views.py 文件源码

def validate_token(key, credits=1):
    """
    Validate that a token is valid to authorize a setup/register operation:
     * Check it's not expired
     * Check it has some credits

    :param credits: number of credits to decrement if valid
    :return 2-tuple (<http response if error, else None>, <registration token if valid, else None>)
    """
    try:
        with transaction.commit_on_success():
            token = RegistrationToken.objects.get(secret = key)
            if not token.credits:
                log.warning("Attempt to register with exhausted token %s" % key)
                return HttpForbidden(), None
            else:
                # Decrement .credits
                RegistrationToken.objects.filter(secret = key).update(credits = token.credits - credits)
    except RegistrationToken.DoesNotExist:
        log.warning("Attempt to register with non-existent token %s" % key)
        return HttpForbidden(), None
    else:
        now = IMLDateTime.utcnow()

        if token.expiry < now:
            log.warning("Attempt to register with expired token %s (now %s, expired at %s)" % (key, now, token.expiry))
            return HttpForbidden(), None
        elif token.cancelled:
            log.warning("Attempt to register with cancelled token %s" % key)
            return HttpForbidden(), None

    return None, token