<?php/** * Zend Framework * * LICENSE * * This source file is subject to the new BSD license that is bundled * with this package in the file LICENSE.txt. * It is also available through the world-wide-web at this URL: * http://framework.zend.com/license/new-bsd * If you did not receive a copy of the license and are unable to * obtain it through the world-wide-web, please send an email * to license@zend.com so we can send you a copy immediately. * * @package    Zend_Memory * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com) * @license    http://framework.zend.com/license/new-bsd     New BSD License *//** Zend_Memory_Container_Movable */require_once 'Zend/Memory/Container/Movable.php';/** Zend_Memory_Container_Locked */require_once 'Zend/Memory/Container/Locked.php';/** Zend_Memory_AccessController */require_once 'Zend/Memory/AccessController.php';/** * Memory manager * * This class encapsulates memory menagement operations, when PHP works * in limited memory mode. * * * @category   Zend * @package    Zend_Memory * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com) * @license    http://framework.zend.com/license/new-bsd     New BSD License */class Zend_Memory_Manager{    /**     * Object storage backend     *     * @var Zend_Cache_Backend_Interface     */    private $_backend = null;    /**     * Memory grow limit.     * Default value is 2/3 of memory_limit php.ini variable     * Negative value means no limit     *     * @var integer     */    private $_memoryLimit = -1;    /**     * Minimum value size to be swapped.     * Default value is 16K     * Negative value means that memory objects are never swapped     *     * @var integer     */    private $_minSize = 16384;    /**     * Overall size of memory, used by values     *     * @var integer     */    private $_memorySize = 0;    /**     * Id for next Zend_Memory object     *     * @var integer     */    private $_nextId = 0;    /**     * List of candidates to unload     *     * It also represents objects access history. Last accessed objects are moved to the end of array     *     * array(     *     <id> => <memory container object>,     *     ...     *      )     *     * @var array     */    private $_unloadCandidates = array();    /**     * List of object sizes.     *     * This list is used to calculate modification of object sizes     *     * array( <id> => <size>, ...)     *     * @var array     */    private $_sizes = array();    /**     * Last modified object     *     * It's used to reduce number of calls necessary to trace objects' modifications     * Modification is not processed by memory manager until we do not switch to another     * object.     * So we have to trace only _first_ object modification and do nothing for others     *     * @var Zend_Memory_Container_Movable     */    private $_lastModified = null;    /**     * Unique memory manager id     *     * @var integer     */    private $_managerId;    /**     * Tags array, used by backend to categorize stored values     *     * @var array     */    private $_tags;    /**     * This function is intended to generate unique id, used by memory manager     */    private function _generateMemManagerId()    {        /**         * @todo !!!         * uniqid() php function doesn't really garantee the id to be unique         * it should be changed by something else         * (Ex. backend interface should be extended to provide this functionality)         */        $this->_managerId = uniqid('ZendMemManager', true);        $this->_tags = array($this->_managerId);        $this->_managerId .= '_';    }    /**     * Memory manager constructor     *     * If backend is not specified, then memory objects are never swapped     *     * @param Zend_Cache_Backend $backend     * @param array $backendOptions associative array of options for the corresponding backend constructor     */    public function __construct($backend = null)    {        if ($backend === null) {            return;        }        $this->_backend = $backend;        $this->_generateMemManagerId();        $memoryLimitStr = trim(ini_get('memory_limit'));        if ($memoryLimitStr != '') {            $this->_memoryLimit = (integer)$memoryLimitStr;            switch (strtolower($memoryLimitStr[strlen($memoryLimitStr)-1])) {                case 'g':                    $this->_memoryLimit *= 1024;                    // Break intentionally omitted                case 'm':                    $this->_memoryLimit *= 1024;                    // Break intentionally omitted                case 'k':                    $this->_memoryLimit *= 1024;                    break;                default:                    break;            }            $this->_memoryLimit = (int)($this->_memoryLimit*2/3);        } // No limit otherwise    }    /**     * Object destructor     *     * Clean up backend storage     */    public function __destruct()    {        if ($this->_backend !== null) {            $this->_backend->clean(Zend_Cache::CLEANING_MODE_MATCHING_TAG, $this->_tags);        }    }    /**     * Set memory grow limit     *     * @param integer $newLimit     * @throws Zend_Exception     */    public function setMemoryLimit($newLimit)    {        $this->_memoryLimit = $newLimit;        $this->_swapCheck();    }    /**     * Get memory grow limit     *     * @return integer     */    public function getMemoryLimit()    {        return $this->_memoryLimit;    }    /**     * Set minimum size of values, which may be swapped     *     * @param integer $newSize     */    public function setMinSize($newSize)    {        $this->_minSize = $newSize;    }    /**     * Get minimum size of values, which may be swapped     *     * @return integer     */    public function getMinSize()    {        return $this->_minSize;    }    /**     * Create new Zend_Memory value container     *     * @param string $value     * @return Zend_Memory_Container_Interface     * @throws Zend_Memory_Exception     */    public function create($value = '')    {        return $this->_create($value,  false);    }    /**     * Create new Zend_Memory value container, which has value always     * locked in memory     *     * @param string $value     * @return Zend_Memory_Container_Interface     * @throws Zend_Memory_Exception     */    public function createLocked($value = '')    {        return $this->_create($value, true);    }    /**     * Create new Zend_Memory object     *     * @param string $value     * @param boolean $locked     * @return Zend_Memory_Container_Interface     * @throws Zend_Memory_Exception     */    private function _create($value, $locked)    {        $id = $this->_nextId++;        if ($locked  ||  ($this->_backend === null) /* Use only memory locked objects if backend is not specified */) {            return new Zend_Memory_Container_Locked($value);        }        // Commit other objects modifications        $this->_commit();        $valueObject = new Zend_Memory_Container_Movable($this, $id, $value);        // Store last object size as 0        $this->_sizes[$id] = 0;        // prepare object for next modifications        $this->_lastModified = $valueObject;        return new Zend_Memory_AccessController($valueObject);    }    /**     * Unlink value container from memory manager     *     * Used by Memory container destroy() method     *     * @internal     * @param integer $id     * @return Zend_Memory_Container     */    public function unlink(Zend_Memory_Container_Movable $container, $id)    {        if ($this->_lastModified === $container) {            // Drop all object modifications            $this->_lastModified = null;            unset($this->_sizes[$id]);            return;        }        if (isset($this->_unloadCandidates[$id])) {            unset($this->_unloadCandidates[$id]);        }        $this->_memorySize -= $this->_sizes[$id];        unset($this->_sizes[$id]);    }    /**     * Process value update     *     * @internal     * @param Zend_Memory_Container_Movable $container     * @param integer $id     */    public function processUpdate(Zend_Memory_Container_Movable $container, $id)    {        /**         * This method is automatically invoked by memory container only once per         * "modification session", but user may call memory container touch() method         * several times depending on used algorithm. So we have to use this check         * to optimize this case.         */        if ($container === $this->_lastModified) {            return;        }        // Remove just updated object from list of candidates to unload        if( isset($this->_unloadCandidates[$id])) {            unset($this->_unloadCandidates[$id]);        }        // Reduce used memory mark        $this->_memorySize -= $this->_sizes[$id];        // Commit changes of previously modified object if necessary        $this->_commit();        $this->_lastModified = $container;    }    /**     * Commit modified object and put it back to the loaded objects list     */    private function _commit()    {        if (($container = $this->_lastModified) === null) {            return;        }        $this->_lastModified = null;        $id = $container->getId();        // Calculate new object size and increase used memory size by this value        $this->_memorySize += ($this->_sizes[$id] = strlen($container->getRef()));        if ($this->_sizes[$id] > $this->_minSize) {            // Move object to "unload candidates list"            $this->_unloadCandidates[$id] = $container;        }        $container->startTrace();        $this->_swapCheck();    }    /**     * Check and swap objects if necessary     *     * @throws Zend_MemoryException     */    private function _swapCheck()    {        if ($this->_memoryLimit < 0  ||  $this->_memorySize < $this->_memoryLimit) {            // Memory limit is not reached            // Do nothing            return;        }        // walk through loaded objects in access history order        foreach ($this->_unloadCandidates as $id => $container) {            $this->_swap($container, $id);            unset($this->_unloadCandidates[$id]);            if ($this->_memorySize < $this->_memoryLimit) {                // We've swapped enough objects                return;            }        }        throw new Zend_Memory_Exception('Memory manager can\'t get enough space.');    }    /**     * Swap object data to disk     * Actualy swaps data or only unloads it from memory,     * if object is not changed since last swap     *     * @param Zend_Memory_Container_Movable $container     * @param integer $id     */    private function _swap(Zend_Memory_Container_Movable $container, $id)    {        if ($container->isLocked()) {            return;        }        if (!$container->isSwapped()) {            $this->_backend->save($container->getRef(), $this->_managerId . $id, $this->_tags);        }        $this->_memorySize -= $this->_sizes[$id];        $container->markAsSwapped();        $container->unloadValue();    }    /**     * Load value from swap file.     *     * @internal     * @param Zend_Memory_Container_Movable $container     * @param integer $id     */    public function load(Zend_Memory_Container_Movable $container, $id)    {        $value = $this->_backend->load($this->_managerId . $id, true);        // Try to swap other objects if necessary        // (do not include specified object into check)        $this->_memorySize += strlen($value);        $this->_swapCheck();        // Add loaded obect to the end of loaded objects list        $container->setValue($value);        if ($this->_sizes[$id] > $this->_minSize) {            // Add object to the end of "unload candidates list"            $this->_unloadCandidates[$id] = $container;        }    }}