1 files changed, 49 insertions, 0 deletions
diff --git a/vendor/open-telemetry/sdk/Common/Time/SystemClock.php b/vendor/open-telemetry/sdk/Common/Time/SystemClock.php
new file mode 100644
index 000000000..f57e98490
--- /dev/null
+++ b/vendor/open-telemetry/sdk/Common/Time/SystemClock.php
@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\SDK\Common\Time;
+
+use function hrtime;
+use function microtime;
+
+final class SystemClock implements ClockInterface
+{
+    private static int $referenceTime = 0;
+
+    public function __construct()
+    {
+        self::init();
+    }
+
+    public static function create(): self
+    {
+        return new self();
+    }
+
+    /** @inheritDoc */
+    public function now(): int
+    {
+        return self::$referenceTime + hrtime(true);
+    }
+
+    private static function init(): void
+    {
+        if (self::$referenceTime > 0) {
+            return;
+        }
+
+        self::$referenceTime = self::calculateReferenceTime(
+            microtime(true),
+            hrtime(true)
+        );
+    }
+
+    /**
+     * Calculates the reference time which is later used to calculate the current wall clock time in nanoseconds by adding the current uptime.
+     */
+    private static function calculateReferenceTime(float $wallClockMicroTime, int $upTime): int
+    {
+        return ((int) ($wallClockMicroTime * ClockInterface::NANOS_PER_SECOND)) - $upTime;
+    }
+}