50 lines
1.1 KiB
PHP
50 lines
1.1 KiB
PHP
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<?php
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declare(strict_types=1);
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namespace OpenTelemetry\SDK\Common\Time;
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use function hrtime;
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use function microtime;
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final class SystemClock implements ClockInterface
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{
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private static int $referenceTime = 0;
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public function __construct()
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{
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self::init();
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}
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public static function create(): self
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{
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return new self();
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}
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/** @inheritDoc */
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public function now(): int
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{
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return self::$referenceTime + hrtime(true);
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}
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private static function init(): void
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{
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if (self::$referenceTime > 0) {
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return;
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}
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self::$referenceTime = self::calculateReferenceTime(
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microtime(true),
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hrtime(true)
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);
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}
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/**
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* Calculates the reference time which is later used to calculate the current wall clock time in nanoseconds by adding the current uptime.
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*/
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private static function calculateReferenceTime(float $wallClockMicroTime, int $upTime): int
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{
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return ((int) ($wallClockMicroTime * ClockInterface::NANOS_PER_SECOND)) - $upTime;
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}
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}
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