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Execute webhooks directly rather than through D.NET

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This commit is contained in:
Ske 2019-12-21 18:50:28 +01:00
parent 530e3aa697
commit 474d561c54
3 changed files with 36 additions and 65 deletions
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1
PluralKit.Bot/PluralKit.Bot.csproj
View File

@ -10,7 +10,6 @@
</ItemGroup>
<ItemGroup>
<PackageReference Include="Discord.Net.Webhook" Version="2.1.1" />
<PackageReference Include="Discord.Net.WebSocket" Version="2.1.1" />
<PackageReference Include="Humanizer.Core" Version="2.6.2" />
<PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="2.2.0" />

1
PluralKit.Bot/Services/WebhookCacheService.cs
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@ -4,7 +4,6 @@ using System.Linq;
using System.Net.Http;
using System.Threading.Tasks;
using Discord;
using Discord.Webhook;
using Discord.WebSocket;
using Serilog;

99
PluralKit.Bot/Services/WebhookExecutorService.cs
View File

@ -3,11 +3,14 @@ using System.Net.Http;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using App.Metrics;
using App.Metrics.Logging;
using Discord;
using Discord.Net;
using Discord.Webhook;
using Microsoft.Extensions.Caching.Memory;
using Humanizer;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Serilog;
namespace PluralKit.Bot
@ -15,14 +18,12 @@ namespace PluralKit.Bot
public class WebhookExecutorService: IDisposable
{
private WebhookCacheService _webhookCache;
private IMemoryCache _cache;
private ILogger _logger;
private IMetrics _metrics;
private HttpClient _client;
public WebhookExecutorService(IMemoryCache cache, IMetrics metrics, WebhookCacheService webhookCache, ILogger logger)
public WebhookExecutorService(IMetrics metrics, WebhookCacheService webhookCache, ILogger logger)
{
_cache = cache;
_metrics = metrics;
_webhookCache = webhookCache;
_logger = logger.ForContext<WebhookExecutorService>();
@ -48,72 +49,44 @@ namespace PluralKit.Bot
private async Task<ulong> ExecuteWebhookInner(IWebhook webhook, string name, string avatarUrl, string content,
IAttachment attachment, bool hasRetried = false)
{
var client = await GetClientFor(webhook);
try
var mfd = new MultipartFormDataContent();
mfd.Add(new StringContent(content.Truncate(2000)), "content");
mfd.Add(new StringContent(FixClyde(name).Truncate(80)), "username");
if (avatarUrl != null) mfd.Add(new StringContent(avatarUrl), "avatar_url");
if (attachment != null)
{
// If we have an attachment, use the special SendFileAsync method
if (attachment != null)
using (var attachmentStream = await _client.GetStreamAsync(attachment.Url))
using (_metrics.Measure.Timer.Time(BotMetrics.WebhookResponseTime))
return await client.SendFileAsync(attachmentStream, attachment.Filename, content,
username: FixClyde(name),
avatarUrl: avatarUrl);
// Otherwise, send normally
return await client.SendMessageAsync(content, username: FixClyde(name), avatarUrl: avatarUrl);
var attachmentResponse = await _client.GetAsync(attachment.Url);
var attachmentStream = await attachmentResponse.Content.ReadAsStreamAsync();
mfd.Add(new StreamContent(attachmentStream), "file", attachment.Filename);
}
catch (HttpException e)
HttpResponseMessage response;
using (_metrics.Measure.Timer.Time(BotMetrics.WebhookResponseTime))
response = await _client.PostAsync($"{DiscordConfig.APIUrl}webhooks/{webhook.Id}/{webhook.Token}?wait=true", mfd);
// TODO: are there cases where an error won't also return a parseable JSON object?
var responseJson = JsonConvert.DeserializeObject<JObject>(await response.Content.ReadAsStringAsync());
if (responseJson.ContainsKey("code"))
{
// If we hit an error, just retry (if we haven't already)
if (e.DiscordCode == 10015 && !hasRetried) // Error 10015 = "Unknown Webhook"
if (responseJson["code"].Value<int>() == 10015 && !hasRetried)
{
_logger.Warning(e, "Error invoking webhook {Webhook} in channel {Channel}", webhook.Id, webhook.ChannelId);
// Error 10015 = "Unknown Webhook" - this likely means the webhook was deleted
// but is still in our cache. Invalidate, refresh, try again
_logger.Warning("Error invoking webhook {Webhook} in channel {Channel}", webhook.Id, webhook.ChannelId);
return await ExecuteWebhookInner(await _webhookCache.InvalidateAndRefreshWebhook(webhook), name, avatarUrl, content, attachment, hasRetried: true);
}
throw;
// TODO: look into what this actually throws, and if this is the correct handling
response.EnsureSuccessStatusCode();
}
}
private async Task<DiscordWebhookClient> GetClientFor(IWebhook webhook)
{
_logger.Verbose("Looking for client for webhook {Webhook} in cache", webhook.Id);
return await _cache.GetOrCreateAsync($"_webhook_client_{webhook.Id}",
(entry) => MakeCachedClientFor(entry, webhook));
}
private Task<DiscordWebhookClient> MakeCachedClientFor(ICacheEntry entry, IWebhook webhook) {
_logger.Information("Client for {Webhook} not found in cache, creating", webhook.Id);
// Define expiration for the client cache
// 10 minutes *without a query* and it gets yoten
entry.SlidingExpiration = TimeSpan.FromMinutes(10);
// IMemoryCache won't automatically dispose of its values when the cache gets evicted
// so we register a hook to do so here.
entry.RegisterPostEvictionCallback((key, value, reason, state) => (value as IDisposable)?.Dispose());
// DiscordWebhookClient has a sync network call in its constructor (!!!)
// and we want to punt that onto a task queue, so we do that.
return Task.Run(async () =>
{
try
{
return new DiscordWebhookClient(webhook);
}
catch (InvalidOperationException)
{
// TODO: does this leak stuff inside the DiscordWebhookClient created above?
// Webhook itself was found in cache, but has been deleted on the channel
// We request a new webhook instead
return new DiscordWebhookClient(await _webhookCache.InvalidateAndRefreshWebhook(webhook));
}
});
// At this point we're sure we have a 2xx status code, so just assume success
// TODO: can we do this without a round-trip to a string?
return responseJson["id"].Value<ulong>();
}
private string FixClyde(string name)
{
// Check if the name contains "Clyde" - if not, do nothing