80 lines
2 KiB
JavaScript
80 lines
2 KiB
JavaScript
/*
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* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
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* or more contributor license agreements. Licensed under the Elastic License;
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* you may not use this file except in compliance with the Elastic License.
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*/
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import _ from 'lodash';
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export class Poller {
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constructor(options) {
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this.functionToPoll = options.functionToPoll; // Must return a Promise
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this.successFunction = options.successFunction || _.noop;
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this.errorFunction = options.errorFunction || _.noop;
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this.pollFrequencyInMillis = options.pollFrequencyInMillis;
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this.trailing = options.trailing || false;
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this.continuePollingOnError = options.continuePollingOnError || false;
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this.pollFrequencyErrorMultiplier = options.pollFrequencyErrorMultiplier || 1;
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this._timeoutId = null;
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this._isRunning = false;
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}
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getPollFrequency() {
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return this.pollFrequencyInMillis;
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}
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_poll() {
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return this.functionToPoll()
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.then(this.successFunction)
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.then(() => {
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if (!this._isRunning) {
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return;
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}
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this._timeoutId = setTimeout(this._poll.bind(this), this.pollFrequencyInMillis);
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})
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.catch(e => {
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this.errorFunction(e);
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if (!this._isRunning) {
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return;
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}
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if (this.continuePollingOnError) {
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this._timeoutId = setTimeout(
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this._poll.bind(this),
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this.pollFrequencyInMillis * this.pollFrequencyErrorMultiplier
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);
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} else {
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this.stop();
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}
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});
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}
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start() {
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if (this._isRunning) {
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return;
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}
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this._isRunning = true;
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if (this.trailing) {
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this._timeoutId = setTimeout(this._poll.bind(this), this.pollFrequencyInMillis);
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} else {
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this._poll();
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}
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}
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stop() {
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if (!this._isRunning) {
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return;
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}
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this._isRunning = false;
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clearTimeout(this._timeoutId);
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this._timeoutId = null;
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}
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isRunning() {
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return this._isRunning;
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}
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}
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