clo/sitegen

lib/progress.ts: get an external reviewer for the default estimation algorithm #76

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opened 2026-01-28 02:35:05 -08:00 by clo · 1 comment

clo commented

2026-01-28 02:35:05 -08:00

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i think it is implemented in a buggy way. i gave it some tests in an isolated place, but not too much on real world cases.

 /**
  * Exponential Moving Average.
  * this is the algorithm used for the default progress estimator.
  * https://en.wikipedia.org/wiki/Exponential_smoothing
  */
 export class Ema implements EstimationAlgorithm {
   start: number | null = null;
   estimate: number | null = null;
   /** smoothing factor (0-1) */
   alpha: number = 0.25;
   constructor(alpha: number = 0.1) {
     this.alpha = alpha;
   }
   /**
    * given a timestamp `time` and a progress value `progress`, return the
    * timestamp that the action will be finished on.
    */
   sample(time: number, progress: number): number | null {
     ASSERT(
       progress >= 0 && progress < 1,
       `progress must be a number between 0 and 1, got ${progress}`,
     );
     if (this.start == null) {
       this.start = time;
       return null;
     }
     const value = (time - this.start) / progress;
     this.estimate = this.estimate != null
       ? ((1 - this.alpha) * this.estimate +
         this.alpha * value)
       : value;
     return time + (1 - progress) * this.estimate;
   }
   reset(): void {
     this.start = null;
     this.estimate = null;
   }
 }

i think it is implemented in a buggy way. i gave it some tests in an isolated place, but not too much on real world cases. https://git.paperclover.net/clo/sitegen/src/commit/8b330ca47d47e63d0c107691ecf75236fd112ba1/lib/progress.ts#L1679-L1721

clo added the

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2026-01-28 02:35:05 -08:00

clo commented

2026-02-02 01:22:16 -08:00

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Owner

my suspicion is that the api interface should be sample(time: number, current: number, total: number) where both numbers must be >= 0 and current < total

my suspicion is that the api interface should be `sample(time: number, current: number, total: number)` where both numbers must be >= 0 and current < total

clo added this to the progress blog post milestone

2026-02-07 01:58:37 -08:00

clo referenced this issue from a commit

2026-02-07 02:20:58 -08:00

WIP: fix: progress estimation interface update

clo referenced this issue from a pull request that will close it,

2026-02-07 02:21:12 -08:00

WIP: fix: progress estimation interface update #84