Struct FileCheckpointStore 

pub struct FileCheckpointStore { /* private fields */ }

Default CheckpointStore backed by an atomically-written JSON file.

The file maps subscription_id -> offset. Each commit rewrites the file via a temp file + std::fs::rename, which is atomic on POSIX, so a crash between the write and the rename leaves the previous valid offset intact (never a torn/partial file).

Implementations

impl FileCheckpointStore

pub fn open<P: AsRef<Path>>(path: P) -> Result<Self>

Open (or initialize) a file-backed checkpoint store at path. A missing or corrupt file is treated as “no checkpoint”; a prior atomic commit could never produce a corrupt file.

Trait Implementations

impl CheckpointStore for FileCheckpointStore

fn load(&self, subscription_id: &str) -> Result<Option<u64>>

Return the last fully-processed offset for subscription_id, or None when no checkpoint has been committed yet.

fn commit(&self, subscription_id: &str, offset: u64) -> Result<()>

Durably record offset as fully processed for subscription_id.