# HG changeset patch
# User cito
# Date 1574962218 -3600
# Node ID 43eee12379347bba49c34b5945a396473f773188
# Parent  b42eaca7d23406d6d038c556c68cfa959ad65191
8232594: Make the output of the JFR command duration more user friendly
Reviewed-by: egahlin, cito
Contributed-by: chiroito107@gmail.com, erik.gahlin@oracle.com

diff -r b42eaca7d234 -r 43eee1237934 src/jdk.jfr/share/classes/jdk/jfr/internal/Utils.java
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/Utils.java	Thu Nov 28 13:02:30 2019 +0000
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/Utils.java	Thu Nov 28 18:30:18 2019 +0100
@@ -45,6 +45,7 @@
 import java.time.Duration;
 import java.time.Instant;
 import java.time.LocalDateTime;
+import java.time.temporal.ChronoUnit;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -78,6 +79,17 @@
     private static Boolean SAVE_GENERATED;
 
 
+    private static final Duration MICRO_SECOND = Duration.ofNanos(1_000);
+    private static final Duration SECOND = Duration.ofSeconds(1);
+    private static final Duration MINUTE = Duration.ofMinutes(1);
+    private static final Duration HOUR = Duration.ofHours(1);
+    private static final Duration DAY = Duration.ofDays(1);
+    private static final int NANO_SIGNIFICANT_FIGURES = 9;
+    private static final int MILL_SIGNIFICANT_FIGURES = 3;
+    private static final int DISPLAY_NANO_DIGIT = 3;
+    private static final int BASE = 10;
+
+
     public static void checkAccessFlightRecorder() throws SecurityException {
         SecurityManager sm = System.getSecurityManager();
         if (sm != null) {
@@ -597,6 +609,90 @@
         return "hotspot-" + "pid-" + pid + idText + "-" + date + ".jfr";
     }
 
+    public static String formatDuration(Duration d) {
+        Duration roundedDuration = roundDuration(d);
+        if (roundedDuration.equals(Duration.ZERO)) {
+            return "0 s";
+        } else if(roundedDuration.isNegative()){
+            return "-" + formatPositiveDuration(roundedDuration.abs());
+        } else {
+            return formatPositiveDuration(roundedDuration);
+        }
+    }
+
+    private static String formatPositiveDuration(Duration d){
+        if (d.compareTo(MICRO_SECOND) < 0) {
+            // 0.000001 ms - 0.000999 ms
+            double outputMs = (double) d.toNanosPart() / 1_000_000;
+            return String.format("%.6f ms",  outputMs);
+        } else if (d.compareTo(SECOND) < 0) {
+            // 0.001 ms - 999 ms
+            int valueLength = countLength(d.toNanosPart());
+            int outputDigit = NANO_SIGNIFICANT_FIGURES - valueLength;
+            double outputMs = (double) d.toNanosPart() / 1_000_000;
+            return String.format("%." + outputDigit + "f ms",  outputMs);
+        } else if (d.compareTo(MINUTE) < 0) {
+            // 1.00 s - 59.9 s
+            int valueLength = countLength(d.toSecondsPart());
+            int outputDigit = MILL_SIGNIFICANT_FIGURES - valueLength;
+            double outputSecond = d.toSecondsPart() + (double) d.toMillisPart() / 1_000;
+            return String.format("%." + outputDigit + "f s",  outputSecond);
+        } else if (d.compareTo(HOUR) < 0) {
+            // 1 m 0 s - 59 m 59 s
+            return String.format("%d m %d s",  d.toMinutesPart(), d.toSecondsPart());
+        } else if (d.compareTo(DAY) < 0) {
+            // 1 h 0 m - 23 h 59 m
+            return String.format("%d h %d m",  d.toHoursPart(), d.toMinutesPart());
+        } else {
+            // 1 d 0 h -
+            return String.format("%d d %d h",  d.toDaysPart(), d.toHoursPart());
+        }
+    }
+
+    private static int countLength(long value){
+        return (int) Math.log10(value) + 1;
+    }
+
+    private static Duration roundDuration(Duration d) {
+        if (d.equals(Duration.ZERO)) {
+            return d;
+        } else if(d.isNegative()){
+            Duration roundedPositiveDuration = roundPositiveDuration(d.abs());
+            return roundedPositiveDuration.negated();
+        } else {
+            return roundPositiveDuration(d);
+        }
+    }
+
+    private static Duration roundPositiveDuration(Duration d){
+        if (d.compareTo(MICRO_SECOND) < 0) {
+            // No round
+            return d;
+        } else if (d.compareTo(SECOND) < 0) {
+            // Round significant figures to three digits
+            int valueLength = countLength(d.toNanosPart());
+            int roundValue = (int) Math.pow(BASE, valueLength - DISPLAY_NANO_DIGIT);
+            long roundedNanos = Math.round((double) d.toNanosPart() / roundValue) * roundValue;
+            return d.truncatedTo(ChronoUnit.SECONDS).plusNanos(roundedNanos);
+        } else if (d.compareTo(MINUTE) < 0) {
+            // Round significant figures to three digits
+            int valueLength = countLength(d.toSecondsPart());
+            int roundValue = (int) Math.pow(BASE, valueLength);
+            long roundedMills = Math.round((double) d.toMillisPart() / roundValue) * roundValue;
+            return d.truncatedTo(ChronoUnit.SECONDS).plusMillis(roundedMills);
+        } else if (d.compareTo(HOUR) < 0) {
+            // Round for more than 500 ms or less
+            return d.plusMillis(SECOND.dividedBy(2).toMillisPart()).truncatedTo(ChronoUnit.SECONDS);
+        } else if (d.compareTo(DAY) < 0) {
+            // Round for more than 30 seconds or less
+            return d.plusSeconds(MINUTE.dividedBy(2).toSecondsPart()).truncatedTo(ChronoUnit.MINUTES);
+        } else {
+            // Round for more than 30 minutes or less
+            return d.plusMinutes(HOUR.dividedBy(2).toMinutesPart()).truncatedTo(ChronoUnit.HOURS);
+        }
+    }
+
+
     public static void takeNap(long millis) {
         try {
             Thread.sleep(millis);
diff -r b42eaca7d234 -r 43eee1237934 src/jdk.jfr/share/classes/jdk/jfr/internal/tool/PrettyWriter.java
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/PrettyWriter.java	Thu Nov 28 13:02:30 2019 +0000
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/tool/PrettyWriter.java	Thu Nov 28 18:30:18 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -57,9 +57,6 @@
  * This class is also used by {@link RecordedObject#toString()}
  */
 public final class PrettyWriter extends EventPrintWriter {
-    private static final Duration MILLSECOND = Duration.ofMillis(1);
-    private static final Duration SECOND = Duration.ofSeconds(1);
-    private static final Duration MINUTE = Duration.ofMinutes(1);
     private static final String TYPE_OLD_OBJECT = Type.TYPES_PREFIX + "OldObject";
     private final static DateTimeFormatter TIME_FORMAT = DateTimeFormatter.ofPattern("HH:mm:ss.SSS");
     private final static Long ZERO = 0L;
@@ -553,15 +550,7 @@
                 println("N/A");
                 return true;
             }
-            if(d.compareTo(MILLSECOND) < 0){
-                println(String.format("%.3f us", (double)d.toNanos() / 1_000));
-            } else if(d.compareTo(SECOND) < 0){
-                println(String.format("%.3f ms", (double)d.toNanos() / 1_000_000));
-            } else if(d.compareTo(MINUTE) < 0){
-                println(String.format("%.3f s", (double)d.toMillis() / 1_000));
-            } else {
-                println(String.format("%d s", d.toSeconds()));
-            }
+            println(Utils.formatDuration(d));
             return true;
         }
         if (value instanceof OffsetDateTime) {
diff -r b42eaca7d234 -r 43eee1237934 test/jdk/jdk/jfr/jvm/TestFormatDuration.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/jdk/jfr/jvm/TestFormatDuration.java	Thu Nov 28 18:30:18 2019 +0100
@@ -0,0 +1,173 @@
+/*
+ * Copyright (c) 2019, 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package jdk.jfr.jvm;
+
+import jdk.jfr.internal.Utils;
+import jdk.test.lib.Asserts;
+
+import java.time.Duration;
+import java.util.Locale;
+
+/**
+ * @test
+ * @key jfr
+ * @requires vm.hasJFR
+ * @library /test/lib
+ * @modules jdk.jfr/jdk.jfr.internal
+ * @run main/othervm jdk.jfr.jvm.TestFormatDuration
+ */
+public class TestFormatDuration {
+    public static void main(String[] args) throws Exception{
+        Locale.setDefault(Locale.US);
+
+        // Nanoseconds
+        assertDuration("0 ns   ", "0 s");
+        assertDuration("1 ns   ", "0.000001 ms");
+        assertDuration("10 ns  ", "0.000010 ms");
+        assertDuration("100 ns ", "0.000100 ms");
+        assertDuration("999 ns ", "0.000999 ms");
+        assertDuration("1000 ns", "0.00100 ms");
+        assertDuration("1004 ns", "0.00100 ms");
+        assertDuration("1005 ns", "0.00101 ms");
+
+        // 10 us
+        assertDuration("9 us 994 ns", "0.00999 ms");
+        assertDuration("9 us 995 ns", "0.0100 ms");
+        assertDuration("10 us      ", "0.0100 ms");
+        assertDuration("10 us 49 ns", "0.0100 ms");
+        assertDuration("10 us 50 ns", "0.0101 ms");
+
+        // 100 us
+        assertDuration("99 us 949 ns ", "0.0999 ms");
+        assertDuration("99 us 950 ns ", "0.100 ms");
+        assertDuration("100 us       ", "0.100 ms");
+        assertDuration("100 us 499 ns", "0.100 ms");
+        assertDuration("100 us 500 ns", "0.101 ms");
+
+        // 1 ms
+        assertDuration("999 us 499 ns       ", "0.999 ms");
+        assertDuration("999 us 500 ns       ", "1.00 ms");
+        assertDuration("1 ms                ", "1.00 ms");
+        assertDuration("1 ms 4 us 999 ns    ", "1.00 ms");
+        assertDuration("1 ms 5 us", "1.01 ms");
+
+        // 10 ms
+        assertDuration("9 ms 994 us 999 ns", "9.99 ms");
+        assertDuration("9 ms 995 us       ", "10.0 ms");
+        assertDuration("10 ms             ", "10.0 ms");
+        assertDuration("10 ms 49 us 999 ns", "10.0 ms");
+        assertDuration("10 ms 50 us 999 ns", "10.1 ms");
+
+        // 100 ms
+        assertDuration("99 ms 949 us 999 ns ", "99.9 ms");
+        assertDuration("99 ms 950 us 000 ns ", "100 ms");
+        assertDuration("100 ms              ", "100 ms");
+        assertDuration("100 ms 499 us 999 ns", "100 ms");
+        assertDuration("100 ms 500 us       ", "101 ms");
+
+        // 1 second
+        assertDuration("999 ms 499 us 999 ns  ", "999 ms");
+        assertDuration("999 ms 500 us         ", "1.00 s");
+        assertDuration("1 s                   ", "1.00 s");
+        assertDuration("1 s 4 ms 999 us 999 ns", "1.00 s");
+        assertDuration("1 s 5 ms              ", "1.01 s");
+
+        // 10 seconds
+        assertDuration("9 s 994 ms 999 us 999 ns ", "9.99 s");
+        assertDuration("9 s 995 ms               ", "10.0 s");
+        assertDuration("10 s                     ", "10.0 s");
+        assertDuration("10 s 049 ms 999 us 999 ns", "10.0 s");
+        assertDuration("10 s 050 ms              ", "10.1 s");
+
+        // 1 minute
+        assertDuration("59 s 949 ms 999 us 999 ns", "59.9 s");
+        assertDuration("59 s 950 ms              ", "1 m 0 s");
+        assertDuration("1 m 0 s                  ", "1 m 0 s");
+        assertDuration("60 s 499 ms 999 us 999 ns", "1 m 0 s");
+        assertDuration("60 s 500 ms              ", "1 m 1 s");
+
+        // 10 minutes
+        assertDuration("10 m 0 s", "10 m 0 s");
+
+        // 1 hour
+        assertDuration("59 m 59 s 499 ms 999 us 999 ns", "59 m 59 s");
+        assertDuration("59 m 59 s 500 ms              ", "1 h 0 m");
+        assertDuration("1 h 0 m                       ", "1 h 0 m");
+        assertDuration("1 h 29 s 999 ms 999 us 999 ns ", "1 h 0 m");
+        assertDuration("1 h 30 s                      ", "1 h 1 m");
+
+        // 1 day
+        assertDuration("23 h 59 m 29 s 999 ms 999 us 999 ns", "23 h 59 m");
+        assertDuration("23 h 59 m 30 s                     ", "1 d 0 h");
+        assertDuration("1 d 0 h                            ", "1 d 0 h");
+        assertDuration("1 d 29 m 59 s 999 ms 999 us 999 ns ", "1 d 0 h");
+        assertDuration("1 d 30 m                           ", "1 d 1 h");
+
+        // 100 days
+        assertDuration("100 d 13 h", "100 d 13 h");
+
+        // 1000 days
+        assertDuration("1000 d 13 h", "1000 d 13 h");
+    }
+
+    private static void assertDuration(String value, String expected) throws Exception {
+        long nanos = parse(value);
+        System.out.println(value + " == " + expected + " ? (" + nanos + " ns) ");
+        Asserts.assertEquals(Utils.formatDuration(Duration.ofNanos(nanos)), expected);
+        if (nanos != 0) {
+            Asserts.assertEquals(Utils.formatDuration(Duration.ofNanos(-nanos)), "-" + expected);
+        }
+    }
+
+
+    private static long parse(String duration) throws Exception {
+        String[] t = duration.trim().split(" ");
+        long nanos = 0;
+        for (int i = 0; i < t.length - 1; i += 2) {
+            nanos += Long.parseLong(t[i]) * parseUnit(t[i + 1]);
+        }
+        return nanos;
+    }
+
+    private static long parseUnit(String unit) throws Exception {
+        switch (unit) {
+            case "ns":
+                return 1L;
+            case "us":
+                return 1_000L;
+            case "ms":
+                return 1_000_000L;
+            case "s":
+                return 1_000_000_000L;
+            case "m":
+                return 60 * 1_000_000_000L;
+            case "h":
+                return 3600 * 1_000_000_000L;
+            case "d":
+                return 24 * 3600 * 1_000_000_000L;
+        }
+        throw new Exception("Test error. Unknown unit " + unit);
+    }
+}