Struct Wal 

pub struct Wal { /* private fields */ }

Write-Ahead Log

Implementations

impl Wal

pub fn create(path: impl AsRef<Path>) -> Result<Self>

Create or open a WAL file (simple API for backward compatibility)

pub fn with_config(config: WalConfig) -> Result<Self>

Create a new WAL with custom configuration

pub fn put(&mut self, key: Key, value: CipherBlob) -> Result<u64>

Append a Put entry

pub fn delete(&mut self, key: Key) -> Result<u64>

Append a Delete entry

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

Rotate to a new WAL file

pub fn cleanup(&self) -> Result<()>

Manually trigger cleanup of old WAL files

pub fn current_file_size(&self) -> u64

Get current WAL file size

pub fn current_file_number(&self) -> u64

Get current WAL file number

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

Flush buffered writes to disk

pub fn sequence(&self) -> u64

Get current sequence number

pub fn path(&self) -> &Path

Get WAL file path

pub fn recover(wal_dir: impl AsRef<Path>) -> Result<(Vec<WalEntry>, u64)>

Recover all entries from WAL files in a directory

Reads all WAL files in sequence order and returns recovered entries. Handles corrupted and incomplete entries gracefully by skipping them.

Returns (entries, max_sequence) where max_sequence is the highest sequence number found during recovery.

pub fn current_size(&self) -> u64

Get current active WAL file size in bytes

pub fn total_wal_size(&self) -> Result<u64>

Get total size of all WAL files in the WAL directory

pub fn truncate_before(&mut self, sequence: u64) -> Result<u64>

Truncate WAL files whose max sequence number is <= the given sequence.

This is used after a memtable flush to remove WAL files that are no longer needed. The current active WAL file is never removed.

Returns the number of files truncated (removed).

pub fn recover_with_stats( wal_dir: impl AsRef<Path>, ) -> Result<(Vec<WalEntry>, u64, RecoveryStats)>

Recover all entries from WAL files with detailed statistics

Like recover(), but also returns RecoveryStats with counts of recovered entries, corrupted entries, and total bytes recovered.

pub fn replay_to_memtable( wal_dir: impl AsRef<Path>, memtable: &Memtable, ) -> Result<u64>

Replay WAL entries to a memtable

Applies all entries from the WAL directory to the provided memtable. This is used during crash recovery to rebuild memtable state.

Returns the maximum sequence number found during replay.