57 lines
1.8 KiB
JavaScript
57 lines
1.8 KiB
JavaScript
export class Backoffs {
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static normalize(backoff) {
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if (Number.isFinite(backoff)) {
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return {
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type: 'fixed',
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delay: backoff,
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};
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}
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else if (backoff) {
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return backoff;
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}
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}
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static calculate(backoff, attemptsMade, err, job, customStrategy) {
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if (backoff) {
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const strategy = lookupStrategy(backoff, customStrategy);
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return strategy(attemptsMade, backoff.type, err, job);
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}
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}
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}
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Backoffs.builtinStrategies = {
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fixed: function (delay, jitter = 0) {
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return function () {
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if (jitter > 0) {
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const minDelay = delay * (1 - jitter);
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return Math.floor(Math.random() * delay * jitter + minDelay);
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}
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else {
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return delay;
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}
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};
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},
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exponential: function (delay, jitter = 0) {
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return function (attemptsMade) {
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if (jitter > 0) {
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const maxDelay = Math.round(Math.pow(2, attemptsMade - 1) * delay);
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const minDelay = maxDelay * (1 - jitter);
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return Math.floor(Math.random() * maxDelay * jitter + minDelay);
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}
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else {
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return Math.round(Math.pow(2, attemptsMade - 1) * delay);
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}
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};
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},
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};
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function lookupStrategy(backoff, customStrategy) {
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if (backoff.type in Backoffs.builtinStrategies) {
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return Backoffs.builtinStrategies[backoff.type](backoff.delay, backoff.jitter);
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}
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else if (customStrategy) {
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return customStrategy;
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}
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else {
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throw new Error(`Unknown backoff strategy ${backoff.type}.
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If a custom backoff strategy is used, specify it when the queue is created.`);
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}
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}
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//# sourceMappingURL=backoffs.js.map
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