111 lines
2.6 KiB
Go
111 lines
2.6 KiB
Go
// Copyright 2011 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package os
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import (
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"syscall"
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"time"
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)
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func sameFile(fs1, fs2 *fileStat) bool {
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a := fs1.sys.(*syscall.Dir)
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b := fs2.sys.(*syscall.Dir)
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return a.Qid.Path == b.Qid.Path && a.Type == b.Type && a.Dev == b.Dev
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}
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func fileInfoFromStat(d *syscall.Dir) FileInfo {
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fs := &fileStat{
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name: d.Name,
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size: int64(d.Length),
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modTime: time.Unix(int64(d.Mtime), 0),
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sys: d,
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}
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fs.mode = FileMode(d.Mode & 0777)
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if d.Mode&syscall.DMDIR != 0 {
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fs.mode |= ModeDir
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}
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if d.Mode&syscall.DMAPPEND != 0 {
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fs.mode |= ModeAppend
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}
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if d.Mode&syscall.DMEXCL != 0 {
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fs.mode |= ModeExclusive
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}
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if d.Mode&syscall.DMTMP != 0 {
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fs.mode |= ModeTemporary
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}
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return fs
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}
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// arg is an open *File or a path string.
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func dirstat(arg interface{}) (*syscall.Dir, error) {
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var name string
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// This is big enough for most stat messages
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// and rounded to a multiple of 128 bytes.
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size := (syscall.STATFIXLEN + 16*4 + 128) &^ 128
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for i := 0; i < 2; i++ {
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buf := make([]byte, size)
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var n int
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var err error
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switch a := arg.(type) {
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case *File:
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name = a.name
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n, err = syscall.Fstat(a.fd, buf)
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case string:
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name = a
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n, err = syscall.Stat(a, buf)
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default:
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panic("phase error in dirstat")
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}
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if err != nil {
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return nil, &PathError{"stat", name, err}
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}
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if n < syscall.STATFIXLEN {
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return nil, &PathError{"stat", name, syscall.ErrShortStat}
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}
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// Pull the real size out of the stat message.
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size = int(uint16(buf[0]) | uint16(buf[1])<<8)
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// If the stat message is larger than our buffer we will
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// go around the loop and allocate one that is big enough.
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if size > n {
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continue
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}
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d, err := syscall.UnmarshalDir(buf[:n])
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if err != nil {
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return nil, &PathError{"stat", name, err}
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}
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return d, nil
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}
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return nil, &PathError{"stat", name, syscall.ErrBadStat}
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}
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// Stat returns a FileInfo describing the named file.
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// If there is an error, it will be of type *PathError.
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func Stat(name string) (fi FileInfo, err error) {
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d, err := dirstat(name)
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if err != nil {
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return nil, err
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}
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return fileInfoFromStat(d), nil
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}
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// Lstat returns a FileInfo describing the named file.
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// If the file is a symbolic link, the returned FileInfo
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// describes the symbolic link. Lstat makes no attempt to follow the link.
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// If there is an error, it will be of type *PathError.
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func Lstat(name string) (fi FileInfo, err error) {
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return Stat(name)
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}
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// For testing.
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func atime(fi FileInfo) time.Time {
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return time.Unix(int64(fi.Sys().(*syscall.Dir).Atime), 0)
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}
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