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    exponential-rate-limit
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    1.1.2 • Public • Published

    npm version

    Exponential Rate Limit

    A small library which handles decaying exponential backoff. This is useful if you want to start throttling something whilst it is going wrong, but recover once things start working again.

    Demo

    The demo source is in "demo.ts".

    To run the demo locally run npm run start.

    It is also hosted here (thanks to Netify).

    Usage

    import { JobQueue, defaultDelayFunction } from './exponential-rate-limit';
     
    const queue = new JobQueue({
      /**
       * The maximum time (seconds) between jobs executing.
       */
      maxInterval: 5
      /**
       * The delay function.
       */
      delayFunctiondefaultDelayFunction
    });
     
    const { remove } = queue.enqueue(({ enqueueTime } => {
      console.log('Executing', enqueueTime);
    });

    Example

    The following example implements throttledFetch, which will start delaying future executions exponentially (up to the default 5 seconds) every time a request fails or does not respond with status 200.

    Every time there is a 200 response, the delays will also start getting shorter again. As time passes without any jobs being executed, the delay the next job would incur also decreases.

    import { JobQueue } from './exponential-rate-limit';
     
    const jobQueue = new JobQueue(); // default options
     
    function throttledFetch(...fetchArgs): Promise<Response> {
      return new Promise((resolve) => {
        jobQueue.enqueue(() => {
          const fetchPromise = fetch(...fetchArgs);
          resolve(fetchPromise);
          return fetchPromise.then((response) => response.status === 200);
        });
      });
    }

    Browser

    This can also be used in the browser thanks to jsDelivr:

    <head>
      <script type="text/javascript" src="https://cdn.jsdelivr.net/npm/exponential-rate-limit@1"></script> 
      <script type="text/javascript">
        var queue = new ExponentialRateLimit.JobQueue();
      </script> 
    </head>

    Install

    npm i exponential-rate-limit

    DownloadsWeekly Downloads

    2

    Version

    1.1.2

    License

    Apache-2.0

    Unpacked Size

    44.1 kB

    Total Files

    21

    Last publish

    Collaborators

    • tjenkinson