diff options
Diffstat (limited to 'vendor/open-telemetry/sdk/Trace/Sampler/TraceIdRatioBasedSampler.php')
-rw-r--r-- | vendor/open-telemetry/sdk/Trace/Sampler/TraceIdRatioBasedSampler.php | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/vendor/open-telemetry/sdk/Trace/Sampler/TraceIdRatioBasedSampler.php b/vendor/open-telemetry/sdk/Trace/Sampler/TraceIdRatioBasedSampler.php new file mode 100644 index 000000000..c11a90d5d --- /dev/null +++ b/vendor/open-telemetry/sdk/Trace/Sampler/TraceIdRatioBasedSampler.php @@ -0,0 +1,70 @@ +<?php + +declare(strict_types=1); + +namespace OpenTelemetry\SDK\Trace\Sampler; + +use InvalidArgumentException; +use OpenTelemetry\Context\ContextInterface; +use OpenTelemetry\SDK\Common\Attribute\AttributesInterface; +use OpenTelemetry\SDK\Trace\SamplerInterface; +use OpenTelemetry\SDK\Trace\SamplingResult; +use OpenTelemetry\SDK\Trace\Span; + +/** + * This implementation of the SamplerInterface records with given probability. + * Example: + * ``` + * use OpenTelemetry\API\Trace\TraceIdRatioBasedSampler; + * $sampler = new TraceIdRatioBasedSampler(0.01); + * ``` + */ +class TraceIdRatioBasedSampler implements SamplerInterface +{ + private float $probability; + + /** + * TraceIdRatioBasedSampler constructor. + * @param float $probability Probability float value between 0.0 and 1.0. + */ + public function __construct(float $probability) + { + if ($probability < 0.0 || $probability > 1.0) { + throw new InvalidArgumentException('probability should be be between 0.0 and 1.0.'); + } + $this->probability = $probability; + } + + /** + * Returns `SamplingResult` based on probability. Respects the parent `SampleFlag` + * {@inheritdoc} + */ + public function shouldSample( + ContextInterface $parentContext, + string $traceId, + string $spanName, + int $spanKind, + AttributesInterface $attributes, + array $links + ): SamplingResult { + // TODO: Add config to adjust which spans get sampled (only default from specification is implemented) + $parentSpan = Span::fromContext($parentContext); + $parentSpanContext = $parentSpan->getContext(); + $traceState = $parentSpanContext->getTraceState(); + + /** + * Since php can only store up to 63 bit positive integers + */ + $traceIdLimit = (1 << 60) - 1; + $lowerOrderBytes = hexdec(substr($traceId, strlen($traceId) - 15, 15)); + $traceIdCondition = $lowerOrderBytes < round($this->probability * $traceIdLimit); + $decision = $traceIdCondition ? SamplingResult::RECORD_AND_SAMPLE : SamplingResult::DROP; + + return new SamplingResult($decision, [], $traceState); + } + + public function getDescription(): string + { + return sprintf('%s{%.6F}', 'TraceIdRatioBasedSampler', $this->probability); + } +} |