement.isUnknown(toUnit)
}
def isUnknown(uom: UnitOfMeasurement): Boolean =
uom == Unknown
def isTime(uom: UnitOfMeasurement): Boolean =
uom.isInstanceOf[Time]
def isMemory(uom: UnitOfMeasurement): Boolean =
uom.isInstanceOf[Memory]
}
/**
* UnitOfMeasurement representing time.
*/
case class Time(factor: Double, label: String) extends UnitOfMeasurement {
override type U = Time
val name = "time"
override def scale(toUnit: Time)(value: Double): Double =
(value * factor) / toUnit.factor
override protected def canScale(toUnit: UnitOfMeasurement): Boolean = UnitOfMeasurement.isTime(toUnit)
}
object Time {
val Nanoseconds = Time(1E-9, "n")
val Microseconds = Time(1E-6, "µs")
val Milliseconds = Time(1E-3, "ms")
val Seconds = Time(1, "s")
val units = List(Nanoseconds, Microseconds, Milliseconds, Seconds)
def apply(time: String): Time = units.find(_.label.toLowerCase == time.toLowerCase) getOrElse {
throw new IllegalArgumentException(s"Can't recognize time unit '$time'")
}
}
/**
* UnitOfMeasurement representing computer memory space.
*/
case class Memory(factor: Double, label: String) extends UnitOfMeasurement {
override type U = Memory
val name = "bytes"
override def scale(toUnit: Memory)(value: Double): Double =
(value * factor) / toUnit.factor
override protected def canScale(toUnit: UnitOfMeasurement): Boolean = UnitOfMeasurement.isMemory(toUnit)
}
object Memory {
val Bytes = Memory(1, "b")
val KiloBytes = Memory(1024, "Kb")
val MegaBytes = Memory(1024 * 1024, "Mb")
val GigaBytes = Memory(1024 * 1024 * 1024, "Gb")
val units = List(Bytes, KiloBytes, MegaBytes, GigaBytes)
def apply(memory: String): Memory = units.find(_.label.toLowerCase == memory.toLowerCase) getOrElse {
throw new IllegalArgumentException(s"Can't recognize memory unit '$memory'")
}
}
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