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patch: fmt, os, runtime, syscall, time

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This commit is contained in:
xushiwei
2024-06-26 17:17:10 +08:00
parent fd0cb4c458
commit 48a1384197
30 changed files with 5373 additions and 24 deletions
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1706
internal/lib/time/format.go Normal file
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internal/lib/time/sys_unix.go Normal file
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// Copyright 2011 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.
//go:build unix || (js && wasm) || wasip1
package time
import (
"errors"
"runtime"
"syscall"
)
// for testing: whatever interrupts a sleep
func interrupt() {
// There is no mechanism in wasi to interrupt the call to poll_oneoff
// used to implement runtime.usleep so this function does nothing, which
// somewhat defeats the purpose of TestSleep but we are still better off
// validating that time elapses when the process calls time.Sleep than
// skipping the test altogether.
if runtime.GOOS != "wasip1" {
syscall.Kill(syscall.Getpid(), syscall.SIGCHLD)
}
}
func open(name string) (uintptr, error) {
fd, err := syscall.Open(name, syscall.O_RDONLY, 0)
if err != nil {
return 0, err
}
return uintptr(fd), nil
}
func read(fd uintptr, buf []byte) (int, error) {
return syscall.Read(int(fd), buf)
}
func closefd(fd uintptr) {
syscall.Close(int(fd))
}
func preadn(fd uintptr, buf []byte, off int) error {
whence := seekStart
if off < 0 {
whence = seekEnd
}
if _, err := syscall.Seek(int(fd), int64(off), whence); err != nil {
return err
}
for len(buf) > 0 {
m, err := syscall.Read(int(fd), buf)
if m <= 0 {
if err == nil {
return errors.New("short read")
}
return err
}
buf = buf[m:]
}
return nil
}

451
internal/lib/time/time.go Normal file
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/*
* Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package time
// llgo:skipall
import (
_ "unsafe"
)
type Time struct {
// wall and ext encode the wall time seconds, wall time nanoseconds,
// and optional monotonic clock reading in nanoseconds.
//
// From high to low bit position, wall encodes a 1-bit flag (hasMonotonic),
// a 33-bit seconds field, and a 30-bit wall time nanoseconds field.
// The nanoseconds field is in the range [0, 999999999].
// If the hasMonotonic bit is 0, then the 33-bit field must be zero
// and the full signed 64-bit wall seconds since Jan 1 year 1 is stored in ext.
// If the hasMonotonic bit is 1, then the 33-bit field holds a 33-bit
// unsigned wall seconds since Jan 1 year 1885, and ext holds a
// signed 64-bit monotonic clock reading, nanoseconds since process start.
wall uint64
ext int64
// loc specifies the Location that should be used to
// determine the minute, hour, month, day, and year
// that correspond to this Time.
// The nil location means UTC.
// All UTC times are represented with loc==nil, never loc==&utcLoc.
loc *Location
}
const (
hasMonotonic = 1 << 63
maxWall = wallToInternal + (1<<33 - 1) // year 2157
minWall = wallToInternal // year 1885
nsecMask = 1<<30 - 1
nsecShift = 30
)
// These helpers for manipulating the wall and monotonic clock readings
// take pointer receivers, even when they don't modify the time,
// to make them cheaper to call.
// nsec returns the time's nanoseconds.
func (t *Time) nsec() int32 {
return int32(t.wall & nsecMask)
}
// sec returns the time's seconds since Jan 1 year 1.
func (t *Time) sec() int64 {
if t.wall&hasMonotonic != 0 {
return wallToInternal + int64(t.wall<<1>>(nsecShift+1))
}
return t.ext
}
// unixSec returns the time's seconds since Jan 1 1970 (Unix time).
func (t *Time) unixSec() int64 { return t.sec() + internalToUnix }
// addSec adds d seconds to the time.
func (t *Time) addSec(d int64) {
if t.wall&hasMonotonic != 0 {
sec := int64(t.wall << 1 >> (nsecShift + 1))
dsec := sec + d
if 0 <= dsec && dsec <= 1<<33-1 {
t.wall = t.wall&nsecMask | uint64(dsec)<<nsecShift | hasMonotonic
return
}
// Wall second now out of range for packed field.
// Move to ext.
t.stripMono()
}
// Check if the sum of t.ext and d overflows and handle it properly.
sum := t.ext + d
if (sum > t.ext) == (d > 0) {
t.ext = sum
} else if d > 0 {
t.ext = 1<<63 - 1
} else {
t.ext = -(1<<63 - 1)
}
}
// setLoc sets the location associated with the time.
func (t *Time) setLoc(loc *Location) {
if loc == &utcLoc {
loc = nil
}
t.stripMono()
t.loc = loc
}
// stripMono strips the monotonic clock reading in t.
func (t *Time) stripMono() {
if t.wall&hasMonotonic != 0 {
t.ext = t.sec()
t.wall &= nsecMask
}
}
// setMono sets the monotonic clock reading in t.
// If t cannot hold a monotonic clock reading,
// because its wall time is too large,
// setMono is a no-op.
func (t *Time) setMono(m int64) {
if t.wall&hasMonotonic == 0 {
sec := t.ext
if sec < minWall || maxWall < sec {
return
}
t.wall |= hasMonotonic | uint64(sec-minWall)<<nsecShift
}
t.ext = m
}
// mono returns t's monotonic clock reading.
// It returns 0 for a missing reading.
// This function is used only for testing,
// so it's OK that technically 0 is a valid
// monotonic clock reading as well.
func (t *Time) mono() int64 {
if t.wall&hasMonotonic == 0 {
return 0
}
return t.ext
}
// After reports whether the time instant t is after u.
func (t Time) After(u Time) bool {
if t.wall&u.wall&hasMonotonic != 0 {
return t.ext > u.ext
}
ts := t.sec()
us := u.sec()
return ts > us || ts == us && t.nsec() > u.nsec()
}
// Before reports whether the time instant t is before u.
func (t Time) Before(u Time) bool {
if t.wall&u.wall&hasMonotonic != 0 {
return t.ext < u.ext
}
ts := t.sec()
us := u.sec()
return ts < us || ts == us && t.nsec() < u.nsec()
}
// Compare compares the time instant t with u. If t is before u, it returns -1;
// if t is after u, it returns +1; if they're the same, it returns 0.
func (t Time) Compare(u Time) int {
var tc, uc int64
if t.wall&u.wall&hasMonotonic != 0 {
tc, uc = t.ext, u.ext
} else {
tc, uc = t.sec(), u.sec()
if tc == uc {
tc, uc = int64(t.nsec()), int64(u.nsec())
}
}
switch {
case tc < uc:
return -1
case tc > uc:
return +1
}
return 0
}
// Equal reports whether t and u represent the same time instant.
// Two times can be equal even if they are in different locations.
// For example, 6:00 +0200 and 4:00 UTC are Equal.
// See the documentation on the Time type for the pitfalls of using == with
// Time values; most code should use Equal instead.
func (t Time) Equal(u Time) bool {
if t.wall&u.wall&hasMonotonic != 0 {
return t.ext == u.ext
}
return t.sec() == u.sec() && t.nsec() == u.nsec()
}
// A Month specifies a month of the year (January = 1, ...).
type Month int
const (
January Month = 1 + iota
February
March
April
May
June
July
August
September
October
November
December
)
// String returns the English name of the month ("January", "February", ...).
func (m Month) String() string {
if January <= m && m <= December {
return longMonthNames[m-1]
}
buf := make([]byte, 20)
n := fmtInt(buf, uint64(m))
return "%!Month(" + string(buf[n:]) + ")"
}
// A Weekday specifies a day of the week (Sunday = 0, ...).
type Weekday int
const (
Sunday Weekday = iota
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
)
// String returns the English name of the day ("Sunday", "Monday", ...).
func (d Weekday) String() string {
if Sunday <= d && d <= Saturday {
return longDayNames[d]
}
buf := make([]byte, 20)
n := fmtInt(buf, uint64(d))
return "%!Weekday(" + string(buf[n:]) + ")"
}
const (
secondsPerMinute = 60
secondsPerHour = 60 * secondsPerMinute
secondsPerDay = 24 * secondsPerHour
secondsPerWeek = 7 * secondsPerDay
daysPer400Years = 365*400 + 97
daysPer100Years = 365*100 + 24
daysPer4Years = 365*4 + 1
)
// daysBefore[m] counts the number of days in a non-leap year
// before month m begins. There is an entry for m=12, counting
// the number of days before January of next year (365).
var daysBefore = [...]int32{
0,
31,
31 + 28,
31 + 28 + 31,
31 + 28 + 31 + 30,
31 + 28 + 31 + 30 + 31,
31 + 28 + 31 + 30 + 31 + 30,
31 + 28 + 31 + 30 + 31 + 30 + 31,
31 + 28 + 31 + 30 + 31 + 30 + 31 + 31,
31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30,
31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31,
31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30,
31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30 + 31,
}
func daysIn(m Month, year int) int {
if m == February && isLeap(year) {
return 29
}
return int(daysBefore[m] - daysBefore[m-1])
}
// daysSinceEpoch takes a year and returns the number of days from
// the absolute epoch to the start of that year.
// This is basically (year - zeroYear) * 365, but accounting for leap days.
func daysSinceEpoch(year int) uint64 {
y := uint64(int64(year) - absoluteZeroYear)
// Add in days from 400-year cycles.
n := y / 400
y -= 400 * n
d := daysPer400Years * n
// Add in 100-year cycles.
n = y / 100
y -= 100 * n
d += daysPer100Years * n
// Add in 4-year cycles.
n = y / 4
y -= 4 * n
d += daysPer4Years * n
// Add in non-leap years.
n = y
d += 365 * n
return d
}
const (
// The unsigned zero year for internal calculations.
// Must be 1 mod 400, and times before it will not compute correctly,
// but otherwise can be changed at will.
absoluteZeroYear = -292277022399
// The year of the zero Time.
// Assumed by the unixToInternal computation below.
internalYear = 1
// Offsets to convert between internal and absolute or Unix times.
absoluteToInternal int64 = (absoluteZeroYear - internalYear) * 365.2425 * secondsPerDay
internalToAbsolute = -absoluteToInternal
unixToInternal int64 = (1969*365 + 1969/4 - 1969/100 + 1969/400) * secondsPerDay
internalToUnix int64 = -unixToInternal
wallToInternal int64 = (1884*365 + 1884/4 - 1884/100 + 1884/400) * secondsPerDay
)
// IsZero reports whether t represents the zero time instant,
// January 1, year 1, 00:00:00 UTC.
func (t Time) IsZero() bool {
return t.sec() == 0 && t.nsec() == 0
}
// Date returns the Time corresponding to
//
// yyyy-mm-dd hh:mm:ss + nsec nanoseconds
//
// in the appropriate zone for that time in the given location.
//
// The month, day, hour, min, sec, and nsec values may be outside
// their usual ranges and will be normalized during the conversion.
// For example, October 32 converts to November 1.
//
// A daylight savings time transition skips or repeats times.
// For example, in the United States, March 13, 2011 2:15am never occurred,
// while November 6, 2011 1:15am occurred twice. In such cases, the
// choice of time zone, and therefore the time, is not well-defined.
// Date returns a time that is correct in one of the two zones involved
// in the transition, but it does not guarantee which.
//
// Date panics if loc is nil.
func Date(year int, month Month, day, hour, min, sec, nsec int, loc *Location) Time {
if loc == nil {
panic("time: missing Location in call to Date")
}
// Normalize month, overflowing into year.
m := int(month) - 1
year, m = norm(year, m, 12)
month = Month(m) + 1
// Normalize nsec, sec, min, hour, overflowing into day.
sec, nsec = norm(sec, nsec, 1e9)
min, sec = norm(min, sec, 60)
hour, min = norm(hour, min, 60)
day, hour = norm(day, hour, 24)
// Compute days since the absolute epoch.
d := daysSinceEpoch(year)
// Add in days before this month.
d += uint64(daysBefore[month-1])
if isLeap(year) && month >= March {
d++ // February 29
}
// Add in days before today.
d += uint64(day - 1)
// Add in time elapsed today.
abs := d * secondsPerDay
abs += uint64(hour*secondsPerHour + min*secondsPerMinute + sec)
unix := int64(abs) + (absoluteToInternal + internalToUnix)
// Look for zone offset for expected time, so we can adjust to UTC.
// The lookup function expects UTC, so first we pass unix in the
// hope that it will not be too close to a zone transition,
// and then adjust if it is.
_, offset, start, end, _ := loc.lookup(unix)
if offset != 0 {
utc := unix - int64(offset)
// If utc is valid for the time zone we found, then we have the right offset.
// If not, we get the correct offset by looking up utc in the location.
if utc < start || utc >= end {
_, offset, _, _, _ = loc.lookup(utc)
}
unix -= int64(offset)
}
t := unixTime(unix, int32(nsec))
t.setLoc(loc)
return t
}
func unixTime(sec int64, nsec int32) Time {
return Time{uint64(nsec), sec + unixToInternal, Local}
}
func isLeap(year int) bool {
return year%4 == 0 && (year%100 != 0 || year%400 == 0)
}
// norm returns nhi, nlo such that
//
// hi * base + lo == nhi * base + nlo
// 0 <= nlo < base
func norm(hi, lo, base int) (nhi, nlo int) {
if lo < 0 {
n := (-lo-1)/base + 1
hi -= n
lo += n * base
}
if lo >= base {
n := lo / base
hi += n
lo -= n * base
}
return hi, lo
}
// fmtInt formats v into the tail of buf.
// It returns the index where the output begins.
func fmtInt(buf []byte, v uint64) int {
w := len(buf)
if v == 0 {
w--
buf[w] = '0'
} else {
for v > 0 {
w--
buf[w] = byte(v%10) + '0'
v /= 10
}
}
return w
}

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internal/lib/time/zoneinfo.go Normal file
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// Copyright 2011 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 "sync"
// A Location maps time instants to the zone in use at that time.
// Typically, the Location represents the collection of time offsets
// in use in a geographical area. For many Locations the time offset varies
// depending on whether daylight savings time is in use at the time instant.
type Location struct {
name string
zone []zone
tx []zoneTrans
// The tzdata information can be followed by a string that describes
// how to handle DST transitions not recorded in zoneTrans.
// The format is the TZ environment variable without a colon; see
// https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html.
// Example string, for America/Los_Angeles: PST8PDT,M3.2.0,M11.1.0
extend string
// Most lookups will be for the current time.
// To avoid the binary search through tx, keep a
// static one-element cache that gives the correct
// zone for the time when the Location was created.
// if cacheStart <= t < cacheEnd,
// lookup can return cacheZone.
// The units for cacheStart and cacheEnd are seconds
// since January 1, 1970 UTC, to match the argument
// to lookup.
cacheStart int64
cacheEnd int64
cacheZone *zone
}
// A zone represents a single time zone such as CET.
type zone struct {
name string // abbreviated name, "CET"
offset int // seconds east of UTC
isDST bool // is this zone Daylight Savings Time?
}
// A zoneTrans represents a single time zone transition.
type zoneTrans struct {
when int64 // transition time, in seconds since 1970 GMT
index uint8 // the index of the zone that goes into effect at that time
isstd, isutc bool // ignored - no idea what these mean
}
// alpha and omega are the beginning and end of time for zone
// transitions.
const (
alpha = -1 << 63 // math.MinInt64
omega = 1<<63 - 1 // math.MaxInt64
)
// UTC represents Universal Coordinated Time (UTC).
var UTC *Location = &utcLoc
// utcLoc is separate so that get can refer to &utcLoc
// and ensure that it never returns a nil *Location,
// even if a badly behaved client has changed UTC.
var utcLoc = Location{name: "UTC"}
// Local represents the system's local time zone.
// On Unix systems, Local consults the TZ environment
// variable to find the time zone to use. No TZ means
// use the system default /etc/localtime.
// TZ="" means use UTC.
// TZ="foo" means use file foo in the system timezone directory.
var Local *Location = &localLoc
// localLoc is separate so that initLocal can initialize
// it even if a client has changed Local.
var localLoc Location
var localOnce sync.Once
func (l *Location) get() *Location {
if l == nil {
return &utcLoc
}
if l == &localLoc {
localOnce.Do(initLocal)
}
return l
}
// String returns a descriptive name for the time zone information,
// corresponding to the name argument to LoadLocation or FixedZone.
func (l *Location) String() string {
return l.get().name
}
// lookup returns information about the time zone in use at an
// instant in time expressed as seconds since January 1, 1970 00:00:00 UTC.
//
// The returned information gives the name of the zone (such as "CET"),
// the start and end times bracketing sec when that zone is in effect,
// the offset in seconds east of UTC (such as -5*60*60), and whether
// the daylight savings is being observed at that time.
func (l *Location) lookup(sec int64) (name string, offset int, start, end int64, isDST bool) {
l = l.get()
if len(l.zone) == 0 {
name = "UTC"
offset = 0
start = alpha
end = omega
isDST = false
return
}
if zone := l.cacheZone; zone != nil && l.cacheStart <= sec && sec < l.cacheEnd {
name = zone.name
offset = zone.offset
start = l.cacheStart
end = l.cacheEnd
isDST = zone.isDST
return
}
/*
if len(l.tx) == 0 || sec < l.tx[0].when {
zone := &l.zone[l.lookupFirstZone()]
name = zone.name
offset = zone.offset
start = alpha
if len(l.tx) > 0 {
end = l.tx[0].when
} else {
end = omega
}
isDST = zone.isDST
return
}
// Binary search for entry with largest time <= sec.
// Not using sort.Search to avoid dependencies.
tx := l.tx
end = omega
lo := 0
hi := len(tx)
for hi-lo > 1 {
m := lo + (hi-lo)/2
lim := tx[m].when
if sec < lim {
end = lim
hi = m
} else {
lo = m
}
}
zone := &l.zone[tx[lo].index]
name = zone.name
offset = zone.offset
start = tx[lo].when
// end = maintained during the search
isDST = zone.isDST
// If we're at the end of the known zone transitions,
// try the extend string.
if lo == len(tx)-1 && l.extend != "" {
if ename, eoffset, estart, eend, eisDST, ok := tzset(l.extend, start, sec); ok {
return ename, eoffset, estart, eend, eisDST
}
}
return
*/
panic("todo: Location.lookup")
}

608
internal/lib/time/zoneinfo_read.go Normal file
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// 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), https://en.wikipedia.org/wiki/Zoneinfo,
// and ftp://munnari.oz.au/pub/oldtz/
package time
import (
"errors"
"runtime"
"syscall"
)
// registerLoadFromEmbeddedTZData is called by the time/tzdata package,
// if it is imported.
func registerLoadFromEmbeddedTZData(f func(string) (string, error)) {
loadFromEmbeddedTZData = f
}
// loadFromEmbeddedTZData is used to load a specific tzdata file
// from tzdata information embedded in the binary itself.
// This is set when the time/tzdata package is imported,
// via registerLoadFromEmbeddedTzdata.
var loadFromEmbeddedTZData func(zipname string) (string, error)
// maxFileSize is the max permitted size of files read by readFile.
// As reference, the zoneinfo.zip distributed by Go is ~350 KB,
// so 10MB is overkill.
const maxFileSize = 10 << 20
type fileSizeError string
func (f fileSizeError) Error() string {
return "time: file " + string(f) + " is too large"
}
// Copies of io.Seek* constants to avoid importing "io":
const (
seekStart = 0
seekCurrent = 1
seekEnd = 2
)
// Simple I/O interface to binary blob of data.
type dataIO struct {
p []byte
error bool
}
func (d *dataIO) 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 *dataIO) big4() (n uint32, ok bool) {
p := d.read(4)
if len(p) < 4 {
d.error = true
return 0, false
}
return uint32(p[3]) | uint32(p[2])<<8 | uint32(p[1])<<16 | uint32(p[0])<<24, true
}
func (d *dataIO) big8() (n uint64, ok bool) {
n1, ok1 := d.big4()
n2, ok2 := d.big4()
if !ok1 || !ok2 {
d.error = true
return 0, false
}
return (uint64(n1) << 32) | uint64(n2), true
}
func (d *dataIO) byte() (n byte, ok bool) {
p := d.read(1)
if len(p) < 1 {
d.error = true
return 0, false
}
return p[0], true
}
// read returns the read of the data in the buffer.
func (d *dataIO) rest() []byte {
r := d.p
d.p = nil
return r
}
// 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)
}
var errBadData = errors.New("malformed time zone information")
// LoadLocationFromTZData returns a Location with the given name
// initialized from the IANA Time Zone database-formatted data.
// The data should be in the format of a standard IANA time zone file
// (for example, the content of /etc/localtime on Unix systems).
func LoadLocationFromTZData(name string, data []byte) (*Location, error) {
d := dataIO{data, false}
// 4-byte magic "TZif"
if magic := d.read(4); string(magic) != "TZif" {
return nil, errBadData
}
// 1-byte version, then 15 bytes of padding
var version int
var p []byte
if p = d.read(16); len(p) != 16 {
return nil, errBadData
} else {
switch p[0] {
case 0:
version = 1
case '2':
version = 2
case '3':
version = 3
default:
return nil, errBadData
}
}
// 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, errBadData
}
if uint32(int(nn)) != nn {
return nil, errBadData
}
n[i] = int(nn)
}
// If we have version 2 or 3, then the data is first written out
// in a 32-bit format, then written out again in a 64-bit format.
// Skip the 32-bit format and read the 64-bit one, as it can
// describe a broader range of dates.
is64 := false
if version > 1 {
// Skip the 32-bit data.
skip := n[NTime]*4 +
n[NTime] +
n[NZone]*6 +
n[NChar] +
n[NLeap]*8 +
n[NStdWall] +
n[NUTCLocal]
// Skip the version 2 header that we just read.
skip += 4 + 16
d.read(skip)
is64 = true
// Read the counts again, they can differ.
for i := 0; i < 6; i++ {
nn, ok := d.big4()
if !ok {
return nil, errBadData
}
if uint32(int(nn)) != nn {
return nil, errBadData
}
n[i] = int(nn)
}
}
size := 4
if is64 {
size = 8
}
// Transition times.
txtimes := dataIO{d.read(n[NTime] * size), false}
// Time zone indices for transition times.
txzones := d.read(n[NTime])
// Zone info structures
zonedata := dataIO{d.read(n[NZone] * 6), false}
// Time zone abbreviations.
abbrev := d.read(n[NChar])
// Leap-second time pairs
d.read(n[NLeap] * (size + 4))
// 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, errBadData
}
var extend string
rest := d.rest()
if len(rest) > 2 && rest[0] == '\n' && rest[len(rest)-1] == '\n' {
extend = string(rest[1 : len(rest)-1])
}
// Now we can build up a useful data structure.
// First the zone information.
// utcoff[4] isdst[1] nameindex[1]
nzone := n[NZone]
if nzone == 0 {
// Reject tzdata files with no zones. There's nothing useful in them.
// This also avoids a panic later when we add and then use a fake transition (golang.org/issue/29437).
return nil, errBadData
}
zones := make([]zone, nzone)
for i := range zones {
var ok bool
var n uint32
if n, ok = zonedata.big4(); !ok {
return nil, errBadData
}
if uint32(int(n)) != n {
return nil, errBadData
}
zones[i].offset = int(int32(n))
var b byte
if b, ok = zonedata.byte(); !ok {
return nil, errBadData
}
zones[i].isDST = b != 0
if b, ok = zonedata.byte(); !ok || int(b) >= len(abbrev) {
return nil, errBadData
}
zones[i].name = byteString(abbrev[b:])
if runtime.GOOS == "aix" && len(name) > 8 && (name[:8] == "Etc/GMT+" || name[:8] == "Etc/GMT-") {
// There is a bug with AIX 7.2 TL 0 with files in Etc,
// GMT+1 will return GMT-1 instead of GMT+1 or -01.
if name != "Etc/GMT+0" {
// GMT+0 is OK
zones[i].name = name[4:]
}
}
}
// Now the transition time info.
tx := make([]zoneTrans, n[NTime])
for i := range tx {
var n int64
if !is64 {
if n4, ok := txtimes.big4(); !ok {
return nil, errBadData
} else {
n = int64(int32(n4))
}
} else {
if n8, ok := txtimes.big8(); !ok {
return nil, errBadData
} else {
n = int64(n8)
}
}
tx[i].when = n
if int(txzones[i]) >= len(zones) {
return nil, errBadData
}
tx[i].index = txzones[i]
if i < len(isstd) {
tx[i].isstd = isstd[i] != 0
}
if i < len(isutc) {
tx[i].isutc = isutc[i] != 0
}
}
if len(tx) == 0 {
// Build fake transition to cover all time.
// This happens in fixed locations like "Etc/GMT0".
tx = append(tx, zoneTrans{when: alpha, index: 0})
}
/*
// Committed to succeed.
l := &Location{zone: zones, tx: tx, name: name, extend: extend}
// Fill in the cache with information about right now,
// since that will be the most common lookup.
sec, _, _ := now()
for i := range tx {
if tx[i].when <= sec && (i+1 == len(tx) || sec < tx[i+1].when) {
l.cacheStart = tx[i].when
l.cacheEnd = omega
l.cacheZone = &l.zone[tx[i].index]
if i+1 < len(tx) {
l.cacheEnd = tx[i+1].when
} else if l.extend != "" {
// If we're at the end of the known zone transitions,
// try the extend string.
if name, offset, estart, eend, isDST, ok := tzset(l.extend, l.cacheStart, sec); ok {
l.cacheStart = estart
l.cacheEnd = eend
// Find the zone that is returned by tzset to avoid allocation if possible.
if zoneIdx := findZone(l.zone, name, offset, isDST); zoneIdx != -1 {
l.cacheZone = &l.zone[zoneIdx]
} else {
l.cacheZone = &zone{
name: name,
offset: offset,
isDST: isDST,
}
}
}
}
break
}
}
return l, nil
*/
_ = extend
panic("todo")
}
func findZone(zones []zone, name string, offset int, isDST bool) int {
for i, z := range zones {
if z.name == name && z.offset == offset && z.isDST == isDST {
return i
}
}
return -1
}
// loadTzinfoFromDirOrZip returns the contents of the file with the given name
// in dir. dir can either be an uncompressed zip file, or a directory.
func loadTzinfoFromDirOrZip(dir, name string) ([]byte, error) {
if len(dir) > 4 && dir[len(dir)-4:] == ".zip" {
return loadTzinfoFromZip(dir, name)
}
if dir != "" {
name = dir + "/" + name
}
return readFile(name)
}
// There are 500+ zoneinfo files. Rather than distribute them all
// individually, we ship them in an uncompressed zip file.
// Used this way, the zip file format serves as a commonly readable
// container for the individual small files. We choose zip over tar
// because zip files have a contiguous table of contents, making
// individual file lookups faster, and because the per-file overhead
// in a zip file is considerably less than tar's 512 bytes.
// get4 returns the little-endian 32-bit value in b.
func get4(b []byte) int {
if len(b) < 4 {
return 0
}
return int(b[0]) | int(b[1])<<8 | int(b[2])<<16 | int(b[3])<<24
}
// get2 returns the little-endian 16-bit value in b.
func get2(b []byte) int {
if len(b) < 2 {
return 0
}
return int(b[0]) | int(b[1])<<8
}
// loadTzinfoFromZip returns the contents of the file with the given name
// in the given uncompressed zip file.
func loadTzinfoFromZip(zipfile, name string) ([]byte, error) {
fd, err := open(zipfile)
if err != nil {
return nil, err
}
defer closefd(fd)
const (
zecheader = 0x06054b50
zcheader = 0x02014b50
ztailsize = 22
zheadersize = 30
zheader = 0x04034b50
)
buf := make([]byte, ztailsize)
if err := preadn(fd, buf, -ztailsize); err != nil || get4(buf) != zecheader {
return nil, errors.New("corrupt zip file " + zipfile)
}
n := get2(buf[10:])
size := get4(buf[12:])
off := get4(buf[16:])
buf = make([]byte, size)
if err := preadn(fd, buf, off); err != nil {
return nil, errors.New("corrupt zip file " + zipfile)
}
for i := 0; i < n; i++ {
// zip entry layout:
// 0 magic[4]
// 4 madevers[1]
// 5 madeos[1]
// 6 extvers[1]
// 7 extos[1]
// 8 flags[2]
// 10 meth[2]
// 12 modtime[2]
// 14 moddate[2]
// 16 crc[4]
// 20 csize[4]
// 24 uncsize[4]
// 28 namelen[2]
// 30 xlen[2]
// 32 fclen[2]
// 34 disknum[2]
// 36 iattr[2]
// 38 eattr[4]
// 42 off[4]
// 46 name[namelen]
// 46+namelen+xlen+fclen - next header
//
if get4(buf) != zcheader {
break
}
meth := get2(buf[10:])
size := get4(buf[24:])
namelen := get2(buf[28:])
xlen := get2(buf[30:])
fclen := get2(buf[32:])
off := get4(buf[42:])
zname := buf[46 : 46+namelen]
buf = buf[46+namelen+xlen+fclen:]
if string(zname) != name {
continue
}
if meth != 0 {
return nil, errors.New("unsupported compression for " + name + " in " + zipfile)
}
// zip per-file header layout:
// 0 magic[4]
// 4 extvers[1]
// 5 extos[1]
// 6 flags[2]
// 8 meth[2]
// 10 modtime[2]
// 12 moddate[2]
// 14 crc[4]
// 18 csize[4]
// 22 uncsize[4]
// 26 namelen[2]
// 28 xlen[2]
// 30 name[namelen]
// 30+namelen+xlen - file data
//
buf = make([]byte, zheadersize+namelen)
if err := preadn(fd, buf, off); err != nil ||
get4(buf) != zheader ||
get2(buf[8:]) != meth ||
get2(buf[26:]) != namelen ||
string(buf[30:30+namelen]) != name {
return nil, errors.New("corrupt zip file " + zipfile)
}
xlen = get2(buf[28:])
buf = make([]byte, size)
if err := preadn(fd, buf, off+30+namelen+xlen); err != nil {
return nil, errors.New("corrupt zip file " + zipfile)
}
return buf, nil
}
return nil, syscall.ENOENT
}
// loadTzinfoFromTzdata returns the time zone information of the time zone
// with the given name, from a tzdata database file as they are typically
// found on android.
var loadTzinfoFromTzdata func(file, name string) ([]byte, error)
// loadTzinfo returns the time zone information of the time zone
// with the given name, from a given source. A source may be a
// timezone database directory, tzdata database file or an uncompressed
// zip file, containing the contents of such a directory.
func loadTzinfo(name string, source string) ([]byte, error) {
if len(source) >= 6 && source[len(source)-6:] == "tzdata" {
return loadTzinfoFromTzdata(source, name)
}
return loadTzinfoFromDirOrZip(source, name)
}
// loadLocation returns the Location with the given name from one of
// the specified sources. See loadTzinfo for a list of supported sources.
// The first timezone data matching the given name that is successfully loaded
// and parsed is returned as a Location.
func loadLocation(name string, sources []string) (z *Location, firstErr error) {
for _, source := range sources {
zoneData, err := loadTzinfo(name, source)
if err == nil {
if z, err = LoadLocationFromTZData(name, zoneData); err == nil {
return z, nil
}
}
if firstErr == nil && err != syscall.ENOENT {
firstErr = err
}
}
if loadFromEmbeddedTZData != nil {
zoneData, err := loadFromEmbeddedTZData(name)
if err == nil {
if z, err = LoadLocationFromTZData(name, []byte(zoneData)); err == nil {
return z, nil
}
}
if firstErr == nil && err != syscall.ENOENT {
firstErr = err
}
}
if source, ok := gorootZoneSource(runtime.GOROOT()); ok {
zoneData, err := loadTzinfo(name, source)
if err == nil {
if z, err = LoadLocationFromTZData(name, zoneData); err == nil {
return z, nil
}
}
if firstErr == nil && err != syscall.ENOENT {
firstErr = err
}
}
if firstErr != nil {
return nil, firstErr
}
return nil, errors.New("unknown time zone " + name)
}
// readFile reads and returns the content of the named file.
// It is a trivial implementation of os.ReadFile, reimplemented
// here to avoid depending on io/ioutil or os.
// It returns an error if name exceeds maxFileSize bytes.
func readFile(name string) ([]byte, error) {
f, err := open(name)
if err != nil {
return nil, err
}
defer closefd(f)
var (
buf [4096]byte
ret []byte
n int
)
for {
n, err = read(f, buf[:])
if n > 0 {
ret = append(ret, buf[:n]...)
}
if n == 0 || err != nil {
break
}
if len(ret) > maxFileSize {
return nil, fileSizeError(name)
}
}
return ret, err
}
func gorootZoneSource(goroot string) (string, bool) {
if goroot == "" {
return "", false
}
return goroot + "/lib/time/zoneinfo.zip", true
}

69
internal/lib/time/zoneinfo_unix.go Normal file
View File

@@ -0,0 +1,69 @@
// 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.
//go:build unix && !ios && !android
// Parse "zoneinfo" time zone file.
// This is a fairly standard file format used on OS X, Linux, BSD, Sun, and others.
// See tzfile(5), https://en.wikipedia.org/wiki/Zoneinfo,
// and ftp://munnari.oz.au/pub/oldtz/
package time
import (
"syscall"
)
// Many systems use /usr/share/zoneinfo, Solaris 2 has
// /usr/share/lib/zoneinfo, IRIX 6 has /usr/lib/locale/TZ,
// NixOS has /etc/zoneinfo.
var platformZoneSources = []string{
"/usr/share/zoneinfo/",
"/usr/share/lib/zoneinfo/",
"/usr/lib/locale/TZ/",
"/etc/zoneinfo",
}
func initLocal() {
// consult $TZ to find the time zone to use.
// no $TZ means use the system default /etc/localtime.
// $TZ="" means use UTC.
// $TZ="foo" or $TZ=":foo" if foo is an absolute path, then the file pointed
// by foo will be used to initialize timezone; otherwise, file
// /usr/share/zoneinfo/foo will be used.
tz, ok := syscall.Getenv("TZ")
switch {
case !ok:
z, err := loadLocation("localtime", []string{"/etc"})
if err == nil {
localLoc = *z
localLoc.name = "Local"
return
}
case tz != "":
if tz[0] == ':' {
tz = tz[1:]
}
if tz != "" && tz[0] == '/' {
if z, err := loadLocation(tz, []string{""}); err == nil {
localLoc = *z
if tz == "/etc/localtime" {
localLoc.name = "Local"
} else {
localLoc.name = tz
}
return
}
} else if tz != "" && tz != "UTC" {
if z, err := loadLocation(tz, platformZoneSources); err == nil {
localLoc = *z
return
}
}
}
// Fall back to UTC.
localLoc.name = "UTC"
}