<?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.

 * @package Swift

 * @subpackage KeyCache

 * @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

   * @access private

   */

  private $_stream;

  /**

   * A path to write to.

   * @var string

   * @access private

   */

  private $_path;

  /**

   * Stored keys.

   * @var array

   * @access private

   */

  private $_keys = array();

  /**

   * Will be true if magic_quotes_runtime is turned on.

   * @var boolean

   * @access private

   */

  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;

    $this->_quotes = ini_get('magic_quotes_runtime');

  }

  /**

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

   * @param string $nsKey

   * @param string $itemKey

   * @param string $string

   * @param int $mode

   * @throws Swift_IoException

   * @see MODE_WRITE, MODE_APPEND

   */

  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.

   * @param string $nsKey

   * @param string $itemKey

   * @param Swift_OutputByteStream $os

   * @param int $mode

   * @see MODE_WRITE, MODE_APPEND

   * @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

   * @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

   * @return string

   * @throws Swift_IoException

   */

  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 boolean

   */

  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);

      }

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

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

    }

  }

  // -- Private methods

  /**

   * Initialize the namespace of $nsKey if needed.

   * @param string $nsKey

   * @access private

   */

  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

   * @access private

   */

  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);

    }

  }

}