Unit System v2 (#243)

* Separated `Time` unit into `TimeDelta` and `TimeStamp` + small fixes

Addition and subtruction between `Timestamp`s is not allowed, but any
other `Unit` operation/comparison is. `TimeDelta`s can be
added/subtructed to/form `Timestamp`s.

Deserialization of `Timestamp`:
- `Number` -> interpreted as millis from Epoch
- `Instant` (string representation) -> converted to Timestamp
- `Duration` (string representation) -> interpreted as duration since
  Epoch (warn msg is logged)

Deserialization of `TimeDelta` is the same as `Time` was before, with the
diference that when an `Instant` is converted to an timedelta since Epoch
a warning message is logged.

* Unit System v2

- Merged `BoundedPercentage` and `UnboundedPercentage`
- Overrided all operation defined in `Unit` in all subclasses to avoid
  as much as possible value classes being boxed in bytecode. If units are used as generics
  (hence also functions defined in Unit<T>) they are boxed (as double would if used as generic).
- All units companions now subclass `UnitId`, and can be used as keys
  (e.g `Map<UnitId, idk>`), while offering `max` `min` and `zero`
  methods.
- Division between the same unit now returns `Percentage`
- Added `Iterable<T>.averageOfUnitOrNull(selector (T) -> <specific unit>)`
- `ifNeg0ThenPos0()` now is optional and not invoked on every
  constructor
- Now methods in `Unit<T>` are all abstract, forcing override and avoid
  boxing in some cases
- Added `@UnintendedOperation` and `UnitOperationException` for methods
  that must be defined but are not intended for use (e.g. `Timestamp` +
  `Timestamp`)

1 files changed, 277 insertions, 0 deletions

diff --git a/opendc-common/src/main/kotlin/org/opendc/common/units/TimeDelta.kt b/opendc-common/src/main/kotlin/org/opendc/common/units/TimeDelta.kt
new file mode 100644
index 00000000..9f3857a8
--- /dev/null
+++ b/opendc-common/src/main/kotlin/org/opendc/common/units/TimeDelta.kt
@@ -0,0 +1,277 @@
+/*
+ * Copyright (c) 2024 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+@file:OptIn(InternalUse::class, NonInlinableUnit::class)
+
+package org.opendc.common.units
+
+import kotlinx.serialization.Serializable
+import org.opendc.common.annotations.InternalUse
+import org.opendc.common.utils.DFLT_MIN_EPS
+import org.opendc.common.utils.approx
+import org.opendc.common.utils.approxLarger
+import org.opendc.common.utils.approxLargerOrEq
+import org.opendc.common.utils.approxSmaller
+import org.opendc.common.utils.approxSmallerOrEq
+import org.opendc.common.utils.ifNeg0thenPos0
+import java.time.Duration
+import java.time.Instant
+import kotlin.text.RegexOption.IGNORE_CASE
+
+/**
+ * Represents time interval values.
+ * @see[Unit]
+ */
+@JvmInline
+@Serializable(with = TimeDelta.Companion.TimeDeltaSerializer::class)
+public value class TimeDelta private constructor(
+    // In milliseconds.
+    public override val value: Double,
+) : Unit<TimeDelta> {
+    override fun toString(): String = fmtValue()
+
+    override fun fmtValue(fmt: String): String = Duration.ofMillis(value.toLong()).toString()
+
+    // //////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // Conversions to Double
+    // //////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+    public fun toNs(): Double = value * 1e6
+
+    public fun toMicros(): Double = value * 1e3
+
+    public fun toMs(): Double = value
+
+    public fun toMsLong(): Long = value.toLong()
+
+    public fun toSec(): Double = value / 1000.0
+
+    public fun toMin(): Double = toSec() / 60
+
+    public fun toHours(): Double = toMin() / 60
+
+    // //////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // Operation Override (to avoid boxing of value classes in byte code)
+    // //////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+    public override fun ifNeg0ThenPos0(): TimeDelta = TimeDelta(value.ifNeg0thenPos0())
+
+    public override operator fun plus(other: TimeDelta): TimeDelta = TimeDelta(value + other.value)
+
+    public override operator fun minus(other: TimeDelta): TimeDelta = TimeDelta(value - other.value)
+
+    public override operator fun div(scalar: Number): TimeDelta = TimeDelta(value / scalar.toDouble())
+
+    public override operator fun div(other: TimeDelta): Percentage = Percentage.ofRatio(value / other.value)
+
+    public override operator fun times(scalar: Number): TimeDelta = TimeDelta(value * scalar.toDouble())
+
+    public override operator fun times(percentage: Percentage): TimeDelta = TimeDelta(value * percentage.value)
+
+    public override operator fun unaryMinus(): TimeDelta = TimeDelta(-value)
+
+    public override operator fun compareTo(other: TimeDelta): Int = this.value.compareTo(other.value)
+
+    public override fun isZero(): Boolean = value == .0
+
+    public override fun approxZero(epsilon: Double): Boolean = value.approx(.0, epsilon = epsilon)
+
+    public override fun approx(
+        other: TimeDelta,
+        minEpsilon: Double,
+        epsilon: Double,
+    ): Boolean = this == other || this.value.approx(other.value, minEpsilon, epsilon)
+
+    public override infix fun approx(other: TimeDelta): Boolean = approx(other, minEpsilon = DFLT_MIN_EPS)
+
+    public override fun approxLarger(
+        other: TimeDelta,
+        minEpsilon: Double,
+        epsilon: Double,
+    ): Boolean = this.value.approxLarger(other.value, minEpsilon, epsilon)
+
+    public override infix fun approxLarger(other: TimeDelta): Boolean = approxLarger(other, minEpsilon = DFLT_MIN_EPS)
+
+    public override fun approxLargerOrEq(
+        other: TimeDelta,
+        minEpsilon: Double,
+        epsilon: Double,
+    ): Boolean = this.value.approxLargerOrEq(other.value, minEpsilon, epsilon)
+
+    public override infix fun approxLargerOrEq(other: TimeDelta): Boolean = approxLargerOrEq(other, minEpsilon = DFLT_MIN_EPS)
+
+    public override fun approxSmaller(
+        other: TimeDelta,
+        minEpsilon: Double,
+        epsilon: Double,
+    ): Boolean = this.value.approxSmaller(other.value, minEpsilon, epsilon)
+
+    public override infix fun approxSmaller(other: TimeDelta): Boolean = approxSmaller(other, minEpsilon = DFLT_MIN_EPS)
+
+    public override fun approxSmallerOrEq(
+        other: TimeDelta,
+        minEpsilon: Double,
+        epsilon: Double,
+    ): Boolean = this.value.approxSmallerOrEq(other.value, minEpsilon, epsilon)
+
+    public override infix fun approxSmallerOrEq(other: TimeDelta): Boolean = approxSmallerOrEq(other, minEpsilon = DFLT_MIN_EPS)
+
+    public override infix fun max(other: TimeDelta): TimeDelta = if (this.value > other.value) this else other
+
+    public override infix fun min(other: TimeDelta): TimeDelta = if (this.value < other.value) this else other
+
+    public override fun abs(): TimeDelta = TimeDelta(kotlin.math.abs(value))
+
+    public override fun roundToIfWithinEpsilon(
+        to: TimeDelta,
+        epsilon: Double,
+    ): TimeDelta =
+        if (this.value in (to.value - epsilon)..(to.value + epsilon)) {
+            to
+        } else {
+            this
+        }
+
+    public fun max(
+        a: TimeDelta,
+        b: TimeDelta,
+    ): TimeDelta = if (a.value > b.value) a else b
+
+    public fun min(
+        a: TimeDelta,
+        b: TimeDelta,
+    ): TimeDelta = if (a.value < b.value) a else b
+
+    // //////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // Unit Specific Operations
+    // //////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+    public fun toInstantFromEpoch(): Instant = Instant.ofEpochMilli(value.toLong())
+
+    public operator fun times(power: Power): Energy = Energy.ofWh(toHours() * power.toWatts())
+
+    public operator fun times(dataRate: DataRate): DataSize = DataSize.ofKB(toSec() * dataRate.toKBps())
+
+    public companion object : UnitId<TimeDelta> {
+        @JvmStatic override val zero: TimeDelta = TimeDelta(.0)
+
+        @JvmStatic override val max: TimeDelta = TimeDelta(Double.MAX_VALUE)
+
+        @JvmStatic override val min: TimeDelta = TimeDelta(Double.MIN_VALUE)
+
+        public operator fun Number.times(unit: TimeDelta): TimeDelta = unit * this
+
+        @JvmStatic
+        @JvmName("ofNanos")
+        public fun ofNanos(nanos: Number): TimeDelta = TimeDelta(nanos.toDouble() / 1e6)
+
+        @JvmStatic
+        @JvmName("ofMicros")
+        public fun ofMicros(micros: Number): TimeDelta = TimeDelta(micros.toDouble() / 1e3)
+
+        @JvmStatic
+        @JvmName("ofMillis")
+        public fun ofMillis(ms: Number): TimeDelta = TimeDelta(ms.toDouble())
+
+        @JvmStatic
+        @JvmName("ofSec")
+        public fun ofSec(sec: Number): TimeDelta = TimeDelta(sec.toDouble() * 1000.0)
+
+        @JvmStatic
+        @JvmName("ofMin")
+        public fun ofMin(min: Number): TimeDelta = TimeDelta(min.toDouble() * 60 * 1000.0)
+
+        @JvmStatic
+        @JvmName("ofHours")
+        public fun ofHours(hours: Number): TimeDelta = TimeDelta(hours.toDouble() * 60 * 60 * 1000.0)
+
+        @JvmStatic
+        @JvmName("ofDuration")
+        public fun ofDuration(duration: Duration): TimeDelta = duration.toTimeDelta()
+
+        // //////////////////////////////////////////////////////////////////////////////////////////////////////////////
+        // Serializer
+        // //////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+        /**
+         * Serializer for [TimeDelta] value class. It needs to be a compile
+         * time constant to be used as serializer automatically,
+         * hence `object :` instead of class instantiation.
+         *
+         * ```json
+         * // e.g.
+         * "timedelta": "10 hours"
+         * "timedelta": "  30    minutes   "
+         * "timedelta": "1 ms"
+         * "timedelta": "PT13H"
+         * // etc.
+         * ```
+         */
+        internal object TimeDeltaSerializer : UnitSerializer<TimeDelta>(
+            ifNumber = {
+                LOG.warn(
+                    "deserialization of number with no unit of measure, assuming it is in milliseconds." +
+                        "Keep in mind that you can also specify the value as '$it ms'",
+                )
+                ofMillis(it.toDouble())
+            },
+            serializerFun = { this.encodeString(it.toString()) },
+            ifMatches("$NUM_GROUP$NANO$SEC(?:|s)\\s*", IGNORE_CASE) { ofNanos(json.decNumFromStr(groupValues[1])) },
+            ifMatches("$NUM_GROUP$MICRO$SEC(?:|s)\\s*", IGNORE_CASE) { ofMicros(json.decNumFromStr(groupValues[1])) },
+            ifMatches("$NUM_GROUP$MILLI$SEC(?:|s)\\s*", IGNORE_CASE) { ofMillis(json.decNumFromStr(groupValues[1])) },
+            ifMatches("$NUM_GROUP$SEC(?:|s)\\s*", IGNORE_CASE) { ofSec(json.decNumFromStr(groupValues[1])) },
+            ifMatches("$NUM_GROUP$MIN(?:|s)\\s*") { ofMin(json.decNumFromStr(groupValues[1])) },
+            ifMatches("$NUM_GROUP$HOUR(?:|s)\\s*") { ofHours(json.decNumFromStr(groupValues[1])) },
+            ifNoExc { ofDuration(Duration.parse(this)) },
+            ifNoExc {
+                val instant = Instant.parse(this)
+                LOG.warn("`TimeDelta` value was expected but `Instant` string representation found. Converting to `TimeDelta` since Epoch")
+
+                ofMillis(instant.toEpochMilli())
+            },
+        )
+
+        /**
+         * @return [this] converted to a [TimeDelta] value, with the highest possible accuracy.
+         *
+         * @throws RuntimeException if [this] cannot be represented as nanos, millis, seconds, minutes or hours with a [Long].
+         */
+        public fun Duration.toTimeDelta(): TimeDelta {
+            fun tryNoThrow(block: () -> TimeDelta?) =
+                try {
+                    block()
+                } catch (_: Exception) {
+                    null
+                }
+
+            return tryNoThrow { ofNanos(this.toNanos()) }
+                ?: tryNoThrow { ofMillis(this.toMillis()) }
+                ?: tryNoThrow { ofSec(this.toSeconds()) }
+                ?: tryNoThrow { ofMin(this.toMinutes()) }
+                ?: tryNoThrow { ofHours(this.toHours()) }
+                ?: throw RuntimeException(
+                    "duration $this cannot be converted to ${TimeDelta::class.simpleName}, " +
+                        "duration value overflow Long representation of nanos, millis, seconds, minutes and hours",
+                )
+        }
+    }
+}