feat: add reverse_pointer to the cache (#4)

Author: bdraco

src/cached_ipaddress/ipaddress.py

@@ -37,6 +37,11 @@ def is_multicast(self) -> bool:  # type: ignore[override]
         """Return True if this is a multicast address."""
         return super().is_multicast
 
+    @cached_property
+    def reverse_pointer(self) -> str:  # type: ignore[override]
+        """Return the reverse DNS pointer name for the IPv4 address."""
+        return super().reverse_pointer
+
 
 class CachedIPv6Address(IPv6Address):
     def __str__(self) -> str:
@@ -68,8 +73,13 @@ def is_multicast(self) -> bool:  # type: ignore[override]
         """Return True if this is a multicast address."""
         return super().is_multicast
 
+    @cached_property
+    def reverse_pointer(self) -> str:  # type: ignore[override]
+        """Return the reverse DNS pointer name for the IPv6 address."""
+        return super().reverse_pointer
+
 
-@lru_cache(maxsize=512)
+@lru_cache(maxsize=535)
 def _cached_ip_addresses(
     address: Union[str, bytes, int]
 ) -> Optional[Union[IPv4Address, IPv6Address]]:

tests/test_ipaddress.py

@@ -24,6 +24,7 @@ def test_cached_ip_addresses_wrapper():
     assert ipv4.is_loopback is False
     assert str(ipv4) == "169.254.0.0"
     assert str(ipv4) == "169.254.0.0"
+    assert ipv4.reverse_pointer == "0.0.254.169.in-addr.arpa"
 
     ipv4 = ipaddress.cached_ip_addresses("0.0.0.0")  # noqa: S104
     assert ipv4 is not None
@@ -38,6 +39,10 @@ def test_cached_ip_addresses_wrapper():
     assert ipv6.is_unspecified is False
     assert ipv6.is_loopback is False
     assert ipv6.is_multicast is False
+    assert (
+        ipv6.reverse_pointer
+        == "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.e.f.ip6.arpa"
+    )
 
     ipv6 = ipaddress.cached_ip_addresses("0:0:0:0:0:0:0:0")
     assert ipv6 is not None