Struct GCounterUpdate 

pub struct GCounterUpdate(/* private fields */);

State for a grow-only distributed counter (GCounter CRDT).

Each rank maintains its own count. The total value is the sum of all ranks’ counts. Merge takes pointwise max.

CRDT Properties

• Commutative: Merge order doesn’t matter
• Associative: Grouping doesn’t matter
• Idempotent: Merging duplicate updates has no effect
• Convergent: All replicas converge to the same state

Implementations

impl GCounterUpdate

pub fn get(&self) -> u64

Total counter value (sum of all ranks’ counts).

pub fn get_rank(&self, rank: usize) -> Option<u64>

Get count for a specific rank.

pub fn num_ranks(&self) -> usize

Number of ranks that have contributed.

Trait Implementations

impl Clone for GCounterUpdate

fn clone(&self) -> GCounterUpdate

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for GCounterUpdate

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

Formats the value using the given formatter.

impl Default for GCounterUpdate

fn default() -> GCounterUpdate

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for GCounterUpdate

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<(usize, u64)> for GCounterUpdate

fn from((rank, count): (usize, u64)) -> Self

Create a GCounter update from (rank, count).

impl JoinSemilattice for GCounterUpdate

fn join(&self, other: &Self) -> Self

The join (least upper bound).

fn join_assign(&mut self, other: &Self)

In-place variant.

fn join_all<I>(it: I) -> Option<Self>

where I: IntoIterator<Item = Self>,

Join a finite iterator of values. Returns None for empty iterators.

impl Named for GCounterUpdate

fn typename() -> &'static str

The globally unique type name for the type. This should typically be the fully qualified Rust name of the type.

fn typehash() -> u64

A globally unique hash for this type. TODO: actually enforce perfect hashing

fn typeid() -> TypeId

The TypeId for this type. TypeIds are unique only within a binary, and should not be used for global identification.

fn port() -> u64

The globally unique port for this type. Typed ports are in the range of 1<<63..1<<64-1.

fn arm(&self) -> Option<&'static str>

If the named type is an enum, this returns the name of the arm of the value self.

unsafe fn arm_unchecked(self_: *const ()) -> Option<&'static str>

An unsafe version of ‘arm’, accepting a pointer to the value, for use in type-erased settings.

impl Serialize for GCounterUpdate

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.