Trait QuorumSet 

pub trait QuorumSet {
    type Id: 'static;
    type Iter: Iterator<Item = Self::Id>;

    // Required methods
    fn is_quorum<'a, I: Iterator<Item = &'a Self::Id> + Clone>(
        &self,
        ids: I,
    ) -> bool;
    fn ids(&self) -> Self::Iter;
}

Common interface for every quorum rule supported by this crate.

A quorum is a collection of nodes that a read or write operation in a distributed system has to contact. See: http://web.mit.edu/6.033/2005/wwwdocs/quorum_note.html

Implementations must be upward-closed: adding IDs to an accepted quorum must keep it accepted. The crate provides implementations for flat majority sets, joint quorum sets, and hierarchical QuorumTree rules.

Required Associated Types

type Id: 'static

Node ID type in this quorum set.

type Iter: Iterator<Item = Self::Id>

Iterator over every voter ID tracked by this quorum set.

Implementations that combine multiple sub-rules return each ID once.

Required Methods

fn is_quorum<'a, I: Iterator<Item = &'a Self::Id> + Clone>( &self, ids: I, ) -> bool

Return true if the candidate IDs satisfy this quorum rule.

fn ids(&self) -> Self::Iter

Return all voter IDs in this quorum set.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl<ID> QuorumSet for BTreeSet<ID>

where ID: PartialOrd + Ord + Clone + 'static,

Majority quorum implementation for a flat voter set.

A candidate set is accepted when it contains more than half of the IDs in this BTreeSet.

type Id = ID

type Iter = IntoIter<ID>

fn is_quorum<'a, I: Iterator<Item = &'a ID> + Clone>(&self, ids: I) -> bool

fn ids(&self) -> Self::Iter

impl<NID> QuorumSet for Vec<BTreeSet<NID>>

where NID: PartialOrd + Ord + Clone + 'static,

Joint quorum implementation for multiple flat voter sets.

A candidate set is accepted only when it is a majority quorum in every member config. ids() returns the deduplicated union of all config IDs.

type Id = NID

type Iter = IntoIter<NID>

fn is_quorum<'a, I: Iterator<Item = &'a NID> + Clone>(&self, ids: I) -> bool

fn ids(&self) -> Self::Iter

impl<T: QuorumSet> QuorumSet for Arc<T>

type Id = <T as QuorumSet>::Id

type Iter = <T as QuorumSet>::Iter

fn is_quorum<'a, I: Iterator<Item = &'a Self::Id> + Clone>( &self, ids: I, ) -> bool

fn ids(&self) -> Self::Iter

Implementors

impl<ID> QuorumSet for QuorumTree<ID>

where ID: Ord + Clone + 'static,

Hierarchical quorum implementation for QuorumTree.

Evaluation follows the tree structure. ids() returns all leaf IDs once, even when the same node appears in more than one subtree.

type Id = ID

type Iter = IntoIter<ID>