Please help. My code keeps overloading my server!

[andy3dfx]

I am trying to split html body in half and insert ad banner between. I originally tried with

$position = split_pos($body);
		$d_content1 = substr($body,0,$position);
		$d_content2 = substr($body,$position+1);
                echo $d_content1;
  /********insert ad code goes here*****/
		echo $d_content2;

/********function split_pos***********/
function split_pos($text) {

/* find middle space in text **/
$mid = (int) strlen($text)/2 - 1;
$cut = strpos($text , ' ' , $mid);
$part1= substr($text , 0 , $cut + 1);

$pos1 = strrpos($part1 , '<');
$pos2 = strrpos($part1 , '>');
if (($pos1 < $pos2) or ($pos1 === False))
	return $cut; /* no html tag around */

$pos3 = strpos($text , '>' , $cut1 + 1);
if($pos3 !== False)
	return $pos3; /* end of middle html tag */
else return $cut; /* unbalancing < > */
}

But this code can cut between HTML <a></a> Tag off which make html a link doesn't work anymore.

So I tried code below:

 //put article into arrays seprated by html tags
$result = preg_split('~(</?[^>]+>)~', $body, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY); 

$max = sizeof($result);

// return middle array key for the article
$position = split_body($result, $max);

// print first half of array		
               $s = '';
        for ($x=0; $x <= $position;  $x++){
		    $s .= $result[$x];
                                      }
echo $s;		    

/********* insert ad banner code here********/		

// print 2nd half of article
		 $z = '';
	for ($y=$position+1;  $y<=$max; $y++){
		    $z .= $result[$y];}
		echo $z;

/***split body function code **/

/**** I tried passing reference to improve performace****/
function split_body(&$array_result, &$array_size){

// find the middle section of article
$mid_key = intval($array_size/2);

$mid_found = false;           // found it or not            

while (!$mid_found) {        //check if middle section found

// check if the line code have <div> or <p> tag. separate 

If (preg_match("/<(div|p)/i", $array_result[$mid_key])){  

    $mid_key -=1;
    $mid_found = true;
} elseif (preg_match("/<\/(div|p)/i", $array_result[$mid_key])){
    $mid_found = true;  

    }
	else{
     $mid_key++; 	
		if ($mid_key == $array_size){
           $mid_found = true;  

		   }
     }
}
return $mid_key;
}

The code above works. It separates the body by html tags and put them into array.
But it causes my server load to go up like 300% or 400%. eventually it will overload the server.

Can anybody explain why it overloaded my server? ( I am thinking the preg_split made too big of array, but I am not sure) or have better solution to this problem? (Split html body in half without breaking <a></a> tags).

Thank you very much.

[johanafm]

Added execution time - there was no equivalent before

$start = microtime(true);
preg_split();
echo 'Time to perform split: ' . (microtime(true) - $start) . '<br/>';

This will take longer, but this is not completely new. This functionality was here before, but you have now replaced the old way of doing it with a new way.

$start = microtime(true);
               $s = '';
        for ($x=0; $x <= $position;  $x++){
            $s .= $result[$x];
                                      }
echo $s;            

/********* insert ad banner code here********/        

// print 2nd half of article
         $z = '';
    for ($y=$position+1;  $y<=$max; $y++){
            $z .= $result[$y];}
        echo $z;

$total_new_way = microtime(true) - $start;

# now do things the old way.
$start = microtime(true);
echo $body;
$total_old_way = microtime(true) - $start;

echo 'Difference between old and new way: ' . ($total_new_way - $total_old_way) . '<br/>';

I'm placing my money on the preg_split function being the main culprit. But, check execution time for all new or modified blocks of code and see how long it really takes.

Also, never do things more than once when you can do it exactly once. In this case, split your article in half, then save those halves to the DB, then

$query = "SELECT part1, part2 ...";

// ...
echo $row['part1'];
echo $ad;
echo $row['part2'];

And suddenly your new code is as fast as it used to be, while still being able to show the ad in the middle. You pay the price when saving the article (once), and don't pay the price when someone is viewing it.