<?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 basic KeyCache backed by an array.

 * @package Swift

 * @subpackage KeyCache

 * @author Chris Corbyn

 */

class Swift_KeyCache_ArrayKeyCache implements Swift_KeyCache

{

  /**

   * Cache contents.

   * @var array

   * @access private

   */

  private $_contents = array();

  /**

   * An InputStream for cloning.

   * @var Swift_KeyCache_KeyCacheInputStream

   * @access private

   */

  private $_stream;

  /**

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

   * InputByteStreams.

   * @param Swift_KeyCache_KeyCacheInputStream $stream

   */

  public function __construct(Swift_KeyCache_KeyCacheInputStream $stream)

  {

    $this->_stream = $stream;

  }

  /**

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

   * @param string $nsKey

   * @param string $itemKey

   * @param string $string

   * @param int $mode

   * @see MODE_WRITE, MODE_APPEND

   */

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

  {

    $this->_prepareCache($nsKey);

    switch ($mode)

    {

      case self::MODE_WRITE:

        $this->_contents[$nsKey][$itemKey] = $string;

        break;

      case self::MODE_APPEND:

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

        {

          $this->_contents[$nsKey][$itemKey] = '';

        }

        $this->_contents[$nsKey][$itemKey] .= $string;

        break;

      default:

        throw new Swift_SwiftException(

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

          $nsKey . ', itemKey=' . $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

   */

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

    $mode)

  {

    $this->_prepareCache($nsKey);

    switch ($mode)

    {

      case self::MODE_WRITE:

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

      case self::MODE_APPEND:

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

        {

          $this->_contents[$nsKey][$itemKey] = '';

        }

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

        {

          $this->_contents[$nsKey][$itemKey] .= $bytes;

        }

        break;

      default:

        throw new Swift_SwiftException(

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

          $nsKey . ', itemKey=' . $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

   */

  public function getString($nsKey, $itemKey)

  {

    $this->_prepareCache($nsKey);

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

    {

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

    }

  }

  /**

   * 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)

  {

    $this->_prepareCache($nsKey);

    $is->write($this->getString($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)

  {

    $this->_prepareCache($nsKey);

    return array_key_exists($itemKey, $this->_contents[$nsKey]);

  }

  /**

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

   * @param string $nsKey

   * @param string $itemKey

   */

  public function clearKey($nsKey, $itemKey)

  {

    unset($this->_contents[$nsKey][$itemKey]);

  }

  /**

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

   * @param string $nsKey

   */

  public function clearAll($nsKey)

  {

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

  }

  // -- Private methods

  /**

   * Initialize the namespace of $nsKey if needed.

   * @param string $nsKey

   * @access private

   */

  private function _prepareCache($nsKey)

  {

    if (!array_key_exists($nsKey, $this->_contents))

    {

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

    }

  }

}