Struct GroupCommitConsolidator 

pub struct GroupCommitConsolidator { /* private fields */ }

The group commit consolidator accumulates frame batches from concurrent writers and flushes them to the WAL file in consolidated groups.

This struct manages the FILLING→FLUSHING→COMPLETE state machine. It is designed to be held behind a Mutex and accessed by concurrent writers through GroupCommitQueue.

Implementations

impl GroupCommitConsolidator

pub fn new(config: GroupCommitConfig) -> Self

Create a new consolidator with the given configuration.

pub const fn phase(&self) -> ConsolidationPhase

Current consolidation phase.

pub const fn epoch(&self) -> u64

Current epoch.

pub const fn max_group_delay(&self) -> Duration

Maximum time a batch may remain in the filling epoch before flush.

pub const fn pending_frame_count(&self) -> usize

Number of pending frames in the current FILLING phase.

pub fn pending_batch_count(&self) -> usize

Number of pending transaction batches.

pub fn submit_batch( &mut self, batch: TransactionFrameBatch, ) -> Result<SubmitReceipt>

Submit a transaction’s frame batch for consolidation.

Returns Flusher if this writer should call flush_group, or Waiter if this writer should wait for the flush to complete.

Errors

Returns Err if the consolidator is in an unexpected phase.

pub fn should_flush_now(&self) -> bool

Check whether the flusher should flush now.

Returns true if:

• The batch is full (pending_frame_count >= max_group_size), OR
• The max group delay has been exceeded.

pub fn time_until_flush(&self) -> Duration

Time remaining before the flusher must flush (for sleep/wait).

pub fn fill_age(&self) -> Duration

Age of the current FILLING epoch from the first submitted batch.

pub fn begin_flush(&mut self) -> Result<Vec<TransactionFrameBatch>>

Transition to FLUSHING phase and take ownership of the pending batches.

Returns the batches to be written and the page size needed for frame construction.

Errors

Returns Err if not in FILLING phase.

pub fn complete_flush(&mut self) -> Result<bool>

Mark the current flush as complete. Waiters can now proceed.

Errors

Returns Err if not in FLUSHING phase. Returns true if pipelined batches were promoted and the caller should flush again. If the original flusher does not continue, a fresh submitter may explicitly claim the promoted epoch via Self::claim_flusher_vacancy.

pub fn has_pipelined_batches(&self) -> bool

Whether pipelined batches are waiting for the next epoch.

pub const fn has_flusher_vacancy(&self) -> bool

Whether a promoted epoch in Filling currently needs an explicit flusher claim before a replacement flusher takes over.

pub fn claim_flusher_vacancy(&mut self) -> bool

Claim the promoted-epoch flusher vacancy after the original flusher stopped before calling begin_flush() again.

Returns true if the caller successfully claimed the vacancy.

pub fn abort_filling(&mut self, expected_epoch: u64) -> Result<u64>

Abort a not-yet-started filling epoch after its elected flusher is cancelled.

No WAL bytes have been written while the consolidator is still in Filling, so every queued batch can fail atomically. The failed epoch is consumed before returning; the next submitter therefore receives a fresh target epoch instead of colliding with retained failure metadata.

Errors

Returns Err unless the expected non-empty filling epoch is active.

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

Abort the current flush after the flusher observed an I/O error.

This transitions the state machine out of Flushing so waiters can be released with the epoch-level failure published by the caller.

Errors

Returns Err if not in Flushing phase.

pub const fn completed_epoch(&self) -> u64

The completed epoch counter (for waiter synchronization).

Trait Implementations

impl Debug for GroupCommitConsolidator

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

Formats the value using the given formatter.