Add TimeUnits, re #57

Author: safris

src/main/java/org/libj/util/concurrent/TimeUnits.java

@@ -0,0 +1,65 @@
+/* Copyright (c) 2024 LibJ
+ *
+ * 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.
+ *
+ * You should have received a copy of The MIT License (MIT) along with this
+ * program. If not, see <http://opensource.org/licenses/MIT/>.
+ */
+
+package org.libj.util.concurrent;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Utility functions for operations pertaining to the {@link java.time} package.
+ */
+public class TimeUnits {
+  /**
+   * Compares two pairs of time values represented by a {@code long} scalar at a {@link TimeUnit}. Returns a negative integer, zero,
+   * or a positive integer as the first time value object is less than, equal to, or greater than the second time value.
+   *
+   * @param time0 The scalar of first time value.
+   * @param unit0 The {@link TimeUnit} of the first time value.
+   * @param time1 The scalar of second time value.
+   * @param unit1 The {@link TimeUnit} of the second time value.
+   * @return A negative integer, zero, or a positive integer as the first time value object is less than, equal to, or greater than
+   *         the second time value.
+   * @throws NullPointerException If {@code unit0} or {@code unit1} is null.
+   */
+  public static int compare(long time0, final TimeUnit unit0, long time1, final TimeUnit unit1) {
+    final int sign;
+    if (time0 < 0) {
+      if (time1 >= 0)
+        return -1;
+
+      sign = -1;
+    }
+    else if (time0 > 0) {
+      if (time1 <= 0)
+        return 1;
+
+      sign = 1;
+    }
+    else {
+      return time1 == 0 ? 0 : time1 > 0 ? -1 : 1;
+    }
+
+    if (unit0 == unit1)
+      return sign * Long.compare(time0, time1);
+
+    if (unit0.compareTo(unit1) < 0)
+      time0 /= unit0.convert(1, unit1);
+    else
+      time1 /= unit1.convert(1, unit0);
+
+    return sign * Long.compare(time0, time1);
+  }
+}

src/test/java/org/libj/util/concurrent/TimeUnitsTest.java

@@ -0,0 +1,61 @@
+package org.libj.util.concurrent;
+
+import static org.junit.Assert.*;
+
+import java.util.concurrent.TimeUnit;
+
+import org.junit.Test;
+
+public class TimeUnitsTest {
+  private static final long[] values = {Long.MIN_VALUE, Integer.MIN_VALUE, Short.MIN_VALUE, Byte.MIN_VALUE, -1, 1, Byte.MAX_VALUE, Short.MAX_VALUE, Integer.MAX_VALUE, Long.MAX_VALUE};
+
+  private static void test(final TimeUnit unit0, final TimeUnit unit1) {
+    assertTrue(unit0.compareTo(unit1) < 0);
+    final long time1 = 1;
+    final long time0 = unit0.convert(time1, unit1);
+    assertEquals(0, TimeUnits.compare(time0, unit0, time1, unit1));
+    assertEquals(0, TimeUnits.compare(time1, unit1, time0, unit0));
+    for (long value : values) {
+      assertEquals(1, TimeUnits.compare(value, unit1, value, unit0));
+      assertEquals(-1, TimeUnits.compare(value, unit0, value, unit1));
+    }
+  }
+
+  @Test
+  public void test() {
+    assertEquals(0, TimeUnits.compare(Long.MAX_VALUE, TimeUnit.MILLISECONDS, Long.MAX_VALUE, TimeUnit.MILLISECONDS));
+    assertEquals(0, TimeUnits.compare(Long.MAX_VALUE, TimeUnit.MICROSECONDS, Long.MAX_VALUE, TimeUnit.MICROSECONDS));
+    assertEquals(0, TimeUnits.compare(Long.MAX_VALUE, TimeUnit.NANOSECONDS, Long.MAX_VALUE, TimeUnit.NANOSECONDS));
+
+    assertEquals(0, TimeUnits.compare(Long.MAX_VALUE, TimeUnit.SECONDS, Long.MAX_VALUE, TimeUnit.SECONDS));
+    assertEquals(1, TimeUnits.compare(Long.MAX_VALUE, TimeUnit.SECONDS, Long.MAX_VALUE - 1, TimeUnit.SECONDS));
+    assertEquals(-1, TimeUnits.compare(Long.MAX_VALUE - 1, TimeUnit.SECONDS, Long.MAX_VALUE, TimeUnit.SECONDS));
+
+    test(TimeUnit.HOURS, TimeUnit.DAYS);
+
+    test(TimeUnit.MINUTES, TimeUnit.HOURS);
+    test(TimeUnit.MINUTES, TimeUnit.DAYS);
+
+    test(TimeUnit.SECONDS, TimeUnit.MINUTES);
+    test(TimeUnit.SECONDS, TimeUnit.HOURS);
+    test(TimeUnit.SECONDS, TimeUnit.DAYS);
+
+    test(TimeUnit.MILLISECONDS, TimeUnit.SECONDS);
+    test(TimeUnit.MILLISECONDS, TimeUnit.MINUTES);
+    test(TimeUnit.MILLISECONDS, TimeUnit.HOURS);
+    test(TimeUnit.MILLISECONDS, TimeUnit.DAYS);
+
+    test(TimeUnit.MICROSECONDS, TimeUnit.MILLISECONDS);
+    test(TimeUnit.MICROSECONDS, TimeUnit.SECONDS);
+    test(TimeUnit.MICROSECONDS, TimeUnit.MINUTES);
+    test(TimeUnit.MICROSECONDS, TimeUnit.HOURS);
+    test(TimeUnit.MICROSECONDS, TimeUnit.DAYS);
+
+    test(TimeUnit.NANOSECONDS, TimeUnit.MICROSECONDS);
+    test(TimeUnit.NANOSECONDS, TimeUnit.MILLISECONDS);
+    test(TimeUnit.NANOSECONDS, TimeUnit.SECONDS);
+    test(TimeUnit.NANOSECONDS, TimeUnit.MINUTES);
+    test(TimeUnit.NANOSECONDS, TimeUnit.HOURS);
+    test(TimeUnit.NANOSECONDS, TimeUnit.DAYS);
+  }
+}