Struct Wal 

pub struct Wal { /* private fields */ }

Write-ahead log for buffering document operations between commits.

Appends records to a .luci.wal file. Records are self-delimiting with per-record xxHash checksums, allowing replay to detect and discard truncated or corrupted trailing records after a crash.

See [[architecture-storage-format#Write-Ahead Log (WAL)]].

Implementations

impl Wal

pub fn open(path: impl AsRef<Path>, mode: DurabilityMode) -> Result<Self>

Open (or create) a WAL file for appending.

New records are appended to the end. If the file already contains records from a previous session (crash recovery), they remain intact until truncate is called.

pub fn append(&mut self, record: &WalRecord) -> Result<()>

Append a record to the WAL.

In Full durability mode, the write is fsynced before returning. In Batch and None modes, the record is buffered and only fsynced on an explicit call to sync.

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

Flush the buffer and fsync the WAL file.

Called by the commit path (in Batch mode) to ensure all appended records are durable before proceeding with the atomic commit.

pub fn truncate(&mut self) -> Result<()>

Truncate the WAL to zero bytes.

Called after a successful commit to discard all buffered records (they are now persisted in the main .luci file as a committed segment).

pub fn mode(&self) -> DurabilityMode

The current durability mode.