fileops

type FSOption interface {
	Parameter() interface{}
}

type File interface {
	io.Closer
	io.Reader
	io.Seeker
	io.Writer
	io.ReaderAt
	Name() string
	Truncate(size int64) error
	Sync() error
	Stat() (os.FileInfo, error)
	SyncUpdateLength() error
	Fd() uintptr
}

type FileLockOption string

type FilePriorityOption int

type VFS interface {
	// Open opens the named file with specified options.
	// the optional opt is: (FileLockOption,FilePriorityOption)
	Open(name string, opt ...FSOption) (File, error)
	// OpenFile opens the named file with specified flag and other options.
	// the optional opt is: (FileLockOption,FilePriorityOption)
	OpenFile(name string, flag int, perm os.FileMode, opt ...FSOption) (File, error)
	// Create creates or truncates the named file. If the file already exists, it is truncated.
	// If the file does not exist, it is created with mode 0666
	// the optional opt is: (FileLockOption,FilePriorityOption)
	Create(name string, opt ...FSOption) (File, error)

	// Remove removes the named file or (empty) directory.
	// the optional opt is: FileLockOption
	Remove(name string, opt ...FSOption) error
	// RemoveAll removes path and any children it contains.
	// the optional opt is: FileLockOption
	RemoveAll(path string, opt ...FSOption) error
	// Mkdir creates a directory named path, it's parents directory must exist.
	// the optional opt is: FileLockOption
	Mkdir(path string, perm os.FileMode, opt ...FSOption) error
	// MkdirAll creates a directory named path, along with any necessary parents
	// the optional opt is: FileLockOption
	MkdirAll(path string, perm os.FileMode, opt ...FSOption) error
	// ReadDir reads the directory named by dirname and returns
	// a list of fs.FileInfo for the directory's contents, sorted by filename.
	ReadDir(dirname string) ([]os.FileInfo, error)
	// Glob returns the names of all files matching pattern or nil if there is no matching file.
	Glob(pattern string) ([]string, error)
	// RenameFile renames (moves) oldPath to newPath.
	// If newPath already exists and is not a directory, Rename replaces it.
	// the optional opt is: FileLockOption
	RenameFile(oldPath, newPath string, opt ...FSOption) error

	// Stat returns a FileInfo describing the named file.
	Stat(name string) (os.FileInfo, error)

	// WriteFile writes data to a file named by filename.
	// If the file does not exist, WriteFile creates it with permissions perm
	// the optional opt is: (FileLockOption,FilePriorityOption)
	WriteFile(filename string, data []byte, perm os.FileMode, opt ...FSOption) error
	// ReadFile reads the file named by filename and returns the contents.
	// the optional opt is: FilePriorityOption
	ReadFile(filename string, opt ...FSOption) ([]byte, error)
	// CopyFile copys file content from srcFile to dstFile until either EOF is reached on srcFile or an errors accurs.
	// the optional opt is: (FileLockOption,FilePriorityOption)
	CopyFile(srcFile, dstFile string, opt ...FSOption) (written int64, err error)

	CreateTime(name string) (*time.Time, error)

	// Truncate changes the size of the file to size.
	// the optional opt is: (FileLockOption)
	Truncate(name string, size int64, opt ...FSOption) error
}