示例#1
0
// newFileWriter returns a prepared fileWriter for the driver and path. This
// could be considered similar to an "open" call on a regular filesystem.
func newFileWriter(ctx context.Context, driver storagedriver.StorageDriver, path string) (*bufferedFileWriter, error) {
	fw := fileWriter{
		driver: driver,
		path:   path,
		ctx:    ctx,
	}

	if fi, err := driver.Stat(ctx, path); err != nil {
		switch err := err.(type) {
		case storagedriver.PathNotFoundError:
			// ignore, offset is zero
		default:
			return nil, err
		}
	} else {
		if fi.IsDir() {
			return nil, fmt.Errorf("cannot write to a directory")
		}

		fw.size = fi.Size()
	}

	buffered := bufferedFileWriter{
		fileWriter: fw,
	}
	buffered.bw = bufio.NewWriterSize(&buffered.fileWriter, fileWriterBufferSize)

	return &buffered, nil
}
示例#2
0
// Exists provides a utility method to test whether or not a path exists in
// the given driver.
func exists(ctx context.Context, drv driver.StorageDriver, path string) (bool, error) {
	if _, err := drv.Stat(ctx, path); err != nil {
		switch err := err.(type) {
		case driver.PathNotFoundError:
			return false, nil
		default:
			return false, err
		}
	}

	return true, nil
}
示例#3
0
// Walk traverses a filesystem defined within driver, starting
// from the given path, calling f on each file
func Walk(ctx context.Context, driver storageDriver.StorageDriver, from string, f WalkFn) error {
	children, err := driver.List(ctx, from)
	if err != nil {
		return err
	}
	for _, child := range children {
		fileInfo, err := driver.Stat(ctx, child)
		if err != nil {
			return err
		}
		err = f(fileInfo)
		skipDir := (err == ErrSkipDir)
		if err != nil && !skipDir {
			return err
		}

		if fileInfo.IsDir() && !skipDir {
			Walk(ctx, driver, child, f)
		}
	}
	return nil
}