Struct http_cache_semantics::CachePolicy [−][src]
pub struct CachePolicy { /* fields omitted */ }
Expand description
Identifies when responses can be reused from a cache, taking into account HTTP RFC 7234 rules for user agents and shared caches. It’s aware of many tricky details such as the Vary header, proxy revalidation, and authenticated responses.
Implementations
Cacheability of an HTTP response depends on how it was requested, so both request and response are required to create the policy.
pub fn new_options<Req: RequestLike, Res: ResponseLike>(
req: &Req,
res: &Res,
response_time: SystemTime,
opts: CacheOptions
) -> Self
pub fn new_options<Req: RequestLike, Res: ResponseLike>(
req: &Req,
res: &Res,
response_time: SystemTime,
opts: CacheOptions
) -> Self
Caching with customized behavior. See CacheOptions
for details.
response_time
is a timestamp when the response has been received, usually SystemTime::now()
.
Returns true
if the response can be stored in a cache. If it’s
false
then you MUST NOT store either the request or the response.
Returns whether the cached response is still fresh in the context of the new request.
If it returns true
, then the given request matches the original
response this cache policy has been created with, and the response can
be reused without contacting the server.
If it returns false
, then the response may not be matching at all
(e.g. it’s for a different URL or method), or may require to be
refreshed first. Either way, the new request’s headers will have been
updated for sending it to the origin server.
Tells how long the response has been sitting in cache(s).
Value of the Age
header, updated for the current time.
Returns approximate time in milliseconds until the response becomes stale (i.e. not fresh).
After that time (when time_to_live() <= 0
) the response might not be
usable without revalidation. However, there are exceptions, e.g. a
client can explicitly allow stale responses, so always check with
before_request()
.
Stale responses shouldn’t be used without contacting the server (revalidation)
pub fn after_response<Req: RequestLike, Res: ResponseLike>(
&self,
request: &Req,
response: &Res,
response_time: SystemTime
) -> AfterResponse
pub fn after_response<Req: RequestLike, Res: ResponseLike>(
&self,
request: &Req,
response: &Res,
response_time: SystemTime
) -> AfterResponse
Creates CachePolicy
with information combined from the previews response,
and the new revalidation response.
Returns {policy, modified}
where modified is a boolean indicating
whether the response body has been modified, and old cached body can’t be used.
Trait Implementations
fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
__D: Deserializer<'de>,
fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
__D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer. Read more
Auto Trait Implementations
impl RefUnwindSafe for CachePolicy
impl Send for CachePolicy
impl Sync for CachePolicy
impl Unpin for CachePolicy
impl UnwindSafe for CachePolicy
Blanket Implementations
Mutably borrows from an owned value. Read more