Perform query abstraction to support Mongodb .

no, i'm not really interested in doing this.

however, i'd consider allowing modules to provide their own tokens.

nope.

It's a shame the maintainer has no interest in this; it would be an excellent feature. As it is I am at the moment faced with the dilemma of either abandoning the Redis cache backend I am using for sessions (by means of the Session Proxy module) or forgoing the use of this module.

Supposing I want to get this to work. This was mentioned: 'however, i'd consider allowing modules to provide their own tokens.' What would that entail, roughly?

For anyone wanting to use a NoSQL session backend with this module, here's how I did it.

I had to abandon Redis for session storage since it stores sessions in a manner very different from Drupal's core sessions. However, the MongoDB module's session backend is feasible, although I had to make a small patch to it.

The incompatibility of the nodejs module with other session backends lies in this function from nodejs.module, since it's a hard-coded db_query:

function nodejs_auth_check_callback($auth_token) {
  $sql = "SELECT uid FROM {sessions} WHERE MD5(sid) = :auth_key OR MD5(ssid) = :auth_key";
  return db_query($sql, array(':auth_key' => $auth_token))->fetchField();
}

This can be changed to a PHP MongoDB driver query to a MongoDB session storage collection. However, I couldn't find a Mongo equivalent to the MD5 in MySQL, so I had to do the md5 checksums in the MongoDB module & store them in the session documents instead. Here are the necessary changes to the mongodb_session.inc in the MongoDB module:

function _drupal_session_write($sid, $value) {
//...
$fields = array(
    'uid' => (int) $user->uid,
    'cache' => isset($user->cache) ? (int) $user->cache : 0,
    'hostname' => ip_address(),
    'session' => $value,
    'timestamp' => REQUEST_TIME,
    //Hacked by H.
    'sidmd5' => md5($sid),
    'ssidmd5' => md5($sid),
    //End hacked by H.
  );
//...
}

Finally, the new function in nodejs.module:

function nodejs_auth_check_callback($auth_token) {
  $session_backend = variable_get('cache_session');
  if (isset($session_backend) && $session_backend == 'DrupalMongoDBCache') {
    $collection = mongodb_collection(variable_get('mongodb_session', 'session'));
    $sess_scheme = variable_get('nodejs_server_scheme');
    if ($sess_scheme == 'https') {
      $session = $collection->findOne(array('ssidmd5' => $auth_token), array('uid'));
    }
    else {
      $session = $collection->findOne(array('sidmd5' => $auth_token), array('uid'));
    }
    $uid = $session['uid'];
    return $uid;
  }
  else {
    $sql = "SELECT uid FROM {sessions} WHERE MD5(sid) = :auth_key OR MD5(ssid) = :auth_key";
    return db_query($sql, array(':auth_key' => $auth_token))->fetchField();
  }
}

I know this won't be added to either module, but thought I'd share a useful hack with future visitors to this issue.

found another issue that wanted this, so just to be clear - you can use whatever code you like in place of nodejs_auth_check_callback().

put this in settings.php:

$conf['nodejs_auth_check_callback'] = 'my_mongo_nodejs_auth_callback';

then define 'my_mongo_nodejs_auth_callback' with whatever code you need.