Struct Partition 

pub struct Partition { /* private fields */ }

Single-partition log with its own writer task.

Owns one Log (segments + sparse index) and a single writer task that serializes all appends — the single-writer-per-partition invariant. Producers and consumers communicate with the writer via an mpsc inbox; the writer publishes the partition’s high-water-mark on a watch channel so consumers can wait for new data without polling.

Implementations

impl Partition

pub async fn open(dir: &Path, config: LogConfig) -> Result<Self>

Opens (or recovers) a partition rooted at dir and spawns its writer task. Usually called by Kafko rather than directly.

pub async fn append(&self, record: Record) -> Result<u64>

Appends a single record and returns its assigned offset. Producers usually call this via Producer::send rather than directly.

pub async fn append_batch(&self, records: Vec<Record>) -> Result<Vec<u64>>

Appends a batch of records as a single atomic unit and returns the assigned offsets in input order. The batch becomes visible at the partition’s high-water-mark together — consumers never observe a partial batch. Producers usually call this via Producer::send_batch rather than directly.

An empty input is a no-op that returns Ok(Vec::new()) without contacting the writer task.

pub async fn read_record_at(&self, offset: u64) -> Result<Option<Record>>

Reads the record at offset, returning Ok(None) if offset is past the current high-water-mark. Consumers usually call this via Consumer::next_record rather than directly.

pub async fn sync(&self) -> Result<()>

Forces the active segment + index to be fsynced to disk. Resolves only after the kernel reports the syscall complete. Use this when you need a hard durability point without shutting the broker down.

pub fn high_water_mark(&self) -> u64

Returns the offset of the next record this partition will assign — i.e., last_assigned_offset + 1, or 0 for an empty partition.

pub fn watch_high_water_mark(&self) -> Receiver<u64>

Returns a watch::Receiver that updates whenever a new record is appended. Useful for building consumers or back-pressure logic without polling high_water_mark.

pub async fn shutdown(self) -> Result<()>

Gracefully shuts the partition’s writer task down: drains the inbox, fsyncs the active segment + index, and exits. Resolves only after the final fsync completes. Usually called by Kafko::shutdown rather than directly.