1// Copyright 2016 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package ptypes
6
7import (
8	"errors"
9	"fmt"
10	"time"
11
12	durationpb "github.com/golang/protobuf/ptypes/duration"
13)
14
15// Range of google.protobuf.Duration as specified in duration.proto.
16// This is about 10,000 years in seconds.
17const (
18	maxSeconds = int64(10000 * 365.25 * 24 * 60 * 60)
19	minSeconds = -maxSeconds
20)
21
22// Duration converts a durationpb.Duration to a time.Duration.
23// Duration returns an error if dur is invalid or overflows a time.Duration.
24func Duration(dur *durationpb.Duration) (time.Duration, error) {
25	if err := validateDuration(dur); err != nil {
26		return 0, err
27	}
28	d := time.Duration(dur.Seconds) * time.Second
29	if int64(d/time.Second) != dur.Seconds {
30		return 0, fmt.Errorf("duration: %v is out of range for time.Duration", dur)
31	}
32	if dur.Nanos != 0 {
33		d += time.Duration(dur.Nanos) * time.Nanosecond
34		if (d < 0) != (dur.Nanos < 0) {
35			return 0, fmt.Errorf("duration: %v is out of range for time.Duration", dur)
36		}
37	}
38	return d, nil
39}
40
41// DurationProto converts a time.Duration to a durationpb.Duration.
42func DurationProto(d time.Duration) *durationpb.Duration {
43	nanos := d.Nanoseconds()
44	secs := nanos / 1e9
45	nanos -= secs * 1e9
46	return &durationpb.Duration{
47		Seconds: int64(secs),
48		Nanos:   int32(nanos),
49	}
50}
51
52// validateDuration determines whether the durationpb.Duration is valid
53// according to the definition in google/protobuf/duration.proto.
54// A valid durpb.Duration may still be too large to fit into a time.Duration
55// Note that the range of durationpb.Duration is about 10,000 years,
56// while the range of time.Duration is about 290 years.
57func validateDuration(dur *durationpb.Duration) error {
58	if dur == nil {
59		return errors.New("duration: nil Duration")
60	}
61	if dur.Seconds < minSeconds || dur.Seconds > maxSeconds {
62		return fmt.Errorf("duration: %v: seconds out of range", dur)
63	}
64	if dur.Nanos <= -1e9 || dur.Nanos >= 1e9 {
65		return fmt.Errorf("duration: %v: nanos out of range", dur)
66	}
67	// Seconds and Nanos must have the same sign, unless d.Nanos is zero.
68	if (dur.Seconds < 0 && dur.Nanos > 0) || (dur.Seconds > 0 && dur.Nanos < 0) {
69		return fmt.Errorf("duration: %v: seconds and nanos have different signs", dur)
70	}
71	return nil
72}
73