FastGithub/FastGithub.DomainResolve/IPAddressStatusService.cs
2021-11-19 22:57:28 +08:00

89 lines
3.4 KiB
C#

using Microsoft.Extensions.Caching.Memory;
using Microsoft.Extensions.Options;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Threading.Tasks;
namespace FastGithub.DomainResolve
{
/// <summary>
/// IP状态服务
/// 连接成功的IP缓存5分钟
/// 连接失败的IP缓存2分钟
/// </summary>
sealed class IPAddressStatusService
{
private readonly TimeSpan activeTTL = TimeSpan.FromMinutes(5d);
private readonly TimeSpan negativeTTL = TimeSpan.FromMinutes(2d);
private readonly TimeSpan connectTimeout = TimeSpan.FromSeconds(5d);
private readonly IMemoryCache statusCache = new MemoryCache(Options.Create(new MemoryCacheOptions()));
/// <summary>
/// 并行获取多个IP的状态
/// </summary>
/// <param name="addresses"></param>
/// <param name="port"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
public Task<IPAddressStatus[]> GetParallelAsync(IEnumerable<IPAddress> addresses, int port, CancellationToken cancellationToken)
{
var statusTasks = addresses.Select(item => this.GetAsync(item, port, cancellationToken));
return Task.WhenAll(statusTasks);
}
/// <summary>
/// 获取IP状态
/// </summary>
/// <param name="address"></param>
/// <param name="port"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
public async Task<IPAddressStatus> GetAsync(IPAddress address, int port, CancellationToken cancellationToken)
{
var endPoint = new IPEndPoint(address, port);
if (this.statusCache.TryGetValue<IPAddressStatus>(endPoint, out var status))
{
return status;
}
status = await this.GetAddressStatusAsync(endPoint, cancellationToken);
var ttl = status.Elapsed < TimeSpan.MaxValue ? this.activeTTL : this.negativeTTL;
return this.statusCache.Set(endPoint, status, ttl);
}
/// <summary>
/// 获取IP状态
/// </summary>
/// <param name="endPoint"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
private async Task<IPAddressStatus> GetAddressStatusAsync(IPEndPoint endPoint, CancellationToken cancellationToken)
{
var stopWatch = Stopwatch.StartNew();
try
{
using var timeoutTokenSource = new CancellationTokenSource(this.connectTimeout);
using var linkedTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, timeoutTokenSource.Token);
using var socket = new Socket(endPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
await socket.ConnectAsync(endPoint, linkedTokenSource.Token);
return new IPAddressStatus(endPoint.Address, stopWatch.Elapsed);
}
catch (Exception)
{
cancellationToken.ThrowIfCancellationRequested();
return new IPAddressStatus(endPoint.Address, TimeSpan.MaxValue);
}
finally
{
stopWatch.Stop();
}
}
}
}