Enum Durability 

pub enum Durability {
    Full,
    NormalMayLoseRecentCommits,
    Unsafe,
}

Durability contract for a DurableConnection (Task 4 — Explicit Durability Contract + Safe Default).

The variant name states the guarantee, so a misread default can never silently cost data. This makes illegal interpretations unrepresentable: you cannot select a lossy mode without naming the loss. Formally this encodes the durability/latency Pareto frontier — expected loss on crash is E[loss] = λ_commit · Δ_unsynced, which is zero only under Durability::Full.

Variants

Full

fsync on every commit: commit returns ⇒ data is on stable storage (ACID durability). This is the safe default and the guarantee the DurableConnection name promises. Pair with group commit (enabled by default) to amortize the fsync across concurrent commits.

NormalMayLoseRecentCommits

fsync deferred to checkpoints (SQLite NORMAL equivalent). Faster, but a power failure can lose the most recent committed transactions. The long name spells out the risk on purpose.

Unsafe

No fsync at all. ANY committed data can be lost on crash. Testing only.

Implementations

impl Durability

pub fn is_crash_durable(self) -> bool

true iff commit returning implies the data is durably on stable storage (i.e. survives a power failure).

impl Durability

pub const Off: Durability = Durability::Unsafe

Compatibility alias for the former SyncModeClient::Off. Prefer Durability::Unsafe — the name states the risk.

pub const Normal: Durability = Durability::NormalMayLoseRecentCommits

Compatibility alias for the former SyncModeClient::Normal. Prefer Durability::NormalMayLoseRecentCommits.

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 Eq for Durability

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