feat: Add portable Timespec implementation for FileInfo

internal/fs/file.go

@@ -7,6 +7,7 @@ import (
 	"io/fs"
 	"os"
 	"sync"
+	"time"
 
 	"github.com/pojntfx/stfs/internal/ioext"
 	"github.com/pojntfx/stfs/pkg/cache"
@@ -124,17 +125,24 @@ func (f *File) syncWithoutLocking() error {
 				// Some OSes like i.e. Windows don't support numeric GIDs and UIDs, so use 0 instead
 				gid := 0
 				uid := 0
+				modTime := f.info.ModTime()
+				accessTime := f.info.ModTime()
+				changeTime := f.info.ModTime()
 				sys, ok := f.info.Sys().(*Stat)
 				if ok {
 					gid = int(sys.Gid)
 					uid = int(sys.Uid)
+					accessTime = time.Unix(0, sys.Atim.Nano())
+					changeTime = time.Unix(0, sys.Ctim.Nano())
 				}
 
 				f.info = NewFileInfo(
 					f.info.Name(),
 					size,
 					f.info.Mode(),
-					f.info.ModTime(),
+					modTime,
+					accessTime,
+					changeTime,
 					gid,
 					uid,
 					f.info.IsDir(),

internal/fs/file_non_unix.go

@@ -1,8 +0,0 @@
-//go:build windows
-
-package fs
-
-type Stat struct {
-	Uid uint32
-	Gid uint32
-}

internal/fs/file_unix.go

@@ -1,7 +0,0 @@
-//go:build !windows
-
-package fs
-
-import "syscall"
-
-type Stat syscall.Stat_t

internal/fs/fileinfo.go

@@ -16,6 +16,8 @@ type FileInfo struct {
 	size       int64
 	mode       fs.FileMode
 	modTime    time.Time
+	accessTime time.Time
+	changeTime time.Time
 	gid        int
 	uid        int
 	isDir      bool
@@ -28,6 +30,8 @@ func NewFileInfo(
 	size int64,
 	mode fs.FileMode,
 	modTime time.Time,
+	accessTime time.Time,
+	changeTime time.Time,
 	gid int,
 	uid int,
 	isDir bool,
@@ -39,6 +43,8 @@ func NewFileInfo(
 		size:       size,
 		mode:       mode,
 		modTime:    modTime,
+		accessTime: accessTime,
+		changeTime: changeTime,
 		gid:        gid,
 		uid:        uid,
 		isDir:      isDir,
@@ -57,6 +63,8 @@ func NewFileInfoFromTarHeader(
 		size:       hdr.FileInfo().Size(),
 		mode:       hdr.FileInfo().Mode(),
 		modTime:    hdr.FileInfo().ModTime(),
+		accessTime: hdr.AccessTime,
+		changeTime: hdr.ChangeTime,
 		gid:        hdr.Gid,
 		uid:        hdr.Uid,
 		isDir:      hdr.FileInfo().IsDir(),
@@ -110,8 +118,11 @@ func (f *FileInfo) Sys() interface{} {
 		"name": f.name,
 	})
 
-	return &Stat{
-		Uid: uint32(f.uid),
-		Gid: uint32(f.gid),
-	}
+	return NewStat(
+		uint32(f.uid),
+		uint32(f.gid),
+		f.modTime.UnixNano(),
+		f.accessTime.UnixNano(),
+		f.changeTime.UnixNano(),
+	)
 }

internal/fs/fileinfo_non_unix.go

@@ -0,0 +1,52 @@
+//go:build !linux
+
+package fs
+
+// From the Go stdlib for linux/amd64
+type Timespec struct {
+	Sec  int64
+	Nsec int64
+}
+
+func (ts *Timespec) Unix() (sec int64, nsec int64) {
+	return int64(ts.Sec), int64(ts.Nsec)
+}
+
+func (ts *Timespec) Nano() int64 {
+	return int64(ts.Sec)*1e9 + int64(ts.Nsec)
+}
+
+func NsecToTimespec(nsec int64) Timespec {
+	sec := nsec / 1e9
+	nsec = nsec % 1e9
+	if nsec < 0 {
+		nsec += 1e9
+		sec--
+	}
+
+	return Timespec{Sec: sec, Nsec: nsec}
+}
+
+type Stat struct {
+	Uid  uint32
+	Gid  uint32
+	Mtim Timespec
+	Atim Timespec
+	Ctim Timespec
+}
+
+func NewStat(
+	uid uint32,
+	gid uint32,
+	mtim int64,
+	atim int64,
+	ctim int64,
+) *Stat {
+	return &Stat{
+		Uid:  uid,
+		Gid:  gid,
+		Mtim: NsecToTimespec(mtim),
+		Atim: NsecToTimespec(atim),
+		Ctim: NsecToTimespec(ctim),
+	}
+}

internal/fs/fileinfo_unix.go

@@ -0,0 +1,23 @@
+//go:build linux
+
+package fs
+
+import "syscall"
+
+type Stat syscall.Stat_t
+
+func NewStat(
+	uid uint32,
+	gid uint32,
+	mtim int64,
+	atim int64,
+	ctim int64,
+) *Stat {
+	return &Stat{
+		Uid:  uid,
+		Gid:  gid,
+		Mtim: syscall.NsecToTimespec(mtim),
+		Atim: syscall.NsecToTimespec(atim),
+		Ctim: syscall.NsecToTimespec(ctim),
+	}
+}