Struct AuditState 

pub struct AuditState {
    pub sink: RwLock<Option<Arc<AuditSink>>>,
    pub sequence: AtomicU64,
}

V-4 audit chain state. Owns the same (sink, sequence) pair the pre-#1192 src/audit.rs module-level statics owned; the public crate::audit::* functions delegate here.

The chain invariants this struct preserves byte-for-byte:

1. sink is wrapped in RwLock<Option<Arc<AuditSink>>> so the init path can swap the sink atomically and emit can clone the Arc without holding the lock for the file write.
2. sequence is an AtomicU64 so concurrent emit threads agree on a monotonic counter; it is seeded from the trailing record’s sequence on init (F2 fix — sequence survives daemon restart).
3. The AuditSink::inner mutex serialises the hash-chain head update + line write, so the chain is consistent across producer threads.

Fields

sink: RwLock<Option<Arc<AuditSink>>>

Process-wide audit sink. None when audit is disabled. Wrapped in RwLock (rather than OnceLock) so tests can swap in an in-memory sink between cases without leaking state across runs.

sequence: AtomicU64

Per-process monotonic sequence counter. Starts at 0; first emit produces sequence 1. init reseeds from the trailing record’s sequence so audit verify doesn’t trip on a restart-induced reset (F2 round-2 fix).

Trait Implementations

impl Debug for AuditState

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

Formats the value using the given formatter.

impl Default for AuditState

fn default() -> AuditState

Returns the “default value” for a type.