Struct UndoStack 

pub struct UndoStack { /* private fields */ }

A stack of FileSnapshots that supports restoring files to earlier states.

The stack has a configurable maximum depth. When the depth is exceeded, the oldest snapshot is discarded.

Atomic writes

restore_last and restore_all write files atomically by first writing to a temporary file in the same directory, then renaming it.

Implementations

impl UndoStack

pub fn new(max_depth: usize) -> UndoStack

Create a new, empty undo stack with the given maximum depth.

Panics

Panics if max_depth is zero.

pub async fn snapshot<P>(&mut self, path: P) -> Result<(), UndoError>

where P: AsRef<Path>,

Capture a snapshot of the file at path.

If the file does not exist, an empty-contents snapshot is recorded (so that restoring will effectively delete the file by writing empty contents, or more precisely, the restore will write the empty string back — matching what was there: nothing).

If the stack is at maximum depth, the oldest snapshot is discarded before the new one is pushed.

Errors

Returns an error if reading the file fails for a reason other than the file not existing.

pub async fn restore_last(&mut self) -> Result<FileSnapshot, UndoError>

Restore the most recent snapshot, removing it from the stack.

The file is written atomically (write to a temp file in the same directory, then rename).

Errors

Returns UndoError::StackEmpty if there are no snapshots to restore. Returns UndoError::Io if writing the file fails.

pub async fn restore_all(&mut self) -> Result<(), UndoError>

Restore all snapshots in reverse order (most recent first).

Each file is written atomically. The stack is emptied after this call regardless of whether any individual restore fails — snapshots that were successfully restored are not re-pushed.

Errors

Returns the first error encountered. Snapshots already processed before the error are restored; those after are lost.

pub fn is_empty(&self) -> bool

Returns true if the stack contains no snapshots.

pub fn len(&self) -> usize

Returns the number of snapshots currently on the stack.

pub fn clear(&mut self)

Discard all snapshots without restoring.

pub fn peek(&self) -> Option<&FileSnapshot>

Peek at the most recent snapshot without removing or restoring it.

Returns None if the stack is empty.

Trait Implementations

impl Debug for UndoStack

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for UndoStack

fn default() -> UndoStack

Returns the “default value” for a type.