a023d33d90
- Applied to TorBox, can be extended easily to other providers - Reads response headers commonplace for pre-emptive rate limit throttling and retry-after - When a rate limit is reached, displays a warning in the UI - Fix socket leak from direct allocation of HttpClient, replaced with factory which handles pooling and re-use of sockets. While HttpClient is Disposable, it doesn't gaurantee (and does not) directly release underlying sockets for queries at the time the client is disposed. These sockets will go into a TCP WAIT state often for a very long time. The expected pattern in C# is to always use the HttClientFactory which will correctly handle re-use of the OS sockets in suqsequent queries reducing resource and memory leaks.
35 lines
1.2 KiB
C#
35 lines
1.2 KiB
C#
using System.Net;
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using Polly.Timeout;
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using RdtClient.Data.Models.Internal;
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namespace RdtClient.Service.Helpers;
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public class RateLimitHandler : DelegatingHandler
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{
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protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
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{
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try
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{
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var response = await base.SendAsync(request, cancellationToken);
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if (response.StatusCode == HttpStatusCode.TooManyRequests)
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{
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var retryAfter = response.Headers.RetryAfter;
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var delay = retryAfter?.Delta ?? (retryAfter?.Date.HasValue == true ? retryAfter.Date.Value - DateTimeOffset.UtcNow : TimeSpan.FromMinutes(2));
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if (delay < TimeSpan.Zero)
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{
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delay = TimeSpan.FromMinutes(2);
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}
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throw new RateLimitException("TorBox rate limit exceeded", delay);
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}
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return response;
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}
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catch (Exception ex) when (ex is TimeoutRejectedException or TaskCanceledException)
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{
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throw new RateLimitException("TorBox rate limit exceeded (timeout)", TimeSpan.FromMinutes(2));
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}
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}
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}
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