Struct Snapshot 

pub struct Snapshot { /* private fields */ }

A captured buffer state.

Snapshots are used for:

• Safety checkpoints before complex operations
• Crash recovery
• Cursor restoration when reopening files

Cursor Isolation (#471)

Cursor is passed explicitly to capture() and returned from restore(). The caller manages cursor via Window, not Buffer.

File Storage

This struct provides accessors for all data needed by the driver layer to serialize/deserialize to files. The kernel does not handle serialization directly.

Example

use reovim_kernel::api::v1::*;

// Create a buffer with some content
let mut buffer = Buffer::from_string("Hello, World!");
let cursor = Position::new(0, 0); // Get from Window in real usage

// Capture state with explicit cursor
let snapshot = Snapshot::capture(&buffer, cursor);

// Later, restore the state
let restored_cursor = snapshot.restore(&mut buffer);
// Caller sets restored_cursor to Window

Implementations

impl Snapshot

pub fn capture(buffer: &Buffer, cursor: Position) -> Self

Capture the current state of a buffer.

Cursor position must be passed explicitly - get it from Window. This is O(1) — the rope is cloned via Arc sharing.

pub fn from_parts( lines: &[String], cursor: Position, buffer_id: BufferId, timestamp: SystemTime, ) -> Self

Create a snapshot from components.

This is useful for restoring from serialized data.

pub fn restore(&self, buffer: &mut Buffer) -> Position

Restore a buffer to this snapshot’s state.

Returns the cursor position that should be set on Window. The buffer ID is not changed.

pub const fn cursor(&self) -> Position

Get the cursor position from this snapshot.

Use this when reopening a file that already has its content loaded - just get the cursor position to set on Window.

pub fn lines(&self) -> Vec<String>

Collect the captured lines as a Vec<String>.

This allocates — prefer line(idx) for individual access.

pub const fn buffer_id(&self) -> BufferId

Get the buffer ID.

pub const fn timestamp(&self) -> SystemTime

Get the timestamp when snapshot was taken.

pub fn matches_buffer(&self, buffer: &Buffer) -> bool

Check if this snapshot matches a buffer’s ID.

pub fn char_count(&self) -> usize

Get the total number of characters in the snapshot.

pub fn line_count(&self) -> usize

Get the number of lines in the snapshot.

pub fn is_empty(&self) -> bool

Check if the snapshot is empty.

Trait Implementations

impl Clone for Snapshot

fn clone(&self) -> Snapshot

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Snapshot

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

Formats the value using the given formatter.