crhumanize: add Duration

Author: RaduBerinde

crhumanize/duration.go

@@ -0,0 +1,45 @@
+//
+// 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 crhumanize
+
+import "time"
+
+// Duration returns a simplified approximation (±10%) of a duration, using a
+// single unit and showing at most one decimal.
+//
+// Examples: "500ms", "0.8s", "23.1m", "1.5h".
+func Duration(d time.Duration) SafeString {
+	// For very large durations, round to the nearest hour.
+	if d > 100*time.Hour {
+		d = d.Round(time.Hour)
+	}
+	unit, denom := func() (string, time.Duration) {
+		switch {
+		case d < 500*time.Nanosecond:
+			return "ns", time.Nanosecond
+		case d < 500*time.Microsecond:
+			return "µs", time.Microsecond
+		case d < 500*time.Millisecond:
+			return "ms", time.Millisecond
+		case d < time.Minute:
+			return "s", time.Second
+		case d < time.Hour:
+			return "m", time.Minute
+		default:
+			return "h", time.Hour
+		}
+	}()
+
+	return Float(float64(d)/float64(denom), 1) + SafeString(unit)
+}

crhumanize/duration_test.go

@@ -0,0 +1,59 @@
+// Copyright 2025 The Cockroach Authors.
+//
+// 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 crhumanize
+
+import (
+	"fmt"
+	"math/rand/v2"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/cockroachdb/crlib/crstrings"
+	"github.com/cockroachdb/crlib/internal/datadriven"
+)
+
+func TestDuration(t *testing.T) {
+	datadriven.RunTest(t, "testdata/duration", func(t *testing.T, td *datadriven.TestData) string {
+		if td.Cmd != "duration" {
+			td.Fatalf(t, "unknown command: %q", td.Cmd)
+		}
+		var buf strings.Builder
+		for _, l := range crstrings.Lines(td.Input) {
+			d, err := time.ParseDuration(l)
+			if err != nil {
+				td.Fatalf(t, "could not parse duration %q: %v", l, err)
+			}
+			fmt.Fprintf(&buf, "%s -> %s\n", d, Duration(d))
+		}
+		return buf.String()
+	})
+}
+
+func TestDurationError(t *testing.T) {
+	for _, v := range []time.Duration{time.Microsecond, time.Second, time.Minute, time.Hour, 100 * time.Hour, 10000 * time.Hour} {
+		for i := 0; i < 1000; i++ {
+			d := time.Duration(rand.Int64N(int64(v)))
+			s := string(Duration(d))
+			d1, err := time.ParseDuration(s)
+			if err != nil {
+				t.Fatalf("%s: could not parse duration %q: %v", d, s, err)
+			}
+			if d1 < 89*d/100 || d1 > 111*d/100 {
+				t.Fatalf("%s -> %s -> %s error is too large\n", d, s, d1)
+			}
+		}
+	}
+}

crhumanize/testdata/duration

@@ -0,0 +1,80 @@
+duration
+1ns
+12345ns
+123456ns
+1234567ns
+5ms
+500ms
+900ms
+1s
+1001ms
+1011ms
+1111ms
+1500ms
+----
+1ns -> 1ns
+12.345µs -> 12.3µs
+123.456µs -> 123.5µs
+1.234567ms -> 1.2ms
+5ms -> 5ms
+500ms -> 0.5s
+900ms -> 0.9s
+1s -> 1s
+1.001s -> 1s
+1.011s -> 1s
+1.111s -> 1.1s
+1.5s -> 1.5s
+
+
+duration
+15s
+30s
+31s
+45s
+59s
+60s
+61s
+66s
+90s
+119s
+121s
+40m20s
+----
+15s -> 15s
+30s -> 30s
+31s -> 31s
+45s -> 45s
+59s -> 59s
+1m0s -> 1m
+1m1s -> 1m
+1m6s -> 1.1m
+1m30s -> 1.5m
+1m59s -> 2m
+2m1s -> 2m
+40m20s -> 40.3m
+
+duration
+61m
+91m
+123m
+1234m
+12345m
+123456m
+1234567m
+12345678m
+123456789m
+----
+1h1m0s -> 1h
+1h31m0s -> 1.5h
+2h3m0s -> 2h
+20h34m0s -> 20.6h
+205h45m0s -> 206h
+2057h36m0s -> 2058h
+20576h7m0s -> 20576h
+205761h18m0s -> 205761h
+2057613h9m0s -> 2057613h
+
+duration
+1h15m13s
+----
+1h15m13s -> 1.3h