<?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 null KeyCache that does not cache at all.
 *
 * @package    Swift
 * @subpackage KeyCache
 * @author     Chris Corbyn
 */
class Swift_KeyCache_NullKeyCache implements Swift_KeyCache
{
    /**
     * 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 integer $mode
     */
    public function setString($nsKey, $itemKey, $string, $mode)
    {
    }

    /**
     * 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 integer                $mode
     */
    public function importFromByteStream($nsKey, $itemKey, Swift_OutputByteStream $os, $mode)
    {
    }

    /**
     * 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)
    {
    }

    /**
     * Get data back out of the cache as a string.
     *
     * @param string $nsKey
     * @param string $itemKey
     *
     * @return string
     */
    public function getString($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)
    {
    }

    /**
     * Check if the given $itemKey exists in the namespace $nsKey.
     *
     * @param string $nsKey
     * @param string $itemKey
     *
     * @return boolean
     */
    public function hasKey($nsKey, $itemKey)
    {
        return false;
    }

    /**
     * Clear data for $itemKey in the namespace $nsKey if it exists.
     *
     * @param string $nsKey
     * @param string $itemKey
     */
    public function clearKey($nsKey, $itemKey)
    {
    }

    /**
     * Clear all data in the namespace $nsKey if it exists.
     *
     * @param string $nsKey
     */
    public function clearAll($nsKey)
    {
    }
}
