Method discard_cache

net/utils.cpp:326–342

    }

    void discard_cache(std::string_view host, IPAddr ip) override {
        auto ipaddr = dnscache_.borrow(host);
        if (ip.undefined() || ipaddr->empty()) {
            ipaddr.recycle(true);
        } else {
            IPAddrNode* node = nullptr;
            DEFER(delete node);
            SCOPED_LOCK(*ipaddr);
            for (auto itr = ipaddr->rbegin(); itr != ipaddr->rend(); itr++) {
                if ((*itr)->addr == ip) {
                    ipaddr->erase(node = *itr);
                    break;
                }
            }
            ipaddr.recycle(ipaddr->empty());
        }
    }

private:
    ObjectCache<std::string, IPAddrList*> dnscache_;