Struct MemoryKvStore 

pub struct MemoryKvStore { /* private fields */ }

A KvStore in memory.

An entry that has expired is removed as the store is written to, not only when its own key is next asked for: most keys are never asked for again — an actor seen once, an activity processed once — and a store that waited for that would grow for as long as its process ran.

MemoryKvStore::with_capacity also bounds how many entries it holds, dropping those nearest to expiring first. Everything Ojak keeps here is a cache, so an entry dropped early costs a refetch, or for an activity’s ID, a duplicate the application’s own writes have to tolerate anyway.

Implementations

impl MemoryKvStore

pub fn new() -> Self

pub fn with_capacity(capacity: usize) -> Self

A store that holds at most capacity entries.

Panics

If capacity is zero.

pub fn len(&self) -> usize

How many entries it holds, expired ones not yet swept out included.

pub fn is_empty(&self) -> bool

Whether it holds no entries at all.

Trait Implementations

impl Debug for MemoryKvStore

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

Formats the value using the given formatter.

impl Default for MemoryKvStore

fn default() -> MemoryKvStore

Returns the “default value” for a type.

impl KvStore for MemoryKvStore

async fn get(&self, key: &[&str]) -> Result<Option<Value>, KvError>

The value under key.

async fn set( &self, key: &[&str], value: Value, ttl: Option<Duration>, ) -> Result<(), KvError>

Put value under key, replacing what was there, to expire after ttl if given.

async fn insert( &self, key: &[&str], value: Value, ttl: Option<Duration>, ) -> Result<bool, KvError>

Put value under key only if nothing is there, and say whether it was put. Of any number of callers at once, in any number of processes, exactly one is told it was: this is what makes “has this activity been processed?” safe to ask from two workers.

async fn delete(&self, key: &[&str]) -> Result<(), KvError>

Remove what is under key, if anything is.