DNS / DNS 解析

NetworkDiagnostic.resolve() tests DNS resolution across multiple servers in parallel, so you can spot the fastest one. Each result is either the system resolver or a raw UDP query against an explicit server.

NetworkDiagnostic.resolve() 并行测试多台 DNS 服务器的解析表现，从而挑出最快的一台。每条结果要么来自系统解析器，要么是对指定服务器的原始 UDP 查询。

Basic / 基础

final results = await NetworkDiagnostic.resolve(
  domain: 'example.com',
  dnsServers: const <String>['1.1.1.1', '8.8.8.8', '114.114.114.114'],
  timeout: const Duration(seconds: 5),
  concurrent: true,
  includeSystemResolver: true,
);
 
for (final r in results) {
  if (r.isSuccess) {
    print('${r.server.padRight(16)} → ${r.resolvedIps.join(", ")} '
          '(${r.responseTimeMs.toStringAsFixed(1)} ms)');
  } else {
    print('${r.server.padRight(16)} ✗ ${r.errorMessage}');
  }
}

Parameter	Default	Meaning
`domain`	`config.dnsDomain`	Domain to resolve
`dnsServers`	`config.dnsServers`	Servers queried in parallel (or in series)
`timeout`	`config.dnsTimeout`	Timeout of one query
`concurrent`	`true`	Query all servers at once
`includeSystemResolver`	`false`	Also add a `system` row

Notes / 说明:

A row with server == 'system' comes from the OS resolver; the others are raw UDP queries against the listed IPs, encoded by the built-in DnsPacket wire codec. server == 'system' 的行来自系统解析器，其余是对指定 IP 的原始 UDP 查询，由内置 DnsPacket 编解码。
includeSystemResolver defaults to false at the facade level — pass true to include it. 门面层默认不包含系统解析器，需显式传 true。

Pick the fastest / 挑出最快的

final fastest = results
    .where((r) => r.isSuccess)
    .reduce((a, b) => a.responseTimeMs <= b.responseTimeMs ? a : b);
print('fastest resolver: ${fastest.server}');

⏱ Latency / Ping 🔌 Ports