1: <?php
 2: 
 3: namespace Psr\Cache;
 4: 
 5: /**
 6:  * CacheItemInterface defines an interface for interacting with objects inside a cache.
 7:  */
 8: interface CacheItemInterface
 9: {
10:     /**
11:      * Returns the key for the current cache item.
12:      *
13:      * The key is loaded by the Implementing Library, but should be available to
14:      * the higher level callers when needed.
15:      *
16:      *   The key string for this cache item.
17:      *
18:      * @return string
19:      */
20:     public function getKey();
21: 
22:     /**
23:      * Retrieves the value of the item from the cache associated with this object's key.
24:      *
25:      * The value returned must be identical to the value originally stored by set().
26:      *
27:      * If isHit() returns false, this method MUST return null. Note that null
28:      * is a legitimate cached value, so the isHit() method SHOULD be used to
29:      * differentiate between "null value was found" and "no value was found."
30:      *
31:      *   The value corresponding to this cache item's key, or null if not found.
32:      *
33:      * @return mixed
34:      */
35:     public function get();
36: 
37:     /**
38:      * Confirms if the cache item lookup resulted in a cache hit.
39:      *
40:      * Note: This method MUST NOT have a race condition between calling isHit()
41:      * and calling get().
42:      *
43:      *   True if the request resulted in a cache hit. False otherwise.
44:      *
45:      * @return bool
46:      */
47:     public function isHit();
48: 
49:     /**
50:      * Sets the value represented by this cache item.
51:      *
52:      * The $value argument may be any item that can be serialized by PHP,
53:      * although the method of serialization is left up to the Implementing
54:      * Library.
55:      *
56:      *   The serializable value to be stored.
57:      *   The invoked object.
58:      *
59:      * @param mixed $value
60:      *
61:      * @return \static
62:      */
63:     public function set($value);
64: 
65:     /**
66:      * Sets the expiration time for this cache item.
67:      *
68:      *   The point in time after which the item MUST be considered expired.
69:      *   If null is passed explicitly, a default value MAY be used. If none is set,
70:      *   the value should be stored permanently or for as long as the
71:      *   implementation allows.
72:      *   The called object.
73:      *
74:      * @param \DateTimeInterface $expiration
75:      *
76:      * @return \static
77:      */
78:     public function expiresAt($expiration);
79: 
80:     /**
81:      * Sets the expiration time for this cache item.
82:      *
83:      *   The period of time from the present after which the item MUST be considered
84:      *   expired. An integer parameter is understood to be the time in seconds until
85:      *   expiration. If null is passed explicitly, a default value MAY be used.
86:      *   If none is set, the value should be stored permanently or for as long as the
87:      *   implementation allows.
88:      *   The called object.
89:      *
90:      * @param int|\DateInterval $time
91:      *
92:      * @return \static
93:      */
94:     public function expiresAfter($time);
95: }
96: