Add some more Duration and Instant helper utils (#139)

* Add some more Duration helpers.

* Add Duration.toMicros() / toRoundedMicros() / toRoundedMillis().

* Add some helpers for Instant.

* Avoid using `Number` for helper functions that cast to Long.

The results are unexpected and undesirable for Float and Double.

src/main/kotlin/org/jitsi/utils/Duration.kt

@@ -17,28 +17,110 @@
 package org.jitsi.utils
 
 import java.time.Duration
+import java.time.temporal.ChronoUnit
 
 /**
- * Helpers to create instance of [Duration] more easily
+ * Helpers to create instances of [Duration] more easily, and Kotlin operators for it
  */
 
-val Number.nanos: Duration
+val Int.nanos: Duration
     get() = Duration.ofNanos(this.toLong())
 
-val Number.ms: Duration
+val Int.micros: Duration
+    get() = Duration.of(this.toLong(), ChronoUnit.MICROS)
+
+val Int.ms: Duration
     get() = Duration.ofMillis(this.toLong())
 
-val Number.secs: Duration
+val Int.secs: Duration
     get() = Duration.ofSeconds(this.toLong())
 
-val Number.hours: Duration
+val Int.hours: Duration
     get() = Duration.ofHours(this.toLong())
 
-val Number.mins: Duration
+val Int.mins: Duration
     get() = Duration.ofMinutes(this.toLong())
 
-val Number.days: Duration
+val Int.days: Duration
     get() = Duration.ofDays(this.toLong())
 
-operator fun Duration.times(x: Int): Duration = Duration.ofNanos(toNanos() * x)
+val Long.nanos: Duration
+    get() = Duration.ofNanos(this)
+
+val Long.micros: Duration
+    get() = Duration.of(this, ChronoUnit.MICROS)
+
+val Long.ms: Duration
+    get() = Duration.ofMillis(this)
+
+val Long.secs: Duration
+    get() = Duration.ofSeconds(this)
+
+val Long.hours: Duration
+    get() = Duration.ofHours(this)
+
+val Long.mins: Duration
+    get() = Duration.ofMinutes(this)
+
+val Long.days: Duration
+    get() = Duration.ofDays(this)
+
+operator fun Duration.times(x: Int): Duration = this.multipliedBy(x.toLong())
+operator fun Duration.times(x: Long): Duration = this.multipliedBy(x)
+
+operator fun Int.times(x: Duration): Duration = x.multipliedBy(this.toLong())
+operator fun Long.times(x: Duration): Duration = x.multipliedBy(this)
+
 operator fun Duration.div(other: Duration): Double = toNanos().toDouble() / other.toNanos()
+
+/** Converts this duration to the total length in milliseconds, rounded to nearest. */
+fun Duration.toRoundedMillis(): Long {
+    var millis = this.toMillis()
+    val remainder = nano % NANOS_PER_MILLI
+    if (remainder > 499_999) {
+        millis++
+    }
+    return millis
+}
+
+/**
+ * Converts this duration to the total length in microseconds.
+ *
+ * If this duration is too large to fit in a `long` microseconds, then an
+ * exception is thrown.
+ *
+ * If this duration has greater than microseconds precision, then the conversion
+ * will drop any excess precision information as though the amount in nanoseconds
+ * was subject to integer division by one thousand.
+ *
+ * @return the total length of the duration in microseconds
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+fun Duration.toMicros(): Long {
+    var tempSeconds: Long = seconds
+    var tempNanos: Long = nano.toLong()
+    if (tempSeconds < 0) {
+        // change the seconds and nano value to
+        // handle Long.MIN_VALUE case
+        tempSeconds += 1
+        tempNanos -= NANOS_PER_SECOND
+    }
+    var micros = Math.multiplyExact(tempSeconds, MICROS_PER_SECOND)
+    micros = Math.addExact(micros, tempNanos / NANOS_PER_MICRO)
+    return micros
+}
+
+/** Converts this duration to the total length in microseconds, rounded to nearest. */
+fun Duration.toRoundedMicros(): Long {
+    var micros = this.toMicros()
+    val remainder = nano % NANOS_PER_MICRO
+    if (remainder > 499) {
+        micros++
+    }
+    return micros
+}
+
+private const val NANOS_PER_MICRO = 1_000
+private const val NANOS_PER_MILLI = 1_000_000
+private const val MICROS_PER_SECOND = 1_000_000
+private const val NANOS_PER_SECOND = 1_000_000_000

src/main/kotlin/org/jitsi/utils/Instant.kt

@@ -0,0 +1,65 @@
+/*
+ * Copyright @ 2018 - present 8x8, Inc.
+ *
+ * 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 org.jitsi.utils
+
+import java.time.Instant
+
+/**
+ * Helpers to create instances of [Instant] more easily, and Kotlin operators for it
+ */
+
+/**
+ * Converts this instant to the number of microseconds from the epoch
+ * of 1970-01-01T00:00:00Z.
+ *
+ *
+ * If this instant represents a point on the time-line too far in the future
+ * or past to fit in a `long` microseconds, then an exception is thrown.
+ *
+ * If this instant has greater than microseconds precision, then the conversion
+ * will drop any excess precision information as though the amount in nanoseconds
+ * was subject to integer division by one thousand.
+ *
+ * @return the number of microseconds since the epoch of 1970-01-01T00:00:00Z
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+fun Instant.toEpochMicro(): Long {
+    if (epochSecond < 0 && nano > 0) {
+        val millis = Math.multiplyExact(epochSecond + 1, 1_000_000).toLong()
+        val adjustment: Long = (nano / 1_000 - 1).toLong()
+        return Math.addExact(millis, adjustment)
+    } else {
+        val millis = Math.multiplyExact(epochSecond, 1_000_000).toLong()
+        return Math.addExact(millis, (nano / 1000).toLong())
+    }
+}
+
+/**
+ * Obtains an instance of {@code Instant} using microseconds from the
+ * epoch of 1970-01-01T00:00:00Z.
+ * <p>
+ * The seconds and nanoseconds are extracted from the specified microseconds.
+ *
+ * @param epochMicro  the number of microseconds from 1970-01-01T00:00:00Z
+ * @return an instant, not null
+ * @throws DateTimeException if the instant exceeds the maximum or minimum instant
+ */
+fun instantOfEpochMicro(epochMicro: Long): Instant {
+    val secs = Math.floorDiv(epochMicro, 1_000_000)
+    val mos = Math.floorMod(epochMicro, 1_000_000).toLong()
+    return Instant.ofEpochSecond(secs, mos * 1000)
+}

src/test/kotlin/org/jitsi/utils/DurationTest.kt

@@ -24,14 +24,29 @@ class DurationTest : ShouldSpec() {
     init {
         context("the duration helpers should work") {
             5.nanos shouldBe Duration.ofNanos(5)
+            5.micros shouldBe Duration.ofNanos(5_000)
             5.ms shouldBe Duration.ofMillis(5)
             5.secs shouldBe Duration.ofSeconds(5)
             5.mins shouldBe Duration.ofMinutes(5)
             5.hours shouldBe Duration.ofHours(5)
             5.days shouldBe Duration.ofDays(5)
 
             1.days * 2 shouldBe Duration.ofDays(2)
+            2 * 4.hours shouldBe Duration.ofHours(8)
             10.days / 2.days shouldBe 5.0
+            5.hours / 2.hours shouldBe 2.5
+
+            4.ms.toMicros() shouldBe 4000
+            2200.nanos.toMicros() shouldBe 2
+            2900.nanos.toMicros() shouldBe 2
+
+            2200.nanos.toRoundedMicros() shouldBe 2
+            2500.nanos.toRoundedMicros() shouldBe 3
+            2900.nanos.toRoundedMicros() shouldBe 3
+
+            2200.micros.toRoundedMillis() shouldBe 2
+            2500.micros.toRoundedMillis() shouldBe 3
+            2900.micros.toRoundedMillis() shouldBe 3
         }
     }
 }

src/test/kotlin/org/jitsi/utils/InstantTest.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright @ 2018 - present 8x8, Inc.
+ *
+ * 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 org.jitsi.utils
+
+import io.kotest.core.spec.style.ShouldSpec
+import io.kotest.matchers.shouldBe
+import java.time.Instant
+
+class InstantTest : ShouldSpec() {
+    init {
+        context("The instant helpers should work") {
+            Instant.ofEpochMilli(123).toEpochMicro() shouldBe 123000L
+            instantOfEpochMicro(123456).toEpochMilli() shouldBe 123L
+            instantOfEpochMicro(123987).toEpochMilli() shouldBe 123L
+        }
+    }
+}