Struct crdts::pncounter::PNCounter

pub struct PNCounter<A: Actor> { /* fields omitted */ }

PNCounter allows the counter to be both incremented and decremented by representing the increments (P) and the decrements (N) in separate internal G-Counters.

Merge is implemented by merging the internal P and N counters. The value of the counter is P minus N.

Examples

use crdts::{PNCounter, CmRDT};

let mut a = PNCounter::new();
a.apply(a.inc("A"));
a.apply(a.inc("A"));
a.apply(a.dec("A"));
a.apply(a.inc("A"));

assert_eq!(a.read(), 2.into());

Methods

impl<A: Actor> PNCounter<A>

pub fn new() -> Self

Produce a new PNCounter.

pub fn inc(&self, actor: A) -> Op<A>

Generate an Op to increment the counter.

pub fn dec(&self, actor: A) -> Op<A>

Generate an Op to increment the counter.

pub fn read(&self) -> BigInt

Return the current value of this counter (P-N).

Trait Implementations

impl<A: Actor> CvRDT for PNCounter<A>

fn merge(&mut self, other: Self)

Merge the given CRDT into the current CRDT.

impl<A: Actor> CmRDT for PNCounter<A>

type Op = Op<A>

Op defines a mutation to the CRDT. As long as Op's from one actor are replayed in exactly the same order they were generated by that actor, the CRDT will converge. In other words, we must have a total ordering on each actors operations, while requiring only a partial order over all ops. E.g.

fn apply(&mut self, op: Self::Op)

Apply an Op to the CRDT

impl<A: Actor> Causal<A> for PNCounter<A>

fn forget(&mut self, clock: &VClock<A>)

Forget data that is strictly smaller than this clock

impl<A: PartialEq + Actor> PartialEq<PNCounter<A>> for PNCounter<A>

fn eq(&self, other: &PNCounter<A>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &PNCounter<A>) -> bool

This method tests for !=.

impl<A: Actor> Default for PNCounter<A>

fn default() -> Self

Returns the "default value" for a type.

impl<A: Clone + Actor> Clone for PNCounter<A>

fn clone(&self) -> PNCounter<A>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<A: Eq + Actor> Eq for PNCounter<A>

impl<A: Hash + Actor> Hash for PNCounter<A>

fn hash<__HA: Hasher>(&self, state: &mut __HA)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl<A: Debug + Actor> Debug for PNCounter<A>

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

Formats the value using the given formatter.

impl<A: Actor> Serialize for PNCounter<A> where
    A: Serialize, 

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

Serialize this value into the given Serde serializer.

impl<'de, A: Actor> Deserialize<'de> for PNCounter<A> where
    A: Deserialize<'de>, 

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
    __D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.