AtomicOptions return atomic *OptionsVisitor.

AtomicOptionsSet atomic setter for *Options.

InstallCallbackOnAtomicOptionsSet install callback.

InstallOptionsWatchDog the installed func will called when NewOptions called.

New 创建 dns.

NewCache 创建带缓存的 dns.

NewOptions new Options.

go:generate optiongen --option_with_struct_name=false --new_func=NewOptions --xconf=true --empty_composite_nil=true --usage_tag_name=usage.

WithDialer 拨号器.

WithLookupTimeout 搜索超时.

WithOnLookup 当成功搜索.

WithPolicy 拨号策略.

WithResolver 解析器.

WithTTL Cache过期ttl.

使用第一个ip.

随机一个可用ip.

EmptyIpCache 空的 ip 缓存信息.

IpCache ip 缓存信息.

Options should use NewOptions to initialize it.

CacheDNS 带缓存的域名解析器.

Dialer 拨号器.

DNS 域名解析器.

OptionsInterface visitor + ApplyOption interface for Options.

OptionsVisitor visitor interface for Options.

Resolver 解析器.

Option option func.

go:generate stringer -type=Policy.