1 <?php

     2     $basechars = '23456789abcdefghjkmnpqrstuvwxyz';

     3     $base = strlen($basechars);

     4     

     5     function my_encode($int) {

     6         global $base, $basechars;

     7         $nb = $int;

     8         $res = '';

     9         while($nb > 0 or strlen($res) == 0) {

    10             $mod = $nb % $base;

    11             $res = $basechars[$mod].$res;

    12             $nb = ($nb - $mod) / $base;

    13         }

    14         return $res;

    15     }

    16     

    17     function my_decode($str) {

    18         global $base, $basechars;

    19         $s = strtolower($str);

    20         $m = 1;

    21         $res = 0;

    22         for ($i = strlen($s)-1; $i >= 0; $i--) {

    23             $res += $m * strpos($basechars, $s[$i]);

    24             $m *= $base;

    25         }

    26         return $res;

    27     };

    28     

    29     require('connect.inc.php');

    30     

    31     session_start();

    32     

    33     $data = isset($_REQUEST['data']) ? $_REQUEST['data'] : false;

    34     $insdata = pg_escape_string($data ? $data : '{}');

    35     

    36     if (isset($_REQUEST['sessionid'])) {

    37         $_SESSION['sessionid'] = $_REQUEST['sessionid'];

    38     }

    39     

    40     if (isset($_REQUEST['sessionkey'])) {

    41         $_SESSION['sessionkey'] = $_REQUEST['sessionkey'];

    42     }

    43     

    44     if (isset($_SESSION['sessionid'])) {

    45         $sidnum = my_decode($_SESSION['sessionid']);

    46         $rq = pg_query("SELECT editkey FROM hdaviz_sessions WHERE id = $sidnum");

    47         if ($ligne = pg_fetch_row($rq)) {

    48             if (isset($_SESSION['sessionkey'])) {

    49                 $keynum = my_decode($_SESSION['sessionkey']);

    50                 if ($keynum == $ligne[0]) {

    51                     $write = true;

    52                 } else {

    53                     $write = false;

    54                     unset($_SESSION['sessionkey']);

    55                 }

    56             } else {

    57                 $keynum = false;

    58                 $write = false;

    59             }

    60         } else {

    61             unset($_SESSION['sessionid']);

    62         }

    63     }

    64     

    65     if (!isset($_SESSION['sessionid'])) {

    66         do {

    67             $sidnum = mt_rand(1000, 100000000);

    68             $rq = pg_query("SELECT COUNT(*) FROM hdaviz_sessions WHERE id=$sidnum");

    69             $l = pg_fetch_row($rq);

    70             $nb = $l[0];

    71             pg_free_result($rq);

    72         } while ($nb > 0);

    73         $keynum = mt_rand(104, 100000001);

    74         $rq = pg_query("INSERT INTO hdaviz_sessions (id, editkey, data) VALUES ($sidnum, $keynum, '{}')");

    75         $write = true;

    76         $_SESSION['sessionid'] = my_encode($sidnum);

    77         $_SESSION['sessionkey'] = my_encode($keynum);

    78     }

    79     

    80     if ($write and $data) {

    81         pg_query("UPDATE hdaviz_sessions SET data='$insdata' WHERE id=$sidnum AND editkey=$keynum");

    82     } else {

    83         $rq = pg_query("SELECT data FROM hdaviz_sessions WHERE id=$sidnum");

    84         $l = pg_fetch_row($rq);

    85         $data = $l[0];

    86         pg_free_result($rq);

    87     }

    88     

    89     $resobj = array("data" => $data, "write_allowed" => $write, "sessionid" => $_SESSION['sessionid']);

    90     if ($write) {

    91         $resobj["sessionkey"] = $_SESSION['sessionkey'];

    92     }

    93     

    94 

    95 echo json_encode($resobj);

    96 ?>