def update(self, doc, process=None):
        if process is None:
            pk = 'id'
            id = doc.id
            doc.synced = False
            set = doc
        elif process == UPDATE_PROCESS:
            if self.db.docs.find({'sid': doc.sid}).count() == 0:
                return self.insert(doc, synced=True)
            pk = 'sid'
            id = doc.sid
            doc.synced = not doc.merged() # must be commited if was merged
            doc.merged(False)
            set = {'tid': doc.tid, 'data': doc.data, 'user': doc.user,
                   'public': doc.public, 'synced': doc.synced}
        elif process == COMMIT_PROCESS:
            pk = 'id'
            id = doc.id
            doc.synced = True
            set = {'sid': doc.sid, 'tid': doc.tid, 'synced': doc.synced}
        else:
            raise DatabaseException('Incorrect update process')

        try:
            rs = self.db.docs.update({pk: id}, {'$set': set}, safe=True)
            assert rs['n'] == 1
        except Exception as e:
            raise DatabaseException(e)
        return doc
def iloc(cls, dataset, index):
        import cudf

        rows, cols = index
        scalar = False
        columns = list(dataset.data.columns)
        if isinstance(cols, slice):
            cols = [d.name for d in dataset.dimensions()][cols]
        elif np.isscalar(cols):
            scalar = np.isscalar(rows)
            cols = [dataset.get_dimension(cols).name]
        else:
            cols = [dataset.get_dimension(d).name for d in index[1]]
        col_index = [columns.index(c) for c in cols]
        if np.isscalar(rows):
            rows = [rows]

        if scalar:
            return dataset.data[cols[0]].iloc[rows[0]]
        result = dataset.data.iloc[rows, col_index]

        # cuDF does not handle single rows and cols indexing correctly
        # as of cudf=0.10.0 so we have to convert Series back to DataFrame
        if isinstance(result, cudf.Series):
            if len(cols) == 1:
                result = result.to_frame(cols[0])
            else:
                result = result.to_frame().T
        return result