def prune_unlinked_dpids(mapping_path_structure, dpids_src_list, dpids_dst_list, check_by_auth=False):
"""
Prunes those paths that do not conform to the passed SRC and DST DPID list.
That is, the resulting paths must contain at least all the required SRC and DST DPIDs.
@param check_by_auth when True, checks if the path contains a DPID with the required authority
when False, looks for exact DPIDs on the path
"""
new_mapping_path_structure = []
for idx, mapping_path_element in enumerate(mapping_path_structure):
# Source sets
src_dpids_avail = set([ x["sdn"] for x in mapping_path_element["src"]["links"] ])
# Destination sets
dst_dpids_avail = set([ x["sdn"] for x in mapping_path_element["dst"]["links"] ])
if check_by_auth:
src_dpids_auth_avail = set(OrgUtils.get_authority(x) for x in src_dpids_avail)
src_dpids_auth_req = set(OrgUtils.get_authority(x) for x in dpids_src_list)
dst_dpids_auth_avail = set(OrgUtils.get_authority(x) for x in dst_dpids_avail)
dst_dpids_auth_req = set(OrgUtils.get_authority(x) for x in dpids_dst_list)
src_dpids_auth_match = src_dpids_auth_avail.intersection(src_dpids_auth_req)
dst_dpids_auth_match = dst_dpids_auth_avail.intersection(dst_dpids_auth_req)
# Loose check -> the authorities of the requested DPIDs must match
full_match = len(src_dpids_auth_match) == len(src_dpids_auth_req) and len(dst_dpids_auth_match) == len(dst_dpids_auth_req)
else:
src_dpids_match = src_dpids_avail.intersection(dpids_src_list)
dst_dpids_match = dst_dpids_avail.intersection(dpids_dst_list)
# Tight check -> all requested DPIDs must be present (i.e. intersected with the available DPIDs)
full_match = len(src_dpids_match) == len(dpids_src_list) and len(dst_dpids_match) == len(dpids_dst_list)
if full_match:
new_mapping_path_structure.append(mapping_path_element)
return new_mapping_path_structure
