63 lines
1.8 KiB
JavaScript
63 lines
1.8 KiB
JavaScript
'use strict';
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var request = require('request');
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var debug = require('../../util/debug')('capacity-http-simple');
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function HttpSimpleCapacity (host, capacityEndpoint) {
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this.host = host;
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this.capacityEndpoint = capacityEndpoint;
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this.lastResponse = null;
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this.lastResponseTime = 0;
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}
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module.exports = HttpSimpleCapacity;
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HttpSimpleCapacity.prototype.getCapacity = function (callback) {
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this.getResponse(function (err, values) {
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var capacity = 1;
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if (err) {
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return callback(null, capacity);
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}
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var availableCores = parseInt(values.available_cores, 10);
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capacity = Math.max(availableCores, 1);
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capacity = Number.isFinite(capacity) ? capacity : 1;
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debug('host=%s, capacity=%s', this.host, capacity);
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return callback(null, capacity);
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}.bind(this));
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};
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HttpSimpleCapacity.prototype.getResponse = function (callback) {
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var requestParams = {
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method: 'POST',
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url: this.capacityEndpoint,
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timeout: 2000,
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json: true
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};
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debug('getCapacity(%s)', this.host);
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// throttle requests for 500 ms
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var now = Date.now();
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if (this.lastResponse !== null && ((now - this.lastResponseTime) < 500)) {
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return callback(null, this.lastResponse);
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}
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request.post(requestParams, function (err, res, jsonRes) {
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if (err) {
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return callback(err);
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}
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if (jsonRes && jsonRes.retcode === 0) {
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this.lastResponse = jsonRes.return_values || {};
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// We could go more aggressive by updating lastResponseTime on failures.
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this.lastResponseTime = now;
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return callback(null, this.lastResponse);
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}
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return callback(new Error('Could not retrieve information from endpoint'));
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}.bind(this));
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};
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