Class HostAnswers

dns/resolver.py:325–373

A dict of DNS stub resolver answers to a host name lookup, indexed by type.

class HostAnswers(Answers):
    """A dict of DNS stub resolver answers to a host name lookup, indexed by
    type.
    """

    @classmethod
    def make(
        cls,
        v6: Answer | None = None,
        v4: Answer | None = None,
        add_empty: bool = True,
    ) -> "HostAnswers":
        answers = HostAnswers()
        if v6 is not None and (add_empty or v6.rrset):
            answers[dns.rdatatype.AAAA] = v6
        if v4 is not None and (add_empty or v4.rrset):
            answers[dns.rdatatype.A] = v4
        return answers

    # Returns pairs of (address, family) from this result, potentially
    # filtering by address family.
    def addresses_and_families(
        self, family: int = socket.AF_UNSPEC
    ) -> Iterator[Tuple[str, int]]:
        if family == socket.AF_UNSPEC:
            yield from self.addresses_and_families(socket.AF_INET6)
            yield from self.addresses_and_families(socket.AF_INET)
            return
        elif family == socket.AF_INET6:
            answer = self.get(dns.rdatatype.AAAA)
        elif family == socket.AF_INET:
            answer = self.get(dns.rdatatype.A)
        else:  # pragma: no cover
            raise NotImplementedError(f"unknown address family {family}")
        if answer:
            for rdata in answer:
                yield (rdata.address, family)

    # Returns addresses from this result, potentially filtering by
    # address family.
    def addresses(self, family: int = socket.AF_UNSPEC) -> Iterator[str]:
        return (pair[0] for pair in self.addresses_and_families(family))

    # Returns the canonical name from this result.
    def canonical_name(self) -> dns.name.Name:
        answer = self.get(dns.rdatatype.AAAA, self.get(dns.rdatatype.A))
        if answer is None:
            raise EmptyHostAnswers
        return answer.canonical_name


class CacheStatistics: