From ccd992355df7192993c666236047820244914598 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Tue, 16 Apr 2024 21:19:13 +0200 Subject: Adding upstream version 1.21.8. Signed-off-by: Daniel Baumann --- src/os/file_posix.go | 256 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 256 insertions(+) create mode 100644 src/os/file_posix.go (limited to 'src/os/file_posix.go') diff --git a/src/os/file_posix.go b/src/os/file_posix.go new file mode 100644 index 0000000..5692657 --- /dev/null +++ b/src/os/file_posix.go @@ -0,0 +1,256 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +//go:build unix || (js && wasm) || wasip1 || windows + +package os + +import ( + "runtime" + "syscall" + "time" +) + +// Close closes the File, rendering it unusable for I/O. +// On files that support SetDeadline, any pending I/O operations will +// be canceled and return immediately with an ErrClosed error. +// Close will return an error if it has already been called. +func (f *File) Close() error { + if f == nil { + return ErrInvalid + } + return f.file.close() +} + +// read reads up to len(b) bytes from the File. +// It returns the number of bytes read and an error, if any. +func (f *File) read(b []byte) (n int, err error) { + n, err = f.pfd.Read(b) + runtime.KeepAlive(f) + return n, err +} + +// pread reads len(b) bytes from the File starting at byte offset off. +// It returns the number of bytes read and the error, if any. +// EOF is signaled by a zero count with err set to nil. +func (f *File) pread(b []byte, off int64) (n int, err error) { + n, err = f.pfd.Pread(b, off) + runtime.KeepAlive(f) + return n, err +} + +// write writes len(b) bytes to the File. +// It returns the number of bytes written and an error, if any. +func (f *File) write(b []byte) (n int, err error) { + n, err = f.pfd.Write(b) + runtime.KeepAlive(f) + return n, err +} + +// pwrite writes len(b) bytes to the File starting at byte offset off. +// It returns the number of bytes written and an error, if any. +func (f *File) pwrite(b []byte, off int64) (n int, err error) { + n, err = f.pfd.Pwrite(b, off) + runtime.KeepAlive(f) + return n, err +} + +// syscallMode returns the syscall-specific mode bits from Go's portable mode bits. +func syscallMode(i FileMode) (o uint32) { + o |= uint32(i.Perm()) + if i&ModeSetuid != 0 { + o |= syscall.S_ISUID + } + if i&ModeSetgid != 0 { + o |= syscall.S_ISGID + } + if i&ModeSticky != 0 { + o |= syscall.S_ISVTX + } + // No mapping for Go's ModeTemporary (plan9 only). + return +} + +// See docs in file.go:Chmod. +func chmod(name string, mode FileMode) error { + longName := fixLongPath(name) + e := ignoringEINTR(func() error { + return syscall.Chmod(longName, syscallMode(mode)) + }) + if e != nil { + return &PathError{Op: "chmod", Path: name, Err: e} + } + return nil +} + +// See docs in file.go:(*File).Chmod. +func (f *File) chmod(mode FileMode) error { + if err := f.checkValid("chmod"); err != nil { + return err + } + if e := f.pfd.Fchmod(syscallMode(mode)); e != nil { + return f.wrapErr("chmod", e) + } + return nil +} + +// Chown changes the numeric uid and gid of the named file. +// If the file is a symbolic link, it changes the uid and gid of the link's target. +// A uid or gid of -1 means to not change that value. +// If there is an error, it will be of type *PathError. +// +// On Windows or Plan 9, Chown always returns the syscall.EWINDOWS or +// EPLAN9 error, wrapped in *PathError. +func Chown(name string, uid, gid int) error { + e := ignoringEINTR(func() error { + return syscall.Chown(name, uid, gid) + }) + if e != nil { + return &PathError{Op: "chown", Path: name, Err: e} + } + return nil +} + +// Lchown changes the numeric uid and gid of the named file. +// If the file is a symbolic link, it changes the uid and gid of the link itself. +// If there is an error, it will be of type *PathError. +// +// On Windows, it always returns the syscall.EWINDOWS error, wrapped +// in *PathError. +func Lchown(name string, uid, gid int) error { + e := ignoringEINTR(func() error { + return syscall.Lchown(name, uid, gid) + }) + if e != nil { + return &PathError{Op: "lchown", Path: name, Err: e} + } + return nil +} + +// Chown changes the numeric uid and gid of the named file. +// If there is an error, it will be of type *PathError. +// +// On Windows, it always returns the syscall.EWINDOWS error, wrapped +// in *PathError. +func (f *File) Chown(uid, gid int) error { + if err := f.checkValid("chown"); err != nil { + return err + } + if e := f.pfd.Fchown(uid, gid); e != nil { + return f.wrapErr("chown", e) + } + return nil +} + +// Truncate changes the size of the file. +// It does not change the I/O offset. +// If there is an error, it will be of type *PathError. +func (f *File) Truncate(size int64) error { + if err := f.checkValid("truncate"); err != nil { + return err + } + if e := f.pfd.Ftruncate(size); e != nil { + return f.wrapErr("truncate", e) + } + return nil +} + +// Sync commits the current contents of the file to stable storage. +// Typically, this means flushing the file system's in-memory copy +// of recently written data to disk. +func (f *File) Sync() error { + if err := f.checkValid("sync"); err != nil { + return err + } + if e := f.pfd.Fsync(); e != nil { + return f.wrapErr("sync", e) + } + return nil +} + +// Chtimes changes the access and modification times of the named +// file, similar to the Unix utime() or utimes() functions. +// A zero time.Time value will leave the corresponding file time unchanged. +// +// The underlying filesystem may truncate or round the values to a +// less precise time unit. +// If there is an error, it will be of type *PathError. +func Chtimes(name string, atime time.Time, mtime time.Time) error { + var utimes [2]syscall.Timespec + set := func(i int, t time.Time) { + if t.IsZero() { + utimes[i] = syscall.Timespec{Sec: _UTIME_OMIT, Nsec: _UTIME_OMIT} + } else { + utimes[i] = syscall.NsecToTimespec(t.UnixNano()) + } + } + set(0, atime) + set(1, mtime) + if e := syscall.UtimesNano(fixLongPath(name), utimes[0:]); e != nil { + return &PathError{Op: "chtimes", Path: name, Err: e} + } + return nil +} + +// Chdir changes the current working directory to the file, +// which must be a directory. +// If there is an error, it will be of type *PathError. +func (f *File) Chdir() error { + if err := f.checkValid("chdir"); err != nil { + return err + } + if e := f.pfd.Fchdir(); e != nil { + return f.wrapErr("chdir", e) + } + return nil +} + +// setDeadline sets the read and write deadline. +func (f *File) setDeadline(t time.Time) error { + if err := f.checkValid("SetDeadline"); err != nil { + return err + } + return f.pfd.SetDeadline(t) +} + +// setReadDeadline sets the read deadline. +func (f *File) setReadDeadline(t time.Time) error { + if err := f.checkValid("SetReadDeadline"); err != nil { + return err + } + return f.pfd.SetReadDeadline(t) +} + +// setWriteDeadline sets the write deadline. +func (f *File) setWriteDeadline(t time.Time) error { + if err := f.checkValid("SetWriteDeadline"); err != nil { + return err + } + return f.pfd.SetWriteDeadline(t) +} + +// checkValid checks whether f is valid for use. +// If not, it returns an appropriate error, perhaps incorporating the operation name op. +func (f *File) checkValid(op string) error { + if f == nil { + return ErrInvalid + } + return nil +} + +// ignoringEINTR makes a function call and repeats it if it returns an +// EINTR error. This appears to be required even though we install all +// signal handlers with SA_RESTART: see #22838, #38033, #38836, #40846. +// Also #20400 and #36644 are issues in which a signal handler is +// installed without setting SA_RESTART. None of these are the common case, +// but there are enough of them that it seems that we can't avoid +// an EINTR loop. +func ignoringEINTR(fn func() error) error { + for { + err := fn() + if err != syscall.EINTR { + return err + } + } +} -- cgit v1.2.3