Struct LockFileOffsetStore 

pub struct LockFileOffsetStore { /* private fields */ }

File-based offset store with lock file protection

Stores offsets in individual files under a base directory:

{base_dir}/{consumer_name}/
├── topic-{topic_id}-consumer-{consumer_id}.offset
└── ...

Uses file locking (flock on Unix, LockFile on Windows) to ensure safe concurrent access from multiple processes.

Implementations

impl LockFileOffsetStore

pub fn open(base_dir: &Path, consumer_name: &str) -> Result<Self, ClientError>

Open or create an offset store at the given directory

Arguments

• base_dir - Base directory for offset files
• consumer_name - Name for this consumer instance (subdirectory name)

Example

let store = LockFileOffsetStore::open(
    Path::new("/var/lib/lance/offsets"),
    "my-service",
)?;

pub fn consumer_name(&self) -> &str

Get the consumer name

pub fn base_dir(&self) -> &Path

Get the base directory

Trait Implementations

impl Debug for LockFileOffsetStore

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

Formats the value using the given formatter.

impl OffsetStore for LockFileOffsetStore

fn load( &self, topic_id: u32, consumer_id: u64, ) -> Result<Option<u64>, ClientError>

Load the stored offset for a topic and consumer

fn save( &self, topic_id: u32, consumer_id: u64, offset: u64, ) -> Result<(), ClientError>

Save the current offset for a topic and consumer

fn delete(&self, topic_id: u32, consumer_id: u64) -> Result<(), ClientError>

Delete stored offset for a topic and consumer

fn list_all(&self) -> Result<HashMap<(u32, u64), u64>, ClientError>

List all stored offsets