note 49022 added to function.microtime

From: Date: Fri, 14 Jan 2005 15:50:28 +0000
Subject: note 49022 added to function.microtime
Groups: php.notes 
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Here's what I use to time my scripts. There's a bit of surrounding code in the function, which will induce errors in short cycles ; this should therefore be used in repetitive context where the error will be amortized (cf. also mcq at supergamez dot hu 's comment below). Note however that the important thing, $now = microtime(TRUE), happens at the very beginning, not suffering from any extraneous delay, and following it at the chronometer start is only one little condition, and a particularly compiler-friendly one at that (I think). Hope this does not turn out too ugly after wordwrap()... /************************************************************ * * void | float chronometer() * * Enables determination of an amount of time between two points in a script, * in milliseconds. * * Call the function a first time (as void) to start the chronometer. The next * call to the function will return the number of milliseconds elapsed since * the chronometer was started (rounded to three decimal places). * * The chronometer is then available for being started again. * ************************************************************/ $CHRONO_STARTTIME = 0; function chronometer() { global $CHRONO_STARTTIME; $now = microtime(TRUE); // float, in _seconds_ if ($CHRONO_STARTTIME > 0) { /* Stop the chronometer : return the amount of time since it was started, in ms with a precision of 3 decimal places, and reset the start time. We could factor the multiplication by 1000 (which converts seconds into milliseconds) to save memory, but considering that floats can reach e+308 but only carry 14 decimals, this is certainly more precise */ $retElapsed = round($now * 1000 - $CHRONO_STARTTIME * 1000, 3); $CHRONO_STARTTIME = 0; return $retElapsed; } else { // Start the chronometer : save the starting time $CHRONO_STARTTIME = $now; } } ---- Manual Page -- http://www.php.net/manual/en/function.microtime.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+49022 Delete -- http://master.php.net/manage/user-notes.php?action=delete+49022&report=yes Reason: bad code -- http://master.php.net/manage/user-notes.php?action=delete+49022&report=yes&reason=bad+code Reason: spam -- http://master.php.net/manage/user-notes.php?action=delete+49022&report=yes&reason=spam Reason: useless example -- http://master.php.net/manage/user-notes.php?action=delete+49022&report=yes&reason=useless+example Reason: contains commercial links -- http://master.php.net/manage/user-notes.php?action=delete+49022&report=yes&reason=contains+commercial+links Reason: useless note -- http://master.php.net/manage/user-notes.php?action=delete+49022&report=yes&reason=useless+note Reject -- http://master.php.net/manage/user-notes.php?action=reject+49022&report=yes Search -- http://master.php.net/manage/user-notes.php

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