asarfuckery/appasar/stable/common/Backoff.js
2019-03-12 18:01:00 +01:00

93 lines
No EOL
1.8 KiB
JavaScript

'use strict';
Object.defineProperty(exports, "__esModule", {
value: true
});
// copied from discord_app/lib because including from there is broken.
class Backoff {
/**
* Create a backoff instance can automatically backoff retries.
*/
constructor(min = 500, max = null, jitter = true) {
this.min = min;
this.max = max != null ? max : min * 10;
this.jitter = jitter;
this._current = min;
this._timeoutId = null;
this._fails = 0;
}
/**
* Return the number of failures.
*/
get fails() {
return this._fails;
}
/**
* Current backoff value in milliseconds.
*/
get current() {
return this._current;
}
/**
* A callback is going to fire.
*/
get pending() {
return this._timeoutId != null;
}
/**
* Clear any pending callbacks and reset the backoff.
*/
succeed() {
this.cancel();
this._fails = 0;
this._current = this.min;
}
/**
* Increment the backoff and schedule a callback if provided.
*/
fail(callback) {
this._fails += 1;
let delay = this._current * 2;
if (this.jitter) {
delay *= Math.random();
}
this._current = Math.min(this._current + delay, this.max);
if (callback != null) {
if (this._timeoutId != null) {
throw new Error('callback already pending');
}
this._timeoutId = setTimeout(() => {
try {
if (callback != null) {
callback();
}
} finally {
this._timeoutId = null;
}
}, this._current);
}
return this._current;
}
/**
* Clear any pending callbacks.
*/
cancel() {
if (this._timeoutId != null) {
clearTimeout(this._timeoutId);
this._timeoutId = null;
}
}
}
exports.default = Backoff;
module.exports = exports['default'];