* feat: Make new functions const when possible
The main reason was to allow to initialize the RateLimitLayer in a const context.
So why not making ever new function const (wherever it's possible). :P
* Change the assert to use an MSRV-compatible function.
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Co-authored-by: Toby Lawrence <tobz@users.noreply.github.com>
these were not used, as the only parameters used
come from the impl block (directly and indirectly)
Co-authored-by: Toby Lawrence <tobz@users.noreply.github.com>
This commit uses the correct form of "it's".
"Its" is possessive describes a noun, while "it's" is a contraction that
is short for "it is". Since "ready" is not a noun, we must use the
contraction in this case.
In addition, this commit adds some missing commas.
Co-authored-by: Eliza Weisman <eliza@buoyant.io>
This layer is similar to a BoxLayer, but produces a BoxCloneService instead, so can be used when
the underlying layers must be clone.
Co-authored-by: Lucio Franco <luciofranco14@gmail.com>
One is handling poll_ready errors (#706).
The other is fixing the TODO about disarming poll_ready, since there is no disarm this makes sure
`poll_ready` is only called if `call` will immediately follow.
Implements Clone for discover::Change, if the underlying key and value
both implement clone.
This is convenient for use-cases where a single change needs to be
duplicated, and sent to multiple discover streams.
Co-authored-by: Lucio Franco <luciofranco14@gmail.com>
Adds `iter_ready` and `iter_ready_mut` to allow iteration over ready
services within the ready_cache. This allows the ready cache to be used
for router-like services that wish to direct requests towards specific
services. Allowing iteration directly means that cache keys do not have
to be redundantly stored separate to the ready_cache.
This adds a new `Backoff` trait and a `ExponentialBackoff`
implementation borrwoed from `linkerd2-proxy`. This provides the initial
building blocks for a more fully batteries included retry policy.
This adds new PRNG utilities that only use libstd and not the external
`rand` crate. This change's motivation are that in tower middleware that
need PRNG don't need the complexity and vast utilities of the `rand`
crate.
This adds a `Rng` trait which abstracts the simple PRNG features tower
needs. This also provides a `HasherRng` which uses the `RandomState`
type from libstd to generate random `u64` values. In addition, there is
an internal only `sample_inplace` which is used within the balance p2c
middleware to randomly pick a ready service. This implementation is
crate private since its quite specific to the balance implementation.
The goal of this in addition to the balance middlware getting `rand`
removed is for the upcoming `Retry` changes. The `next_f64` will be used
in the jitter portion of the backoff utilities in #685.
Co-authored-by: Eliza Weisman <eliza@buoyant.io>
This changes the `Policy` trait in the `retry` layer to accept `&mut
self` instead of `&self` and changes the output type of the returned
future to `()`. The motivation for this change is to simplify
the trait a bit. By the trait methods having mutable references it means
that for each retry request session you can mutate the local policy.
This is because the policy is cloned for each individual request that
arrives into the retry middleware. In addition, this allows the `Policy`
trait to be object safe.
