How to control a cakephp cache duration

I’m using CakePHP1.2.5.
Cache is very powerful function for web pages using heavy SQL queries. If you use the CakePHP default Cache, you can see cache files in the app/tmp/cache directory.
I want to use the Cake Cache function at many points of my system and set different cache duration.
Firstly, check the core.php for using Cache.

//in core.php
Cache::config('default', array('engine' => 'File'));

This is a sample script using cache function, duration is 1 minute.

class PostController extends AppController {

var $uses = array('Post');

function index() {

$return_data = null;
Cache::set(array('duration' => '+60 seconds'));
if( ($return_data = Cache::read('PostController-index') ) === false ){

$return_data = $this->Post->find('all');
Cache::set(array('duration' => '+60 seconds'));
Cache::write('PostController-index' , $return_data);
}

$this->set('data',$return_data);
}
}

If there is no cache file(PostController-index),get DB data with the Post model and create cache file with its result. Array data is serialized.
You access same page within 1 minute, cake read cache file(PostController-index)
and return it insted of getting data from the Post model.
Key point is to use Cache::set() before each Cache::read and Cache::write(), we can change cache duration in each point.
http://book.cakephp.org/view/773/Cache-set
Be careful setting cache file name without overlap at each point. I recommend the rule, Class name + function name + parameter.
BTW, we can set Cache::config parameter in Cache::read() and Cache::write().
http://book.cakephp.org/view/766/Cache-read
http://book.cakephp.org/view/767/Cache-write
So, we can define multiple cache config as follow and use it each cache point.

//in core.php
Cache::config('default', array('engine' => 'File'));
Cache::config('onemin', array('engine' =>'File','duration'=> 60,));
Cache::config('onehour', array('engine' => 'File','duration'=> 3600,));

Cache::read('PostController-index', 'onemin')
Cache::write('PostController-index' , $return_data,'onemin');