[SOLVED] Cache included PHP file

[Yves]

Is it possible to cache an included php file for 30 minutes (as a txt somewhere) and chache another included php file for 10 minutes without having APC installed? The thing is I don't want to cache a whole page, because there is a log in. When logged out, it showes as if you're still logged in. If I could cache included files, that would ofcourse be fabulous.

[Daniel0]

I'm not quite sure what you're trying to accomplish. Is it template files you wish to cache so they don't have to be parsed at every request?

[Yves]

Well, I have around 300 article categories with around 60,000 articles on my site. All 300 categories are all linked on the homepage. Each category also has the number of articles in it next to it. So you can imagine how many tables it has to go through to find the number of articles currently in the database, for each seperate category..

 

As of now the menu displaying the categories/subcategories is included in the index.php. Each time someone visits or revisits the homepage it takes a while to load. What I would like is to have the included (display menu) file cached for 30 minutes. After that, it can regenerate a new cache and update the content of the menu to represent to current number of articles in each category.

 

If I could accomplish that, I would be very pleased. If I could repeat that on aother included, but this time cache for 10 minutes, my day would be made.

 

I hope I explained well enough. !thanks

[Daniel0]

You could do something like this:

<?php
$cache_file = 'cache/menu.html';

if(filemtime($cache_file) + 30*60 > time())
{
// generate the content here and store it in $menu_html;

file_put_contents($cache_file, $menu_html);
}
else {
$menu_html = file_get_contents($cache_html);
}
?>

 

You might want to expand it and make it into a class so you can do this:

 

<?php
$cache = new Cache('menu.html');
if($cache->isOlderThan(30 * 60))
{
// generate content and store in $menu_html
$cache->update($menu_html);
}
else {
$menu_html = $cache->getContents();
}
?>

[Daniel0]

I feel generous so I decided to make the class:

 

<?php
class Cache
{
static protected $cache_dir;

protected $contents;
protected $path;

public function __construct($filename)
{
	$this->path = self::$cache_dir . $filename;

	if(!file_exists($filename))
	{
		throw new Exception("Cache file '{$filename}' could not be found");
		return false;
	}

	$this->contents = file_get_contents($this->path);
}

public function isOlderThan($seconds)
{
	return filemtime($this->path) + 30*60 < time();
}

public function update($new_content)
{
	$this->contents = $new_content;
	file_put_contents($this->path, $this->contents);
}

public function getContents()
{
	return $this->contents;
}

public function __toString()
{
	return $this->getContents();
}

static public function setCacheDir($dir)
{
	self::$$cache_dir = $dir;
}
}

// In another file:

require_once 'library/Cache.php';

Cache::setCacheDir('/home/somebody/cache/');

// ...

$cache = new Cache('menu.html');
if($cache->isOlderThan(30 * 60))
{
// generate content and store in $menu_html
$cache->update($menu_html);
}
else {
$menu_html = $cache->getContents();
}
?>

[Daniel0]

Just spotted an error in the class. Updated:

<?php
class Cache
{
static protected $cache_dir;

protected $contents;
protected $path;

public function __construct($filename)
{
	$this->path = self::$cache_dir . $filename;

	if(!file_exists($filename))
	{
		throw new Exception("Cache file '{$filename}' could not be found");
		return false;
	}

	$this->contents = file_get_contents($this->path);
}

public function isOlderThan($seconds)
{
	return filemtime($this->path) + $seconds < time();
}

public function update($new_content)
{
	$this->contents = $new_content;
	file_put_contents($this->path, $this->contents);
}

public function getContents()
{
	return $this->contents;
}

public function __toString()
{
	return $this->getContents();
}

static public function setCacheDir($dir)
{
	self::$$cache_dir = $dir;
}
}
?>

 

Note: I have not tested this version or any other code I have posted in this topic.

[Yves]

I'm still trying to make the first code you wrote work. It doesn't seem to put the generated content (or html code) in cache/menu.html

What I did was create the cache/ folder and menu.html file (empty) and uploaded it. Then I reloaded the homepage to see if it worked. It did display the menu so I thought it worked. However when I downloaded the menu.html file I saw it was still empty. So I'm a bit puzzled w/ that atm.

 

EDIT: ofcourse I uploaded my edited menu.php file too.

[Daniel0]

Could you post the code you have?

[Yves]

sorry for taking a while

<?php 
require_once("system/display.inc.php"); 

$cache_file = 'cache/menu.html';

if(filemtime($cache_file) + 1*60 > time())
{
// generate the content here and store it in $menu_html;
$menu_html = "
<td>".echo Display($obj_db,0,left)."</td>
<td width=\"25\"> </td>
<td>".echo Display($obj_db,0,right)."</td>
";

file_put_contents($cache_file, $menu_html);
}
else {
$menu_html = file_get_contents($cache_html);
}
?>

[Daniel0]

Try to change

if(filemtime($cache_file) + 1*60 > time())

to

if(filemtime($cache_file) - 1*60 > time() || !file_exists($cache_file))

 

Then delete cache/menu.html and try again.

[Yves]

Warning: filemtime() [function.filemtime]: stat failed for cache/menu.html in inc/navigation.inc.php on line 6

 

Warning: file_put_contents(cache/menu.html) [function.file-put-contents]: failed to open stream: No such file or directory in inc/navigation.inc.php on line 25

 

I think I need to add that the included file is in an inc/ folder and the cache/ folder is in the inc/ folder too

[PFMaBiSmAd]

Caching results is fine, but make sure that there is not a bigger problem elsewhere first -

 

Here is your performance problem -

 

So you can imagine how many tables it has to go through to find the number of articles currently in the database, for each separate category..

 

By using a separate table for each category, your code is doomed to execute a query for each table present. Also, if you truly have a list of 300 categories displayed at one time on one page, you are not going to get many repeat visitors because no one wants to try and wade through that much information at one time.

 

If the database was designed with one table for all the articles, with just a column to identify the category, it would only take one query.

 

My guess is that the method being used to count the articles in a category is not the most efficient. Could you post just a sample of one query (or the query loop) that is getting the count(s).

[Yves]

I luckally understand what you're saying. But I had to write 'rows'. Sorry about that.

So you can imagine how many rows it has to go through to find the number of articles currently in the database, for each separate category ID..

 

Here's the function Display($obj_db="",$ParentID,$pos) to display the menu. It's the system/display.inc.php file. If you look at my site in my signature, you can see 2 columns of menu links.

 

The left one is generate by this code:

 

<?php echo Display($obj_db,0,left); ?>

 

The right one is generate by this code:

 

<?php echo Display($obj_db,0,right); ?>

 

<?php
// Display Menu's - BEGIN //
function Display($obj_db="",$ParentID,$pos) 
{
$query = mysql_query("SELECT * FROM tblcategories  WHERE intParentID = ".$ParentID." ORDER BY varCategory ASC");
$all = mysql_num_rows($query);
$half = floor($all / 2);

if($pos == "left") {  
$start = 0;
if ($all % 2 == 1) { $end = $half; }
if ($all % 2 == 0) { $end = $half-1; }
}
if($pos == "right") { 
if ($all % 2 == 1) { $start = $half+1; }
if ($all % 2 == 0) { $start = $half; }
$end = $all-1;
}

for($i=0; $i <= $all; $i++)
{
$row = mysql_fetch_array($query);
if(($i >= $start )&& ($i <= $end))
{
$query2 = mysql_query("SELECT * FROM tblcategories  WHERE intParentID = ".$row['intID']." ORDER BY varCategory ASC");
$numchild = mysql_num_rows($query2);
if($numchild>0)
{
echo "<div class=\"ctitle\"><a class=\"ctitle\" href=\"javascript:display('cat_".($i+1)."');\">".$row['varCategory']."</a><img src=\"images/arrow_down.gif\" alt=\"\"></div>";
echo "<div style=\"display:none;\" id=\"cat_".($i+1)."\">";
echo "<a class=\"stitle\" href=\"?Cat=".str_replace(" ","-",$row['varCategory'])."\" rel=\"nofollow\">".$row['varCategory']."</a>";
echo "<br>";
for($j=0; $j < $numchild; $j++)
{
$row2 = mysql_fetch_array($query2);
$query3 = mysql_query("SELECT count(intID) FROM `tblarticles`  WHERE intCategory = ".$row2['intID']."");
$row3 = mysql_fetch_array($query3);
$numArticles = $row3['count(intID)'];
if($numArticles!=0) {
$numArticles = "<span class=\"stitle\">[".$numArticles."]</span>";
} else { $numArticles = ""; }
echo "<a class=\"stitle\" href=\"?Cat=".str_replace(" ","-",$row['varCategory']).":".str_replace(" ","-",$row2['varCategory'])."\" rel=\"nofollow\">".$row2['varCategory']."</a>".$numArticles."";
echo "<br>";
}
echo "</div>\n";
} else {
echo "<div><a class=\"ctitle\" href=\"".$location."?Cat=".str_replace(" ","-",$row['varCategory'])."\" rel=\"nofollow\">".$row['varCategory']."</a> </div>";
echo "<span style=\"display:none;\" id=\"cat_".($i+1)."\"></span>\n";
}
}
}
}
// Display Menu's - END //
?>

[PFMaBiSmAd]

By the way, there is an existing php mmcache that was designed to cache database data like your counts - http://www.php.net/manual/en/ref.memcache.php

 

... which was especially designed to decrease database load in dynamic web applications.

[Yves]

By the way, there is an existing php mmcache that was designed to cache database data like your counts - http://www.php.net/manual/en/ref.memcache.php

 

... which was especially designed to decrease database load in dynamic web applications.

 

I knew. But I have no idea how to install such a thing. Plus I read it uses 2GB os space. Imo Danial's solution looks like it could work for what I need. All pages load fast except for the homepage. The homepage may load slow but never on every pageload. Once every 30 minutes seems suitable.

[Daniel0]

Try what I have attached. I tested it on my computer and it worked.

 

[attachment deleted by admin]

[Yves]

Ok, thank you Daniel. I will have a thourough look!

[Yves]

Ok. It works like a charm!

 

Thank you soo much, Daniel. You've made my day cause I can now apply it to cache one other thing for 10 minutes instead o 30.

 

Yeeha!