Enum JoinPolicy 

pub enum JoinPolicy {
    AllOrNothing,
    BestEffort,
    Threshold(usize),
}

How a fan-in treats shards reaching terminal states. The default (AllOrNothing) is strict map-reduce; the others are escape hatches the structure supports without API breakage (corrections #2).

Variants

AllOrNothing

Reduce fires only when all shards are Done; any Failed shard fails the join. The default.

BestEffort

Reduce fires once every shard is terminal (Done or Failed); the reducer inspects which succeeded. For embarrassingly-parallel work where partial results are usable.

Threshold(usize)

Reduce fires once at least n shards are Done (quorum map-reduce); becomes unsatisfiable — and so Failed — once too many shards have failed for n to be reachable.

Trait Implementations

impl Clone for JoinPolicy

fn clone(&self) -> JoinPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for JoinPolicy

impl Debug for JoinPolicy

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

Formats the value using the given formatter.

impl Default for JoinPolicy

fn default() -> JoinPolicy

Returns the “default value” for a type.

impl Eq for JoinPolicy

impl PartialEq for JoinPolicy

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for JoinPolicy