Stefan Hacker
47 lines
2.0 KiB
JavaScript
47 lines
2.0 KiB
JavaScript
"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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var Contracts = require("../Declarations/Contracts");
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/**
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* A telemetry processor that handles sampling.
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*/
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function samplingTelemetryProcessor(envelope, contextObjects) {
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var samplingPercentage = envelope.sampleRate; // Set for us in Client.getEnvelope
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var isSampledIn = false;
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if (samplingPercentage === null || samplingPercentage === undefined || samplingPercentage >= 100) {
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return true;
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}
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else if (envelope.data && Contracts.TelemetryType.Metric === Contracts.baseTypeToTelemetryType(envelope.data.baseType)) {
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// Exclude MetricData telemetry from sampling
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return true;
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}
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else if (contextObjects.correlationContext && contextObjects.correlationContext.operation) {
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// If we're using dependency correlation, sampling should retain all telemetry from a given request
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isSampledIn = getSamplingHashCode(contextObjects.correlationContext.operation.id) < samplingPercentage;
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}
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else {
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// If we're not using dependency correlation, sampling should use a random distribution on each item
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isSampledIn = (Math.random() * 100) < samplingPercentage;
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}
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return isSampledIn;
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}
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exports.samplingTelemetryProcessor = samplingTelemetryProcessor;
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/** Ported from AI .NET SDK */
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function getSamplingHashCode(input) {
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var csharpMin = -2147483648;
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var csharpMax = 2147483647;
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var hash = 5381;
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if (!input) {
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return 0;
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}
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while (input.length < 8) {
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input = input + input;
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}
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for (var i = 0; i < input.length; i++) {
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// JS doesn't respond to integer overflow by wrapping around. Simulate it with bitwise operators ( | 0)
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hash = ((((hash << 5) + hash) | 0) + input.charCodeAt(i) | 0);
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}
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hash = hash <= csharpMin ? csharpMax : Math.abs(hash);
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return (hash / csharpMax) * 100;
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}
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exports.getSamplingHashCode = getSamplingHashCode;
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//# sourceMappingURL=SamplingTelemetryProcessor.js.map
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