remove cached mod data not requested within 48 hours (#651)

src/SMAPI.Web/BackgroundService.cs

@@ -5,6 +5,7 @@ using Hangfire;
 using Microsoft.Extensions.Hosting;
 using StardewModdingAPI.Toolkit;
 using StardewModdingAPI.Toolkit.Framework.Clients.Wiki;
+using StardewModdingAPI.Web.Framework.Caching.Mods;
 using StardewModdingAPI.Web.Framework.Caching.Wiki;
 
 namespace StardewModdingAPI.Web
@@ -19,9 +20,12 @@ namespace StardewModdingAPI.Web
         /// <summary>The background task server.</summary>
         private static BackgroundJobServer JobServer;
 
-        /// <summary>The cache in which to store mod metadata.</summary>
+        /// <summary>The cache in which to store wiki metadata.</summary>
         private static IWikiCacheRepository WikiCache;
 
+        /// <summary>The cache in which to store mod data.</summary>
+        private static IModCacheRepository ModCache;
+
 
         /*********
         ** Public methods
@@ -30,10 +34,12 @@ namespace StardewModdingAPI.Web
         ** Hosted service
         ****/
         /// <summary>Construct an instance.</summary>
-        /// <param name="wikiCache">The cache in which to store mod metadata.</param>
+        /// <param name="wikiCache">The cache in which to store wiki metadata.</param>
-        public BackgroundService(IWikiCacheRepository wikiCache)
+        /// <param name="modCache">The cache in which to store mod data.</param>
+        public BackgroundService(IWikiCacheRepository wikiCache, IModCacheRepository modCache)
         {
             BackgroundService.WikiCache = wikiCache;
+            BackgroundService.ModCache = modCache;
         }
 
         /// <summary>Start the service.</summary>
@@ -44,9 +50,11 @@ namespace StardewModdingAPI.Web
 
             // set startup tasks
             BackgroundJob.Enqueue(() => BackgroundService.UpdateWikiAsync());
+            BackgroundJob.Enqueue(() => BackgroundService.RemoveStaleMods());
 
             // set recurring tasks
-            RecurringJob.AddOrUpdate(() => BackgroundService.UpdateWikiAsync(), "*/10 * * * *");
+            RecurringJob.AddOrUpdate(() => BackgroundService.UpdateWikiAsync(), "*/10 * * * *"); // every 10 minutes
+            RecurringJob.AddOrUpdate(() => BackgroundService.RemoveStaleMods(), "0 * * * *"); // hourly
 
             return Task.CompletedTask;
         }
@@ -75,6 +83,12 @@ namespace StardewModdingAPI.Web
             BackgroundService.WikiCache.SaveWikiData(wikiCompatList.StableVersion, wikiCompatList.BetaVersion, wikiCompatList.Mods, out _, out _);
         }
 
+        /// <summary>Remove mods which haven't been requested in over 48 hours.</summary>
+        public static async Task RemoveStaleMods()
+        {
+            BackgroundService.ModCache.RemoveStaleMods(TimeSpan.FromHours(48));
+        }
+
 
         /*********
         ** Private method

src/SMAPI.Web/Framework/Caching/Mods/IModCacheRepository.cs

@@ -1,3 +1,4 @@
+using System;
 using StardewModdingAPI.Toolkit.Framework.UpdateData;
 using StardewModdingAPI.Web.Framework.ModRepositories;
 
@@ -22,5 +23,9 @@ namespace StardewModdingAPI.Web.Framework.Caching.Mods
         /// <param name="mod">The mod data.</param>
         /// <param name="cachedMod">The stored mod record.</param>
         void SaveMod(ModRepositoryKey site, string id, ModInfoModel mod, out CachedMod cachedMod);
+
+        /// <summary>Delete data for mods which haven't been requested within a given time limit.</summary>
+        /// <param name="age">The minimum age for which to remove mods.</param>
+        void RemoveStaleMods(TimeSpan age);
     }
 }

src/SMAPI.Web/Framework/Caching/Mods/ModCacheRepository.cs

@@ -67,6 +67,14 @@ namespace StardewModdingAPI.Web.Framework.Caching.Mods
             cachedMod = this.SaveMod(new CachedMod(site, id, mod));
         }
 
+        /// <summary>Delete data for mods which haven't been requested within a given time limit.</summary>
+        /// <param name="age">The minimum age for which to remove mods.</param>
+        public void RemoveStaleMods(TimeSpan age)
+        {
+            DateTimeOffset minDate = DateTimeOffset.UtcNow.Subtract(age);
+            var result = this.Mods.DeleteMany(p => p.LastRequested < minDate);
+        }
+
 
         /*********
         ** Private methods