def search(self, regex):
        try:
            spec = {'$or': [{'data.content'    : {'$regex': regex, '$options': 'im'}},
                            {'data.description': {'$regex': regex, '$options': 'im'}}]}
            fields = {'_id': 0}
            cur = self.db.docs.find(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        return [Document(**row) for row in cur]
def has_commit(cls, location, rev):
        """
        Check if rev is a commit that is available in the local repository.
        """
        try:
            cls.run_command(
                ['rev-parse', '-q', '--verify', "sha^" + rev],
                cwd=location,
                log_failed_cmd=False,
            )
        except InstallationError:
            return False
        else:
            return True