Expand description
If-Range header, defined
in RFC 7233 §3.2
If a client has a partial copy of a representation and wishes to have an up-to-date copy of the entire representation, it could use the Range header field with a conditional GET (using either or both of If-Unmodified-Since and If-Match.) However, if the precondition fails because the representation has been modified, the client would then have to make a second request to obtain the entire current representation.
The If-Range header field allows a client to "short-circuit" the
second request. Informally, its meaning is as follows: if the
representation is unchanged, send me the part(s) that I am requesting
in Range; otherwise, send me the entire representation.
ABNF
If-Range = entity-tag / HTTP-date
Example Values
Sat, 29 Oct 1994 19:43:31 GMT\"xyzzy\"
Examples
use actix_web::HttpResponse;
use actix_web::http::header::{EntityTag, IfRange};
let mut builder = HttpResponse::Ok();
builder.insert_header(
IfRange::EntityTag(
EntityTag::new(false, "abc".to_owned())
)
);use std::time::{Duration, SystemTime};
use actix_web::{http::header::IfRange, HttpResponse};
let mut builder = HttpResponse::Ok();
let fetched = SystemTime::now() - Duration::from_secs(60 * 60 * 24);
builder.insert_header(
IfRange::Date(fetched.into())
);Variants
EntityTag(EntityTag)
The entity-tag the client has of the resource.
Date(HttpDate)
The date when the client retrieved the resource.
Trait Implementations
sourceimpl Header for IfRange
impl Header for IfRange
sourcefn name() -> HeaderName
fn name() -> HeaderName
sourcefn parse<T>(msg: &T) -> Result<Self, ParseError>where
T: HttpMessage,
fn parse<T>(msg: &T) -> Result<Self, ParseError>where
T: HttpMessage,
sourceimpl TryIntoHeaderValue for IfRange
impl TryIntoHeaderValue for IfRange
type Error = InvalidHeaderValue
type Error = InvalidHeaderValue
sourcefn try_into_value(self) -> Result<HeaderValue, Self::Error>
fn try_into_value(self) -> Result<HeaderValue, Self::Error>
impl Eq for IfRange
impl StructuralEq for IfRange
impl StructuralPartialEq for IfRange
Auto Trait Implementations
impl RefUnwindSafe for IfRange
impl Send for IfRange
impl Sync for IfRange
impl Unpin for IfRange
impl UnwindSafe for IfRange
Blanket Implementations
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
sourceimpl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
impl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
sourcefn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
key and return true if they are equal.