Struct FailuresCache

pub struct FailuresCache<T>
where
    T: Eq + Hash,
{ /* private fields */ }

A TTL cache where items get inactive instead of discarded.

The items need to be explicitly removed from the cache. This allows us to implement exponential backoff based TTL.

Implementations

impl<T> FailuresCache<T>

where T: Eq + Hash,

pub fn new() -> FailuresCache<T>

Available on crate feature e2e-encryption only.

pub fn with_settings(max_delay: Duration, multiplier: u8) -> FailuresCache<T>

Available on crate feature e2e-encryption only.

pub fn contains<Q>(&self, key: &Q) -> bool

where T: Borrow<Q>, Q: Hash + Eq + ?Sized,

Available on crate feature e2e-encryption only.

Is the given key non-expired and part of the cache.

pub fn failure_count<Q>(&self, key: &Q) -> Option<u8>

where T: Borrow<Q>, Q: Hash + Eq + ?Sized,

Available on crate feature e2e-encryption only.

Get the failure count for a given key.

Returns

• None if this key is not in the failure cache. (It has never failed, or it has been FailuresCache::remove()d since the last failure.)

• Some(u8): the number of times it has failed since it was first added to the failure cache. (In other words, one less than the total number of failures.)

pub fn insert(&self, item: T)

Available on crate feature e2e-encryption only.

Add a single item to the cache.

pub fn extend(&self, iterator: impl IntoIterator<Item = T>)

Available on crate feature e2e-encryption only.

Extend the cache with the given iterator of items.

Items that are already part of the cache, whether they are expired or not, will have their TTL extended using an exponential backoff algorithm.

pub fn remove<'a, I, Q>(&'a self, iterator: I)

where I: Iterator<Item = &'a Q>, T: Borrow<Q>, Q: Hash + Eq + 'a + ?Sized,

Available on crate feature e2e-encryption only.

Remove the items contained in the iterator from the cache.

Trait Implementations

impl<T> Clone for FailuresCache<T>

where T: Clone + Eq + Hash,

fn clone(&self) -> FailuresCache<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> Debug for FailuresCache<T>

where T: Debug + Eq + Hash,

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

Formats the value using the given formatter.

impl<T> Default for FailuresCache<T>

where T: Eq + Hash,

fn default() -> FailuresCache<T>

Returns the “default value” for a type.