1 <?php

     2 /**

     3  * Zend Framework

     4  *

     5  * LICENSE

     6  *

     7  * This source file is subject to the new BSD license that is bundled

     8  * with this package in the file LICENSE.txt.

     9  * It is also available through the world-wide-web at this URL:

    10  * http://framework.zend.com/license/new-bsd

    11  * If you did not receive a copy of the license and are unable to

    12  * obtain it through the world-wide-web, please send an email

    13  * to license@zend.com so we can send you a copy immediately.

    14  *

    15  * @category   Zend

    16  * @package    Zend_Cache

    17  * @subpackage Zend_Cache_Backend

    18  * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

    19  * @license    http://framework.zend.com/license/new-bsd     New BSD License

    20  * @version    $Id: TwoLevels.php 22736 2010-07-30 16:25:54Z andyfowler $

    21  */

    22 

    23 

    24 /**

    25  * @see Zend_Cache_Backend_ExtendedInterface

    26  */

    27 require_once 'Zend/Cache/Backend/ExtendedInterface.php';

    28 

    29 /**

    30  * @see Zend_Cache_Backend

    31  */

    32 require_once 'Zend/Cache/Backend.php';

    33 

    34 

    35 /**

    36  * @package    Zend_Cache

    37  * @subpackage Zend_Cache_Backend

    38  * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

    39  * @license    http://framework.zend.com/license/new-bsd     New BSD License

    40  */

    41 

    42 class Zend_Cache_Backend_TwoLevels extends Zend_Cache_Backend implements Zend_Cache_Backend_ExtendedInterface

    43 {

    44     /**

    45      * Available options

    46      *

    47      * =====> (string) slow_backend :

    48      * - Slow backend name

    49      * - Must implement the Zend_Cache_Backend_ExtendedInterface

    50      * - Should provide a big storage

    51      *

    52      * =====> (string) fast_backend :

    53      * - Flow backend name

    54      * - Must implement the Zend_Cache_Backend_ExtendedInterface

    55      * - Must be much faster than slow_backend

    56      *

    57      * =====> (array) slow_backend_options :

    58      * - Slow backend options (see corresponding backend)

    59      *

    60      * =====> (array) fast_backend_options :

    61      * - Fast backend options (see corresponding backend)

    62      *

    63      * =====> (int) stats_update_factor :

    64      * - Disable / Tune the computation of the fast backend filling percentage

    65      * - When saving a record into cache :

    66      *     1               => systematic computation of the fast backend filling percentage

    67      *     x (integer) > 1 => computation of the fast backend filling percentage randomly 1 times on x cache write

    68      *

    69      * =====> (boolean) slow_backend_custom_naming :

    70      * =====> (boolean) fast_backend_custom_naming :

    71      * =====> (boolean) slow_backend_autoload :

    72      * =====> (boolean) fast_backend_autoload :

    73      * - See Zend_Cache::factory() method

    74      *

    75      * =====> (boolean) auto_refresh_fast_cache

    76      * - If true, auto refresh the fast cache when a cache record is hit

    77      *

    78      * @var array available options

    79      */

    80     protected $_options = array(

    81         'slow_backend' => 'File',

    82         'fast_backend' => 'Apc',

    83         'slow_backend_options' => array(),

    84         'fast_backend_options' => array(),

    85         'stats_update_factor' => 10,

    86         'slow_backend_custom_naming' => false,

    87         'fast_backend_custom_naming' => false,

    88         'slow_backend_autoload' => false,

    89         'fast_backend_autoload' => false,

    90         'auto_refresh_fast_cache' => true

    91     );

    92 

    93     /**

    94      * Slow Backend

    95      *

    96      * @var Zend_Cache_Backend_ExtendedInterface

    97      */

    98     protected $_slowBackend;

    99 

   100     /**

   101      * Fast Backend

   102      *

   103      * @var Zend_Cache_Backend_ExtendedInterface

   104      */

   105     protected $_fastBackend;

   106 

   107     /**

   108      * Cache for the fast backend filling percentage

   109      *

   110      * @var int

   111      */

   112     protected $_fastBackendFillingPercentage = null;

   113 

   114     /**

   115      * Constructor

   116      *

   117      * @param  array $options Associative array of options

   118      * @throws Zend_Cache_Exception

   119      * @return void

   120      */

   121     public function __construct(array $options = array())

   122     {

   123         parent::__construct($options);

   124 

   125         if ($this->_options['slow_backend'] === null) {

   126             Zend_Cache::throwException('slow_backend option has to set');

   127         } elseif ($this->_options['slow_backend'] instanceof Zend_Cache_Backend_ExtendedInterface) {

   128             $this->_slowBackend = $this->_options['slow_backend'];

   129         } else {

   130             $this->_slowBackend = Zend_Cache::_makeBackend(

   131                 $this->_options['slow_backend'],

   132                 $this->_options['slow_backend_options'],

   133                 $this->_options['slow_backend_custom_naming'],

   134                 $this->_options['slow_backend_autoload']

   135             );

   136             if (!in_array('Zend_Cache_Backend_ExtendedInterface', class_implements($this->_slowBackend))) {

   137                 Zend_Cache::throwException('slow_backend must implement the Zend_Cache_Backend_ExtendedInterface interface');

   138             }

   139         }

   140 

   141         if ($this->_options['fast_backend'] === null) {

   142             Zend_Cache::throwException('fast_backend option has to set');

   143         } elseif ($this->_options['fast_backend'] instanceof Zend_Cache_Backend_ExtendedInterface) {

   144             $this->_fastBackend = $this->_options['fast_backend'];

   145         } else {

   146             $this->_fastBackend = Zend_Cache::_makeBackend(

   147                 $this->_options['fast_backend'],

   148                 $this->_options['fast_backend_options'],

   149                 $this->_options['fast_backend_custom_naming'],

   150                 $this->_options['fast_backend_autoload']

   151             );

   152             if (!in_array('Zend_Cache_Backend_ExtendedInterface', class_implements($this->_fastBackend))) {

   153                 Zend_Cache::throwException('fast_backend must implement the Zend_Cache_Backend_ExtendedInterface interface');

   154             }

   155         }

   156 

   157         $this->_slowBackend->setDirectives($this->_directives);

   158         $this->_fastBackend->setDirectives($this->_directives);

   159     }

   160 

   161     /**

   162      * Test if a cache is available or not (for the given id)

   163      *

   164      * @param  string $id cache id

   165      * @return mixed|false (a cache is not available) or "last modified" timestamp (int) of the available cache record

   166      */

   167     public function test($id)

   168     {

   169         $fastTest = $this->_fastBackend->test($id);

   170         if ($fastTest) {

   171             return $fastTest;

   172         } else {

   173             return $this->_slowBackend->test($id);

   174         }

   175     }

   176 

   177     /**

   178      * Save some string datas into a cache record

   179      *

   180      * Note : $data is always "string" (serialization is done by the

   181      * core not by the backend)

   182      *

   183      * @param  string $data            Datas to cache

   184      * @param  string $id              Cache id

   185      * @param  array $tags             Array of strings, the cache record will be tagged by each string entry

   186      * @param  int   $specificLifetime If != false, set a specific lifetime for this cache record (null => infinite lifetime)

   187      * @param  int   $priority         integer between 0 (very low priority) and 10 (maximum priority) used by some particular backends

   188      * @return boolean true if no problem

   189      */

   190     public function save($data, $id, $tags = array(), $specificLifetime = false, $priority = 8)

   191     {

   192         $usage = $this->_getFastFillingPercentage('saving');

   193         $boolFast = true;

   194         $lifetime = $this->getLifetime($specificLifetime);

   195         $preparedData = $this->_prepareData($data, $lifetime, $priority);

   196         if (($priority > 0) && (10 * $priority >= $usage)) {

   197             $fastLifetime = $this->_getFastLifetime($lifetime, $priority);

   198             $boolFast = $this->_fastBackend->save($preparedData, $id, array(), $fastLifetime);

   199             $boolSlow = $this->_slowBackend->save($preparedData, $id, $tags, $lifetime);

   200         } else {

   201             $boolSlow = $this->_slowBackend->save($preparedData, $id, $tags, $lifetime);

   202             if ($boolSlow === true) {

   203                 $boolFast = $this->_fastBackend->remove($id);

   204                 if (!$boolFast && !$this->_fastBackend->test($id)) {

   205                     // some backends return false on remove() even if the key never existed. (and it won't if fast is full)

   206                     // all we care about is that the key doesn't exist now

   207                     $boolFast = true;

   208                 }

   209             }

   210         }

   211 

   212         return ($boolFast && $boolSlow);

   213     }

   214 

   215     /**

   216      * Test if a cache is available for the given id and (if yes) return it (false else)

   217      *

   218      * Note : return value is always "string" (unserialization is done by the core not by the backend)

   219      *

   220      * @param  string  $id                     Cache id

   221      * @param  boolean $doNotTestCacheValidity If set to true, the cache validity won't be tested

   222      * @return string|false cached datas

   223      */

   224     public function load($id, $doNotTestCacheValidity = false)

   225     {

   226         $res = $this->_fastBackend->load($id, $doNotTestCacheValidity);

   227         if ($res === false) {

   228             $res = $this->_slowBackend->load($id, $doNotTestCacheValidity);

   229             if ($res === false) {

   230                 // there is no cache at all for this id

   231                 return false;

   232             }

   233         }

   234         $array = unserialize($res);

   235         // maybe, we have to refresh the fast cache ?

   236         if ($this->_options['auto_refresh_fast_cache']) {

   237             if ($array['priority'] == 10) {

   238                 // no need to refresh the fast cache with priority = 10

   239                 return $array['data'];

   240             }

   241             $newFastLifetime = $this->_getFastLifetime($array['lifetime'], $array['priority'], time() - $array['expire']);

   242             // we have the time to refresh the fast cache

   243             $usage = $this->_getFastFillingPercentage('loading');

   244             if (($array['priority'] > 0) && (10 * $array['priority'] >= $usage)) {

   245                 // we can refresh the fast cache

   246                 $preparedData = $this->_prepareData($array['data'], $array['lifetime'], $array['priority']);

   247                 $this->_fastBackend->save($preparedData, $id, array(), $newFastLifetime);

   248             }

   249         }

   250         return $array['data'];

   251     }

   252 

   253     /**

   254      * Remove a cache record

   255      *

   256      * @param  string $id Cache id

   257      * @return boolean True if no problem

   258      */

   259     public function remove($id)

   260     {

   261         $boolFast = $this->_fastBackend->remove($id);

   262         $boolSlow = $this->_slowBackend->remove($id);

   263         return $boolFast && $boolSlow;

   264     }

   265 

   266     /**

   267      * Clean some cache records

   268      *

   269      * Available modes are :

   270      * Zend_Cache::CLEANING_MODE_ALL (default)    => remove all cache entries ($tags is not used)

   271      * Zend_Cache::CLEANING_MODE_OLD              => remove too old cache entries ($tags is not used)

   272      * Zend_Cache::CLEANING_MODE_MATCHING_TAG     => remove cache entries matching all given tags

   273      *                                               ($tags can be an array of strings or a single string)

   274      * Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG => remove cache entries not {matching one of the given tags}

   275      *                                               ($tags can be an array of strings or a single string)

   276      * Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG => remove cache entries matching any given tags

   277      *                                               ($tags can be an array of strings or a single string)

   278      *

   279      * @param  string $mode Clean mode

   280      * @param  array  $tags Array of tags

   281      * @throws Zend_Cache_Exception

   282      * @return boolean true if no problem

   283      */

   284     public function clean($mode = Zend_Cache::CLEANING_MODE_ALL, $tags = array())

   285     {

   286         switch($mode) {

   287             case Zend_Cache::CLEANING_MODE_ALL:

   288                 $boolFast = $this->_fastBackend->clean(Zend_Cache::CLEANING_MODE_ALL);

   289                 $boolSlow = $this->_slowBackend->clean(Zend_Cache::CLEANING_MODE_ALL);

   290                 return $boolFast && $boolSlow;

   291                 break;

   292             case Zend_Cache::CLEANING_MODE_OLD:

   293                 return $this->_slowBackend->clean(Zend_Cache::CLEANING_MODE_OLD);

   294             case Zend_Cache::CLEANING_MODE_MATCHING_TAG:

   295                 $ids = $this->_slowBackend->getIdsMatchingTags($tags);

   296                 $res = true;

   297                 foreach ($ids as $id) {

   298                     $bool = $this->remove($id);

   299                     $res = $res && $bool;

   300                 }

   301                 return $res;

   302                 break;

   303             case Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG:

   304                 $ids = $this->_slowBackend->getIdsNotMatchingTags($tags);

   305                 $res = true;

   306                 foreach ($ids as $id) {

   307                     $bool = $this->remove($id);

   308                     $res = $res && $bool;

   309                 }

   310                 return $res;

   311                 break;

   312             case Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG:

   313                 $ids = $this->_slowBackend->getIdsMatchingAnyTags($tags);

   314                 $res = true;

   315                 foreach ($ids as $id) {

   316                     $bool = $this->remove($id);

   317                     $res = $res && $bool;

   318                 }

   319                 return $res;

   320                 break;

   321             default:

   322                 Zend_Cache::throwException('Invalid mode for clean() method');

   323                 break;

   324         }

   325     }

   326 

   327     /**

   328      * Return an array of stored cache ids

   329      *

   330      * @return array array of stored cache ids (string)

   331      */

   332     public function getIds()

   333     {

   334         return $this->_slowBackend->getIds();

   335     }

   336 

   337     /**

   338      * Return an array of stored tags

   339      *

   340      * @return array array of stored tags (string)

   341      */

   342     public function getTags()

   343     {

   344         return $this->_slowBackend->getTags();

   345     }

   346 

   347     /**

   348      * Return an array of stored cache ids which match given tags

   349      *

   350      * In case of multiple tags, a logical AND is made between tags

   351      *

   352      * @param array $tags array of tags

   353      * @return array array of matching cache ids (string)

   354      */

   355     public function getIdsMatchingTags($tags = array())

   356     {

   357         return $this->_slowBackend->getIdsMatchingTags($tags);

   358     }

   359 

   360     /**

   361      * Return an array of stored cache ids which don't match given tags

   362      *

   363      * In case of multiple tags, a logical OR is made between tags

   364      *

   365      * @param array $tags array of tags

   366      * @return array array of not matching cache ids (string)

   367      */

   368     public function getIdsNotMatchingTags($tags = array())

   369     {

   370         return $this->_slowBackend->getIdsNotMatchingTags($tags);

   371     }

   372 

   373     /**

   374      * Return an array of stored cache ids which match any given tags

   375      *

   376      * In case of multiple tags, a logical AND is made between tags

   377      *

   378      * @param array $tags array of tags

   379      * @return array array of any matching cache ids (string)

   380      */

   381     public function getIdsMatchingAnyTags($tags = array())

   382     {

   383         return $this->_slowBackend->getIdsMatchingAnyTags($tags);

   384     }

   385 

   386 

   387     /**

   388      * Return the filling percentage of the backend storage

   389      *

   390      * @return int integer between 0 and 100

   391      */

   392     public function getFillingPercentage()

   393     {

   394         return $this->_slowBackend->getFillingPercentage();

   395     }

   396 

   397     /**

   398      * Return an array of metadatas for the given cache id

   399      *

   400      * The array must include these keys :

   401      * - expire : the expire timestamp

   402      * - tags : a string array of tags

   403      * - mtime : timestamp of last modification time

   404      *

   405      * @param string $id cache id

   406      * @return array array of metadatas (false if the cache id is not found)

   407      */

   408     public function getMetadatas($id)

   409     {

   410         return $this->_slowBackend->getMetadatas($id);

   411     }

   412 

   413     /**

   414      * Give (if possible) an extra lifetime to the given cache id

   415      *

   416      * @param string $id cache id

   417      * @param int $extraLifetime

   418      * @return boolean true if ok

   419      */

   420     public function touch($id, $extraLifetime)

   421     {

   422         return $this->_slowBackend->touch($id, $extraLifetime);

   423     }

   424 

   425     /**

   426      * Return an associative array of capabilities (booleans) of the backend

   427      *

   428      * The array must include these keys :

   429      * - automatic_cleaning (is automating cleaning necessary)

   430      * - tags (are tags supported)

   431      * - expired_read (is it possible to read expired cache records

   432      *                 (for doNotTestCacheValidity option for example))

   433      * - priority does the backend deal with priority when saving

   434      * - infinite_lifetime (is infinite lifetime can work with this backend)

   435      * - get_list (is it possible to get the list of cache ids and the complete list of tags)

   436      *

   437      * @return array associative of with capabilities

   438      */

   439     public function getCapabilities()

   440     {

   441         $slowBackendCapabilities = $this->_slowBackend->getCapabilities();

   442         return array(

   443             'automatic_cleaning' => $slowBackendCapabilities['automatic_cleaning'],

   444             'tags' => $slowBackendCapabilities['tags'],

   445             'expired_read' => $slowBackendCapabilities['expired_read'],

   446             'priority' => $slowBackendCapabilities['priority'],

   447             'infinite_lifetime' => $slowBackendCapabilities['infinite_lifetime'],

   448             'get_list' => $slowBackendCapabilities['get_list']

   449         );

   450     }

   451 

   452     /**

   453      * Prepare a serialized array to store datas and metadatas informations

   454      *

   455      * @param string $data data to store

   456      * @param int $lifetime original lifetime

   457      * @param int $priority priority

   458      * @return string serialize array to store into cache

   459      */

   460     private function _prepareData($data, $lifetime, $priority)

   461     {

   462         $lt = $lifetime;

   463         if ($lt === null) {

   464             $lt = 9999999999;

   465         }

   466         return serialize(array(

   467             'data' => $data,

   468             'lifetime' => $lifetime,

   469             'expire' => time() + $lt,

   470             'priority' => $priority

   471         ));

   472     }

   473 

   474     /**

   475      * Compute and return the lifetime for the fast backend

   476      *

   477      * @param int $lifetime original lifetime

   478      * @param int $priority priority

   479      * @param int $maxLifetime maximum lifetime

   480      * @return int lifetime for the fast backend

   481      */

   482     private function _getFastLifetime($lifetime, $priority, $maxLifetime = null)

   483     {

   484         if ($lifetime === null) {

   485             // if lifetime is null, we have an infinite lifetime

   486             // we need to use arbitrary lifetimes

   487             $fastLifetime = (int) (2592000 / (11 - $priority));

   488         } else {

   489             $fastLifetime = (int) ($lifetime / (11 - $priority));

   490         }

   491         if (($maxLifetime !== null) && ($maxLifetime >= 0)) {

   492             if ($fastLifetime > $maxLifetime) {

   493                 return $maxLifetime;

   494             }

   495         }

   496         return $fastLifetime;

   497     }

   498 

   499     /**

   500      * PUBLIC METHOD FOR UNIT TESTING ONLY !

   501      *

   502      * Force a cache record to expire

   503      *

   504      * @param string $id cache id

   505      */

   506     public function ___expire($id)

   507     {

   508         $this->_fastBackend->remove($id);

   509         $this->_slowBackend->___expire($id);

   510     }

   511 

   512     private function _getFastFillingPercentage($mode)

   513     {

   514 

   515         if ($mode == 'saving') {

   516             // mode saving

   517             if ($this->_fastBackendFillingPercentage === null) {

   518                 $this->_fastBackendFillingPercentage = $this->_fastBackend->getFillingPercentage();

   519             } else {

   520                 $rand = rand(1, $this->_options['stats_update_factor']);

   521                 if ($rand == 1) {

   522                     // we force a refresh

   523                     $this->_fastBackendFillingPercentage = $this->_fastBackend->getFillingPercentage();

   524                 }

   525             }

   526         } else {

   527             // mode loading

   528             // we compute the percentage only if it's not available in cache

   529             if ($this->_fastBackendFillingPercentage === null) {

   530                 $this->_fastBackendFillingPercentage = $this->_fastBackend->getFillingPercentage();

   531             }

   532         }

   533         return $this->_fastBackendFillingPercentage;

   534     }

   535 

   536 }