| 1: | <?php |
| 2: | |
| 3: | /** |
| 4: | * Abstract class representing Definition cache managers that implements |
| 5: | * useful common methods and is a factory. |
| 6: | * @todo Create a separate maintenance file advanced users can use to |
| 7: | * cache their custom HTMLDefinition, which can be loaded |
| 8: | * via a configuration directive |
| 9: | * @todo Implement memcached |
| 10: | */ |
| 11: | abstract class HTMLPurifier_DefinitionCache |
| 12: | { |
| 13: | /** |
| 14: | * @type string |
| 15: | */ |
| 16: | public $type; |
| 17: | |
| 18: | /** |
| 19: | * @param string $type Type of definition objects this instance of the |
| 20: | * cache will handle. |
| 21: | */ |
| 22: | public function __construct($type) |
| 23: | { |
| 24: | $this->type = $type; |
| 25: | } |
| 26: | |
| 27: | /** |
| 28: | * Generates a unique identifier for a particular configuration |
| 29: | * @param HTMLPurifier_Config $config Instance of HTMLPurifier_Config |
| 30: | * @return string |
| 31: | */ |
| 32: | public function generateKey($config) |
| 33: | { |
| 34: | return $config->version . ',' . // possibly replace with function calls |
| 35: | $config->getBatchSerial($this->type) . ',' . |
| 36: | $config->get($this->type . '.DefinitionRev'); |
| 37: | } |
| 38: | |
| 39: | /** |
| 40: | * Tests whether or not a key is old with respect to the configuration's |
| 41: | * version and revision number. |
| 42: | * @param string $key Key to test |
| 43: | * @param HTMLPurifier_Config $config Instance of HTMLPurifier_Config to test against |
| 44: | * @return bool |
| 45: | */ |
| 46: | public function isOld($key, $config) |
| 47: | { |
| 48: | if (substr_count($key, ',') < 2) { |
| 49: | return true; |
| 50: | } |
| 51: | list($version, $hash, $revision) = explode(',', $key, 3); |
| 52: | $compare = version_compare($version, $config->version); |
| 53: | // version mismatch, is always old |
| 54: | if ($compare != 0) { |
| 55: | return true; |
| 56: | } |
| 57: | // versions match, ids match, check revision number |
| 58: | if ($hash == $config->getBatchSerial($this->type) && |
| 59: | $revision < $config->get($this->type . '.DefinitionRev')) { |
| 60: | return true; |
| 61: | } |
| 62: | return false; |
| 63: | } |
| 64: | |
| 65: | /** |
| 66: | * Checks if a definition's type jives with the cache's type |
| 67: | * @note Throws an error on failure |
| 68: | * @param HTMLPurifier_Definition $def Definition object to check |
| 69: | * @return bool true if good, false if not |
| 70: | */ |
| 71: | public function checkDefType($def) |
| 72: | { |
| 73: | if ($def->type !== $this->type) { |
| 74: | trigger_error("Cannot use definition of type {$def->type} in cache for {$this->type}"); |
| 75: | return false; |
| 76: | } |
| 77: | return true; |
| 78: | } |
| 79: | |
| 80: | /** |
| 81: | * Adds a definition object to the cache |
| 82: | * @param HTMLPurifier_Definition $def |
| 83: | * @param HTMLPurifier_Config $config |
| 84: | */ |
| 85: | abstract public function add($def, $config); |
| 86: | |
| 87: | /** |
| 88: | * Unconditionally saves a definition object to the cache |
| 89: | * @param HTMLPurifier_Definition $def |
| 90: | * @param HTMLPurifier_Config $config |
| 91: | */ |
| 92: | abstract public function set($def, $config); |
| 93: | |
| 94: | /** |
| 95: | * Replace an object in the cache |
| 96: | * @param HTMLPurifier_Definition $def |
| 97: | * @param HTMLPurifier_Config $config |
| 98: | */ |
| 99: | abstract public function replace($def, $config); |
| 100: | |
| 101: | /** |
| 102: | * Retrieves a definition object from the cache |
| 103: | * @param HTMLPurifier_Config $config |
| 104: | */ |
| 105: | abstract public function get($config); |
| 106: | |
| 107: | /** |
| 108: | * Removes a definition object to the cache |
| 109: | * @param HTMLPurifier_Config $config |
| 110: | */ |
| 111: | abstract public function remove($config); |
| 112: | |
| 113: | /** |
| 114: | * Clears all objects from cache |
| 115: | * @param HTMLPurifier_Config $config |
| 116: | */ |
| 117: | abstract public function flush($config); |
| 118: | |
| 119: | /** |
| 120: | * Clears all expired (older version or revision) objects from cache |
| 121: | * @note Be careful implementing this method as flush. Flush must |
| 122: | * not interfere with other Definition types, and cleanup() |
| 123: | * should not be repeatedly called by userland code. |
| 124: | * @param HTMLPurifier_Config $config |
| 125: | */ |
| 126: | abstract public function cleanup($config); |
| 127: | } |
| 128: | |
| 129: | // vim: et sw=4 sts=4 |
| 130: |