moby/pkg/system/chtimes.go
Sebastiaan van Stijn 0b8444aa0c
pkg/system: rename maxTime and re-use, define unixEpochTime, update GoDoc
This more closely matches to how it's used everywhere. Also move the comment
describing "what" ChTimes() does inside its GoDoc.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2022-10-07 18:34:44 +02:00

48 lines
1.3 KiB
Go

package system // import "github.com/docker/docker/pkg/system"
import (
"os"
"syscall"
"time"
"unsafe"
)
// Used by Chtimes
var unixEpochTime, unixMaxTime time.Time
func init() {
unixEpochTime = time.Unix(0, 0)
if unsafe.Sizeof(syscall.Timespec{}.Nsec) == 8 {
// This is a 64 bit timespec
// os.Chtimes limits time to the following
//
// Note that this intentionally sets nsec (not sec), which sets both sec
// and nsec internally in time.Unix();
// https://github.com/golang/go/blob/go1.19.2/src/time/time.go#L1364-L1380
unixMaxTime = time.Unix(0, 1<<63-1)
} else {
// This is a 32 bit timespec
unixMaxTime = time.Unix(1<<31-1, 0)
}
}
// Chtimes changes the access time and modified time of a file at the given path.
// If the modified time is prior to the Unix Epoch (unixMinTime), or after the
// end of Unix Time (unixEpochTime), os.Chtimes has undefined behavior. In this
// case, Chtimes defaults to Unix Epoch, just in case.
func Chtimes(name string, atime time.Time, mtime time.Time) error {
if atime.Before(unixEpochTime) || atime.After(unixMaxTime) {
atime = unixEpochTime
}
if mtime.Before(unixEpochTime) || mtime.After(unixMaxTime) {
mtime = unixEpochTime
}
if err := os.Chtimes(name, atime, mtime); err != nil {
return err
}
// Take platform specific action for setting create time.
return setCTime(name, mtime)
}