Update dnspython-2.2.0

lib/dns/rdataclass.py

@@ -1,4 +1,6 @@
-# Copyright (C) 2001-2007, 2009-2011 Nominum, Inc.
+# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
+
+# Copyright (C) 2001-2017 Nominum, Inc.
 #
 # Permission to use, copy, modify, and distribute this software and its
 # documentation for any purpose with or without fee is hereby granted,
@@ -13,105 +15,87 @@
 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-"""DNS Rdata Classes.
-
-@var _by_text: The rdata class textual name to value mapping
-@type _by_text: dict
-@var _by_value: The rdata class value to textual name mapping
-@type _by_value: dict
-@var _metaclasses: If an rdataclass is a metaclass, there will be a mapping
-whose key is the rdatatype value and whose value is True in this dictionary.
-@type _metaclasses: dict"""
-
-import re
+"""DNS Rdata Classes."""
 
+import dns.enum
 import dns.exception
 
-RESERVED0 = 0
-IN = 1
-CH = 3
-HS = 4
-NONE = 254
-ANY = 255
+class RdataClass(dns.enum.IntEnum):
+    """DNS Rdata Class"""
+    RESERVED0 = 0
+    IN = 1
+    INTERNET = IN
+    CH = 3
+    CHAOS = CH
+    HS = 4
+    HESIOD = HS
+    NONE = 254
+    ANY = 255
 
-_by_text = {
-    'RESERVED0': RESERVED0,
-    'IN': IN,
-    'CH': CH,
-    'HS': HS,
-    'NONE': NONE,
-    'ANY': ANY
-}
+    @classmethod
+    def _maximum(cls):
+        return 65535
 
-# We construct the inverse mapping programmatically to ensure that we
-# cannot make any mistakes (e.g. omissions, cut-and-paste errors) that
-# would cause the mapping not to be true inverse.
+    @classmethod
+    def _short_name(cls):
+        return "class"
 
-_by_value = dict((y, x) for x, y in _by_text.items())
+    @classmethod
+    def _prefix(cls):
+        return "CLASS"
 
-# Now that we've built the inverse map, we can add class aliases to
-# the _by_text mapping.
+    @classmethod
+    def _unknown_exception_class(cls):
+        return UnknownRdataclass
 
-_by_text.update({
-    'INTERNET': IN,
-    'CHAOS': CH,
-    'HESIOD': HS
-})
+globals().update(RdataClass.__members__)
 
-_metaclasses = {
-    NONE: True,
-    ANY: True
-}
-
-_unknown_class_pattern = re.compile('CLASS([0-9]+)$', re.I)
+_metaclasses = {RdataClass.NONE, RdataClass.ANY}
 
 
 class UnknownRdataclass(dns.exception.DNSException):
-
     """A DNS class is unknown."""
 
 
 def from_text(text):
     """Convert text into a DNS rdata class value.
-    @param text: the text
-    @type text: string
-    @rtype: int
-    @raises dns.rdataclass.UnknownRdataclass: the class is unknown
-    @raises ValueError: the rdata class value is not >= 0 and <= 65535
+
+    The input text can be a defined DNS RR class mnemonic or
+    instance of the DNS generic class syntax.
+
+    For example, "IN" and "CLASS1" will both result in a value of 1.
+
+    Raises ``dns.rdatatype.UnknownRdataclass`` if the class is unknown.
+
+    Raises ``ValueError`` if the rdata class value is not >= 0 and <= 65535.
+
+    Returns an ``int``.
     """
 
-    value = _by_text.get(text.upper())
-    if value is None:
-        match = _unknown_class_pattern.match(text)
-        if match is None:
-            raise UnknownRdataclass
-        value = int(match.group(1))
-        if value < 0 or value > 65535:
-            raise ValueError("class must be between >= 0 and <= 65535")
-    return value
+    return RdataClass.from_text(text)
 
 
 def to_text(value):
-    """Convert a DNS rdata class to text.
-    @param value: the rdata class value
-    @type value: int
-    @rtype: string
-    @raises ValueError: the rdata class value is not >= 0 and <= 65535
+    """Convert a DNS rdata class value to text.
+
+    If the value has a known mnemonic, it will be used, otherwise the
+    DNS generic class syntax will be used.
+
+    Raises ``ValueError`` if the rdata class value is not >= 0 and <= 65535.
+
+    Returns a ``str``.
     """
 
-    if value < 0 or value > 65535:
-        raise ValueError("class must be between >= 0 and <= 65535")
-    text = _by_value.get(value)
-    if text is None:
-        text = 'CLASS' + repr(value)
-    return text
+    return RdataClass.to_text(value)
 
 
 def is_metaclass(rdclass):
-    """True if the class is a metaclass.
-    @param rdclass: the rdata class
-    @type rdclass: int
-    @rtype: bool"""
+    """True if the specified class is a metaclass.
+
+    The currently defined metaclasses are ANY and NONE.
+
+    *rdclass* is an ``int``.
+    """
 
     if rdclass in _metaclasses:
         return True