type_desc: Define TypeDisp class for re-usability

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

4 files changed, 64 insertions, 131 deletions

diff --git a/ryu/lib/packet/bgp.py b/ryu/lib/packet/bgp.py
index 1c79052e..34025ad8 100644
--- a/ryu/lib/packet/bgp.py
+++ b/ryu/lib/packet/bgp.py
@@ -42,6 +42,7 @@ from ryu.lib.packet import vxlan
 from ryu.lib.packet import mpls
 from ryu.lib import addrconv
 from ryu.lib import type_desc
+from ryu.lib.type_desc import TypeDisp
 from ryu.lib import ip
 from ryu.lib.pack_utils import msg_pack_into
 from ryu.utils import binary_str
@@ -192,43 +193,6 @@ class _Value(object):
         return struct.pack(self._VALUE_PACK_STR, *args)
 
 
-class _TypeDisp(object):
-    _TYPES = {}
-    _REV_TYPES = None
-    _UNKNOWN_TYPE = None
-
-    @classmethod
-    def register_unknown_type(cls):
-        def _register_type(subcls):
-            cls._UNKNOWN_TYPE = subcls
-            return subcls
-        return _register_type
-
-    @classmethod
-    def register_type(cls, type_):
-        cls._TYPES = cls._TYPES.copy()
-
-        def _register_type(subcls):
-            cls._TYPES[type_] = subcls
-            cls._REV_TYPES = None
-            return subcls
-        return _register_type
-
-    @classmethod
-    def _lookup_type(cls, type_):
-        try:
-            return cls._TYPES[type_]
-        except KeyError:
-            return cls._UNKNOWN_TYPE
-
-    @classmethod
-    def _rev_lookup_type(cls, targ_cls):
-        if cls._REV_TYPES is None:
-            rev = dict((v, k) for k, v in cls._TYPES.items())
-            cls._REV_TYPES = rev
-        return cls._REV_TYPES[targ_cls]
-
-
 class BgpExc(Exception):
     """Base bgp exception."""
 
@@ -629,7 +593,7 @@ def pad(binary, len_):
     return binary + b'\0' * (len_ - len(binary))
 
 
-class _RouteDistinguisher(StringifyMixin, _TypeDisp, _Value):
+class _RouteDistinguisher(StringifyMixin, TypeDisp, _Value):
     _PACK_STR = '!H'
     TWO_OCTET_AS = 0
     IPV4_ADDRESS = 1
@@ -1039,7 +1003,7 @@ class LabelledVPNIP6AddrPrefix(_LabelledAddrPrefix, _VPNAddrPrefix,
         return "%s:%s" % (self.route_dist, self.prefix)
 
 
-class EvpnEsi(StringifyMixin, _TypeDisp, _Value):
+class EvpnEsi(StringifyMixin, TypeDisp, _Value):
     """
     Ethernet Segment Identifier
     """
@@ -1286,7 +1250,7 @@ class EvpnASBasedEsi(EvpnEsi):
         self.local_disc = local_disc
 
 
-class EvpnNLRI(StringifyMixin, _TypeDisp):
+class EvpnNLRI(StringifyMixin, TypeDisp):
     """
     BGP Network Layer Reachability Information (NLRI) for EVPN
     """
@@ -2122,7 +2086,7 @@ def _get_addr_class(afi, safi):
         return _BinAddrPrefix
 
 
-class _OptParam(StringifyMixin, _TypeDisp, _Value):
+class _OptParam(StringifyMixin, TypeDisp, _Value):
     _PACK_STR = '!BB'  # type, length
 
     def __init__(self, type_, value=None, length=None):
@@ -2169,7 +2133,7 @@ class BGPOptParamUnknown(_OptParam):
 
 
 @_OptParam.register_type(BGP_OPT_CAPABILITY)
-class _OptParamCapability(_OptParam, _TypeDisp):
+class _OptParamCapability(_OptParam, TypeDisp):
     _CAP_HDR_PACK_STR = '!BB'
 
     def __init__(self, cap_code=None, cap_value=None, cap_length=None,
@@ -2338,7 +2302,7 @@ class BGPWithdrawnRoute(IPAddrPrefix):
     pass
 
 
-class _PathAttribute(StringifyMixin, _TypeDisp, _Value):
+class _PathAttribute(StringifyMixin, TypeDisp, _Value):
     _PACK_STR = '!BB'  # flags, type
     _PACK_STR_LEN = '!B'  # length
     _PACK_STR_EXT_LEN = '!H'  # length w/ BGP_ATTR_FLAG_EXTENDED_LENGTH
@@ -2898,7 +2862,7 @@ class BGPPathAttributeExtendedCommunities(_PathAttribute):
         return self._community_list(3)
 
 
-class _ExtendedCommunity(StringifyMixin, _TypeDisp, _Value):
+class _ExtendedCommunity(StringifyMixin, TypeDisp, _Value):
     _PACK_STR = '!B7s'  # type high (+ type low), value
     _PACK_STR_SIZE = struct.calcsize(_PACK_STR)
     _SUBTYPE_PACK_STR = '!B'  # subtype
@@ -3549,7 +3513,7 @@ class BGPPathAttributePmsiTunnel(_PathAttribute):
         return ins
 
 
-class _PmsiTunnelId(StringifyMixin, _TypeDisp):
+class _PmsiTunnelId(StringifyMixin, TypeDisp):
 
     @classmethod
     def parse(cls, tunnel_type, buf):
@@ -3616,7 +3580,7 @@ class BGPNLRI(IPAddrPrefix):
     pass
 
 
-class BGPMessage(packet_base.PacketBase, _TypeDisp):
+class BGPMessage(packet_base.PacketBase, TypeDisp):
     """Base class for BGP-4 messages.
 
     An instance has the following attributes at least.
diff --git a/ryu/lib/packet/bmp.py b/ryu/lib/packet/bmp.py
index b3a097c0..9d1cda3b 100644
--- a/ryu/lib/packet/bmp.py
+++ b/ryu/lib/packet/bmp.py
@@ -17,13 +17,15 @@
 BGP Monitoring Protocol draft-ietf-grow-bmp-07
 """
 
-import six
 import struct
 
+import six
+
+from ryu.lib import addrconv
 from ryu.lib.packet import packet_base
 from ryu.lib.packet import stream_parser
 from ryu.lib.packet.bgp import BGPMessage
-from ryu.lib import addrconv
+from ryu.lib.type_desc import TypeDisp
 
 VERSION = 3
 
@@ -66,44 +68,7 @@ BMP_PEER_DOWN_REASON_REMOTE_BGP_NOTIFICATION = 3
 BMP_PEER_DOWN_REASON_REMOTE_NO_NOTIFICATION = 4
 
 
-class _TypeDisp(object):
-    _TYPES = {}
-    _REV_TYPES = None
-    _UNKNOWN_TYPE = None
-
-    @classmethod
-    def register_unknown_type(cls):
-        def _register_type(subcls):
-            cls._UNKNOWN_TYPE = subcls
-            return subcls
-        return _register_type
-
-    @classmethod
-    def register_type(cls, type_):
-        cls._TYPES = cls._TYPES.copy()
-
-        def _register_type(subcls):
-            cls._TYPES[type_] = subcls
-            cls._REV_TYPES = None
-            return subcls
-        return _register_type
-
-    @classmethod
-    def _lookup_type(cls, type_):
-        try:
-            return cls._TYPES[type_]
-        except KeyError:
-            return cls._UNKNOWN_TYPE
-
-    @classmethod
-    def _rev_lookup_type(cls, targ_cls):
-        if cls._REV_TYPES is None:
-            rev = dict((v, k) for k, v in cls._TYPES.items())
-            cls._REV_TYPES = rev
-        return cls._REV_TYPES[targ_cls]
-
-
-class BMPMessage(packet_base.PacketBase, _TypeDisp):
+class BMPMessage(packet_base.PacketBase, TypeDisp):
     """Base class for BGP Monitoring Protocol messages.
 
     An instance has the following attributes at least.
diff --git a/ryu/lib/packet/ospf.py b/ryu/lib/packet/ospf.py
index 464f089b..552be1fd 100644
--- a/ryu/lib/packet/ospf.py
+++ b/ryu/lib/packet/ospf.py
@@ -17,7 +17,7 @@
 RFC 2328 OSPF version 2
 """
 
-import six
+import logging
 import struct
 
 try:
@@ -27,13 +27,17 @@ except ImportError:
     # Python 2
     pass
 
-from ryu.lib.stringify import StringifyMixin
+import six
+
+from ryu.lib import addrconv
 from ryu.lib.packet import packet_base
 from ryu.lib.packet import packet_utils
 from ryu.lib.packet import stream_parser
+from ryu.lib.stringify import StringifyMixin
+from ryu.lib import type_desc
 
-from ryu.lib import addrconv
-import logging
+
+LOG = logging.getLogger(__name__)
 
 _VERSION = 2
 
@@ -88,43 +92,6 @@ class InvalidChecksum(Exception):
     pass
 
 
-class _TypeDisp(object):
-    _TYPES = {}
-    _REV_TYPES = None
-    _UNKNOWN_TYPE = None
-
-    @classmethod
-    def register_unknown_type(cls):
-        def _register_type(subcls):
-            cls._UNKNOWN_TYPE = subcls
-            return subcls
-        return _register_type
-
-    @classmethod
-    def register_type(cls, type_):
-        cls._TYPES = cls._TYPES.copy()
-
-        def _register_type(subcls):
-            cls._TYPES[type_] = subcls
-            cls._REV_TYPES = None
-            return subcls
-        return _register_type
-
-    @classmethod
-    def _lookup_type(cls, type_):
-        try:
-            return cls._TYPES[type_]
-        except KeyError:
-            return cls._UNKNOWN_TYPE
-
-    @classmethod
-    def _rev_lookup_type(cls, targ_cls):
-        if cls._REV_TYPES is None:
-            rev = dict((v, k) for k, v in cls._TYPES.items())
-            cls._REV_TYPES = rev
-        return cls._REV_TYPES[targ_cls]
-
-
 class LSAHeader(StringifyMixin):
     _HDR_PACK_STR = '!HBB4s4sIHH'
     _HDR_LEN = struct.calcsize(_HDR_PACK_STR)
@@ -189,7 +156,7 @@ class LSAHeader(StringifyMixin):
                          self.ls_seqnum, self.checksum, self.length))
 
 
-class LSA(_TypeDisp, StringifyMixin):
+class LSA(type_desc.TypeDisp, StringifyMixin):
     def __init__(self, ls_age=0, options=0, type_=OSPF_UNKNOWN_LSA,
                  id_='0.0.0.0', adv_router='0.0.0.0', ls_seqnum=0,
                  checksum=0, length=0, opaque_type=OSPF_OPAQUE_TYPE_UNKNOWN,
@@ -468,7 +435,7 @@ class NSSAExternalLSA(LSA):
     pass
 
 
-class ExtendedPrefixTLV(StringifyMixin, _TypeDisp):
+class ExtendedPrefixTLV(StringifyMixin, type_desc.TypeDisp):
     pass
 
 
@@ -541,7 +508,7 @@ class PrefixSIDSubTLV(ExtendedPrefixTLV):
                            self.algorithm, 0, self.range_size, 0, self.index)
 
 
-class OpaqueBody(StringifyMixin, _TypeDisp):
+class OpaqueBody(StringifyMixin, type_desc.TypeDisp):
     def __init__(self, tlvs=None):
         tlvs = tlvs if tlvs else []
         self.tlvs = tlvs
@@ -639,7 +606,7 @@ class ASOpaqueLSA(OpaqueLSA):
                                           length, opaque_type, opaque_id)
 
 
-class OSPFMessage(packet_base.PacketBase, _TypeDisp):
+class OSPFMessage(packet_base.PacketBase, type_desc.TypeDisp):
     """Base class for OSPF version 2 messages.
     """
 
diff --git a/ryu/lib/type_desc.py b/ryu/lib/type_desc.py
index cb10b09b..3e4061a5 100644
--- a/ryu/lib/type_desc.py
+++ b/ryu/lib/type_desc.py
@@ -122,3 +122,40 @@ class UnknownType(TypeDescr):
             return base64.b64encode(data)
 
     from_user = staticmethod(base64.b64decode)
+
+
+class TypeDisp(object):
+    _TYPES = {}
+    _REV_TYPES = None
+    _UNKNOWN_TYPE = None
+
+    @classmethod
+    def register_unknown_type(cls):
+        def _register_type(subcls):
+            cls._UNKNOWN_TYPE = subcls
+            return subcls
+        return _register_type
+
+    @classmethod
+    def register_type(cls, type_):
+        cls._TYPES = cls._TYPES.copy()
+
+        def _register_type(subcls):
+            cls._TYPES[type_] = subcls
+            cls._REV_TYPES = None
+            return subcls
+        return _register_type
+
+    @classmethod
+    def _lookup_type(cls, type_):
+        try:
+            return cls._TYPES[type_]
+        except KeyError:
+            return cls._UNKNOWN_TYPE
+
+    @classmethod
+    def _rev_lookup_type(cls, targ_cls):
+        if cls._REV_TYPES is None:
+            rev = dict((v, k) for k, v in cls._TYPES.items())
+            cls._REV_TYPES = rev
+        return cls._REV_TYPES[targ_cls]