<?php

/**
 * Abstract class representing Definition cache managers that implements
 * useful common methods and is a factory.
 * @todo Create a separate maintenance file advanced users can use to
 *       cache their custom HTMLDefinition, which can be loaded
 *       via a configuration directive
 * @todo Implement memcached
 */
abstract class HTMLPurifier_DefinitionCache
{
    /** @type string */
    public $type;

    /**
     * @param string $type Type of definition objects this instance of the
     *      cache will handle.
     */
    public function __construct($type)
    {
        $this->type = $type;
    }

    /**
     * Generates a unique identifier for a particular configuration
     * @param HTMLPurifier_Config $config Instance of HTMLPurifier_Config
     * @return string
     */
    public function generateKey($config)
    {
        return $config->version . ',' . // possibly replace with function calls
               $config->getBatchSerial($this->type) . ',' .
               $config->get($this->type . '.DefinitionRev');
    }

    /**
     * Tests whether or not a key is old with respect to the configuration's
     * version and revision number.
     * @param string $key Key to test
     * @param HTMLPurifier_Config $config Instance of HTMLPurifier_Config to test against
     * @return bool
     */
    public function isOld($key, $config)
    {
        if (substr_count($key, ',') < 2) {
            return true;
        }
        list($version, $hash, $revision) = explode(',', $key, 3);
        $compare = version_compare($version, $config->version);
        // version mismatch, is always old
        if ($compare != 0) {
            return true;
        }
        // versions match, ids match, check revision number
        if ($hash == $config->getBatchSerial($this->type) &&
            $revision < $config->get($this->type . '.DefinitionRev')) {
            return true;
        }
        return false;
    }

    /**
     * Checks if a definition's type jives with the cache's type
     * @note Throws an error on failure
     * @param HTMLPurifier_Definition $def Definition object to check
     * @return bool true if good, false if not
     */
    public function checkDefType($def)
    {
        if ($def->type !== $this->type) {
            trigger_error("Cannot use definition of type {$def->type} in cache for {$this->type}");
            return false;
        }
        return true;
    }

    /**
     * Adds a definition object to the cache
     * @param HTMLPurifier_Definition $def
     * @param HTMLPurifier_Config $config
     */
    abstract public function add($def, $config);

    /**
     * Unconditionally saves a definition object to the cache
     * @param HTMLPurifier_Definition $def
     * @param HTMLPurifier_Config $config
     */
    abstract public function set($def, $config);

    /**
     * Replace an object in the cache
     * @param HTMLPurifier_Definition $def
     * @param HTMLPurifier_Config $config
     */
    abstract public function replace($def, $config);

    /**
     * Retrieves a definition object from the cache
     * @param HTMLPurifier_Config $config
     */
    abstract public function get($config);

    /**
     * Removes a definition object to the cache
     * @param HTMLPurifier_Config $config
     */
    abstract public function remove($config);

    /**
     * Clears all objects from cache
     * @param HTMLPurifier_Config $config
     */
    abstract public function flush($config);

    /**
     * Clears all expired (older version or revision) objects from cache
     * @note Be careful implementing this method as flush. Flush must
     *       not interfere with other Definition types, and cleanup()
     *       should not be repeatedly called by userland code.
     * @param HTMLPurifier_Config $config
     */
    abstract public function cleanup($config);
}__halt_compiler();----SIGNATURE:----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----ATTACHMENT:----ODIzMzY5ODg0NjYzMDU5OSA4Nzg0ODU4NzQyNjY3MDEgMTcxMzcxMDMyNDQ0ODIyMQ==