feat: move scheduled tasks to separate project

PluralKit.ScheduledTasks/PluralKit.ScheduledTasks.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\PluralKit.Core\PluralKit.Core.csproj" />
+  </ItemGroup>
+
+  <PropertyGroup>
+      <RestorePackagesWithLockFile>true</RestorePackagesWithLockFile>
+  </PropertyGroup>
+</Project>

PluralKit.ScheduledTasks/Startup.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Threading.Tasks;
+
+using Autofac;
+
+using Microsoft.Extensions.Configuration;
+
+using PluralKit.Core;
+
+namespace PluralKit.ScheduledTasks
+{
+    class Startup
+    {
+        static async Task Main(string[] args)
+        {
+            // Load configuration and run global init stuff
+            var config = InitUtils.BuildConfiguration(args).Build();
+            InitUtils.InitStatic();
+
+            var services = BuildContainer(config);
+            services.Resolve<TaskHandler>().Run();
+
+            await Task.Delay(-1);
+        }
+
+        private static IContainer BuildContainer(IConfiguration config)
+        {
+            var builder = new ContainerBuilder();
+
+            builder.RegisterInstance(config);
+            builder.RegisterModule(new ConfigModule<CoreConfig>());
+            builder.RegisterModule(new LoggingModule("ScheduledTasks"));
+            builder.RegisterModule(new MetricsModule());
+            builder.RegisterModule<DataStoreModule>();
+            builder.RegisterType<TaskHandler>().AsSelf().SingleInstance();
+
+            return builder.Build();
+        }
+    }
+}

PluralKit.ScheduledTasks/TaskHandler.cs

@@ -0,0 +1,75 @@
+using System;
+using System.Diagnostics;
+using System.Threading;
+using System.Threading.Tasks;
+
+using NodaTime;
+using NodaTime.Extensions;
+
+using Serilog;
+
+using PluralKit.Core;
+
+namespace PluralKit.ScheduledTasks
+{
+    public class TaskHandler
+    {
+
+        private static readonly Duration CommandMessageRetention = Duration.FromHours(24);
+        private Timer _periodicTask;
+
+        private readonly ILogger _logger;
+        private readonly IDatabase _db;
+        private readonly ModelRepository _repo;
+
+        public TaskHandler(ILogger logger, IDatabase db, ModelRepository repo)
+        {
+            _logger = logger;
+            _db = db;
+            _repo = repo;
+        }
+
+        public void Run()
+        {
+            _logger.Information("Starting scheduled task runner...");
+            var timeNow = SystemClock.Instance.GetCurrentInstant();
+            var timeTillNextWholeMinute = TimeSpan.FromMilliseconds(60000 - timeNow.ToUnixTimeMilliseconds() % 60000 + 250);
+            _periodicTask = new Timer(_ =>
+            {
+                var __ = UpdatePeriodic();
+            }, null, timeTillNextWholeMinute, TimeSpan.FromMinutes(1));
+        }
+
+        private async Task UpdatePeriodic()
+        {
+            _logger.Information("Running per-minute scheduled tasks.");
+            var stopwatch = new Stopwatch();
+            stopwatch.Start();
+
+            _logger.Information("Updating database stats...");
+            await _repo.UpdateStats();
+
+            // Clean up message cache in postgres
+            await CleanupOldMessages();
+
+            stopwatch.Stop();
+            _logger.Information("Ran scheduled tasks in {Time}", stopwatch.ElapsedDuration());
+        }
+
+        private async Task CleanupOldMessages()
+        {
+            var deleteThresholdInstant = SystemClock.Instance.GetCurrentInstant() - CommandMessageRetention;
+            var deleteThresholdSnowflake = InstantToSnowflake(deleteThresholdInstant);
+
+            var deletedRows = await _repo.DeleteCommandMessagesBefore(deleteThresholdSnowflake);
+
+            _logger.Information("Pruned {DeletedRows} command messages older than retention {Retention} (older than {DeleteThresholdInstant} / {DeleteThresholdSnowflake})",
+                deletedRows, CommandMessageRetention, deleteThresholdInstant, deleteThresholdSnowflake);
+        }
+
+        // we don't have access to PluralKit.Bot here, so this needs to be vendored
+        public static ulong InstantToSnowflake(Instant time) =>
+            (ulong)(time - Instant.FromUtc(2015, 1, 1, 0, 0, 0)).TotalMilliseconds << 22;
+
+    }
+}