Struct PacScriptCacheLayer 

pub struct PacScriptCacheLayer { /* private fields */ }

Available on crate features js and pac and std only.

Keeps a fetched script for ttl, so an always-fetching provider does not hit the network per request.

At most one refresh per script URI runs at a time, however many callers arrive. A slow obsolete URI therefore cannot block a newly configured URI. A caller with a usable script gets it right away; callers for the same URI share the outcome of the attempt already in flight.

Implementations

impl PacScriptCacheLayer

pub const DEFAULT_TTL: Duration

How long a fetched script is reused by default.

Browsers hold a pac file for hours; a script uri change bypasses the ttl anyway, so a long default costs little.

pub const REFRESH_BACKOFF: Duration

How long a failed refresh is remembered before the origin is tried again.

Within the window a stale script is served straight away — and the refresh error returned right away when serve_stale is off — so an unreachable origin costs one attempt per window instead of one per caller.

pub fn new() -> PacScriptCacheLayer

Create a new PacScriptCacheLayer.

pub fn with_ttl(self, ttl: Duration) -> PacScriptCacheLayer

Reuse a fetched script for this long (defaults to Self::DEFAULT_TTL).

pub fn set_ttl(&mut self, ttl: Duration) -> &mut PacScriptCacheLayer

Reuse a fetched script for this long (defaults to Self::DEFAULT_TTL).

pub fn with_serve_stale(self, serve_stale: bool) -> PacScriptCacheLayer

Keep serving an expired script when the refresh fails (defaults to true: a stale policy beats no policy).

Either way a failed refresh opens a Self::REFRESH_BACKOFF window in which the origin is left alone.

pub fn set_serve_stale(&mut self, serve_stale: bool) -> &mut PacScriptCacheLayer

Keep serving an expired script when the refresh fails (defaults to true: a stale policy beats no policy).

Either way a failed refresh opens a Self::REFRESH_BACKOFF window in which the origin is left alone.

Trait Implementations

impl Clone for PacScriptCacheLayer

fn clone(&self) -> PacScriptCacheLayer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PacScriptCacheLayer

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

Formats the value using the given formatter.

impl Default for PacScriptCacheLayer

fn default() -> PacScriptCacheLayer

Returns the “default value” for a type.

impl<S> Layer<S> for PacScriptCacheLayer

type Service = PacScriptCache<S>

The service produced by the layer.

fn layer(&self, inner: S) -> <PacScriptCacheLayer as Layer<S>>::Service

Wrap the given service with the middleware, returning a new service.

fn into_layer(self, inner: S) -> Self::Service

Same as layer but consuming self after the service was created.