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time: implement timezones for windows

Fixes #761.

R=PeterGo, adg, rsc
CC=golang-dev
https://golang.org/cl/1121042
This commit is contained in:
Alex Brainman 2010-06-29 22:29:09 -07:00 committed by Russ Cox
parent 42852feb56
commit 9d5f80b0c6
7 changed files with 517 additions and 19 deletions

View File

@ -127,20 +127,13 @@ func getSysProcAddr(m uint32, pname string) uintptr {
//sys GetComputerName(buf *uint16, n *uint32) (ok bool, errno int) = GetComputerNameW
//sys SetEndOfFile(handle int32) (ok bool, errno int)
//sys GetSystemTimeAsFileTime(time *Filetime)
//sys sleep(msec uint32) = Sleep
//sys sleep(msec uint32) = Sleep
//sys GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, errno int) [failretval=0xffffffff]
//sys CreateIoCompletionPort(filehandle int32, cphandle int32, key uint32, threadcnt uint32) (handle int32, errno int)
//sys GetQueuedCompletionStatus(cphandle int32, qty *uint32, key *uint32, overlapped **Overlapped, timeout uint32) (ok bool, errno int)
// syscall interface implementation for other packages
func Sleep(nsec int64) (errno int) {
nsec += 999999 // round up to milliseconds
msec := uint32(nsec / 1e6)
sleep(msec)
errno = 0
return
}
func Errstr(errno int) string {
if errno == EWINDOWS {
return "not supported by windows"
@ -379,6 +372,11 @@ func Gettimeofday(tv *Timeval) (errno int) {
return 0
}
func Sleep(nsec int64) (errno int) {
sleep(uint32((nsec + 1e6 - 1) / 1e6)) // round up to milliseconds
return 0
}
// TODO(brainman): implement Utimes, or rewrite os.file.Chtimes() instead
func Utimes(path string, tv []Timeval) (errno int) {
return EWINDOWS

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@ -37,6 +37,7 @@ var (
procSetEndOfFile = getSysProcAddr(modkernel32, "SetEndOfFile")
procGetSystemTimeAsFileTime = getSysProcAddr(modkernel32, "GetSystemTimeAsFileTime")
procSleep = getSysProcAddr(modkernel32, "Sleep")
procGetTimeZoneInformation = getSysProcAddr(modkernel32, "GetTimeZoneInformation")
procCreateIoCompletionPort = getSysProcAddr(modkernel32, "CreateIoCompletionPort")
procGetQueuedCompletionStatus = getSysProcAddr(modkernel32, "GetQueuedCompletionStatus")
procWSAStartup = getSysProcAddr(modwsock32, "WSAStartup")
@ -341,6 +342,17 @@ func sleep(msec uint32) {
return
}
func GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, errno int) {
r0, _, e1 := Syscall(procGetTimeZoneInformation, uintptr(unsafe.Pointer(tzi)), 0, 0)
rc = uint32(r0)
if rc == 0xffffffff {
errno = int(e1)
} else {
errno = 0
}
return
}
func CreateIoCompletionPort(filehandle int32, cphandle int32, key uint32, threadcnt uint32) (handle int32, errno int) {
r0, _, e1 := Syscall6(procCreateIoCompletionPort, uintptr(filehandle), uintptr(cphandle), uintptr(key), uintptr(threadcnt), 0, 0)
handle = int32(r0)

View File

@ -79,7 +79,11 @@ const (
MAX_COMPUTERNAME_LENGTH = 15
INFINITE = 0xffffffff
TIME_ZONE_ID_UNKNOWN = 0
TIME_ZONE_ID_STANDARD = 1
TIME_ZONE_ID_DAYLIGHT = 2
INFINITE = 0xffffffff
WAIT_TIMEOUT = 258
)
@ -155,6 +159,27 @@ type Stat_t struct {
Mode uint32
}
type Systemtime struct {
Year uint16
Month uint16
DayOfWeek uint16
Day uint16
Hour uint16
Minute uint16
Second uint16
Milliseconds uint16
}
type Timezoneinformation struct {
Bias int32
StandardName [32]uint16
StandardDate Systemtime
StandardBias int32
DaylightName [32]uint16
DaylightDate Systemtime
DaylightBias int32
}
// Socket related.
const (

View File

@ -10,6 +10,22 @@ GOFILES=\
sleep.go\
tick.go\
time.go\
zoneinfo.go\
GOFILES_freebsd=\
zoneinfo_unix.go\
GOFILES_darwin=\
zoneinfo_unix.go\
GOFILES_linux=\
zoneinfo_unix.go\
GOFILES_nacl=\
zoneinfo_unix.go\
GOFILES_windows=\
zoneinfo_windows.go\
GOFILES+=$(GOFILES_$(GOOS))
include ../../Make.pkg

View File

@ -2,7 +2,6 @@ package time
import (
"bytes"
"once"
"os"
"strconv"
)
@ -581,13 +580,9 @@ func Parse(alayout, avalue string) (*Time, os.Error) {
}
// It's a valid format.
t.Zone = p
// Can we find it in the table?
once.Do(setupZone)
for _, z := range zones {
if p == z.zone.name {
t.ZoneOffset = z.zone.utcoff
break
}
// Can we find its offset?
if offset, found := lookupByName(p); found {
t.ZoneOffset = offset
}
}
if rangeErrString != "" {

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@ -0,0 +1,261 @@
// Copyright 2009 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 "zoneinfo" time zone file.
// This is a fairly standard file format used on OS X, Linux, BSD, Sun, and others.
// See tzfile(5), http://en.wikipedia.org/wiki/Zoneinfo,
// and ftp://munnari.oz.au/pub/oldtz/
package time
import (
"io/ioutil"
"once"
"os"
)
const (
headerSize = 4 + 16 + 4*7
zoneDir = "/usr/share/zoneinfo/"
)
// Simple I/O interface to binary blob of data.
type data struct {
p []byte
error bool
}
func (d *data) read(n int) []byte {
if len(d.p) < n {
d.p = nil
d.error = true
return nil
}
p := d.p[0:n]
d.p = d.p[n:]
return p
}
func (d *data) big4() (n uint32, ok bool) {
p := d.read(4)
if len(p) < 4 {
d.error = true
return 0, false
}
return uint32(p[0])<<24 | uint32(p[1])<<16 | uint32(p[2])<<8 | uint32(p[3]), true
}
func (d *data) byte() (n byte, ok bool) {
p := d.read(1)
if len(p) < 1 {
d.error = true
return 0, false
}
return p[0], true
}
// Make a string by stopping at the first NUL
func byteString(p []byte) string {
for i := 0; i < len(p); i++ {
if p[i] == 0 {
return string(p[0:i])
}
}
return string(p)
}
// Parsed representation
type zone struct {
utcoff int
isdst bool
name string
}
type zonetime struct {
time int32 // transition time, in seconds since 1970 GMT
zone *zone // the zone that goes into effect at that time
isstd, isutc bool // ignored - no idea what these mean
}
func parseinfo(bytes []byte) (zt []zonetime, ok bool) {
d := data{bytes, false}
// 4-byte magic "TZif"
if magic := d.read(4); string(magic) != "TZif" {
return nil, false
}
// 1-byte version, then 15 bytes of padding
var p []byte
if p = d.read(16); len(p) != 16 || p[0] != 0 && p[0] != '2' {
return nil, false
}
// six big-endian 32-bit integers:
// number of UTC/local indicators
// number of standard/wall indicators
// number of leap seconds
// number of transition times
// number of local time zones
// number of characters of time zone abbrev strings
const (
NUTCLocal = iota
NStdWall
NLeap
NTime
NZone
NChar
)
var n [6]int
for i := 0; i < 6; i++ {
nn, ok := d.big4()
if !ok {
return nil, false
}
n[i] = int(nn)
}
// Transition times.
txtimes := data{d.read(n[NTime] * 4), false}
// Time zone indices for transition times.
txzones := d.read(n[NTime])
// Zone info structures
zonedata := data{d.read(n[NZone] * 6), false}
// Time zone abbreviations.
abbrev := d.read(n[NChar])
// Leap-second time pairs
d.read(n[NLeap] * 8)
// Whether tx times associated with local time types
// are specified as standard time or wall time.
isstd := d.read(n[NStdWall])
// Whether tx times associated with local time types
// are specified as UTC or local time.
isutc := d.read(n[NUTCLocal])
if d.error { // ran out of data
return nil, false
}
// If version == 2, the entire file repeats, this time using
// 8-byte ints for txtimes and leap seconds.
// We won't need those until 2106.
// Now we can build up a useful data structure.
// First the zone information.
// utcoff[4] isdst[1] nameindex[1]
z := make([]zone, n[NZone])
for i := 0; i < len(z); i++ {
var ok bool
var n uint32
if n, ok = zonedata.big4(); !ok {
return nil, false
}
z[i].utcoff = int(n)
var b byte
if b, ok = zonedata.byte(); !ok {
return nil, false
}
z[i].isdst = b != 0
if b, ok = zonedata.byte(); !ok || int(b) >= len(abbrev) {
return nil, false
}
z[i].name = byteString(abbrev[b:])
}
// Now the transition time info.
zt = make([]zonetime, n[NTime])
for i := 0; i < len(zt); i++ {
var ok bool
var n uint32
if n, ok = txtimes.big4(); !ok {
return nil, false
}
zt[i].time = int32(n)
if int(txzones[i]) >= len(z) {
return nil, false
}
zt[i].zone = &z[txzones[i]]
if i < len(isstd) {
zt[i].isstd = isstd[i] != 0
}
if i < len(isutc) {
zt[i].isutc = isutc[i] != 0
}
}
return zt, true
}
func readinfofile(name string) ([]zonetime, bool) {
buf, err := ioutil.ReadFile(name)
if err != nil {
return nil, false
}
return parseinfo(buf)
}
var zones []zonetime
func setupZone() {
// consult $TZ to find the time zone to use.
// no $TZ means use the system default /etc/localtime.
// $TZ="" means use UTC.
// $TZ="foo" means use /usr/share/zoneinfo/foo.
tz, err := os.Getenverror("TZ")
switch {
case err == os.ENOENV:
zones, _ = readinfofile("/etc/localtime")
case len(tz) > 0:
zones, _ = readinfofile(zoneDir + tz)
case len(tz) == 0:
// do nothing: use UTC
}
}
// Look up the correct time zone (daylight savings or not) for the given unix time, in the current location.
func lookupTimezone(sec int64) (zone string, offset int) {
once.Do(setupZone)
if len(zones) == 0 {
return "UTC", 0
}
// Binary search for entry with largest time <= sec
tz := zones
for len(tz) > 1 {
m := len(tz) / 2
if sec < int64(tz[m].time) {
tz = tz[0:m]
} else {
tz = tz[m:]
}
}
z := tz[0].zone
return z.name, z.utcoff
}
// lookupByName returns the time offset for the
// time zone with the given abbreviation. It only considers
// time zones that apply to the current system.
// For example, for a system configured as being in New York,
// it only recognizes "EST" and "EDT".
// For a system in San Francisco, "PST" and "PDT".
// For a system in Sydney, "EST" and "EDT", though they have
// different meanings than they do in New York.
func lookupByName(name string) (off int, found bool) {
once.Do(setupZone)
for _, z := range zones {
if name == z.zone.name {
return z.zone.utcoff, true
}
}
return 0, false
}

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@ -0,0 +1,191 @@
// Copyright 2009 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.
package time
import (
"syscall"
"os"
"once"
)
// BUG(brainman): The Windows implementation assumes that
// this year's rules for daylight savings time apply to all previous
// and future years as well.
// TODO(brainman): use GetDynamicTimeZoneInformation, whenever posible (Vista and up),
// to improve on situation described in the bug above.
type zone struct {
name string
offset int
year int64
month, day, dayofweek int
hour, minute, second int
abssec int64
prev *zone
}
// Populate zone struct with Windows supplied information. Returns true, if data is valid.
func (z *zone) populate(bias, biasdelta int32, d *syscall.Systemtime, name []uint16) (dateisgood bool) {
z.name = syscall.UTF16ToString(name)
z.offset = int(bias)
z.year = int64(d.Year)
z.month = int(d.Month)
z.day = int(d.Day)
z.dayofweek = int(d.DayOfWeek)
z.hour = int(d.Hour)
z.minute = int(d.Minute)
z.second = int(d.Second)
dateisgood = d.Month != 0
if dateisgood {
z.offset += int(biasdelta)
}
z.offset = -z.offset * 60
return
}
// Pre-calculte cutoff time in seconds since the Unix epoch, if data is supplied in "absolute" format.
func (z *zone) preCalculateAbsSec() {
if z.year != 0 {
z.abssec = (&Time{z.year, int(z.month), int(z.day), int(z.hour), int(z.minute), int(z.second), 0, 0, ""}).Seconds()
// Time given is in "local" time. Adjust it for "utc".
z.abssec -= int64(z.prev.offset)
}
}
// Convert zone cutoff time to sec in number of seconds since the Unix epoch, given particualar year.
func (z *zone) cutoffSeconds(year int64) int64 {
// Windows specifies daylight savings information in "day in month" format:
// z.month is month number (1-12)
// z.dayofweek is appropriate weekday (Sunday=0 to Saturday=6)
// z.day is week within the month (1 to 5, where 5 is last week of the month)
// z.hour, z.minute and z.second are absolute time
t := &Time{year, int(z.month), 1, int(z.hour), int(z.minute), int(z.second), 0, 0, ""}
t = SecondsToUTC(t.Seconds())
i := int(z.dayofweek) - t.Weekday
if i < 0 {
i += 7
}
t.Day += i
if week := int(z.day) - 1; week < 4 {
t.Day += week * 7
} else {
// "Last" instance of the day.
t.Day += 4 * 7
if t.Day > months(year)[t.Month] {
t.Day -= 7
}
}
// Result is in "local" time. Adjust it for "utc".
return t.Seconds() - int64(z.prev.offset)
}
// Is t before the cutoff for switching to z?
func (z *zone) isBeforeCutoff(t *Time) bool {
var coff int64
if z.year == 0 {
// "day in month" format used
coff = z.cutoffSeconds(t.Year)
} else {
// "absolute" format used
coff = z.abssec
}
return t.Seconds() < coff
}
type zoneinfo struct {
disabled bool // daylight saving time is not used localy
offsetIfDisabled int
januaryIsStd bool // is january 1 standard time?
std, dst zone
}
// Pick zone (std or dst) t time belongs to.
func (zi *zoneinfo) pickZone(t *Time) *zone {
z := &zi.std
if tz.januaryIsStd {
if !zi.dst.isBeforeCutoff(t) && zi.std.isBeforeCutoff(t) {
// after switch to daylight time and before the switch back to standard
z = &zi.dst
}
} else {
if zi.std.isBeforeCutoff(t) || !zi.dst.isBeforeCutoff(t) {
// before switch to standard time or after the switch back to daylight
z = &zi.dst
}
}
return z
}
var tz zoneinfo
var initError os.Error
func setupZone() {
var i syscall.Timezoneinformation
if _, e := syscall.GetTimeZoneInformation(&i); e != 0 {
initError = os.NewSyscallError("GetTimeZoneInformation", e)
return
}
if !tz.std.populate(i.Bias, i.StandardBias, &i.StandardDate, i.StandardName[0:]) {
tz.disabled = true
tz.offsetIfDisabled = tz.std.offset
return
}
tz.std.prev = &tz.dst
tz.dst.populate(i.Bias, i.DaylightBias, &i.DaylightDate, i.DaylightName[0:])
tz.dst.prev = &tz.std
tz.std.preCalculateAbsSec()
tz.dst.preCalculateAbsSec()
// Is january 1 standard time this year?
t := UTC()
tz.januaryIsStd = tz.dst.cutoffSeconds(t.Year) < tz.std.cutoffSeconds(t.Year)
}
// Look up the correct time zone (daylight savings or not) for the given unix time, in the current location.
func lookupTimezone(sec int64) (zone string, offset int) {
once.Do(setupZone)
if initError != nil {
return "", 0
}
if tz.disabled {
return "", tz.offsetIfDisabled
}
t := SecondsToUTC(sec)
z := &tz.std
if tz.std.year == 0 {
// "day in month" format used
z = tz.pickZone(t)
} else {
// "absolute" format used
if tz.std.year == t.Year {
// we have rule for the year in question
z = tz.pickZone(t)
} else {
// we do not have any information for that year,
// will assume standard offset all year around
}
}
return z.name, z.offset
}
// lookupByName returns the time offset for the
// time zone with the given abbreviation. It only considers
// time zones that apply to the current system.
func lookupByName(name string) (off int, found bool) {
once.Do(setupZone)
if initError != nil {
return 0, false
}
if tz.disabled {
return tz.offsetIfDisabled, false
}
switch name {
case tz.std.name:
return tz.std.offset, true
case tz.dst.name:
return tz.dst.offset, true
}
return 0, false
}