1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
// Copyright 2020 New Relic Corporation. All rights reserved.
// SPDX-License-Identifier: Apache-2.0
package internal
import (
"net/http"
"strconv"
"strings"
"time"
)
const (
xRequestStart = "X-Request-Start"
xQueueStart = "X-Queue-Start"
)
var (
earliestAcceptableSeconds = time.Date(2000, time.January, 1, 0, 0, 0, 0, time.UTC).Unix()
latestAcceptableSeconds = time.Date(2050, time.January, 1, 0, 0, 0, 0, time.UTC).Unix()
)
func checkQueueTimeSeconds(secondsFloat float64) time.Time {
seconds := int64(secondsFloat)
nanos := int64((secondsFloat - float64(seconds)) * (1000.0 * 1000.0 * 1000.0))
if seconds > earliestAcceptableSeconds && seconds < latestAcceptableSeconds {
return time.Unix(seconds, nanos)
}
return time.Time{}
}
func parseQueueTime(s string) time.Time {
f, err := strconv.ParseFloat(s, 64)
if nil != err {
return time.Time{}
}
if f <= 0 {
return time.Time{}
}
// try microseconds
if t := checkQueueTimeSeconds(f / (1000.0 * 1000.0)); !t.IsZero() {
return t
}
// try milliseconds
if t := checkQueueTimeSeconds(f / (1000.0)); !t.IsZero() {
return t
}
// try seconds
if t := checkQueueTimeSeconds(f); !t.IsZero() {
return t
}
return time.Time{}
}
// QueueDuration TODO
func QueueDuration(hdr http.Header, txnStart time.Time) time.Duration {
s := hdr.Get(xQueueStart)
if "" == s {
s = hdr.Get(xRequestStart)
}
if "" == s {
return 0
}
s = strings.TrimPrefix(s, "t=")
qt := parseQueueTime(s)
if qt.IsZero() {
return 0
}
if qt.After(txnStart) {
return 0
}
return txnStart.Sub(qt)
}
|
