How to speed up the execution of this PHP script - php

Question

I have write a script for webscraping where i am fetching each link from the page and getting load that url in the code and this working extremely slow this is taking about 50 sec for first output and taking an age to complete about 100 links, I am not getting why this is working so slow, I am thinking about caching but don't know how this could help us.
1) Page caching OR Opcode cache.
code is :
public function searchForum(){
global $wpdb;
$sUrl = $this->getSearchUrl();
$this->logToCrawler();
$cid = $this->getCrawlId();
$html = file_get_dom($sUrl);
$c=1;
foreach($html('div.gridBlobTitle a:first-child') as $element){
$post_page = file_get_dom($element->href);
$post_meta = array();
foreach($post_page('table#mytable img:first-child') as $img){
if(isset($img->src)){
$post_meta['image_main'] = self::$forumurl.$img->src;
}
else{
$post_meta['image_main']=NULL;
}
}
foreach($post_page('table.preferences td:odd') as $elm){
$post_meta[] = strip_tags($elm->getInnerText());
unset($elm);
}
/*Check if can call getPlainText for description fetch*/
$object = $post_page('td.collection',2);
$methodVariable = array($object, 'getPlainText');
if(is_callable($methodVariable, true, $callable_name)){
$post_meta['description'] = utf8_encode($object->getPlainText());
}
else{
$post_meta['description'] = NULL;
}
$methodVariable = array($object, 'getInnerText');
if(is_callable($methodVariable, true, $callable_name)){
/*Get all the images we found*/
$rough_html = $object->getInnerText();
preg_match_all("/<img .*?(?=src)src=\"([^\"]+)\"/si", $rough_html, $matches);
$images = array_map('self::addUrlToItems',$matches[1]);
$images = json_encode($images);
}
if($post_meta[8]=='WTB: Want To Buy'){
$status='buy';
}
else{
$status='sell';
}
$lastdate = strtotime(date('Y-m-d',strtotime("-1 month")));
$listdate = strtotime(date('Y-m-d',strtotime($post_meta[9])));
/*Check for date*/
if($listdate>=$lastdate){
$wpdb->query("INSERT
INTO tbl_scrubed_data SET
keywords='".esc_sql($this->getForumSettings()->search_meta)."',
url_to_post='".esc_sql($element->href)."',
description='".esc_sql($post_meta['description'])."',
date_captured=now(),crawl_id='".$cid."',
image_main='".esc_sql($post_meta['image_main'])."',
images='".esc_sql($images)."',brand='".esc_sql($post_meta[0])."',
series='".esc_sql($post_meta[1])."',model='".esc_sql($post_meta[2])."',
watch_condition='".esc_sql($post_meta[3])."',box='".esc_sql($post_meta[4])."',
papers='".esc_sql($post_meta[5])."',year='".esc_sql($post_meta[6])."',case_size='".esc_sql($post_meta[7])."',status='".esc_sql($post_meta[8])."',listed='".esc_sql($post_meta[9])."',
asking_price='".esc_sql($post_meta[10])."',retail_price='".esc_sql($post_meta[11])."',payment_info='".esc_sql($post_meta[12])."',forum_id='".$this->getForumSettings()->ID."'");
unset($element,$post_page,$images);
} /*END: Check for date*/
}
$c++;
}
Note :
1) I am using [Ganon DOM Parser][1] for parsing the HTML.
[1]: https://code.google.com/p/ganon/wiki/AccesElements
2) On windows XP with WAMP, Mysql 5.5 PHP 5.3, 1 GB of RAM.
If you need more info please comment them.
Thanks

Answer 1

You need to figure out what parts of your program are being slow. There are two ways to do that.
1) Put in some print statements that print out the time in various places, so you can say "Hey, look, this took 5 seconds to go from here to here."
2) Use a profiler like xdebug that will run your program and analyze it while it's running and then you can know which parts of the code are slow.
Just looking at a program you can't say "Oh, that's the slow part to speed up." Without knowing what's slow, you'll probably waste time speeding up parts that aren't the slow parts.