Struct StorageWriteAheadLog 

pub struct StorageWriteAheadLog { /* private fields */ }

In-memory write-ahead log for crash-safe block operations.

Unlike WriteAheadLog which is CID-centric and thread-safe via Mutex/AtomicU64, StorageWriteAheadLog is a single-threaded, tick-driven WAL that tracks total data bytes and supports indexed checkpoint replay.

Implementations

impl StorageWriteAheadLog

pub fn new(config: WalConfig) -> Self

Creates a new StorageWriteAheadLog with the given configuration.

pub fn append( &mut self, kind: WalEntryKind, key: &str, data: Vec<u8>, ) -> Result<u64, String>

Appends a new entry to the WAL.

If appending would exceed max_entries, the oldest entry is evicted first. Returns the assigned sequence number.

Errors

Returns an error if adding data would exceed max_data_bytes.

pub fn get_entry(&self, sequence: u64) -> Option<&StorageWalEntry>

Returns a reference to the entry with the given sequence number, if present.

pub fn entries_since(&self, sequence: u64) -> Vec<&StorageWalEntry>

Returns references to all entries with sequence numbers strictly greater than sequence.

pub fn create_checkpoint(&mut self) -> u64

Records the current head sequence as a checkpoint and returns it.

pub fn truncate_before(&mut self, sequence: u64)

Removes all entries with sequence numbers strictly less than sequence, updating total_data_bytes accordingly.

pub fn replay_from_checkpoint( &self, checkpoint_idx: usize, ) -> Result<Vec<&StorageWalEntry>, String>

Returns all entries from the given checkpoint index to the end.

Errors

Returns an error if checkpoint_idx is out of range.

pub fn should_checkpoint(&self) -> bool

Returns true if the number of ticks since the last checkpoint is at least checkpoint_interval.

pub fn tick(&mut self)

Advances the logical clock by one tick.

pub fn entry_count(&self) -> usize

Returns the number of entries currently in the log.

pub fn data_bytes(&self) -> u64

Returns the total data bytes across all entries.

pub fn stats(&self) -> StorageWalStats

Returns a point-in-time statistics snapshot.

Trait Implementations

impl Debug for StorageWriteAheadLog

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

Formats the value using the given formatter.