From 98bb980c5354021376ac0223a8946fb3a99c94cc Mon Sep 17 00:00:00 2001
From: Chip Kent <chipkent@deephaven.io>
Date: Mon, 20 May 2024 13:18:26 -0600
Subject: [PATCH] Added functions to multiply durations and periods.

---
 .../java/io/deephaven/time/DateTimeUtils.java | 61 +++++++++++++++++++
 .../io/deephaven/time/TestDateTimeUtils.java  | 25 ++++++++
 2 files changed, 86 insertions(+)

diff --git a/engine/time/src/main/java/io/deephaven/time/DateTimeUtils.java b/engine/time/src/main/java/io/deephaven/time/DateTimeUtils.java
index 934ebcc6c0a..ea06842f56e 100644
--- a/engine/time/src/main/java/io/deephaven/time/DateTimeUtils.java
+++ b/engine/time/src/main/java/io/deephaven/time/DateTimeUtils.java
@@ -1871,6 +1871,67 @@ public static long minus(@Nullable final ZonedDateTime dateTime1, @Nullable fina
         return checkUnderflowMinus(epochNanos(dateTime1), epochNanos(dateTime2), true);
     }
 
+    /**
+     * Multiply a duration by a scalar.
+     *
+     * @param duration the duration to multiply
+     * @param scalar the scalar to multiply by
+     * @return {@code null} if either input is {@code null}; otherwise the duration multiplied by the scalar
+     */
+    public static Duration multiply(final Duration duration, final long scalar) {
+        if (duration == null || scalar == NULL_LONG) {
+            return null;
+        }
+
+        return duration.multipliedBy(scalar);
+    }
+
+    /**
+     * Multiply a duration by a scalar.
+     *
+     * @param duration the duration to multiply
+     * @param scalar the scalar to multiply by
+     * @return {@code null} if either input is {@code null}; otherwise the duration multiplied by the scalar
+     */
+    public static Duration multiply(final long scalar, final Duration duration) {
+        if (duration == null || scalar == NULL_LONG) {
+            return null;
+        }
+
+        return duration.multipliedBy(scalar);
+    }
+
+    /**
+     * Multiply a period by a scalar.
+     *
+     * @param period the period to multiply
+     * @param scalar the scalar to multiply by
+     * @return {@code null} if either input is {@code null}; otherwise the period multiplied by the scalar
+     */
+    public static Period multiply(final Period period, final int scalar) {
+        if (period == null || scalar == NULL_INT) {
+            return null;
+        }
+
+        return period.multipliedBy(scalar);
+    }
+
+    /**
+     * Multiply a period by a scalar.
+     *
+     * @param period the period to multiply
+     * @param scalar the scalar to multiply by
+     * @return {@code null} if either input is {@code null}; otherwise the period multiplied by the scalar
+     */
+    public static Period multiply(final int scalar, final Period period) {
+        if (period == null || scalar == NULL_INT) {
+            return null;
+        }
+
+        return period.multipliedBy(scalar);
+    }
+
+
     /**
      * Returns the difference in nanoseconds between two instant values.
      *
diff --git a/engine/time/src/test/java/io/deephaven/time/TestDateTimeUtils.java b/engine/time/src/test/java/io/deephaven/time/TestDateTimeUtils.java
index 68bf3c51a26..b3d583b3e98 100644
--- a/engine/time/src/test/java/io/deephaven/time/TestDateTimeUtils.java
+++ b/engine/time/src/test/java/io/deephaven/time/TestDateTimeUtils.java
@@ -2347,6 +2347,31 @@ public void testMinus() {
 
     }
 
+    public void testMultiply() {
+        final Period p = Period.ofDays(3);
+        final Duration d = Duration.ofNanos(123456789L);
+
+        TestCase.assertEquals(Period.ofDays(6), DateTimeUtils.multiply(p, 2));
+        TestCase.assertEquals(Period.ofDays(9), DateTimeUtils.multiply(p, 3));
+        TestCase.assertEquals(Period.ofDays(3), DateTimeUtils.multiply(p, 1));
+        TestCase.assertEquals(Period.ofDays(0), DateTimeUtils.multiply(p, 0));
+        TestCase.assertEquals(Period.ofDays(-3), DateTimeUtils.multiply(p, -1));
+        TestCase.assertEquals(Period.ofDays(-6), DateTimeUtils.multiply(p, -2));
+        TestCase.assertEquals(Period.ofDays(-9), DateTimeUtils.multiply(p, -3));
+        TestCase.assertNull(DateTimeUtils.multiply((Period) null, 3));
+        TestCase.assertNull(DateTimeUtils.multiply(p, NULL_INT));
+
+        TestCase.assertEquals(Duration.ofNanos(246913578L), DateTimeUtils.multiply(d, 2));
+        TestCase.assertEquals(Duration.ofNanos(370370367L), DateTimeUtils.multiply(d, 3));
+        TestCase.assertEquals(Duration.ofNanos(123456789L), DateTimeUtils.multiply(d, 1));
+        TestCase.assertEquals(Duration.ofNanos(0), DateTimeUtils.multiply(d, 0));
+        TestCase.assertEquals(Duration.ofNanos(-123456789L), DateTimeUtils.multiply(d, -1));
+        TestCase.assertEquals(Duration.ofNanos(-246913578L), DateTimeUtils.multiply(d, -2));
+        TestCase.assertEquals(Duration.ofNanos(-370370367L), DateTimeUtils.multiply(d, -3));
+        TestCase.assertNull(DateTimeUtils.multiply((Duration) null, 3));
+        TestCase.assertNull(DateTimeUtils.multiply(d, NULL_LONG));
+    }
+
     public void testDiffNanos() {
         final Instant i1 = DateTimeUtils.epochNanosToInstant(12345678987654321L);
         final Instant i2 = DateTimeUtils.epochNanosToInstant(98765432123456789L);