1: <?php
 2: 
 3: namespace webfilesframework\core\datastore;
 4: 
 5: 
 6: /**
 7:  * Defines and provides basic functionality for caching a datastore.<br />
 8:  * Basically the cached datastore is a combination between a efficient
 9:  * datastore which can be used as cache and an slower datastore
10:  * (e.g. a directory datastore or a remote datastore).<br />
11:  * Actually cache is invalidated after one day.
12:  *
13:  * @author     Sebastian Monzel < mail@sebastianmonzel.de >
14:  * @since      0.1.7
15:  */
16: abstract class MAbstractCachableDatastore extends MAbstractDatastore
17: {
18:     const ONE_DAY_IN_SECONDS = 86400;
19: 
20:     /** @var MAbstractDatastore $cachingDatastore **/
21:     protected $cachingDatastore;
22: 
23:     protected $latestCachingTime;
24: 
25:     /**
26:      * sets the datastore used for caching data from the original datastore.
27:      *
28:      * @param MAbstractDatastore $cachingDatastore
29:      * @throws \Exception
30:      */
31:     public function setCachingDatastore(MAbstractDatastore $cachingDatastore)
32:     {
33: 
34:         if ($cachingDatastore->isReadOnly()) {
35:             throw new MDatastoreException("Datastore for caching data cannot be readOnly.");
36:         }
37: 
38:         $this->cachingDatastore = $cachingDatastore;
39:     }
40: 
41:     public function fillCachingDatastore()
42:     {
43:         $datastoreTransfer = new MDatastoreTransfer($this, $this->cachingDatastore);
44:         $datastoreTransfer->transfer();
45:     }
46: 
47:     public function isDatastoreCached()
48:     {
49:         return isset($this->cachingDatastore);
50:     }
51: 
52:     public function getLatestCachingTime() {
53:         return $this->latestCachingTime;
54:     }
55: 
56:     /**
57:      * Define a criteria which indicates the actual datastore
58:      * with cache is not outdated.
59:      *
60:      * Default implemention checks if last caching was more than one day ago.
61:      *
62:      * @return mixed
63:      */
64:     public function isCacheActual() {
65: 
66:         if ( !isset($this->latestCachingTime) ) {
67:             return false;
68:         }
69: 
70:         return
71:             ( (time() - $this->latestCachingTime)
72:               > self::ONE_DAY_IN_SECONDS );
73:     }
74: 
75: }