Struct WalConfig 

pub struct WalConfig {
    pub segment_size: u64,
    pub max_record_size: u32,
}

Configuration for a WAL instance.

Both fields are caller-supplied (§11 of docs/wal_design_v6.md). Tests use tiny sizes to force segment rolls and commit-time splits.

Fields

segment_size: u64

Bytes pre-allocated per segment file. Default in production: 128 MiB.

max_record_size: u32

Hard upper bound on a single record’s payload length.

A record must not span segments (§5.3), so this is constrained by max_record_size + 91 <= segment_size (64-byte segment header + 20-byte record header + up to 7 padding bytes). The bound is written in additive form on purpose: the equivalent segment_size - 91 underflows for segment_size < 91, which would bypass the check. That precondition is not enforced by this struct; Wal::open validates it and returns InvalidConfig when violated.

Trait Implementations

impl Clone for WalConfig

fn clone(&self) -> WalConfig

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for WalConfig

impl Debug for WalConfig

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

Formats the value using the given formatter.

impl Default for WalConfig

fn default() -> Self

Production-oriented defaults: a 128 MiB segment with a 1 MiB max payload.

These match the sizing guidance in §5.3/§11 (payloads ≤ ~1 MiB with a 64–128 MiB segment) and satisfy the max_record_size ≤ segment_size − 91 precondition with large headroom, so a default-configured WAL always passes open()’s validation.