Enum Durability 

#[repr(u8)]
pub enum Durability {
    Sync = 1,
    Batched = 2,
    Buffered = 3,
}

Durability tier requested by the producer for a given record. Wire values are fixed and must not change without a WIRE_VERSION bump.

Sync and Batched carry the same durability guarantee today: the record is written and fdatasynced — as part of one batch-boundary group fsync — before the ACK is sent, so an ack means the bytes are on stable storage and replay after a crash. They remain distinct wire values for historical and forward-compatibility reasons (originally Sync fsynced once per record and Batched once per batch; both now share the batch-boundary group fsync — see docs/architecture.md). Buffered trades durability for latency: it acks before any fsync.

Variants

Sync = 1

Durable before ACK: written and fdatasynced (via the batch-boundary group fsync) before the ACK — on stable storage, replays after a crash.

Batched = 2

Durable before ACK — the same guarantee as Durability::Sync today: written and fdatasynced at the batch boundary before the ACK. (Historically Batched deferred fsync to the batch boundary while Sync fsynced per record; both now share the batch-boundary group fsync.)

Buffered = 3

Memory write only. ACK is sent after the record enters the in-memory queue.

Trait Implementations

impl Clone for Durability

fn clone(&self) -> Durability

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Durability

impl Debug for Durability

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

Formats the value using the given formatter.

impl Display for Durability

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

Formats the value using the given formatter.

impl Eq for Durability

impl From<Durability> for u8

fn from(d: Durability) -> u8

The wire byte for this tier. Inverse of Durability::try_from.

impl PartialEq for Durability

fn eq(&self, other: &Durability) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Durability

impl TryFrom<u8> for Durability

type Error = UnknownDurability

The type returned in the event of a conversion error.

fn try_from(value: u8) -> Result<Self, Self::Error>

Performs the conversion.