com.jnape.palatable.lambda.functions.builtin.fn4

Class RateLimit<A>

java.lang.Object

com.jnape.palatable.lambda.functions.builtin.fn4.RateLimit<A>

Type Parameters:

A - the Iterable element type

All Implemented Interfaces:

Fn1<Fn0<Instant>,Fn1<Long,Fn1<Duration,Fn1<Iterable<A>,Iterable<A>>>>>, Fn2<Fn0<Instant>,Long,Fn1<Duration,Fn1<Iterable<A>,Iterable<A>>>>, Fn3<Fn0<Instant>,Long,Duration,Fn1<Iterable<A>,Iterable<A>>>, Fn4<Fn0<Instant>,Long,Duration,Iterable<A>,Iterable<A>>, Applicative<Fn1<Long,Fn1<Duration,Fn1<Iterable<A>,Iterable<A>>>>,Fn1<Fn0<Instant>,?>>, Cartesian<Fn0<Instant>,Fn1<Long,Fn1<Duration,Fn1<Iterable<A>,Iterable<A>>>>,Fn1<?,?>>, Cocartesian<Fn0<Instant>,Fn1<Long,Fn1<Duration,Fn1<Iterable<A>,Iterable<A>>>>,Fn1<?,?>>, Contravariant<Fn0<Instant>,Profunctor<?,Fn1<Long,Fn1<Duration,Fn1<Iterable<A>,Iterable<A>>>>,Fn1<?,?>>>, Functor<Fn1<Long,Fn1<Duration,Fn1<Iterable<A>,Iterable<A>>>>,Fn1<Fn0<Instant>,?>>, Profunctor<Fn0<Instant>,Fn1<Long,Fn1<Duration,Fn1<Iterable<A>,Iterable<A>>>>,Fn1<?,?>>, Monad<Fn1<Long,Fn1<Duration,Fn1<Iterable<A>,Iterable<A>>>>,Fn1<Fn0<Instant>,?>>, MonadReader<Fn0<Instant>,Fn1<Long,Fn1<Duration,Fn1<Iterable<A>,Iterable<A>>>>,Fn1<Fn0<Instant>,?>>, MonadRec<Fn1<Long,Fn1<Duration,Fn1<Iterable<A>,Iterable<A>>>>,Fn1<Fn0<Instant>,?>>, MonadWriter<Fn0<Instant>,Fn1<Long,Fn1<Duration,Fn1<Iterable<A>,Iterable<A>>>>,Fn1<Fn0<Instant>,?>>

public final class RateLimit<A>
extends Object
implements Fn4<Fn0<Instant>,Long,Duration,Iterable<A>,Iterable<A>>

Given an Fn0 of Instants (presumably backed by a clock), a limit, a Duration, and an Iterable as, return an Iterable that iterates as according to the threshold specified by the limit per duration, using the Fn0 to advance time.

As an example, the following will print at most 10 elements per second:

 rateLimit(Clock.systemUTC()::instant, 10L, Duration.ofSeconds(1), iterate(x -> x + 1, 1))
     .forEach(System.out::println);
 

Currying allows different rate limits to be combined naturally:

 Iterable<Integer> elements = iterate(x -> x + 1, 1);

 Supplier<Instant> instantFn0 = Clock.systemUTC()::instant;
 Fn1<Iterable<Integer>, Iterable<Integer>> tenPerSecond =
     rateLimit(instantFn0, 10L, Duration.ofSeconds(1));
 Fn1<Iterable<Integer>, Iterable<Integer>> oneHundredEveryTwoMinutes =
     rateLimit(instantFn0, 100L, Duration.ofMinutes(2));

 tenPerSecond.fmap(oneHundredEveryTwoMinutes).apply(elements).forEach(System.out::println);
 

In the preceding example, the elements will be printed at most 10 elements per second and 100 elements per 120 seconds.

If the host Thread is interrupted while the returned Iterable is waiting for the next available time slice, an IterationInterruptedException will immediately be thrown.

Note that the returned Iterable will never iterate faster than the specified rate limit, but the earliest the next element is available will be dependent on the precision of the underlying instant supplier as well as any overhead involved in producing the element from the original Iterable.

Method Summary

Modifier and Type	Method and Description
Iterable<A>	checkedApply(Fn0<Instant> instantFn0, Long limit, Duration duration, Iterable<A> as)
static <A> RateLimit<A>	rateLimit()
static <A> Fn3<Long,Duration,Iterable<A>,Iterable<A>>	rateLimit(Fn0<Instant> instantFn0)
static <A> Fn2<Duration,Iterable<A>,Iterable<A>>	rateLimit(Fn0<Instant> instantFn0, Long limit)
static <A> Fn1<Iterable<A>,Iterable<A>>	rateLimit(Fn0<Instant> instantFn0, Long limit, Duration duration)
static <A> Iterable<A>	rateLimit(Fn0<Instant> instantFn0, Long limit, Duration duration, Iterable<A> as)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.jnape.palatable.lambda.functions.Fn4

apply, apply, apply, apply, checkedApply, compose, contraMap, diMapL, discardR, flip, fn4, fn4, fn4, fn4, uncurry, widen

Methods inherited from interface com.jnape.palatable.lambda.functions.Fn3

checkedApply, fn3, fn3, fn3

Methods inherited from interface com.jnape.palatable.lambda.functions.Fn2

checkedApply, curried, curry, fn2, fromBiFunction, toBiFunction

Methods inherited from interface com.jnape.palatable.lambda.functions.Fn1

andThen, carry, cartesian, censor, choose, cocartesian, diMap, diMapR, discardL, flatMap, fmap, fn1, fromFunction, lazyZip, listens, local, pure, pureFn1, thunk, toFunction, trampolineM, zip, zip

Methods inherited from interface com.jnape.palatable.lambda.monad.Monad

join

Methods inherited from interface com.jnape.palatable.lambda.functor.Functor

coerce

Method Detail

checkedApply

public Iterable<A> checkedApply(Fn0<Instant> instantFn0,
                                Long limit,
                                Duration duration,
                                Iterable<A> as)

Specified by:

checkedApply in interface Fn4<Fn0<Instant>,Long,Duration,Iterable<A>,Iterable<A>>

rateLimit

public static <A> RateLimit<A> rateLimit()

rateLimit

public static <A> Fn3<Long,Duration,Iterable<A>,Iterable<A>> rateLimit(Fn0<Instant> instantFn0)

rateLimit

public static <A> Fn2<Duration,Iterable<A>,Iterable<A>> rateLimit(Fn0<Instant> instantFn0,
                                                                  Long limit)

rateLimit

public static <A> Fn1<Iterable<A>,Iterable<A>> rateLimit(Fn0<Instant> instantFn0,
                                                         Long limit,
                                                         Duration duration)

rateLimit

public static <A> Iterable<A> rateLimit(Fn0<Instant> instantFn0,
                                        Long limit,
                                        Duration duration,
                                        Iterable<A> as)