Struct tower::balance::p2c::Balance[−][src]

pub struct Balance<D, Req> where
    D: Discover,
    D::Key: Hash,  { /* fields omitted */ }
This is supported on crate feature balance only.
Expand description

Efficiently distributes requests across an arbitrary number of services.

See the module-level documentation for details.

Note that Balance requires that the Discover you use is Unpin in order to implement Service. This is because it needs to be accessed from Service::poll_ready, which takes &mut self. You can achieve this easily by wrapping your Discover in Box::pin before you construct the Balance instance. For more details, see #319.

Implementations

impl<D, Req> Balance<D, Req> where
    D: Discover,
    D::Key: Hash,
    D::Service: Service<Req>,
    <D::Service as Service<Req>>::Error: Into<BoxError>, [src]

pub fn new(discover: D) -> Self[src]

Constructs a load balancer that uses operating system entropy.

pub fn from_rng<R: Rng>(discover: D, rng: R) -> Result<Self, Error>[src]

Constructs a load balancer seeded with the provided random number generator.

pub fn len(&self) -> usize[src]

Returns the number of endpoints currently tracked by the balancer.

pub fn is_empty(&self) -> bool[src]

Returns whether or not the balancer is empty.

Trait Implementations

impl<D: Discover, Req> Debug for Balance<D, Req> where
    D: Debug,
    D::Key: Hash + Debug,
    D::Service: Debug,
    Req: Debug, [src]

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

Formats the value using the given formatter. Read more

impl<D, Req> Service<Req> for Balance<D, Req> where
    D: Discover + Unpin,
    D::Key: Hash + Clone,
    D::Error: Into<BoxError>,
    D::Service: Service<Req> + Load,
    <D::Service as Load>::Metric: Debug,
    <D::Service as Service<Req>>::Error: Into<BoxError>, [src]

type Response = <D::Service as Service<Req>>::Response

Responses given by the service.

type Error = BoxError

Errors produced by the service.

type Future = MapErr<<D::Service as Service<Req>>::Future, fn(_: <D::Service as Service<Req>>::Error) -> BoxError>

The future response value.

fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>>[src]

Returns Poll::Ready(Ok(())) when the service is able to process requests. Read more

fn call(&mut self, request: Req) -> Self::Future[src]

Process the request and return the response asynchronously. Read more

Auto Trait Implementations

impl<D, Req> !RefUnwindSafe for Balance<D, Req>

impl<D, Req> Send for Balance<D, Req> where
    D: Send,
    Req: Send,
    <D as Discover>::Key: Send,
    <D as Discover>::Service: Send, 

impl<D, Req> Sync for Balance<D, Req> where
    D: Sync,
    Req: Sync,
    <D as Discover>::Key: Sync,
    <D as Discover>::Service: Sync, 

impl<D, Req> Unpin for Balance<D, Req> where
    D: Unpin,
    Req: Unpin, 

impl<D, Req> !UnwindSafe for Balance<D, Req>

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized, [src]

pub fn type_id(&self) -> TypeId[src]

Gets the TypeId of self. Read more

impl<T> Borrow<T> for T where
    T: ?Sized, [src]

pub fn borrow(&self) -> &T[src]

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for T where
    T: ?Sized, [src]

pub fn borrow_mut(&mut self) -> &mut T[src]

Mutably borrows from an owned value. Read more

impl<T> From<T> for T[src]

pub fn from(t: T) -> T[src]

Performs the conversion.

impl<T> Instrument for T[src]

fn instrument(self, span: Span) -> Instrumented<Self>[src]

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

fn in_current_span(self) -> Instrumented<Self>[src]

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

impl<T, U> Into<U> for T where
    U: From<T>, [src]

pub fn into(self) -> U[src]

Performs the conversion.

impl<T, Request> ServiceExt<Request> for T where
    T: Service<Request> + ?Sized, [src]

fn ready(&mut self) -> Ready<'_, Self, Request>ⓘ

Notable traits for Ready<'a, T, Request>

impl<'a, T, Request> Future for Ready<'a, T, Request> where
    T: Service<Request>,  type Output = Result<&'a mut T, T::Error>;
 where
    Self: Sized, [src]

This is supported on crate feature util only.

Yields a mutable reference to the service when it is ready to accept a request.

fn ready_and(&mut self) -> ReadyAnd<'_, Self, Request> where
    Self: Sized, [src]

👎 Deprecated since 0.4.6:

please use the ServiceExt::ready method instead

This is supported on crate feature util only.

Yields a mutable reference to the service when it is ready to accept a request.

fn ready_oneshot(self) -> ReadyOneshot<Self, Request>ⓘ

Notable traits for ReadyOneshot<T, Request>

impl<T, Request> Future for ReadyOneshot<T, Request> where
    T: Service<Request>,  type Output = Result<T, T::Error>;
 where
    Self: Sized, [src]

This is supported on crate feature util only.

Yields the service when it is ready to accept a request.

fn oneshot(self, req: Request) -> Oneshot<Self, Request>ⓘ

Notable traits for Oneshot<S, Req>

impl<S, Req> Future for Oneshot<S, Req> where
    S: Service<Req>,  type Output = Result<S::Response, S::Error>;
 where
    Self: Sized, [src]

This is supported on crate feature util only.

Consume this Service, calling with the providing request once it is ready.

fn call_all<S>(self, reqs: S) -> CallAll<Self, S> where
    Self: Sized,
    Self::Error: Into<BoxError>,
    S: Stream<Item = Request>, [src]

This is supported on crate feature util only.

Process all requests from the given Stream, and produce a Stream of their responses. Read more

fn and_then<F>(self, f: F) -> AndThen<Self, F> where
    Self: Sized,
    F: Clone, [src]

This is supported on crate feature util only.

Executes a new future after this service’s future resolves. This does not alter the behaviour of the poll_ready method. Read more

fn map_response<F, Response>(self, f: F) -> MapResponse<Self, F> where
    Self: Sized,
    F: FnOnce(Self::Response) -> Response + Clone, [src]

This is supported on crate feature util only.

Maps this service’s response value to a different value. This does not alter the behaviour of the poll_ready method. Read more

fn map_err<F, Error>(self, f: F) -> MapErr<Self, F> where
    Self: Sized,
    F: FnOnce(Self::Error) -> Error + Clone, [src]

This is supported on crate feature util only.

Maps this service’s error value to a different value. This does not alter the behaviour of the poll_ready method. Read more

fn map_result<F, Response, Error>(self, f: F) -> MapResult<Self, F> where
    Self: Sized,
    Error: From<Self::Error>,
    F: FnOnce(Result<Self::Response, Self::Error>) -> Result<Response, Error> + Clone, [src]

This is supported on crate feature util only.

Maps this service’s result type (Result<Self::Response, Self::Error>) to a different value, regardless of whether the future succeeds or fails. Read more

fn map_request<F, NewRequest>(self, f: F) -> MapRequest<Self, F> where
    Self: Sized,
    F: FnMut(NewRequest) -> Request + Clone, [src]

This is supported on crate feature util only.

Composes a function in front of the service. Read more

fn filter<F, NewRequest>(self, filter: F) -> Filter<Self, F> where
    Self: Sized,
    F: Predicate<NewRequest>, [src]

This is supported on crate features util and filter only.

Composes this service with a Filter that conditionally accepts or rejects requests based on a predicate. Read more

fn filter_async<F, NewRequest>(self, filter: F) -> AsyncFilter<Self, F> where
    Self: Sized,
    F: AsyncPredicate<NewRequest>, [src]

This is supported on crate features util and filter only.

Composes this service with an AsyncFilter that conditionally accepts or rejects requests based on an [async predicate]. Read more

fn then<F, Response, Error, Fut>(self, f: F) -> Then<Self, F> where
    Self: Sized,
    Error: From<Self::Error>,
    F: FnOnce(Result<Self::Response, Self::Error>) -> Fut + Clone,
    Fut: Future<Output = Result<Response, Error>>, [src]

This is supported on crate feature util only.

Composes an asynchronous function after this service. Read more

fn map_future<F, Fut, Response, Error>(self, f: F) -> MapFuture<Self, F> where
    Self: Sized,
    F: FnMut(Self::Future) -> Fut,
    Error: From<Self::Error>,
    Fut: Future<Output = Result<Response, Error>>, [src]

This is supported on crate feature util only.

Composes a function that transforms futures produced by the service. Read more

impl<T, U> TryFrom<U> for T where
    U: Into<T>, [src]

type Error = Infallible

The type returned in the event of a conversion error.

pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>[src]

Performs the conversion.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, [src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>[src]

Performs the conversion.

impl<V, T> VZip<V> for T where
    V: MultiLane<T>, 

pub fn vzip(self) -> V