+

vendor/react/http/src/Io/Clock.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace React\Http\Io;
+
+use React\EventLoop\LoopInterface;
+
+/**
+ * [internal] Clock source that returns current timestamp and memoize clock for same tick
+ *
+ * This is mostly used as an internal optimization to avoid unneeded syscalls to
+ * get the current system time multiple times within the same loop tick. For the
+ * purpose of the HTTP server, the clock is assumed to not change to a
+ * significant degree within the same loop tick. If you need a high precision
+ * clock source, you may want to use `\hrtime()` instead (PHP 7.3+).
+ *
+ * The API is modelled to resemble the PSR-20 `ClockInterface` (in draft at the
+ * time of writing this), but uses a `float` return value for performance
+ * reasons instead.
+ *
+ * Note that this is an internal class only and nothing you should usually care
+ * about for outside use.
+ *
+ * @internal
+ */
+class Clock
+{
+    /** @var LoopInterface $loop */
+    private $loop;
+
+    /** @var ?float */
+    private $now;
+
+    public function __construct(LoopInterface $loop)
+    {
+        $this->loop = $loop;
+    }
+
+    /** @return float */
+    public function now()
+    {
+        if ($this->now === null) {
+            $this->now = \microtime(true);
+
+            // remember clock for current loop tick only and update on next tick
+            $now =& $this->now;
+            $this->loop->futureTick(function () use (&$now) {
+                assert($now !== null);
+                $now = null;
+            });
+        }
+
+        return $this->now;
+    }
+}