16ec1a3703
In T340552, the official PHP OpenTelemetry client was effectively rejected for inclusion in MediaWiki due to its size. Implement a minimal tracing library instead that eschews conformance with the OTEL client specification in favor of simplicity, while remaining capable of emitting trace data in OTLP format and thus retaining compatibility with any ingestion endpoint capable of handling OTLP. In its current state, the library supports a basic feature set that should be sufficient for basic tracing integration: * Span creation, inclusive span activation and automatic parent span assignment, * Span attributes and span kinds, * Basic resource (process/request)-level metadata generation, * Data export over OTLP. Additional functionality, such as trace propagation, can then be incrementally added to the library. Bug: T340552 Change-Id: Ibc3910058cd7ed064cad293a3cdc091344e66b86
37 lines
927 B
PHP
37 lines
927 B
PHP
<?php
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namespace Wikimedia\Telemetry;
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use Wikimedia\Assert\Assert;
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/**
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* A {@link SamplerInterface} implementation that samples a given percentage of root spans,
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* while respecting sampling decisions made by other samplers for a given trace.
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*
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* @since 1.43
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* @internal
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*/
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class ProbabilisticSampler implements SamplerInterface {
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/**
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* The chance of sampling a root span, as a percentage (0-100).
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* @var int
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*/
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private int $percentChance;
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public function __construct( int $percentChance ) {
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Assert::parameter(
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$percentChance >= 0 && $percentChance <= 100,
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'$percentChance',
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'must be between 0 and 100 inclusive'
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);
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$this->percentChance = $percentChance;
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}
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/** @inheritDoc */
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public function shouldSample( ?SpanContext $parentSpanContext ): bool {
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if ( $parentSpanContext !== null ) {
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return $parentSpanContext->isSampled();
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}
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return mt_rand( 1, 100 ) <= $this->percentChance;
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}
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}
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