<?php
/****
inc_db.php
****/
$server = "localhost";
$login = "root";
$password = "";
$database = "tests_cache";



$conn = mysql_connect($server, $login, $password);
mysql_select_db($database,$conn);

/**
 * Make a SQL Simple Query (no caching)
 * @author eka808
 * @param $sql : SQL Statement
 */
function SQLQrySimple($sql)
{
    //Simple statement, no cachin
    $req = mysql_query($sql) or die(mysql_error());
    while ($datarow = mysql_fetch_assoc($req))
        $data[] = $datarow;
    return $data;
}

/**
 * Generate a cache file corresponding to a cached data
 * @param unknown_type $cachefile : the cache file URI
 * @param unknown_type $sql : the SQL statement of the data cached
 */
function GenerateCacheFile($cachefile, $sql)
{
    $cache_timelimit = 5;

    $cacheobject = new CachedLine();
    $cacheobject->generation_time = time();
    $cacheobject->data = SQLQrySimple($sql);
    $cacheobject->time_limit = $cache_timelimit;

    $fh = fopen($cachefile, 'w');
    file_put_contents($cachefile, serialize($cacheobject));

    return $cacheobject;

}


/**
 * Make a sql query with caching capabilities
 * @param $sql : the sql statement of the data
 * @param $query_id_forcaching : a UNIQUE id of a statement for caching
 */
function SQLQry($sql, $query_id_forcaching=null)
{
    //Folder when put the cache
    $cache_folder = $_SERVER['DOCUMENT_ROOT'] . '/ILikeCache/cachetmp/';


    if ($query_id_forcaching == null)
    {
        //
        //No caching query
        //
        print_rr("NO CACHING");
        return SQLQrySimple($sql);
    }
    else
    {
        //
        //Cached query
        //
        //Cache file generated (one file per query)
        $cachefile = $cache_folder.$query_id_forcaching.".cache";


        if (file_exists($cachefile))
        {
            //The file exists, there is a cache file for this query
            print_rr("CACHED");

            $cached = file_get_contents($cachefile);
            $cached = unserialize($cached);

            $current_timestamp = time();

            if (($current_timestamp - $cached->generation_time) > $cached->time_limit)
            {
                //If the current timestamp minus generation time timestamp > time limit,
                //it's that the cache is expired, so regenerate one
                print_rr("EXPIRED");

                unlink($cachefile);
                $cacheobject = GenerateCacheFile($cachefile, $sql);
                return $cacheobject;
            }

            return $cached->data;


        }
        else
        {
            //
            //Not cache for the query and it should ! (first generation of the cache ?)
            //Generate the line
            //
            print_rr("NOT CACHED");
            $cacheobject = GenerateCacheFile($cachefile, $sql);
            return $cacheobject->data;
        }


    }

}

/**
 * Tool class used by generation : represent a line
 * @author eka808
 *
 */
class CachedLine
{
    public $data;
    public $generation_time;
    public $time_limit;
}
?>

<?php
/****
inc_fonc.php
****/
function print_rr($statement)
{
    echo "<pre>";
    print_r($statement);
    echo "</pre>";
}
?>

<?php
/****
indexphp
****/
include_once ("inc/inc_db.php");
include_once ("inc/inc_fonc.php");

$sql = "select * from News";
$data = SQLQry($sql, 1);
print_rr($data);
?>
?>