Cache System Explanation (datastore)

[seko3]

Originally Posted by briansol

With a couple tweaks (probably because this is 2 years old...), i've successfully got my first datastore plugin working

Thanks for the write up Ken. Never experienced with the datastore much.

Can you please share it with us. I am so tired of trying to make this work. It has been 5 days but I couldn't cache anything yet. It would be great to know how to cache sql queries.

[RobDog888]

Originally Posted by briansol

With a couple tweaks (probably because this is 2 years old...), i've successfully got my first datastore plugin working

Thanks for the write up Ken. Never experienced with the datastore much.

What was different from the posted solutions?

[briansol]

i'm still trying to figure out how to export this entire thing (with all my crons/ phrases etc) but no one is helping me out on .com
http://www.vbulletin.com/forum/showthread.php?t=274552
otherwise, i'd just post my entire product.


basically, this is what i did.

1) I made a cron job to populate a table from live post/thread table data. (Perhaps this table is useless now altogether, but i like having a table i can reference during testing. next version probably won't include this cache_ table at all)

<?php

error_reporting(E_ALL & ~E_NOTICE);
if (!is_object($vbulletin->db))
{
exit;
}

//clean up...
$vbulletin->db->query_write('TRUNCATE TABLE ' . TABLE_PREFIX . 'cache_activetopics');


$vbulletin->db->query_write('insert into ' . TABLE_PREFIX . 'cache_activetopics
/// my big select query here
');

// now, this loads that new data into an array, which is then shoved into the build datastore function:

$query = $vbulletin->db->query_read('SELECT * from ' . TABLE_PREFIX . 'cache_activetopics');

while ($variable = $vbulletin->db->fetch_array($query))
{
        $variable_array[] = $variable;
}

build_datastore('skm_active_cache', serialize($variable_array), true); 


log_cron_action('', $nextitem, 1);

?>

Again, you can skip truncating and building the table... just run the big query here as the $query = part to get your array/data.


Set up the cron job to run this script as you like.
Run it once manually to make sure you have data in the datastore row.

there will actually be a row with the name skm_active_cache in the datastore table.


2) from there, i have 4 plugins in my product

Product : SKM - Active threads from past 24 hours
SKM Active Threads - Cache output templates cache_templates
SKM Active Threads - Cache Special Templates (datastore row) init_startup
SKM Active Threads - Parse and Print forumhome_complete
SKM Active Threads - Template Group template_groups

a) cache_templates hook : contains the simple caching of my custom template which prints 1 row of data (ie, <tr><td>1</td><td>2</td></tr> ) similar to the 'threadbits' template

it contains a simple line:

$globaltemplates[] = 'skm_activethreads24_forumhome';

b) init_startup hook : special templates is probably a mis-nomer at this point, as i'm NOT using the special templates array merge style.
This file pulls the datastore row into memory:

$datastore_fetch[] = "'skm_active_cache'";

note the quotes are important. This name should match what you ran in your cron under the build_datastore() function.

c) forumhome_complete hook : parse the data and print it to the template step. obviously, forumhome_complete should match the area you are trying to hook into. in my case, it was on the forum home.

foreach ($vbulletin->skm_active_cache AS $mycache)
{
	$output['threadid'] = $mycache['tid'];
	
	eval("\$mythreadbits .= \"".fetch_template('skm_activethreads24_forumhome')."\";");
}

d) the template will look for the $output array to print, ala:

<a href="showthread.php?t=$output[threadid]&amp;goto=newpost">

e) the template group is not required... just makes things easier to group when you have a lot of templates.


That's about it.

basically, you need to fill the datastore with your query, and pull with a foreach of the array once the data has been initialized.

[gabrielt]

Hello,

Thank you so much for your tutorial. This was exactly what I was looking for. I write my own products/plugins (our forums is huge) and I was wondering how to cache stuff around.

However I faced one problem: I couldn't read data back.

The solution was to add a "1" parameter on the store command:

build_datastore('name',serialize($variable),1);

When retrieving you don't need to "unserialize" it.

Also I was trying to call my cached array inside a class that hasn't had $vbulletin as a global variable, so I needed to add:

global $vbulletin;

On the top of my plugin.

And I also needed to add a plugin for the init_startup hook, adding:

$datastore_fetch[]="'name'";

I hope this feedback helps other coders.

Cheers,
Gabriel.

[Jafo232]

Originally Posted by gabrielt

And I also needed to add a plugin for the init_startup hook, adding:

$datastore_fetch[]="'name'";

This should really be added to the first post. Took forever to figure this out.

[bananalive]

Is there a datastore per user?

[mokujin]

If you have this, now How can I delete one of the data (red below) ???

a:3:{
        i:0; a:3:{
                s:2:"id";s:1:"1";
                s:4:"name";s:3:"Dog";
                s:5:"value";s:3:"Dog";
        }

        i:1; a:3:{
                s:2:"id";s:1:"2";
                s:4:"name";s:3:"Cat";
                s:5:"value";s:3:"Cat";
        }

        i:2; a:3:{
                s:2:"id";s:1:"3";
                s:4:"name";s:3:"Cow";
                s:5:"value";s:3:"Cow";
        }
}

[rob01]

it could be possible to fetch more than 1 value

for example

(ID: 1) (Title: Dog) (Value: Dog , dog2, dog4)

and be able to delete dog4

(ID: 1) (Title: Dog) (Value: Dog , dog2)

or add more

any ideas?

maybe first check if its empty or :S?

[solita_ugc]

Hello,

I seem to be unable to persist the values in datastore. Variables built and stored to datastore in global_start plugin are lost in subsequent requests.

I wish the purpose, usage, lifecycle, limitations and performance of datastore would be discussed more in the article.

-Pete

[IdanB]

Originally Posted by gabrielt

And I also needed to add a plugin for the init_startup hook, adding:

$datastore_fetch[]="'name'";

Thank you for this, was pulling my hair out my head trying to get this to work.
That's what i was missing