<?php



/*

 * This file is part of SwiftMailer.

 * (c) 2004-2009 Chris Corbyn

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */



/**

 * A KeyCache which streams to and from disk.

 *

 * @author Chris Corbyn

 */

class Swift_KeyCache_DiskKeyCache implements Swift_KeyCache

{

    /** Signal to place pointer at start of file */

    const POSITION_START = 0;



    /** Signal to place pointer at end of file */

    const POSITION_END = 1;



    /** Signal to leave pointer in whatever position it currently is */

    const POSITION_CURRENT = 2;



    /**

     * An InputStream for cloning.

     *

     * @var Swift_KeyCache_KeyCacheInputStream

     */

    private $_stream;



    /**

     * A path to write to.

     *

     * @var string

     */

    private $_path;



    /**

     * Stored keys.

     *

     * @var array

     */

    private $_keys = array();



    /**

     * Will be true if magic_quotes_runtime is turned on.

     *

     * @var bool

     */

    private $_quotes = false;



    /**

     * Create a new DiskKeyCache with the given $stream for cloning to make

     * InputByteStreams, and the given $path to save to.

     *

     * @param Swift_KeyCache_KeyCacheInputStream $stream

     * @param string                             $path   to save to

     */

    public function __construct(Swift_KeyCache_KeyCacheInputStream $stream, $path)

    {

        $this->_stream = $stream;

        $this->_path = $path;



        if (function_exists('get_magic_quotes_runtime') && @get_magic_quotes_runtime() == 1) {

            $this->_quotes = true;

        }

    }



    /**

     * Set a string into the cache under $itemKey for the namespace $nsKey.

     *

     * @see MODE_WRITE, MODE_APPEND

     *

     * @param string $nsKey

     * @param string $itemKey

     * @param string $string

     * @param int    $mode

     *

     * @throws Swift_IoException

     */

    public function setString($nsKey, $itemKey, $string, $mode)

    {

        $this->_prepareCache($nsKey);

        switch ($mode) {

            case self::MODE_WRITE:

                $fp = $this->_getHandle($nsKey, $itemKey, self::POSITION_START);

                break;

            case self::MODE_APPEND:

                $fp = $this->_getHandle($nsKey, $itemKey, self::POSITION_END);

                break;

            default:

                throw new Swift_SwiftException(

                    'Invalid mode ['.$mode.'] used to set nsKey='.

                    $nsKey.', itemKey='.$itemKey

                    );

                break;

        }

        fwrite($fp, $string);

        $this->_freeHandle($nsKey, $itemKey);

    }



    /**

     * Set a ByteStream into the cache under $itemKey for the namespace $nsKey.

     *

     * @see MODE_WRITE, MODE_APPEND

     *

     * @param string                 $nsKey

     * @param string                 $itemKey

     * @param Swift_OutputByteStream $os

     * @param int                    $mode

     *

     * @throws Swift_IoException

     */

    public function importFromByteStream($nsKey, $itemKey, Swift_OutputByteStream $os, $mode)

    {

        $this->_prepareCache($nsKey);

        switch ($mode) {

            case self::MODE_WRITE:

                $fp = $this->_getHandle($nsKey, $itemKey, self::POSITION_START);

                break;

            case self::MODE_APPEND:

                $fp = $this->_getHandle($nsKey, $itemKey, self::POSITION_END);

                break;

            default:

                throw new Swift_SwiftException(

                    'Invalid mode ['.$mode.'] used to set nsKey='.

                    $nsKey.', itemKey='.$itemKey

                    );

                break;

        }

        while (false !== $bytes = $os->read(8192)) {

            fwrite($fp, $bytes);

        }

        $this->_freeHandle($nsKey, $itemKey);

    }



    /**

     * Provides a ByteStream which when written to, writes data to $itemKey.

     *

     * NOTE: The stream will always write in append mode.

     *

     * @param string                $nsKey

     * @param string                $itemKey

     * @param Swift_InputByteStream $writeThrough

     *

     * @return Swift_InputByteStream

     */

    public function getInputByteStream($nsKey, $itemKey, Swift_InputByteStream $writeThrough = null)

    {

        $is = clone $this->_stream;

        $is->setKeyCache($this);

        $is->setNsKey($nsKey);

        $is->setItemKey($itemKey);

        if (isset($writeThrough)) {

            $is->setWriteThroughStream($writeThrough);

        }



        return $is;

    }



    /**

     * Get data back out of the cache as a string.

     *

     * @param string $nsKey

     * @param string $itemKey

     *

     * @throws Swift_IoException

     *

     * @return string

     */

    public function getString($nsKey, $itemKey)

    {

        $this->_prepareCache($nsKey);

        if ($this->hasKey($nsKey, $itemKey)) {

            $fp = $this->_getHandle($nsKey, $itemKey, self::POSITION_START);

            if ($this->_quotes) {

                ini_set('magic_quotes_runtime', 0);

            }

            $str = '';

            while (!feof($fp) && false !== $bytes = fread($fp, 8192)) {

                $str .= $bytes;

            }

            if ($this->_quotes) {

                ini_set('magic_quotes_runtime', 1);

            }

            $this->_freeHandle($nsKey, $itemKey);



            return $str;

        }

    }



    /**

     * Get data back out of the cache as a ByteStream.

     *

     * @param string                $nsKey

     * @param string                $itemKey

     * @param Swift_InputByteStream $is      to write the data to

     */

    public function exportToByteStream($nsKey, $itemKey, Swift_InputByteStream $is)

    {

        if ($this->hasKey($nsKey, $itemKey)) {

            $fp = $this->_getHandle($nsKey, $itemKey, self::POSITION_START);

            if ($this->_quotes) {

                ini_set('magic_quotes_runtime', 0);

            }

            while (!feof($fp) && false !== $bytes = fread($fp, 8192)) {

                $is->write($bytes);

            }

            if ($this->_quotes) {

                ini_set('magic_quotes_runtime', 1);

            }

            $this->_freeHandle($nsKey, $itemKey);

        }

    }



    /**

     * Check if the given $itemKey exists in the namespace $nsKey.

     *

     * @param string $nsKey

     * @param string $itemKey

     *

     * @return bool

     */

    public function hasKey($nsKey, $itemKey)

    {

        return is_file($this->_path.'/'.$nsKey.'/'.$itemKey);

    }



    /**

     * Clear data for $itemKey in the namespace $nsKey if it exists.

     *

     * @param string $nsKey

     * @param string $itemKey

     */

    public function clearKey($nsKey, $itemKey)

    {

        if ($this->hasKey($nsKey, $itemKey)) {

            $this->_freeHandle($nsKey, $itemKey);

            unlink($this->_path.'/'.$nsKey.'/'.$itemKey);

        }

    }



    /**

     * Clear all data in the namespace $nsKey if it exists.

     *

     * @param string $nsKey

     */

    public function clearAll($nsKey)

    {

        if (array_key_exists($nsKey, $this->_keys)) {

            foreach ($this->_keys[$nsKey] as $itemKey => $null) {

                $this->clearKey($nsKey, $itemKey);

            }

            if (is_dir($this->_path.'/'.$nsKey)) {

                rmdir($this->_path.'/'.$nsKey);

            }

            unset($this->_keys[$nsKey]);

        }

    }



    /**

     * Initialize the namespace of $nsKey if needed.

     *

     * @param string $nsKey

     */

    private function _prepareCache($nsKey)

    {

        $cacheDir = $this->_path.'/'.$nsKey;

        if (!is_dir($cacheDir)) {

            if (!mkdir($cacheDir)) {

                throw new Swift_IoException('Failed to create cache directory '.$cacheDir);

            }

            $this->_keys[$nsKey] = array();

        }

    }



    /**

     * Get a file handle on the cache item.

     *

     * @param string $nsKey

     * @param string $itemKey

     * @param int    $position

     *

     * @return resource

     */

    private function _getHandle($nsKey, $itemKey, $position)

    {

        if (!isset($this->_keys[$nsKey][$itemKey])) {

            $openMode = $this->hasKey($nsKey, $itemKey)

                ? 'r+b'

                : 'w+b'

                ;

            $fp = fopen($this->_path.'/'.$nsKey.'/'.$itemKey, $openMode);

            $this->_keys[$nsKey][$itemKey] = $fp;

        }

        if (self::POSITION_START == $position) {

            fseek($this->_keys[$nsKey][$itemKey], 0, SEEK_SET);

        } elseif (self::POSITION_END == $position) {

            fseek($this->_keys[$nsKey][$itemKey], 0, SEEK_END);

        }



        return $this->_keys[$nsKey][$itemKey];

    }



    private function _freeHandle($nsKey, $itemKey)

    {

        $fp = $this->_getHandle($nsKey, $itemKey, self::POSITION_CURRENT);

        fclose($fp);

        $this->_keys[$nsKey][$itemKey] = null;

    }



    /**

     * Destructor.

     */

    public function __destruct()

    {

        foreach ($this->_keys as $nsKey => $null) {

            $this->clearAll($nsKey);

        }

    }

}