Speedup Your Website With Cache_Lite

What does the \'lifeTime\' => 3600 in $options array do?

It means if a cached page is older than 3600 secs (1 hour), it should be removed. This way you automatically get fresh content every hour.

Be careful of Cache_Lite - if you have a large number of cache objects, you may get corrupted results back (I have assumed it\'s duplicate keys). Moved to memcached instead.

What happens if two users view the same uncached page at the same time? Do you risk two PHP processes writing to the same file at the same time?

@ svetzal: You kan define the keys so that\'s up to the programmer I think. You can also have Cache_Lite use different directories.

@ Kon: Cache_Lite support some mechanisms to ensure a file has been successfully written to the filesystem. You will have to decide whether or not to use those based on the situation, because of course, every check that\'s implemented costs performance.

I really don\'t understand caching.

in which file di I include realcontent.php?

it\'s all explained half.

@ Moritz: You\'re free to cache any page or part of a page you want. You could create a new index.php and rename your old one to real_content.php, you could also do this for a part of your page which isn\'t very dynamic but does require some heavy php & db operations. So in that case you keep your old index.php but you use the example code to only cache (for example) your sidebar. The original sidebar code goes moves to it\'s own: sidebar.php, and then that\'s the file you include instead of real_content.php

@Kevin

Thanks,

it works so far, but i still get this error message at the end of the page:

Warning: Cache_Lite::include_once(PEAR.php) [function.Cache-Lite-include-once]: failed to open stream: No such file or directory in /customers/zweiteherren.com/zweiteherr... on line 536

Warning: Cache_Lite::include_once() [function.include]: Failed opening \'PEAR.php\' for inclusion (include_path=\'.:\') in /customers/zweiteherren.com/zweiteherr... on line 536

Fatal error: Class \'PEAR\' not found in /customers/zweiteherren.com/zweiteherr... on line 537

What\'s wrong with it?

@ Moritz: You\'ve installed PEAR in /customers/zweiteherren.com/zweiteherr... and which is not in the include_path. PEAR should be in PHP\'s include_path so Cache_Lite can find all it\'s dependencies.

@Kevin
thanks for your help, but i guess i\'m too stupid.
Now i get this error message:
Warning: Invalid argument supplied for foreach() in /....www/PEAR/Cache/Lite.php on line 282

@ Moritz: I think you are not providing Cache_Lite with an $options array.

$Cache_Lite = new Cache_Lite($options);

You have to define some options in the options array just like in the example.

Hi Kevin,
I want to ask about how to assign $id
one $id for one cache file or what ?
So if I create template files in cache ->
I need assign one file with unique $id or how ?
I read in somewhere \"
$id = md5($strSQL);
if($cache->get($id)){
//
$result = $cache->get($id);
} else {
$result = getAll($strSQL)
$cache->save($result, $id);
}

Hmm, what do you think about code ?

@ seonet: Hi, for example. If I wanted to cache this entire article, a logical $id would be: \'speedup_your_website_with_cache_lite\' or maybe the internal article id like: 189 or something. If I only wanted to cache the comments section a logical id would be: \'speedup_your_website_with_cache_lite.comments\'

See? You\'re totally free in what id to pick, just as long as it\'s unique and logically for you

Thanks Kevin
:D

Hi,

Thanks for this, do you have any idea on using this with Smarty?

Any tips?

@ Ashish: I\'ve never used Smarty, but you should at least be able to implement it for caching entire pages. I would say play around with it a bit and see how flexibile Smarty really is.

Hey.

Good introduction to Cache_Lite.

However if you want to cache bigger sites than blogs,little portals etc. You should look deeper into Cache_Lite functionalities its really powerfull. Thereis a good article on the Sitepoint\'s page.

One more thing, if you dont want your data to duplicate at the first time the page is loaded add ob_end_clean() just after \"$Cache_Lite->save($data, $id);\" line to clear output buffering data. That should be noticed.

Cheers.

@ wireholic: maybe i\'ll write another article some day that diggs a little deeper. thanks for your remark and you\'re right, I\'ll update the article

Great article, It helped me a lot.
I searched for infromation regarding cache hit, cache miss and regarding cache stat and I did not find any. Someone please refer any URL regarding them. I am confused regarding how to flush my cache, simplying deleted cached directory work or not? Please help.

@ Dilli R. Maharjan: You could do that yes, but Cache_Lite also provides methods to delete specific cached keys. You should review the (tiny) manual.

Thanks

Thanks Kevin, I was busy on other stuff. Thanks again for the suggestions.

The code works but I can\'t get it to work fine with a php file that contains a msqyl query and is included in a parent file (e.g. template page). That template page contains about 4 cached block and all work fine, except this one that has mysql queries. The cache for that file rewrites with every refresh and I don\'t know why. If I remove the query it works just fine.

I think I got it. I was using the var $id for all block but for this one it didn\'t work. After I renamed it to some other name (say $ident) it worked.

Kevin:

Your article is good and clear. My cache file is being written but my cache is never hit, apparently because the filename changes. I am just trying to cache a string although later it will be an array of objects populated from a database. Everytime I try to retrieve it , instead of getting the cached data (which I can view in the cached file), it creates a new cache entry. Also, the cache filename seems to change each time. Is therre a way to fix it so it doesn\'t change and pulls from the cache?

Here\'s the code

In my main file which the user views (Contact.php) I have :

$quote=new QuoteBL();
$quotevalue=$quote->GetNextQuote();
echo \"cache=\".$quotevalue;

in QuoteBL I have:

class QuoteBL {

//constructor
public function QuoteBL(){

}
public function GetNextQuote(){
//tries to get quote from cache and if no cached data, retrieves data and saves to cache
$data=null;
$cacheid = \'quotearray\';
$cache_options = array(
\'cacheDir\' =>\'Cache/data/\', //this is the temp directory of the cache files
\'lifeTime\' =>3600, //time, in seconds, of how long the cache will be valid
\'fileNameProtection\' => true, //make sure filename is valid
\'writeControl\' => \'true\',
\'readControl\' => \'true\',
\'readControlType\' => \'md5\'
);

$cache=new Cache_Lite($cache_options);
if ($data = $cache->get($cacheid)) {

// data is in our cache, access it through $data
echo \"got data from cache<BR>\";
}
else { // Not found in cache, it needs to be added
$data=\"The quality of mercy is not strained\";
$cache->save($data,$cacheid,null);
echo \"cache empty, save new data in cache<BR>\";
}
return $data;

}

}

TIA,

Steve Shier

Hello, how do I install cache lite manually? If i am on a shared server?