Module write_ahead_log 

Production-grade Write-Ahead Log (WAL) for crash recovery and durability.

Entries are encoded in a binary format and stored in an in-memory Vec<u8> segment buffer. The encoding is self-describing and checksum-protected so that any corruption is detected deterministically during recovery.

Entry layout

[magic(4)] [seq_num(8)] [tx_id(8)] [op_type(1)] [key_len(4)] [key(n)]
[value_len(4)] [value(m)] [timestamp(8)] [checksum(8)]

The checksum is the FNV-1a 64-bit hash of all preceding bytes in the entry.

Structs

RecoveryResult

Summary of a recovery scan over a WAL segment buffer.

Transaction

An in-memory transaction record tracking accumulated entries.

WalConfig

Configuration knobs for WalWriteAheadLog.

WalEntry

A single decoded entry in the write-ahead log.

WalStats

Live statistics snapshot of a WalWriteAheadLog.

WalWriteAheadLog

In-memory, crash-recovery Write-Ahead Log.

Enums

TxState

Lifecycle state of an in-flight or completed transaction.

WalError

Errors returned by WalWriteAheadLog operations.

WalOpType

Discriminant for WAL entry operations.

Constants

WAL_MAGIC

WAL entry magic bytes — detect non-WAL or truncated data immediately.

Functions

fnv1a_64

Computes the FNV-1a 64-bit hash of data.