cache.py 文件源码

def _lookup(self, name, cls, type, timeout):
        now = time.time()
        q = dns.Query(name, type, cls)
        try:
            when, (ans, auth, add) = self.cache[q]
        except KeyError:
            if self.verbose > 1:
                log.msg('Cache miss for ' + repr(name))
            return defer.fail(failure.Failure(dns.DomainError(name)))
        else:
            if self.verbose:
                log.msg('Cache hit for ' + repr(name))
            diff = now - when
            return defer.succeed((
                [dns.RRHeader(str(r.name), r.type, r.cls, r.ttl - diff, r.payload) for r in ans],
                [dns.RRHeader(str(r.name), r.type, r.cls, r.ttl - diff, r.payload) for r in auth],
                [dns.RRHeader(str(r.name), r.type, r.cls, r.ttl - diff, r.payload) for r in add]
            ))