File size: 2,244 Bytes
e36aeda | 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 76 77 78 79 80 81 82 83 84 85 86 87 88 | // Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Parse the "tzdata" packed timezone file used on Android.
// The format is lifted from ZoneInfoDB.java and ZoneInfo.java in
// java/libcore/util in the AOSP.
package time
import (
"errors"
"syscall"
)
var platformZoneSources = []string{
"/system/usr/share/zoneinfo/tzdata",
"/data/misc/zoneinfo/current/tzdata",
}
func initLocal() {
// TODO(elias.naur): getprop persist.sys.timezone
localLoc = *UTC
}
func init() {
loadTzinfoFromTzdata = androidLoadTzinfoFromTzdata
}
var allowGorootSource = true
func gorootZoneSource(goroot string) (string, bool) {
if goroot == "" || !allowGorootSource {
return "", false
}
return goroot + "/lib/time/zoneinfo.zip", true
}
func androidLoadTzinfoFromTzdata(file, name string) ([]byte, error) {
const (
headersize = 12 + 3*4
namesize = 40
entrysize = namesize + 3*4
)
if len(name) > namesize {
return nil, errors.New(name + " is longer than the maximum zone name length (40 bytes)")
}
fd, err := open(file)
if err != nil {
return nil, err
}
defer closefd(fd)
buf := make([]byte, headersize)
if err := preadn(fd, buf, 0); err != nil {
return nil, errors.New("corrupt tzdata file " + file)
}
d := dataIO{buf, false}
if magic := d.read(6); string(magic) != "tzdata" {
return nil, errors.New("corrupt tzdata file " + file)
}
d = dataIO{buf[12:], false}
indexOff, _ := d.big4()
dataOff, _ := d.big4()
indexSize := dataOff - indexOff
entrycount := indexSize / entrysize
buf = make([]byte, indexSize)
if err := preadn(fd, buf, int(indexOff)); err != nil {
return nil, errors.New("corrupt tzdata file " + file)
}
for i := 0; i < int(entrycount); i++ {
entry := buf[i*entrysize : (i+1)*entrysize]
// len(name) <= namesize is checked at function entry
if string(entry[:len(name)]) != name {
continue
}
d := dataIO{entry[namesize:], false}
off, _ := d.big4()
size, _ := d.big4()
buf := make([]byte, size)
if err := preadn(fd, buf, int(off+dataOff)); err != nil {
return nil, errors.New("corrupt tzdata file " + file)
}
return buf, nil
}
return nil, syscall.ENOENT
}
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