Crate throttle_my_fn[−][src]
Expand description
throttle_my_fn
is a Rust attribute macro to limit a function’s number of runs over a
specified period of time.
throttle_my_fn
is a Rust attribute macro to limit a function’s number of runs over a
specified period of time, even when called from multiple threads.
The primary use-case for this attribute macro is rate-limiting, e.g. to avoid hammering an online service or to avoid serving too many requests over a period of time.
The macro works by rewriting the function and prefixing it with the necessary
book-keeping for throttling (see Usage
below). The resulting function is
thread-safe.
Usage
Add the dependency to your Cargo.toml
:
[dependencies]
throttle_my_fn = "0.2"
parking_lot = "0.11"
Or, using cargo add
:
$ cargo add throttle_my_fn
$ cargo add parking_lot
Include the macro:
use throttle_my_fn::throttle;
Annotate the functions you want to throttle:
#[throttle(10, Duration::from_secs(1))]
pub(crate) fn run_10_times_per_second(arg: &str) -> String {
...
}
#[throttle(1, Duration::from_millis(100))]
pub(crate) fn run_once_per_100_milliseconds(arg: &str) -> String {
...
}
Note that the function signatures are modified to wrap the return type in an Option
,
like so:
pub(crate) fn run_10_times_per_second(arg: &str) -> Option<String> {
...
}
pub(crate) fn run_once_per_100_milliseconds(arg: &str) -> Option<String> {
...
}
The Option<T>
returned signifies whether the function executed or not.
Attribute Macros
Throttle a function’s execution count over a period of time.