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path: root/src/lib/time/zoneinfo.go
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Diffstat (limited to 'src/lib/time/zoneinfo.go')
-rw-r--r--src/lib/time/zoneinfo.go145
1 files changed, 73 insertions, 72 deletions
diff --git a/src/lib/time/zoneinfo.go b/src/lib/time/zoneinfo.go
index 5dc74d4ee..ea75f8cb9 100644
--- a/src/lib/time/zoneinfo.go
+++ b/src/lib/time/zoneinfo.go
@@ -16,8 +16,10 @@ import (
)
const (
- _MaxFileSize = 8192; // actual files are closer to 1K
- _HeaderSize = 4+16+4*7
+ maxFileSize = 8192; // actual files are closer to 1K
+ headerSize = 4+16+4*7;
+
+ zoneDir = "/usr/share/zoneinfo/";
)
var (
@@ -26,13 +28,13 @@ var (
)
// Simple I/O interface to binary blob of data.
-type _Data struct {
+type data struct {
p []byte;
error bool;
}
-func (d *_Data) Read(n int) []byte {
+func (d *data) read(n int) []byte {
if len(d.p) < n {
d.p = nil;
d.error = true;
@@ -43,8 +45,8 @@ func (d *_Data) Read(n int) []byte {
return p
}
-func (d *_Data) Big4() (n uint32, ok bool) {
- p := d.Read(4);
+func (d *data) big4() (n uint32, ok bool) {
+ p := d.read(4);
if len(p) < 4 {
d.error = true;
return 0, false
@@ -52,8 +54,8 @@ func (d *_Data) Big4() (n uint32, ok bool) {
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);
+func (d *data) byte() (n byte, ok bool) {
+ p := d.read(1);
if len(p) < 1 {
d.error = true;
return 0, false
@@ -63,7 +65,7 @@ func (d *_Data) Byte() (n byte, ok bool) {
// Make a string by stopping at the first NUL
-func _ByteString(p []byte) string {
+func byteString(p []byte) string {
for i := 0; i < len(p); i++ {
if p[i] == 0 {
return string(p[0:i])
@@ -73,31 +75,29 @@ func _ByteString(p []byte) string {
}
// Parsed representation
-type _Zone struct {
+type zone struct {
utcoff int;
isdst bool;
name string;
}
-type _Zonetime struct {
+type zonetime struct {
time int32; // transition time, in seconds since 1970 GMT
- zone *_Zone; // the zone that goes into effect at that time
+ 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, err *os.Error) {
-
- data1 := _Data(bytes, false);
- data := &data1;
+func parseinfo(bytes []byte) (zt []zonetime, err *os.Error) {
+ d := data(bytes, false);
// 4-byte magic "TZif"
- if magic := data.Read(4); string(magic) != "TZif" {
+ if magic := d.read(4); string(magic) != "TZif" {
return nil, BadZoneinfo
}
// 1-byte version, then 15 bytes of padding
var p []byte;
- if p = data.Read(16); len(p) != 16 || p[0] != 0 && p[0] != '2' {
+ if p = d.read(16); len(p) != 16 || p[0] != 0 && p[0] != '2' {
return nil, BadZoneinfo
}
vers := p[0];
@@ -119,7 +119,7 @@ func parseinfo(bytes []byte) (zt []_Zonetime, err *os.Error) {
)
var n [6]int;
for i := 0; i < 6; i++ {
- nn, ok := data.Big4();
+ nn, ok := d.big4();
if !ok {
return nil, BadZoneinfo
}
@@ -127,32 +127,29 @@ func parseinfo(bytes []byte) (zt []_Zonetime, err *os.Error) {
}
// Transition times.
- txtimes1 := _Data(data.Read(n[NTime]*4), false);
- txtimes := &txtimes1;
+ txtimes := data(d.read(n[NTime]*4), false);
// Time zone indices for transition times.
- txzones := data.Read(n[NTime]);
+ txzones := d.read(n[NTime]);
// Zone info structures
- zonedata1 := _Data(data.Read(n[NZone]*6), false);
- zonedata := &zonedata1;
+ zonedata := data(d.read(n[NZone]*6), false);
// Time zone abbreviations.
- abbrev := data.Read(n[NChar]);
+ abbrev := d.read(n[NChar]);
// Leap-second time pairs
- leapdata1 := _Data(data.Read(n[NLeap]*8), false);
- leapdata := &leapdata1;
+ leapdata := data(d.read(n[NLeap]*8), false);
// Whether tx times associated with local time types
// are specified as standard time or wall time.
- isstd := data.Read(n[NStdWall]);
+ isstd := d.read(n[NStdWall]);
// Whether tx times associated with local time types
// are specified as UTC or local time.
- isutc := data.Read(n[NUTCLocal]);
+ isutc := d.read(n[NUTCLocal]);
- if data.error { // ran out of data
+ if d.error { // ran out of data
return nil, BadZoneinfo
}
@@ -163,38 +160,38 @@ func parseinfo(bytes []byte) (zt []_Zonetime, err *os.Error) {
// Now we can build up a useful data structure.
// First the zone information.
// utcoff[4] isdst[1] nameindex[1]
- zone := make([]_Zone, n[NZone]);
- for i := 0; i < len(zone); i++ {
+ z := make([]zone, n[NZone]);
+ for i := 0; i < len(z); i++ {
var ok bool;
var n uint32;
- if n, ok = zonedata.Big4(); !ok {
+ if n, ok = zonedata.big4(); !ok {
return nil, BadZoneinfo
}
- zone[i].utcoff = int(n);
+ z[i].utcoff = int(n);
var b byte;
- if b, ok = zonedata.Byte(); !ok {
+ if b, ok = zonedata.byte(); !ok {
return nil, BadZoneinfo
}
- zone[i].isdst = b != 0;
- if b, ok = zonedata.Byte(); !ok || int(b) >= len(abbrev) {
+ z[i].isdst = b != 0;
+ if b, ok = zonedata.byte(); !ok || int(b) >= len(abbrev) {
return nil, BadZoneinfo
}
- zone[i].name = _ByteString(abbrev[b:len(abbrev)])
+ z[i].name = byteString(abbrev[b:len(abbrev)])
}
// Now the transition time info.
- zt = make([]_Zonetime, n[NTime]);
+ zt = make([]zonetime, n[NTime]);
for i := 0; i < len(zt); i++ {
var ok bool;
var n uint32;
- if n, ok = txtimes.Big4(); !ok {
+ if n, ok = txtimes.big4(); !ok {
return nil, BadZoneinfo
}
zt[i].time = int32(n);
- if int(txzones[i]) >= len(zone) {
+ if int(txzones[i]) >= len(z) {
return nil, BadZoneinfo
}
- zt[i].zone = &zone[txzones[i]];
+ zt[i].zone = &z[txzones[i]];
if i < len(isstd) {
zt[i].isstd = isstd[i] != 0
}
@@ -208,52 +205,56 @@ func parseinfo(bytes []byte) (zt []_Zonetime, err *os.Error) {
func readfile(name string, max int) (p []byte, err *os.Error) {
fd, e := os.Open(name, os.O_RDONLY, 0);
if e != nil {
- return nil, e
- }
- p = make([]byte, max+1)[0:0];
- n := 0;
- for len(p) < max {
- nn, e := fd.Read(p[n:cap(p)]);
- if e != nil {
- fd.Close();
- return nil, e
- }
- if nn == 0 {
- fd.Close();
- return p, nil
- }
- p = p[0:n+nn]
+ return nil, e;
}
+ p = make([]byte, max);
+ n, err1 := io.Readn(fd, p);
fd.Close();
- return nil, BadZoneinfo // too long
+ if err1 == nil { // too long
+ return nil, BadZoneinfo;
+ }
+ if err1 != io.ErrEOF {
+ return nil, err1;
+ }
+ return p[0:n], nil;
}
-
-func readinfofile(name string) (tx []_Zonetime, err *os.Error) {
- data, e := readfile(name, _MaxFileSize);
+func readinfofile(name string) (tx []zonetime, err *os.Error) {
+ buf, e := readfile(name, maxFileSize);
if e != nil {
return nil, e
}
- tx, err = parseinfo(data);
+ tx, err = parseinfo(buf);
return tx, err
}
-var zones []_Zonetime
+var zones []zonetime
var zoneerr *os.Error
-func _SetupZone() {
- // TODO: /etc/localtime is the default time zone info
- // for the system, but libc allows setting an environment
- // variable in order to direct reading a different file
- // (in /usr/share/zoneinfo). We should check that
- // environment variable.
- zones, zoneerr = readinfofile("/etc/localtime");
+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.Getenv("TZ");
+ var file string;
+ switch {
+ case err == os.ENOENV:
+ zones, zoneerr = readinfofile("/etc/localtime");
+ case err != nil:
+ zoneerr = err;
+ case len(tz) > 0:
+ zones, zoneerr = readinfofile(zoneDir + tz);
+ case len(tz) == 0:
+ // do nothing: use UTC
+ }
}
func LookupTimezone(sec int64) (zone string, offset int, err *os.Error) {
- once.Do(_SetupZone);
+ once.Do(setupZone);
if zoneerr != nil || len(zones) == 0 {
- return "GMT", 0, zoneerr
+ return "UTC", 0, zoneerr
}
// Binary search for entry with largest time <= sec
generated by cgit v1.2.3 (git 2.39.1) at 2025-06-05 07:31:30 +0000