Struct Journal 

pub struct Journal { /* private fields */ }

An At-Least-Once journal for storing fixed-size entries, with RocksDB-backed persistence.

All indices here are monotonic u64, wrapping around on overflow.

Invariant: consumed_index <= write_index.

Writes go directly to RocksDB (synchronous and durable), so there is no separate “persisted” boundary — write_index is the persisted boundary.

Implementations

impl Journal

pub fn with_capacity(capacity: usize) -> Result<Self, Error>

Create a new journal with the specified capacity and default configuration.

pub fn with_capacity_and_config( capacity: usize, config: JournalConfig, ) -> Result<Self, Error>

Create a new journal with the specified capacity and configuration.

pub fn reader(&self) -> JournalReader

Acquires a reader for this journal.

Panics

Panics if a reader is already taken.

pub fn try_reader(&self) -> Option<JournalReader>

Try acquires a reader for this journal.

If a reader is already taken, returns None.

pub fn commit(&self, data: &[u8])

Commit a new entry to the journal.

The entry is written to RocksDB synchronously.

Panics

Panics if the journal is full or has encountered a fatal error.

pub fn try_commit(&self, data: &[u8]) -> Result<(), Error>

Try commit a new entry to the journal.

The entry is written to RocksDB synchronously.

pub fn consumed_index(&self) -> u64

Get the current consumed index.

pub fn write_index(&self) -> u64

Get the current write index.

Trait Implementations

impl Clone for Journal

fn clone(&self) -> Journal

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Journal

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

Formats the value using the given formatter.