backoff-timeout.js
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"use strict";
/*
* Copyright 2019 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
Object.defineProperty(exports, "__esModule", { value: true });
const INITIAL_BACKOFF_MS = 1000;
const BACKOFF_MULTIPLIER = 1.6;
const MAX_BACKOFF_MS = 120000;
const BACKOFF_JITTER = 0.2;
/**
* Get a number uniformly at random in the range [min, max)
* @param min
* @param max
*/
function uniformRandom(min, max) {
return Math.random() * (max - min) + min;
}
class BackoffTimeout {
constructor(callback, options) {
this.callback = callback;
this.initialDelay = INITIAL_BACKOFF_MS;
this.multiplier = BACKOFF_MULTIPLIER;
this.maxDelay = MAX_BACKOFF_MS;
this.jitter = BACKOFF_JITTER;
this.running = false;
if (options) {
if (options.initialDelay) {
this.initialDelay = options.initialDelay;
}
if (options.multiplier) {
this.multiplier = options.multiplier;
}
if (options.jitter) {
this.jitter = options.jitter;
}
if (options.maxDelay) {
this.maxDelay = options.maxDelay;
}
}
this.nextDelay = this.initialDelay;
this.timerId = setTimeout(() => { }, 0);
clearTimeout(this.timerId);
}
/**
* Call the callback after the current amount of delay time
*/
runOnce() {
this.running = true;
this.timerId = setTimeout(() => {
this.callback();
this.running = false;
}, this.nextDelay);
const nextBackoff = Math.min(this.nextDelay * this.multiplier, this.maxDelay);
const jitterMagnitude = nextBackoff * this.jitter;
this.nextDelay =
nextBackoff + uniformRandom(-jitterMagnitude, jitterMagnitude);
}
/**
* Stop the timer. The callback will not be called until `runOnce` is called
* again.
*/
stop() {
clearTimeout(this.timerId);
this.running = false;
}
/**
* Reset the delay time to its initial value.
*/
reset() {
this.nextDelay = this.initialDelay;
}
isRunning() {
return this.running;
}
}
exports.BackoffTimeout = BackoffTimeout;
//# sourceMappingURL=backoff-timeout.js.map