PHP - Microtime()

I am trying to run tests on my pages and see how much time each one of em take to execute.
For this purpose, i'm using this code which i got online:
Code: [Select]
<?php 
   $mtime = microtime(); 
   $mtime = explode(" ",$mtime); 
   $mtime = $mtime[1] + $mtime[0]; 
   $starttime = $mtime; 
?>
<!-- Rest of the php and validation and form elements -->
<?php 
   $mtime = microtime(); 
   $mtime = explode(" ",$mtime); 
   $mtime = $mtime[1] + $mtime[0]; 
   $endtime = $mtime; 
   $totaltime = ($endtime - $starttime); 
   echo "This page was created in ".$totaltime." seconds"; 
?>

microtime() returns microseconds & secs since Unix epoch. So after exploding, why do we add them both?
Cant we just use the microseconds part?

I've tried this code & the one above & both return same time(almost).

Code: [Select]
<?php 
   $mtime = microtime(); 
   $mtime = explode(" ",$mtime); 
   $mtime = $mtime[0]; 
   $starttime = $mtime; 
?>
<!-- Rest of the php and validation and form elements -->
<?php 
   $mtime = microtime(); 
   $mtime = explode(" ",$mtime); 
   $mtime = $mtime[0]; 
   $endtime = $mtime; 
   $totaltime = ($endtime - $starttime); 
   echo "This page was created in ".$totaltime." seconds"; 
?>

I'm using microtime to capture $start_time and $finish_time bothing using microtime() function. I then pass both $start_time and $finish_time into date() function to parse a date. The difference between $start_time and $finish_time is also calculated. The problem being the date() function is producing incorrect values.

list($total_count, $success_count, $errors_data, $start_time, $finish_time) = $summary_data;
$duration_time = $finish_time - $start_time;

echo "<b>Started Processing At:</b> ".date('m/d/Y H:i:m', $start_time)."<br/>";
echo "<b>Completed Processing At:</b> ".date('m/d/Y H:i:m', $finish_time)."<br/>";
echo "<b>Processing Duration:</b> $duration_time seconds<br/><br/>";


The output:

Started Processing At: 11/22/2010 18:45:11
Completed Processing At: 11/22/2010 18:45:11
Processing Duration: 8.0499620437622 seconds

Hi all,

I post a strange behavior that could be reproduced (at least on apache2+php5).
I don't know if I am doing wrong but let me explain what I try to achieve.

I need to send chunks of binary data (let's say 30) and analyze the average Kbit/s at the end :

I sum each chunk output time, each chunk size, and perform my Kbit/s calculation at the end.

Code: [Select]
<?php

// build my binary chunk
$var= '';
$o=9000;
while($o--)
{
$var.= "testtest";
}

// get the size, prepare the memory.
$size = strlen($var);
$tt_sent = 0;
$tt_time = 0;

// I send my chunk 30 times
for ($i = 0; $i < 30; $i++)
{
// start time
$t = microtime(true);
echo $var."\n";
ob_flush();
flush();
$e = microtime(true);
// end time
// the difference should reprenent what it takes to the server to 
// transmit chunk to client right ?

// add this chuck bench to the total
$tt_time += round($e-$t,4);
$tt_sent += $size;
}

// total result
echo "\n total: ".(($tt_sent*8)/($tt_time)/1024)."\n";

?>

In this example above, it works so far ( on localhost, it oscillate from 7000 to 10000 Kbit/s through different tests).

Now, let's say I want to shape the transmission, because I know that the client will have enough of a chunk of data to process for a second.

I decide to use usleep(1000000), to mark a pause between chunk transmission.

Code: [Select]
<?php

// build my binary chunk
$var= '';
$o=9000;
while($o--)
{
$var.= "testtest";
}

// get the size, prepare the memory.
$size = strlen($var);
$tt_sent = 0;
$tt_time = 0;

// I send my chunk 30 times
for ($i = 0; $i < 30; $i++)
{
// start time
$t = microtime(true);
echo $var."\n";
ob_flush();
flush();
$e = microtime(true);
// end time
// the difference should reprenent what it takes to the server to 
// transmit chunk to client right ?

// add this chuck bench to the total
$tt_time += round($e-$t,4);
$tt_sent += $size;

usleep(1000000);
}

// total result
echo "\n total: ".(($tt_sent*8)/($tt_time)/1024)."\n";

?>

I am doing something wrong ? Does the buffer output is not synchronous ?

Thanks a Lot


Nunja