<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_current_url(request, ignore_params=None):
 """ Giving a django request, return the current http url, possibly ignoring some GET parameters :param django.http.HttpRequest request: The current request object. :param set ignore_params: An optional set of GET parameters to ignore :return: The URL of the current page, possibly omitting some parameters from ``ignore_params`` in the querystring. :rtype: unicode """

    if ignore_params is None:
        ignore_params = set()
    protocol = u'https' if request.is_secure() else u"http"
    service_url = u"%s://%s%s" % (protocol, request.get_host(), request.path)
    if request.GET:
        params = copy_params(request.GET, ignore_params)
        if params:
            service_url += u"?%s" % urlencode(params)
    return service_url