forked from toolshed/abra
		
	
		
			
				
	
	
		
			92 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			92 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
//go:build plan9
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// +build plan9
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package osfs
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import (
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	"io"
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	"os"
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	"path/filepath"
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	"syscall"
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)
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func (f *file) Lock() error {
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	// Plan 9 uses a mode bit instead of explicit lock/unlock syscalls.
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	//
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	// Per http://man.cat-v.org/plan_9/5/stat: “Exclusive use files may be open
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	// for I/O by only one fid at a time across all clients of the server. If a
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	// second open is attempted, it draws an error.”
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	//
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	// There is no obvious way to implement this function using the exclusive use bit.
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	// See https://golang.org/src/cmd/go/internal/lockedfile/lockedfile_plan9.go
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	// for how file locking is done by the go tool on Plan 9.
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	return nil
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}
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func (f *file) Unlock() error {
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	return nil
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}
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func rename(from, to string) error {
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	// If from and to are in different directories, copy the file
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	// since Plan 9 does not support cross-directory rename.
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	if filepath.Dir(from) != filepath.Dir(to) {
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		fi, err := os.Stat(from)
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		if err != nil {
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			return &os.LinkError{"rename", from, to, err}
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		}
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		if fi.Mode().IsDir() {
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			return &os.LinkError{"rename", from, to, syscall.EISDIR}
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		}
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		fromFile, err := os.Open(from)
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		if err != nil {
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			return &os.LinkError{"rename", from, to, err}
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		}
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		toFile, err := os.OpenFile(to, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, fi.Mode())
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		if err != nil {
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			return &os.LinkError{"rename", from, to, err}
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		}
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		_, err = io.Copy(toFile, fromFile)
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		if err != nil {
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			return &os.LinkError{"rename", from, to, err}
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		}
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		// Copy mtime and mode from original file.
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		// We need only one syscall if we avoid os.Chmod and os.Chtimes.
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		dir := fi.Sys().(*syscall.Dir)
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		var d syscall.Dir
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		d.Null()
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		d.Mtime = dir.Mtime
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		d.Mode = dir.Mode
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		if err = dirwstat(to, &d); err != nil {
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			return &os.LinkError{"rename", from, to, err}
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		}
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		// Remove original file.
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		err = os.Remove(from)
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		if err != nil {
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			return &os.LinkError{"rename", from, to, err}
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		}
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		return nil
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	}
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	return os.Rename(from, to)
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}
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func dirwstat(name string, d *syscall.Dir) error {
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	var buf [syscall.STATFIXLEN]byte
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	n, err := d.Marshal(buf[:])
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	if err != nil {
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		return &os.PathError{"dirwstat", name, err}
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	}
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	if err = syscall.Wstat(name, buf[:n]); err != nil {
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		return &os.PathError{"dirwstat", name, err}
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	}
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	return nil
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}
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func umask(new int) func() {
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	return func() {
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	}
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}
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