Imported Upstream version 1upstream/1

1 files changed, 43 insertions, 184 deletions

diff --git a/src/pkg/time/zoneinfo_unix.go b/src/pkg/time/zoneinfo_unix.go
index f3ea7b6fd..2c951a983 100644
--- a/src/pkg/time/zoneinfo_unix.go
+++ b/src/pkg/time/zoneinfo_unix.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build darwin freebsd linux netbsd openbsd
+
 // 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,
@@ -10,204 +12,61 @@
 package time
 
 import (
-	"io/ioutil"
-	"os"
-)
-
-const (
-	headerSize = 4 + 16 + 4*7
+	"errors"
+	"runtime"
+	"syscall"
 )
 
-// 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
+func initTestingZone() {
+	z, err := loadZoneFile(runtime.GOROOT()+"/lib/time/zoneinfo.zip", "America/Los_Angeles")
+	if err != nil {
+		panic("cannot load America/Los_Angeles for testing: " + err.Error())
 	}
-	return p[0], true
+	z.name = "Local"
+	localLoc = *z
 }
 
-// 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)
+// Many systems use /usr/share/zoneinfo, Solaris 2 has
+// /usr/share/lib/zoneinfo, IRIX 6 has /usr/lib/locale/TZ.
+var zoneDirs = []string{
+	"/usr/share/zoneinfo/",
+	"/usr/share/lib/zoneinfo/",
+	"/usr/lib/locale/TZ/",
+	runtime.GOROOT() + "/lib/time/zoneinfo/",
 }
 
-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:])
-	}
+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" means use /usr/share/zoneinfo/foo.
 
-	// 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
+	tz, ok := syscall.Getenv("TZ")
+	switch {
+	case !ok:
+		z, err := loadZoneFile("", "/etc/localtime")
+		if err == nil {
+			localLoc = *z
+			localLoc.name = "Local"
+			return
 		}
-		if i < len(isutc) {
-			zt[i].isutc = isutc[i] != 0
+	case tz != "" && tz != "UTC":
+		if z, err := loadLocation(tz); err == nil {
+			localLoc = *z
+			return
 		}
 	}
-	return zt, true
-}
 
-func readinfofile(name string) ([]zonetime, bool) {
-	buf, err := ioutil.ReadFile(name)
-	if err != nil {
-		return nil, false
-	}
-	return parseinfo(buf)
+	// Fall back to UTC.
+	localLoc.name = "UTC"
 }
 
-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.
-	// Many systems use /usr/share/zoneinfo, Solaris 2 has
-	// /usr/share/lib/zoneinfo, IRIX 6 has /usr/lib/locale/TZ.
-	zoneDirs := []string{"/usr/share/zoneinfo/",
-		"/usr/share/lib/zoneinfo/",
-		"/usr/lib/locale/TZ/"}
-
-	tz, err := os.Getenverror("TZ")
-	switch {
-	case err == os.ENOENV:
-		zones, _ = readinfofile("/etc/localtime")
-	case len(tz) > 0:
-		for _, zoneDir := range zoneDirs {
-			var ok bool
-			if zones, ok = readinfofile(zoneDir + tz); ok {
-				break
-			}
+func loadLocation(name string) (*Location, error) {
+	for _, zoneDir := range zoneDirs {
+		if z, err := loadZoneFile(zoneDir, name); err == nil {
+			z.name = name
+			return z, nil
 		}
-	case len(tz) == 0:
-		// do nothing: use UTC
 	}
+	return nil, errors.New("unknown time zone " + name)
 }