iconcur
iconcur
is a concurrency limiting library for Promises
. If you're ready to stop pegging your processor or client's browser with millions of concurrent promises, then look no further. You think this is a great idea. I concur!
Usage
mapWithConcurrency
The simplest way to use iconcur
is with this mapping function.
; .fillnull .mapPromise.resolvei;;
Pool
Pools are good general-purposes concurrency controllers. You can specify a certain concurrency limit when you generate a pool, and when you pass a generated pool object a list of promises, it will continuously resolve promises at the concurrency limit until they are all completely settled.
This controller supports cancellation. Cacellation does not halt execution of pending promises.
More features are planned for this controller. However, for now, the only difference between using this and using mapWithConcurrency
is cancellation support.
; ; .fillnull .mapPromise.resolvei; ; // By calling promises.all(), the promises begin execution.;promises.cancel;
Note: Having multiple instances of pool(fns)
will result in a seperate concurrency limitation context for each one.
;;; ;; // This results in a total concurrency limit of 4// instead of 2.firstPromises.all;secondPromises.all;
Generator
Generators are useful for when you want the execution of your concurrent promises to come up for air every once in a while and allow you to operate on the data in some grouping of settled promises before the entire array of promises is settled.
This controller supports cancellation. Cacellation does not halt execution of pending promises.
; ; .fillnull .mapPromise.resolvei; ; // By calling promises.all(), the promises begin execution.// This will resolve promises in partitions by the given// concurrency limit.// This can be inconvenient if a grouping of promises includes// one long-running promise, as execution of another batch// will be deferred until the long-running promise of the current// batch settles.; // Generators are also cancellable.promises.cancel; // Another way to begin execution is with .next() ;while !promises2.isFinished
As with pool
, having multiple instances of generator(fns)
will result in a different concurrency limitation context for each one. Be careful!