1// Copyright 2018 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
5// +build js,wasm
6
7package time
8
9import (
10	"runtime"
11	"syscall/js"
12)
13
14var zoneSources = []string{
15	"/usr/share/zoneinfo/",
16	"/usr/share/lib/zoneinfo/",
17	"/usr/lib/locale/TZ/",
18	runtime.GOROOT() + "/lib/time/zoneinfo.zip",
19}
20
21func initLocal() {
22	localLoc.name = "Local"
23
24	z := zone{}
25	d := js.Global().Get("Date").New()
26	offset := d.Call("getTimezoneOffset").Int() * -1
27	z.offset = offset * 60
28	// According to https://tc39.github.io/ecma262/#sec-timezoneestring,
29	// the timezone name from (new Date()).toTimeString() is an implementation-dependent
30	// result, and in Google Chrome, it gives the fully expanded name rather than
31	// the abbreviation.
32	// Hence, we construct the name from the offset.
33	z.name = "UTC"
34	if offset < 0 {
35		z.name += "-"
36		offset *= -1
37	} else {
38		z.name += "+"
39	}
40	z.name += itoa(offset / 60)
41	min := offset % 60
42	if min != 0 {
43		z.name += ":" + itoa(min)
44	}
45	localLoc.zone = []zone{z}
46}
47
48// itoa is like strconv.Itoa but only works for values of i in range [0,99].
49// It panics if i is out of range.
50func itoa(i int) string {
51	if i < 10 {
52		return digits[i : i+1]
53	}
54	return smallsString[i*2 : i*2+2]
55}
56
57const smallsString = "00010203040506070809" +
58	"10111213141516171819" +
59	"20212223242526272829" +
60	"30313233343536373839" +
61	"40414243444546474849" +
62	"50515253545556575859" +
63	"60616263646566676869" +
64	"70717273747576777879" +
65	"80818283848586878889" +
66	"90919293949596979899"
67const digits = "0123456789"
68