diff options
Diffstat (limited to 'vendor/gopkg.in/src-d/go-billy.v4/util/util.go')
-rw-r--r-- | vendor/gopkg.in/src-d/go-billy.v4/util/util.go | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/vendor/gopkg.in/src-d/go-billy.v4/util/util.go b/vendor/gopkg.in/src-d/go-billy.v4/util/util.go new file mode 100644 index 0000000000..cf7fb57f75 --- /dev/null +++ b/vendor/gopkg.in/src-d/go-billy.v4/util/util.go @@ -0,0 +1,224 @@ +package util + +import ( + "io" + "os" + "path/filepath" + "strconv" + "sync" + "time" + + "gopkg.in/src-d/go-billy.v4" +) + +// RemoveAll removes path and any children it contains. It removes everything it +// can but returns the first error it encounters. If the path does not exist, +// RemoveAll returns nil (no error). +func RemoveAll(fs billy.Basic, path string) error { + fs, path = getUnderlyingAndPath(fs, path) + + if r, ok := fs.(removerAll); ok { + return r.RemoveAll(path) + } + + return removeAll(fs, path) +} + +type removerAll interface { + RemoveAll(string) error +} + +func removeAll(fs billy.Basic, path string) error { + // This implementation is adapted from os.RemoveAll. + + // Simple case: if Remove works, we're done. + err := fs.Remove(path) + if err == nil || os.IsNotExist(err) { + return nil + } + + // Otherwise, is this a directory we need to recurse into? + dir, serr := fs.Stat(path) + if serr != nil { + if os.IsNotExist(serr) { + return nil + } + + return serr + } + + if !dir.IsDir() { + // Not a directory; return the error from Remove. + return err + } + + dirfs, ok := fs.(billy.Dir) + if !ok { + return billy.ErrNotSupported + } + + // Directory. + fis, err := dirfs.ReadDir(path) + if err != nil { + if os.IsNotExist(err) { + // Race. It was deleted between the Lstat and Open. + // Return nil per RemoveAll's docs. + return nil + } + + return err + } + + // Remove contents & return first error. + err = nil + for _, fi := range fis { + cpath := fs.Join(path, fi.Name()) + err1 := removeAll(fs, cpath) + if err == nil { + err = err1 + } + } + + // Remove directory. + err1 := fs.Remove(path) + if err1 == nil || os.IsNotExist(err1) { + return nil + } + + if err == nil { + err = err1 + } + + return err + +} + +// WriteFile writes data to a file named by filename in the given filesystem. +// If the file does not exist, WriteFile creates it with permissions perm; +// otherwise WriteFile truncates it before writing. +func WriteFile(fs billy.Basic, filename string, data []byte, perm os.FileMode) error { + f, err := fs.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm) + if err != nil { + return err + } + + n, err := f.Write(data) + if err == nil && n < len(data) { + err = io.ErrShortWrite + } + + if err1 := f.Close(); err == nil { + err = err1 + } + + return err +} + +// Random number state. +// We generate random temporary file names so that there's a good +// chance the file doesn't exist yet - keeps the number of tries in +// TempFile to a minimum. +var rand uint32 +var randmu sync.Mutex + +func reseed() uint32 { + return uint32(time.Now().UnixNano() + int64(os.Getpid())) +} + +func nextSuffix() string { + randmu.Lock() + r := rand + if r == 0 { + r = reseed() + } + r = r*1664525 + 1013904223 // constants from Numerical Recipes + rand = r + randmu.Unlock() + return strconv.Itoa(int(1e9 + r%1e9))[1:] +} + +// TempFile creates a new temporary file in the directory dir with a name +// beginning with prefix, opens the file for reading and writing, and returns +// the resulting *os.File. If dir is the empty string, TempFile uses the default +// directory for temporary files (see os.TempDir). Multiple programs calling +// TempFile simultaneously will not choose the same file. The caller can use +// f.Name() to find the pathname of the file. It is the caller's responsibility +// to remove the file when no longer needed. +func TempFile(fs billy.Basic, dir, prefix string) (f billy.File, err error) { + // This implementation is based on stdlib ioutil.TempFile. + + if dir == "" { + dir = os.TempDir() + } + + nconflict := 0 + for i := 0; i < 10000; i++ { + name := filepath.Join(dir, prefix+nextSuffix()) + f, err = fs.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600) + if os.IsExist(err) { + if nconflict++; nconflict > 10 { + randmu.Lock() + rand = reseed() + randmu.Unlock() + } + continue + } + break + } + return +} + +// TempDir creates a new temporary directory in the directory dir +// with a name beginning with prefix and returns the path of the +// new directory. If dir is the empty string, TempDir uses the +// default directory for temporary files (see os.TempDir). +// Multiple programs calling TempDir simultaneously +// will not choose the same directory. It is the caller's responsibility +// to remove the directory when no longer needed. +func TempDir(fs billy.Dir, dir, prefix string) (name string, err error) { + // This implementation is based on stdlib ioutil.TempDir + + if dir == "" { + dir = os.TempDir() + } + + nconflict := 0 + for i := 0; i < 10000; i++ { + try := filepath.Join(dir, prefix+nextSuffix()) + err = fs.MkdirAll(try, 0700) + if os.IsExist(err) { + if nconflict++; nconflict > 10 { + randmu.Lock() + rand = reseed() + randmu.Unlock() + } + continue + } + if os.IsNotExist(err) { + if _, err := os.Stat(dir); os.IsNotExist(err) { + return "", err + } + } + if err == nil { + name = try + } + break + } + return +} + +type underlying interface { + Underlying() billy.Basic +} + +func getUnderlyingAndPath(fs billy.Basic, path string) (billy.Basic, string) { + u, ok := fs.(underlying) + if !ok { + return fs, path + } + if ch, ok := fs.(billy.Chroot); ok { + path = fs.Join(ch.Root(), path) + } + + return u.Underlying(), path +} |