减少DnsClient的分配

This commit is contained in:
老九 2021-11-18 21:11:28 +08:00
parent de5016a23f
commit 8e2e3802f0

View File

@ -39,7 +39,7 @@ namespace FastGithub.DomainResolve
private readonly int resolveTimeout = (int)TimeSpan.FromSeconds(2d).TotalMilliseconds;
private static readonly TimeSpan connectTimeout = TimeSpan.FromSeconds(2d);
private record LookupResult(IPAddress[] Addresses, TimeSpan TimeToLive);
private record LookupResult(IList<IPAddress> Addresses, TimeSpan TimeToLive);
/// <summary>
/// DNS客户端
@ -110,7 +110,7 @@ namespace FastGithub.DomainResolve
/// <param name="fastSort"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
private async Task<IPAddress[]> LookupAsync(IPEndPoint dns, DnsEndPoint endPoint, bool fastSort, CancellationToken cancellationToken = default)
private async Task<IList<IPAddress>> LookupAsync(IPEndPoint dns, DnsEndPoint endPoint, bool fastSort, CancellationToken cancellationToken = default)
{
var key = $"{dns}/{endPoint}";
var semaphore = this.semaphoreSlims.GetOrAdd(key, _ => new SemaphoreSlim(1, 1));
@ -118,7 +118,7 @@ namespace FastGithub.DomainResolve
try
{
if (this.dnsCache.TryGetValue<IPAddress[]>(key, out var value))
if (this.dnsCache.TryGetValue<IList<IPAddress>>(key, out var value))
{
return value;
}
@ -155,7 +155,16 @@ namespace FastGithub.DomainResolve
{
if (endPoint.Host == LOCALHOST)
{
return new LookupResult(new[] { IPAddress.Loopback }, TimeSpan.MaxValue);
var loopbacks = new List<IPAddress>();
if (Socket.OSSupportsIPv4 == true)
{
loopbacks.Add(IPAddress.Loopback);
}
if (Socket.OSSupportsIPv6 == true)
{
loopbacks.Add(IPAddress.IPv6Loopback);
}
return new LookupResult(loopbacks, TimeSpan.MaxValue);
}
var resolver = dns.Port == DNS_PORT
@ -163,17 +172,17 @@ namespace FastGithub.DomainResolve
: new UdpRequestResolver(dns, new TcpRequestResolver(dns), this.resolveTimeout);
var addressRecords = await GetAddressRecordsAsync(resolver, endPoint.Host, cancellationToken);
var addresses = addressRecords
var addresses = (IList<IPAddress>)addressRecords
.Where(item => IPAddress.IsLoopback(item.IPAddress) == false)
.Select(item => item.IPAddress)
.ToArray();
if (addresses.Length == 0)
if (addresses.Count == 0)
{
return new LookupResult(addresses, this.minTimeToLive);
}
if (fastSort && addresses.Length > 1)
if (fastSort == true)
{
addresses = await OrderByConnectAnyAsync(addresses, endPoint.Port, cancellationToken);
}
@ -238,8 +247,13 @@ namespace FastGithub.DomainResolve
/// <param name="port"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
private static async Task<IPAddress[]> OrderByConnectAnyAsync(IPAddress[] addresses, int port, CancellationToken cancellationToken)
private static async Task<IList<IPAddress>> OrderByConnectAnyAsync(IList<IPAddress> addresses, int port, CancellationToken cancellationToken)
{
if (addresses.Count <= 1)
{
return addresses;
}
using var controlTokenSource = new CancellationTokenSource(connectTimeout);
using var linkedTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, controlTokenSource.Token);
@ -247,7 +261,7 @@ namespace FastGithub.DomainResolve
var fastestAddress = await await Task.WhenAny(connectTasks);
controlTokenSource.Cancel();
if (fastestAddress == null)
if (fastestAddress == null || addresses.First().Equals(fastestAddress))
{
return addresses;
}
@ -260,7 +274,7 @@ namespace FastGithub.DomainResolve
list.Add(address);
}
}
return list.ToArray();
return list;
}
/// <summary>