78 lines
1.4 KiB
TypeScript
78 lines
1.4 KiB
TypeScript
/**
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* Initialize backoff timer with `opts`.
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*
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* - `min` initial timeout in milliseconds [100]
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* - `max` max timeout [10000]
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* - `jitter` [0]
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* - `factor` [2]
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*
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* @param {Object} opts
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* @api public
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*/
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export function Backoff(this: any, opts) {
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opts = opts || {}
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this.ms = opts.min || 100
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this.max = opts.max || 10000
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this.factor = opts.factor || 2
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this.jitter = opts.jitter > 0 && opts.jitter <= 1 ? opts.jitter : 0
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this.attempts = 0
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}
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/**
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* Return the backoff duration.
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*
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* @return {Number}
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* @api public
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*/
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Backoff.prototype.duration = function () {
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var ms = this.ms * Math.pow(this.factor, this.attempts++)
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if (this.jitter) {
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var rand = Math.random()
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var deviation = Math.floor(rand * this.jitter * ms)
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ms = (Math.floor(rand * 10) & 1) == 0 ? ms - deviation : ms + deviation
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}
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return Math.min(ms, this.max) | 0
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}
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/**
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* Reset the number of attempts.
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*
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* @api public
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*/
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Backoff.prototype.reset = function () {
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this.attempts = 0
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}
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/**
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* Set the minimum duration
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*
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* @api public
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*/
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Backoff.prototype.setMin = function (min) {
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this.ms = min
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}
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/**
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* Set the maximum duration
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*
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* @api public
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*/
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Backoff.prototype.setMax = function (max) {
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this.max = max
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}
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/**
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* Set the jitter
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*
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* @api public
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*/
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Backoff.prototype.setJitter = function (jitter) {
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this.jitter = jitter
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}
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