# TooBasic: Cache ## We All Know What It Is True, we all know what a [cache](http://en.wikipedia.org/wiki/Cache_%28computing%29) system is, the real question is *what does __TooBasic__ have to say about it?* ## What is it cached? Internally, __TooBasic__ separates the stuff it caches in two kinds: * __Computing Cache__: This can also be called _controller cache_ because it stores all the assignments made by a controller. * __View Cache__: You can see this as a HTML cache where you store the final result of rendering a controller call. _Why is it separated?_ Well, if recall a cached controller but requesting a different format, you wouldn't want to run all your logics and queries and etc. when you only need a different format. ## Adapters From factory, __TooBasic__ provides five basic types of cache adaptations you can choose on for your site and we are going to describe them. ### File cache adapter The most basic (and default) cache adapter provided by __TooBasic__ is a class called __\TooBasic\Adapters\Cache\File__ and it stores data inside files. When active, you'll find files coming and going inside __ROOTDIR/cache/filecache__. ### Database cache adapter A not very polite way of caching data is to store it inside a database, but in some cases it could be useful (I hope _Mr.Potato_ won't kill for suggesting this mechanism). For those cases, __TooBasic__ provides an abstract adapter class called __\TooBasic\Adapters\Cache\DB__ and a specification for __MySQL__ called __\TooBasic\Adapters\Cache\DBMySQL__. This adapter makes use of a table called __cache__ (if there's a table prefix it will use it) inside the database configured in `$Connections[GC_CONNECTIONS_DEFAULTS][GC_CONNECTIONS_DEFAULTS_CACHE]` (or `$Connections[GC_CONNECTIONS_DEFAULTS][GC_CONNECTIONS_DEFAULTS_DB]` if none) and its structure will be created with a query like the next one (if __MySQL__): ```sql create table if not exists cache ( cch_key varchar(256) collate utf8_bin not null, cch_data blob not null, cch_date timestamp not null default current_timestamp, primary key(cch_key) ) engine=myisam default charset=utf8 collate=utf8_bin ``` By default, __TooBasic__ will attempt to create this table every time it's invoked, if you want to avoid this behavior you can set the global `$Defaults[GC_DEFAULTS_INSTALLED]` to `true`. #### Also Also, __TooBasic__ provides __\TooBasic\Adapters\Cache\DBSQLite__ and __\TooBasic\Adapters\Cache\DBPostgreSQL__ as cache on database adapters for _SQLite_ and _PostgreSQL_. ### Memcached adapter A better approach is to use something like [__Memcached__](http://php.net/manual/en/book.memcached.php) where you can store data in memory inside a cache service prepared for that task. For this, __TooBasic__ provides a cache adapter class called __\TooBasic\Adapters\Cache\Memcached__ and it requires settings like these: ```php <?php $Defaults[GC_DEFAULTS_MEMCACHED][GC_DEFAULTS_MEMCACHED_SERVER] = 'localhost'; $Defaults[GC_DEFAULTS_MEMCACHED][GC_DEFAULTS_MEMCACHED_PORT] = 11211; $Defaults[GC_DEFAULTS_MEMCACHED][GC_DEFAULTS_MEMCACHED_PREFIX] = ''; ``` If you are wondering about `$Defaults[GC_DEFAULTS_MEMCACHED][GC_DEFAULTS_MEMCACHED_PREFIX]`, well when you have more than one __TooBasic__ based site using the same __Memcached__ service, you may find some collision problems and this global allows you to tag each cache key with a prefix depending on your site. ### Memcache adapter If you are using _memcache_ libraries (not _memcached_), try this: ```php <?php $Defaults[GC_DEFAULTS_CACHE_ADAPTER] = '\\TooBasic\\Adapters\\Cache\\Memcache'; $Defaults[GC_DEFAULTS_MEMCACHE][GC_DEFAULTS_MEMCACHE_SERVER] = 'localhost'; $Defaults[GC_DEFAULTS_MEMCACHE][GC_DEFAULTS_MEMCACHE_PORT] = 11211; $Defaults[GC_DEFAULTS_MEMCACHE][GC_DEFAULTS_MEMCACHE_PREFIX] = ''; ``` ## Setting an adapter We've been talking about cache adapter classes but we haven't said how to use them, well, that's the easy part, you just need to set something like the next piece of code and that's all: ```php <?php $Defaults[GC_DEFAULTS_CACHE_ADAPTER] = '\\TooBasic\\Adapters\\Cache\\Memcached'; ``` ## Cached controller Now that you know all this about __TooBasic__'s cache system, you need to know how to configure it for your controller. Once again, let's use a simple example, suppose we have a controller that displays a users' information... something like this: ```php <?php class UserinfoController extends \TooBasic\Controller { protected function basicRun() { $user = $this->representations->users->item($this->params->get->userid); $this->assign('info', $user->toArray()); $this->assign('bgcolor', isset($this->params->get->bgcolor) ? $this->params->get->bgcolor : 'red'); return $this->status(); } protected function init() { parent::init(); $this->_requiredParams['GET'][] = 'userid'; } } ``` Now, let's say we want to cache this controller's calls based on the _user ID_ and a parameter called _bgcolor_. For that we need to do two things: * First, we need to activate the use of cache: ```php <?php class UserinfoController extends \TooBasic\Controller { protected $_cached = true; . . . } ``` * And second we need to specify which parameters to take in consideration when generating a cache key: ```php <?php class UserinfoController extends \TooBasic\Controller { . . . protected function init() { . . . $this->_cacheParams['GET'][] = 'userid'; $this->_cacheParams['GET'][] = 'bgcolor'; . . . } } ``` All together will look like this: ```php <?php class UserinfoController extends \TooBasic\Controller { protected $_cached = true; protected function basicRun() { $user = $this->representations->users->item($this->params->get->userid); $this->assign('info', $user->toArray()); $this->assign('bgcolor', isset($this->params->get->bgcolor) ? $this->params->get->bgcolor : 'red'); return $this->status(); } protected function init() { parent::init(); $this->_cacheParams['GET'][] = 'userid'; $this->_cacheParams['GET'][] = 'bgcolor'; $this->_requiredParams['GET'][] = 'userid'; } } ``` And that's it, from now on, our controller saves cache entries and calls like these will have different entries: * http://www.example.com/?action=userinfo&userid=10&bgcolor=green * http://www.example.com/?action=userinfo&userid=10&bgcolor=blue * http://www.example.com/?action=userinfo&userid=12&bgcolor=green * http://www.example.com/?action=userinfo&userid=10 What about the last one? well, if you don't pass a parameter called _bgcolor_ it will consider it as empty and generate a different key. ## Cached services? Yes, services can also be cached in the same way a controller does. ## What if you don't want it? Yes, what if you don't want any cache system and the use of `&debugresetcache` in the url annoys you? Well, there's an adapter called __\TooBasic\Adapters\Cache\NoCache__ that acts as a dummy providing you with the solution. It will interact as any other cache adapter but it won't do a thing and you'll be working without cache. ## Duration Before version 0.3.0, every cache entry had a duration of 3600 seconds (one hour) and it couldn't be changed, but now it is possible adding something like this in your site's configuration file: ```php <?php $Defaults[GC_DEFAULTS_CACHE_EXPIRATION] = 86400; // 1 day ``` You can also change your controllers and use something like this: ```php <?php class MyactionController extends \TooBasic\Controller { protected $_cached = \TooBasic\Adapters\Cache\Adapter::ExpirationSizeLarge; public function basicRun() { . . . ``` This constant will tell __TooBasic__ to use an expiration time as long as it's configured. Available constants are: * `\TooBasic\Adapters\Cache\Adapter::ExpirationSizeDouble`: Double of `$Defaults[GC_DEFAULTS_CACHE_EXPIRATION]`. * `\TooBasic\Adapters\Cache\Adapter::ExpirationSizeLarge`: Same size as `$Defaults[GC_DEFAULTS_CACHE_EXPIRATION]`. * `\TooBasic\Adapters\Cache\Adapter::ExpirationSizeMedium`: A half of `$Defaults[GC_DEFAULTS_CACHE_EXPIRATION]`. * `\TooBasic\Adapters\Cache\Adapter::ExpirationSizeSmall`: A quarter of `$Defaults[GC_DEFAULTS_CACHE_EXPIRATION]`. Any other value will be considered as `\TooBasic\Adapters\Cache\Adapter::ExpirationSizeLarge`, including the boolean `true` used in versions before 0.3.0. <!--:GBSUMMARY:Cache:1:Cache:-->
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