Base functionality useful to various parts of Twisted Names.
| Variable | EMPTY_RESULT | Undocumented |
| Class | ResolverBase | ResolverBase is a base class for implementations of interfaces.IResolver which deals with a lot of the boilerplate of implementing all of the lookup methods. |
| Function | extractRecord | Resolve a name to an IP address, following CNAME records and NS referrals recursively. |
| Variable | typeToMethod | Undocumented |
| Variable | _ANS | Undocumented |
| Variable | _AUTH | Undocumented |
| Variable | _ADD | Undocumented |
Resolve a name to an IP address, following CNAME records and NS referrals recursively.
This is an implementation detail of ResolverBase.getHostByName.
| Parameters | resolver | The resolver to use for the next query (unless handling an NS referral). (type: IResolver) |
| name | The name being looked up. (type: dns.Name) | |
| answers | All of the records returned by the previous query (answers, authority, and additional concatenated). (type: list of dns.RRHeader) | |
| level | Remaining recursion budget. This is decremented at each recursion. The query returns None when it reaches 0. (type: int) | |
| Returns | The first IPv4 or IPv6 address (as a dotted quad or colon quibbles), or None when no result is found. (type: native str or None) | |