Struct retainer::entry::CacheExpiration

pub struct CacheExpiration { /* private fields */ }

Small structure to represent expiration in a cache.

Expirations are constructed using the From and Into traits from the standard library; there are no other functions.

There are currently several supported conversions:

• u64 -> a number of milliseconds to pass before an entry should expire.
• Instant -> an exact time that an entry should expire.
• Duration -> a duration to pass before an entry should expire.
• Range<u64> -> a random range of milliseconds to sample from to determine when an entry should expire.

Other conversions may be added in future, but this should suffice for most cases. Any of these types may be passed to the insertion methods on a cache type when adding entries to a cache.

Implementations

impl CacheExpiration

pub fn new<I>(instant: I) -> Self where
    I: Into<Instant>, 

Create an expiration at a given instant.

pub fn none() -> Self

Create an empty expiration (i.e. no expiration).

pub fn instant(&self) -> &Option<Instant>

Retrieve the instant associated with this expiration.

pub fn is_expired(&self) -> bool

Retrieve whether a cache entry has passed expiration.

pub fn remaining(&self) -> Option<Duration>

Retrieve the time remaining before expiration.

Trait Implementations

impl Debug for CacheExpiration

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

Formats the value using the given formatter.

impl From<Duration> for CacheExpiration

fn from(duration: Duration) -> Self

Converts to this type from the input type.

impl From<Instant> for CacheExpiration

fn from(instant: Instant) -> Self

Converts to this type from the input type.

impl From<Range<u64>> for CacheExpiration

fn from(range: Range<u64>) -> Self

Converts to this type from the input type.

impl From<u64> for CacheExpiration

fn from(millis: u64) -> Self

Converts to this type from the input type.