Code Coverage for /workspace/src/includes/libs/Telemetry/Clock.php

1	<?php
2	namespace Wikimedia\Telemetry;
3
4	use Wikimedia\Assert\Assert;
5
6	/**
7	* A click providing the current time in nanoseconds, backed by {@link hrtime}.
8	*
9	* @since 1.43
10	* @internal
11	*/
12	class Clock {
13	/**
14	* Timestamp to return in place of the current time, or `null` to use the current time.
15	* @var int\|null
16	*/
17	private static ?int $mockTime = null;
18
19	/**
20	* The reference UNIX timestamp in nanoseconds which hrtime() offsets should be added to
21	* to derive an absolute timestamp.
22	* @var int\|null
23	*/
24	private ?int $referenceTime = null;
25
26	public function __construct() {
27	Assert::precondition(
28	PHP_INT_SIZE >= 8,
29	'The Clock class requires 64-bit integers to support nanosecond timing'
30	);
31	}
32
33	/**
34	* Get the current time, represented as the number of nanoseconds since the UNIX epoch.
35	*/
36	public function getCurrentNanoTime(): int {
37	$this->referenceTime ??= (int)( 1e9 * microtime( true ) ) - hrtime( true );
38	return self::$mockTime ?? ( $this->referenceTime + hrtime( true ) );
39	}
40
41	/**
42	* Set a mock time to override the timestamp returned by {@link Clock::getCurrentNanoTime()}.
43	* Useful for testing.
44	*
45	* @param int\|null $epochNanos The override timestamp, or `null` to return to using the current time.
46	* @return void
47	*/
48	public static function setMockTime( ?int $epochNanos ): void {
49	Assert::precondition( defined( 'MW_PHPUNIT_TEST' ), 'This method should only be used in tests' );
50	self::$mockTime = $epochNanos;
51	}
52	}