Simplest way to profile a PHP script

Question

What's the easiest way to profile a PHP script?

I'd love tacking something on that shows me a dump of all function calls and how long they took but I'm also OK with putting something around specific functions.

I tried experimenting with the microtime function:

$then = microtime();
myFunc();
$now = microtime();

echo sprintf("Elapsed:  %f", $now-$then);

but that sometimes gives me negative results. Plus it's a lot of trouble to sprinkle that all over my code.

Answer 1

You want xdebug I think. Install it on the server, turn it on, pump the output through kcachegrind (for linux) or wincachegrind (for windows) and it'll show you a few pretty charts that detail the exact timings, counts and memory usage (but you'll need another extension for that).

It rocks, seriously :D

Answer 2

No extensions are needed, just use these two functions for simple profiling.

// Call this at each point of interest, passing a descriptive string
function prof_flag($str)
{
    global $prof_timing, $prof_names;
    $prof_timing[] = microtime(true);
    $prof_names[] = $str;
}

// Call this when you're done and want to see the results
function prof_print()
{
    global $prof_timing, $prof_names;
    $size = count($prof_timing);
    for($i=0;$i<$size - 1; $i++)
    {
        echo "<b>{$prof_names[$i]}</b><br>";
        echo sprintf("&nbsp;&nbsp;&nbsp;%f<br>", $prof_timing[$i+1]-$prof_timing[$i]);
    }
    echo "<b>{$prof_names[$size-1]}</b><br>";
}

Here is an example, calling prof_flag() with a description at each checkpoint, and prof_print() at the end:

prof_flag("Start");

   include '../lib/database.php';
   include '../lib/helper_func.php';

prof_flag("Connect to DB");

   connect_to_db();

prof_flag("Perform query");

   // Get all the data

   $select_query = "SELECT * FROM data_table";
   $result = mysql_query($select_query);

prof_flag("Retrieve data");

   $rows = array();
   $found_data=false;
   while($r = mysql_fetch_assoc($result))
   {
       $found_data=true;
       $rows[] = $r;
   }

prof_flag("Close DB");

   mysql_close();   //close database connection

prof_flag("Done");
prof_print();

Output looks like this:

Start
   0.004303
Connect to DB
   0.003518
Perform query
   0.000308
Retrieve data
   0.000009
Close DB
   0.000049
Done

Answer 3

The PECL APD extension is used as follows:

<?php
apd_set_pprof_trace();

//rest of the script
?>

After, parse the generated file using pprofp.

Example output:

Trace for /home/dan/testapd.php
Total Elapsed Time = 0.00
Total System Time  = 0.00
Total User Time    = 0.00


Real         User        System             secs/    cumm
%Time (excl/cumm)  (excl/cumm)  (excl/cumm) Calls    call    s/call  Memory Usage Name
--------------------------------------------------------------------------------------
100.0 0.00 0.00  0.00 0.00  0.00 0.00     1  0.0000   0.0009            0 main
56.9 0.00 0.00  0.00 0.00  0.00 0.00     1  0.0005   0.0005            0 apd_set_pprof_trace
28.0 0.00 0.00  0.00 0.00  0.00 0.00    10  0.0000   0.0000            0 preg_replace
14.3 0.00 0.00  0.00 0.00  0.00 0.00    10  0.0000   0.0000            0 str_replace

Warning: the latest release of APD is dated 2004, the extension is no longer maintained and has various compability issues (see comments).