driver

type ErrUnsupportedMethod struct {
	DriverName string
}

type Error struct {
	DriverName string
	Enclosed   error
}

type FileInfo interface {
	// Path provides the full path of the target of this file info.
	Path() string

	// Size returns current length in bytes of the file. The return value can
	// be used to write to the end of the file at path. The value is
	// meaningless if IsDir returns true.
	Size() int64

	// ModTime returns the modification time for the file. For backends that
	// don't have a modification time, the creation time should be returned.
	ModTime() time.Time

	// IsDir returns true if the path is a directory.
	IsDir() bool
}

type FileInfoFields struct {
	// Path provides the full path of the target of this file info.
	Path string

	// Size is current length in bytes of the file. The value of this field
	// can be used to write to the end of the file at path. The value is
	// meaningless if IsDir is set to true.
	Size int64

	// ModTime returns the modification time for the file. For backends that
	// don't have a modification time, the creation time should be returned.
	ModTime time.Time

	// IsDir returns true if the path is a directory.
	IsDir bool
}

type FileInfoInternal struct {
	FileInfoFields
}

type FileWriter interface {
	io.WriteCloser

	// Size returns the number of bytes written to this FileWriter.
	Size() int64

	// Cancel removes any written content from this FileWriter.
	Cancel() error

	// Commit flushes all content written to this FileWriter and makes it
	// available for future calls to StorageDriver.GetContent and
	// StorageDriver.Reader.
	Commit() error
}

type InvalidOffsetError struct {
	Path       string
	Offset     int64
	DriverName string
}

type InvalidPathError struct {
	Path       string
	DriverName string
}

type PathNotFoundError struct {
	Path       string
	DriverName string
}

type StorageDriver interface {
	// Name returns the human-readable "name" of the driver, useful in error
	// messages and logging. By convention, this will just be the registration
	// name, but drivers may provide other information here.
	Name() string

	// GetContent retrieves the content stored at "path" as a []byte.
	// This should primarily be used for small objects.
	GetContent(ctx context.Context, path string) ([]byte, error)

	// PutContent stores the []byte content at a location designated by "path".
	// This should primarily be used for small objects.
	PutContent(ctx context.Context, path string, content []byte) error

	// Reader retrieves an io.ReadCloser for the content stored at "path"
	// with a given byte offset.
	// May be used to resume reading a stream by providing a nonzero offset.
	Reader(ctx context.Context, path string, offset int64) (io.ReadCloser, error)

	// Writer returns a FileWriter which will store the content written to it
	// at the location designated by "path" after the call to Commit.
	Writer(ctx context.Context, path string, append bool) (FileWriter, error)

	// Stat retrieves the FileInfo for the given path, including the current
	// size in bytes and the creation time.
	Stat(ctx context.Context, path string) (FileInfo, error)

	// List returns a list of the objects that are direct descendants of the
	//given path.
	List(ctx context.Context, path string) ([]string, error)

	// Move moves an object stored at sourcePath to destPath, removing the
	// original object.
	// Note: This may be no more efficient than a copy followed by a delete for
	// many implementations.
	Move(ctx context.Context, sourcePath string, destPath string) error

	// Delete recursively deletes all objects stored at "path" and its subpaths.
	Delete(ctx context.Context, path string) error

	// URLFor returns a URL which may be used to retrieve the content stored at
	// the given path, possibly using the given options.
	// May return an ErrUnsupportedMethod in certain StorageDriver
	// implementations.
	URLFor(ctx context.Context, path string, options map[string]interface{}) (string, error)

	// Walk traverses a filesystem defined within driver, starting
	// from the given path, calling f on each file.
	// If the returned error from the WalkFn is ErrSkipDir and fileInfo refers
	// to a directory, the directory will not be entered and Walk
	// will continue the traversal.  If fileInfo refers to a normal file, processing stops
	Walk(ctx context.Context, path string, f WalkFn) error
}

type Version string

type WalkFn func(fileInfo FileInfo) error