<?php

// $Id: session.inc,v 1.44.2.6 2008/12/11 00:29:34 goba Exp $

/**

 * @file

 * User session handling functions.

 */

function sess_open($save_path, $session_name) {

  return TRUE;

}

function sess_close() {

  return TRUE;

}

function sess_read($key) {

  global $user;

  // Write and Close handlers are called after destructing objects since PHP 5.0.5

  // Thus destructors can use sessions but session handler can't use objects.

  // So we are moving session closure before destructing objects.

  register_shutdown_function('session_write_close');

  // Handle the case of first time visitors and clients that don't store cookies (eg. web crawlers).

  if (!isset($_COOKIE[session_name()])) {

    $user = drupal_anonymous_user();

    return '';

  }

  // Otherwise, if the session is still active, we have a record of the client's session in the database.

  $user = db_fetch_object(db_query("SELECT u.*, s.* FROM {users} u INNER JOIN {sessions} s ON u.uid = s.uid WHERE s.sid = '%s'", $key));

  // We found the client's session record and they are an authenticated user

  if ($user && $user->uid > 0) {

    // This is done to unserialize the data member of $user

    $user = drupal_unpack($user);

    // Add roles element to $user

    $user->roles = array();

    $user->roles[DRUPAL_AUTHENTICATED_RID] = 'authenticated user';

    $result = db_query("SELECT r.rid, r.name FROM {role} r INNER JOIN {users_roles} ur ON ur.rid = r.rid WHERE ur.uid = %d", $user->uid);

    while ($role = db_fetch_object($result)) {

      $user->roles[$role->rid] = $role->name;

    }

  }

  // We didn't find the client's record (session has expired), or they are an anonymous user.

  else {

    $session = isset($user->session) ? $user->session : '';

    $user = drupal_anonymous_user($session);

  }

  return $user->session;

}

function sess_write($key, $value) {

  global $user;

  // If saving of session data is disabled or if the client doesn't have a session,

  // and one isn't being created ($value), do nothing. This keeps crawlers out of

  // the session table. This reduces memory and server load, and gives more useful

  // statistics. We can't eliminate anonymous session table rows without breaking

  // the throttle module and the "Who's Online" block.

  if (!session_save_session() || ($user->uid == 0 && empty($_COOKIE[session_name()]) && empty($value))) {

    return TRUE;

  }

  db_query("UPDATE {sessions} SET uid = %d, cache = %d, hostname = '%s', session = '%s', timestamp = %d WHERE sid = '%s'", $user->uid, isset($user->cache) ? $user->cache : '', ip_address(), $value, time(), $key);

  if (db_affected_rows()) {

    // Last access time is updated no more frequently than once every 180 seconds.

    // This reduces contention in the users table.

    if ($user->uid && time() - $user->access > variable_get('session_write_interval', 180)) {

      db_query("UPDATE {users} SET access = %d WHERE uid = %d", time(), $user->uid);

    }

  }

  else {

    // If this query fails, another parallel request probably got here first.

    // In that case, any session data generated in this request is discarded.

    @db_query("INSERT INTO {sessions} (sid, uid, cache, hostname, session, timestamp) VALUES ('%s', %d, %d, '%s', '%s', %d)", $key, $user->uid, isset($user->cache) ? $user->cache : '', ip_address(), $value, time());

  }

  return TRUE;

}

/**

 * Called when an anonymous user becomes authenticated or vice-versa.

 */

function sess_regenerate() {

  $old_session_id = session_id();

  // We code around http://bugs.php.net/bug.php?id=32802 by destroying

  // the session cookie by setting expiration in the past (a negative

  // value).  This issue only arises in PHP versions before 4.4.0,

  // regardless of the Drupal configuration.

  // TODO: remove this when we require at least PHP 4.4.0

  if (isset($_COOKIE[session_name()])) {

    setcookie(session_name(), '', time() - 42000, '/');

  }

  session_regenerate_id();

  db_query("UPDATE {sessions} SET sid = '%s' WHERE sid = '%s'", session_id(), $old_session_id);

}

/**

 * Counts how many users have sessions. Can count either anonymous sessions or authenticated sessions.

 *

 * @param int $timestamp

 *   A Unix timestamp representing a point of time in the past.

 *   The default is 0, which counts all existing sessions.

 * @param boolean $anonymous

 *   TRUE counts only anonymous users.

 *   FALSE counts only authenticated users.

 * @return  int

 *   The number of users with sessions.

 */

function sess_count($timestamp = 0, $anonymous = true) {

  $query = $anonymous ? ' AND uid = 0' : ' AND uid > 0';

  return db_result(db_query('SELECT COUNT(sid) AS count FROM {sessions} WHERE timestamp >= %d'. $query, $timestamp));

}

/**

 * Called by PHP session handling with the PHP session ID to end a user's session.

 *

 * @param  string $sid

 *   the session id

 */

function sess_destroy_sid($sid) {

  db_query("DELETE FROM {sessions} WHERE sid = '%s'", $sid);

}

/**

 * End a specific user's session

 *

 * @param  string $uid

 *   the user id

 */

function sess_destroy_uid($uid) {

  db_query('DELETE FROM {sessions} WHERE uid = %d', $uid);

}

function sess_gc($lifetime) {

  // Be sure to adjust 'php_value session.gc_maxlifetime' to a large enough

  // value. For example, if you want user sessions to stay in your database

  // for three weeks before deleting them, you need to set gc_maxlifetime

  // to '1814400'. At that value, only after a user doesn't log in after

  // three weeks (1814400 seconds) will his/her session be removed.

  db_query("DELETE FROM {sessions} WHERE timestamp < %d", time() - $lifetime);

  return TRUE;

}

/**

 * Determine whether to save session data of the current request.

 *

 * This function allows the caller to temporarily disable writing of session data,

 * should the request end while performing potentially dangerous operations, such as

 * manipulating the global $user object.  See http://drupal.org/node/218104 for usage

 *

 * @param $status

 *   Disables writing of session data when FALSE, (re-)enables writing when TRUE.

 * @return

 *   FALSE if writing session data has been disabled. Otherwise, TRUE.

 */

function session_save_session($status = NULL) {

  static $save_session = TRUE;

  if (isset($status)) {

    $save_session = $status;

  }

  return ($save_session);

}