<?php

/*
 +-----------------------------------------------------------------------+
 | program/include/cache.inc                                             |
 |                                                                       |
 | This file is part of the RoundCube Webmail client                     |
 | Copyright (C) 2005, RoundCube Dev, - Switzerland                      |
 | Licensed under the GNU GPL                                            |
 |                                                                       |
 | PURPOSE:                                                              |
 |   Provide access to the application cache                             |
 |                                                                       |
 +-----------------------------------------------------------------------+
 | Author: Thomas Bruederli <roundcube@gmail.com>                        |
 +-----------------------------------------------------------------------+

 $Id$

*/


function rcube_read_cache($key)
  {
  global $DB, $CACHE_KEYS;
  
  // query db
  $sql_result = $DB->query(sprintf("SELECT cache_id, data
                                    FROM   %s
                                    WHERE  user_id=%d
                                    AND    cache_key='%s'",
                                   get_table_name('cache'),
                                   $_SESSION['user_id'],
                                   $key));

  // get cached data
  if ($sql_arr = $DB->fetch_assoc($sql_result))
    {
    $data = $sql_arr['data'];
    $CACHE_KEYS[$key] = $sql_arr['cache_id'];
    }
  else
    $data = FALSE;

  return $data;
  }
  
  
function rcube_write_cache($key, $data, $session_cache=FALSE)
  {
  global $DB, $CACHE_KEYS, $sess_id;
  
  // check if we already have a cache entry for this key
  if (!isset($CACHE_KEYS[$key]))
    {
    $sql_result = $DB->query(sprintf("SELECT cache_id
                                      FROM   %s
                                      WHERE  user_id=%d
                                      AND    cache_key='%s'",
                                     get_table_name('cache'),
                                     $_SESSION['user_id'],
                                     $key));
                                     
    if ($sql_arr = $DB->fetch_assoc($sql_result))
      $CACHE_KEYS[$key] = $sql_arr['cache_id'];
    else
      $CACHE_KEYS[$key] = FALSE;
    }

  // update existing cache record
  if ($CACHE_KEYS[$key])
    {
    $DB->query(sprintf("UPDATE %s
                        SET    created=NOW(),
                               data='%s'
                        WHERE  user_id=%d
                        AND    cache_key='%s'",
                       get_table_name('cache'),
                       addslashes($data),
                       $_SESSION['user_id'],
                       $key));
    }
  // add new cache record
  else
    {
    $DB->query(sprintf("INSERT INTO %s
                        (created, user_id, session_id, cache_key, data)
                        VALUES (NOW(), %d, %s, '%s', '%s')",
                       get_table_name('cache'),
                       $_SESSION['user_id'],
                       $session_cache ? "'$sess_id'" : 'NULL',
                       $key,
                       addslashes($data)));
    }
  }


function rcube_clear_cache($key)
  {
  global $DB;

  $DB->query(sprintf("DELETE FROM %s
                      WHERE  user_id=%d
                      AND    cache_key='%s'",
                     get_table_name('cache'),
                     $_SESSION['user_id'],
                     $key));
  }


?>