Reworked client assembly loading.

src/MultiShop/Client/App.razor.cs

@@ -5,6 +5,7 @@ using System.Net.Http;
 using System.Net.Http.Json;
 using System.Reflection;
 using System.Threading.Tasks;
+using MultiShop.Client.Module;
 using MultiShop.Shop.Framework;
 using SimpleLogger;
 
@@ -15,99 +16,84 @@ namespace MultiShop.Client
         private bool modulesLoaded = false;
 
         private Dictionary<string, IShop> shops = new Dictionary<string, IShop>();
-        private Dictionary<string, byte[]> assemblyData = new Dictionary<string, byte[]>();
-        private Dictionary<string, Assembly> assemblyCache = new Dictionary<string, Assembly>();
         protected override async Task OnInitializedAsync()
         {
-            await DownloadShopModules();
             await base.OnInitializedAsync();
+            await DownloadShopModules();
         }
         private async Task DownloadShopModules()
         {
             HttpClient http = HttpFactory.CreateClient("Public-MultiShop.ServerAPI");
-            Logger.Log($"Fetching shop modules.", LogLevel.Debug);
-            string[] assemblyFileNames = await http.GetFromJsonAsync<string[]>("ShopModules");
-            Dictionary<Task<byte[]>, string> downloadTasks = new Dictionary<Task<byte[]>, string>(assemblyFileNames.Length);
 
-            foreach (string assemblyFileName in assemblyFileNames)
+            Dictionary<string, byte[]> assemblyData = new Dictionary<string, byte[]>();
+
+            string[] moduleNames = await http.GetFromJsonAsync<string[]>("ShopModule/Modules");
+            string[] dependencyNames = await http.GetFromJsonAsync<string[]>("ShopModule/Dependencies");
+            Dictionary<Task<byte[]>, string> downloadTasks = new Dictionary<Task<byte[]>, string>();
+
+            Logger.Log("Beginning to download shop modules...");
+            foreach (string moduleName in moduleNames)
             {
-                Logger.Log($"Downloading \"{assemblyFileName}\"...", LogLevel.Debug);
-                downloadTasks.Add(http.GetByteArrayAsync(Path.Join("ShopModules", assemblyFileName)), assemblyFileName);
+                Logger.Log($"Downloading shop: {moduleName}", LogLevel.Debug);
+                downloadTasks.Add(http.GetByteArrayAsync("shopModule/Modules/" + moduleName), moduleName);
+            }
+            Logger.Log("Beginning to download shop module dependencies...");
+            foreach (string depName in dependencyNames)
+            {
+                Logger.Log($"Downloading shop module dependency: {depName}", LogLevel.Debug);
+                downloadTasks.Add(http.GetByteArrayAsync("ShopModule/Dependencies/" + depName), depName);
             }
 
-            while (downloadTasks.Count != 0)
+            while (downloadTasks.Count > 0)
             {
-                Task<byte[]> data = await Task.WhenAny(downloadTasks.Keys);
-                string assemblyFileName = downloadTasks[data];
-                Logger.Log($"\"{assemblyFileName}\" completed downloading.", LogLevel.Debug);
-                assemblyData.Add(assemblyFileName, data.Result);
-                downloadTasks.Remove(data);
+                Task<byte[]> downloadTask = await Task.WhenAny(downloadTasks.Keys);
+                assemblyData.Add(downloadTasks[downloadTask], await downloadTask);
+                Logger.Log($"Shop module \"{downloadTasks[downloadTask]}\" completed downloading.", LogLevel.Debug);
+                downloadTasks.Remove(downloadTask);
             }
+            Logger.Log($"Downloaded {assemblyData.Count} assemblies in total.");
 
-            AppDomain.CurrentDomain.AssemblyResolve += OnAssemblyDependencyRequest;
-
-            foreach (string assemblyFileName in assemblyData.Keys)
+            ShopModuleLoadContext context = new ShopModuleLoadContext(assemblyData);
+            Logger.Log("Beginning to load shop modules.");
+            foreach (string moduleName in moduleNames)
             {
-                Assembly assembly = AppDomain.CurrentDomain.Load(assemblyData[assemblyFileName]);
-                bool used = false;
-                foreach (Type type in assembly.GetTypes())
+                Logger.Log($"Attempting to load shop module: \"{moduleName}\"", LogLevel.Debug);
+                Assembly moduleAssembly = context.LoadFromAssemblyName(new AssemblyName(moduleName));
+                bool shopLoaded = false;
+                foreach (Type type in moduleAssembly.GetTypes())
                 {
-                    if (typeof(IShop).IsAssignableFrom(type))
-                    {
+                    if (typeof(IShop).IsAssignableFrom(type)) {
                         IShop shop = Activator.CreateInstance(type) as IShop;
-                        if (shop != null)
-                        {
+                        if (shop != null) {
+                            shopLoaded = true;
                             shop.Initialize();
                             shops.Add(shop.ShopName, shop);
-                            Logger.Log($"Registered and started lifetime of module for \"{shop.ShopName}\".", LogLevel.Debug);
-                            used = true;
+                            Logger.Log($"Added shop: {shop.ShopName}", LogLevel.Debug);
                         }
                     }
                 }
-                if (!used) {
-                    Logger.Log($"Since unused, caching \"{assemblyFileName}\".", LogLevel.Debug);
-                    assemblyCache.Add(assemblyFileName, assembly);
+                if (!shopLoaded) {
+                    Logger.Log($"Module \"{moduleName}\" was reported to be a shop module, but did not contain a shop interface. Please report this to the site administrator.", LogLevel.Warning);
                 }
-                assemblyData.Remove(assemblyFileName);
             }
-            foreach (string assembly in assemblyData.Keys)
-            {
-                Logger.Log($"\"{assembly}\" was unused.", LogLevel.Warning);
-            }
-            foreach (string assembly in assemblyCache.Keys)
-            {
-                Logger.Log($"\"{assembly}\" was unused.", LogLevel.Warning);
-            }
-            assemblyData.Clear();
-            assemblyCache.Clear();
+            Logger.Log($"Shop module loading complete. Loaded a total of {shops.Count} shops.");
             modulesLoaded = true;
-        }
-
-
-        private Assembly OnAssemblyDependencyRequest(object sender, ResolveEventArgs args)
-        {
-            string dependencyName = args.Name.Substring(0, args.Name.IndexOf(','));
-            Logger.Log($"Assembly \"{args.RequestingAssembly.GetName().Name}\" is requesting dependency assembly \"{dependencyName}\".", LogLevel.Debug);
-            if (assemblyCache.ContainsKey(dependencyName)) {
-                Logger.Log($"Found \"{dependencyName}\" in cache.", LogLevel.Debug);
-                Assembly dep = assemblyCache[dependencyName];
-                assemblyCache.Remove(dependencyName);
-                return dep;
-            } else if (assemblyData.ContainsKey(dependencyName)) {
-                return AppDomain.CurrentDomain.Load(assemblyData[dependencyName]);
-            } else {
-                Logger.Log($"No dependency under name \"{args.Name}\"", LogLevel.Warning);
-                return null;
+            foreach (string assemblyName in context.UseCounter.Keys)
+            {
+                int usage = context.UseCounter[assemblyName];
+                Logger.Log($"\"{assemblyName}\" was used {usage} times.", LogLevel.Debug);
+                if (usage <= 0) {
+                    Logger.Log($"\"{assemblyName}\" was not used at all.", LogLevel.Warning);
+                }
             }
         }
 
-
         public void Dispose()
         {
             foreach (string name in shops.Keys)
             {
                 shops[name].Dispose();
-                Logger.Log($"Ending lifetime of shop module for \"{name}\".");
+                Logger.Log($"Ending lifetime of shop module for \"{name}\".", LogLevel.Debug);
             }
         }
     }

src/MultiShop/Client/Extensions/ResultProfileExtensions.cs

@@ -2,7 +2,7 @@ using System;
 using MultiShop.Shared;
 using MultiShop.Shared.Models;
 
-namespace MultiShop.Client.Extensions.Models
+namespace MultiShop.Client.Extensions
 {
     public static class ResultProfileExtensions
     {

src/MultiShop/Client/Extensions/SearchProfileExtensions.cs

@@ -1,6 +1,6 @@
 using MultiShop.Shared.Models;
 
-namespace MultiShop.Client.Extensions.Models
+namespace MultiShop.Client.Extensions
 {
     public static class SearchProfileExtensions
     {

src/MultiShop/Client/Module/ShopModuleLoadContext.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Reflection;
+using System.Runtime.Loader;
+using SimpleLogger;
+
+namespace MultiShop.Client.Module
+{
+    public class ShopModuleLoadContext : AssemblyLoadContext
+    {
+        private IDictionary<string, byte[]> rawAssemblies;
+        private Dictionary<string, int> useCounter;
+        public IReadOnlyDictionary<string, int> UseCounter {get => useCounter;}
+        public ShopModuleLoadContext(IEnumerable<KeyValuePair<string, byte[]>> assemblies)
+        {
+            this.rawAssemblies = new Dictionary<string, byte[]>(assemblies);
+            useCounter = new Dictionary<string, int>();
+        }
+
+        protected override Assembly Load(AssemblyName assemblyName)
+        {
+            Logger.Log("ShopModuleLoadContext is attempting to load assembly: " + assemblyName.FullName, LogLevel.Debug);
+            if (!rawAssemblies.ContainsKey(assemblyName.FullName)) return null;
+
+            useCounter[assemblyName.FullName] = useCounter.GetValueOrDefault(assemblyName.FullName) + 1;
+
+            using (MemoryStream stream = new MemoryStream(rawAssemblies[assemblyName.FullName]))
+            {
+                return LoadFromStream(stream);
+            }
+        }
+
+        protected override IntPtr LoadUnmanagedDll(string unmanagedDllName)
+        {
+            throw new NotImplementedException($"Cannot load unmanaged dll \"{unmanagedDllName}\".");
+        }
+    }
+}

src/MultiShop/Client/Pages/Search.razor

@@ -1,6 +1,6 @@
 @page "/search/{Query?}"
 
-@using MultiShop.Client.Extensions.Models
+@using MultiShop.Client.Extensions
 
 <div class="my-2">
     <div class="input-group my-2">

src/MultiShop/Client/Pages/Search.razor.cs

@@ -6,7 +6,7 @@ using System.Text.Json;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Components;
 using Microsoft.AspNetCore.Components.Authorization;
-using MultiShop.Client.Extensions.Models;
+using MultiShop.Client.Extensions;
 using MultiShop.Client.Listing;
 using MultiShop.Shared.Models;
 using MultiShop.Shop.Framework;

src/MultiShop/Server/Controllers/ShopModuleController.cs

@@ -0,0 +1,88 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Reflection;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Configuration;
+using MultiShop.Server.Options;
+using SimpleLogger;
+
+namespace MultiShop.Server.Controllers
+{
+    [ApiController]
+    [Route("[controller]")]
+    public class ShopModuleController : ControllerBase
+    {
+        private readonly IConfiguration configuration;
+        private IDictionary<string, byte[]> shopModules;
+        private IDictionary<string, byte[]> shopModuleDependencies;
+        
+
+        public ShopModuleController(IConfiguration configuration)
+        {
+            this.configuration = configuration;
+            this.shopModules = new Dictionary<string, byte[]>();
+            this.shopModuleDependencies = new Dictionary<string, byte[]>();
+
+            ShopModulesOptions options = configuration.GetSection(ShopModulesOptions.ShopModules).Get<ShopModulesOptions>();
+            foreach (string file in Directory.EnumerateFiles(options.Directory))
+            {
+                try
+                {
+                    AssemblyName assemblyName = AssemblyName.GetAssemblyName(file);
+                    shopModules.Add(assemblyName.FullName, System.IO.File.ReadAllBytes(file));
+                }
+                catch (BadImageFormatException e) {
+                    Logger.Log($"\"{e.FileName}\" is not a valid assembly. Ignoring.", LogLevel.Warning);
+                }
+                catch (ArgumentException) {
+                    Logger.Log($"\"{Path.GetFileName(file)}\" has the same full name as another assembly. Ignoring this one.", LogLevel.Warning);
+                }
+            }
+
+            foreach (string file in Directory.EnumerateFiles(Path.Join(options.Directory, "dependencies")))
+            {
+                try
+                {
+                    AssemblyName assemblyName = AssemblyName.GetAssemblyName(file);
+                    shopModuleDependencies.Add(assemblyName.FullName, System.IO.File.ReadAllBytes(file));
+                }
+                catch (BadImageFormatException e) {
+                    Logger.Log($"\"{e.FileName}\" is not a valid assembly. Ignoring.", LogLevel.Warning);
+                }
+                catch (ArgumentException) {
+                    Logger.Log($"\"{Path.GetFileName(file)}\" has the same full name as another assembly. Ignoring this one.", LogLevel.Warning);
+                }
+            }
+        }
+        
+        [HttpGet]
+        [Route("Modules")]
+        public IActionResult GetShopModuleNames() {
+            return Ok(shopModules.Keys);
+        }
+
+        [HttpGet]
+        [Route("Modules/{shopModuleName}")]
+        public IActionResult GetModule(string shopModuleName) {
+            ShopModulesOptions options = configuration.GetSection(ShopModulesOptions.ShopModules).Get<ShopModulesOptions>();
+            if (!shopModules.ContainsKey(shopModuleName)) return NotFound();
+            if (options.Disabled != null && options.Disabled.Contains(shopModuleName)) return Forbid();
+            return File(shopModules[shopModuleName], "application/module-dll");
+        }
+
+        [HttpGet]
+        [Route("Dependencies")]
+        public IActionResult GetDependencyNames() {
+            return Ok(shopModuleDependencies.Keys);
+        }
+
+        [HttpGet]
+        [Route("Dependencies/{dependencyName}")]
+        public IActionResult GetDependency(string dependencyName) {
+            ShopModulesOptions options = configuration.GetSection(ShopModulesOptions.ShopModules).Get<ShopModulesOptions>();
+            if (!shopModuleDependencies.ContainsKey(dependencyName)) return NotFound();
+            return File(shopModuleDependencies[dependencyName], "application/module-dep-dll");
+        }
+    }
+}

src/MultiShop/Server/Controllers/ShopModulesController.cs

@@ -1,49 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using Microsoft.AspNetCore.Mvc;
-using Microsoft.Extensions.Configuration;
-using MultiShop.Server.Options;
-
-namespace MultiShop.Server.Controllers
-{
-    [ApiController]
-    [Route("[controller]")]
-    public class ShopModulesController : ControllerBase
-    {
-        private readonly IConfiguration configuration;
-        private IDictionary<string, byte[]> shopAssemblyData;
-
-        
-
-        public ShopModulesController(IConfiguration configuration)
-        {
-            this.configuration = configuration;
-            this.shopAssemblyData = new Dictionary<string, byte[]>();
-        }
-        
-        public IActionResult GetShopModuleNames() {
-            List<string> moduleNames = new List<string>();
-            ShopOptions options = configuration.GetSection(ShopOptions.Shop).Get<ShopOptions>();
-            foreach (string file in Directory.EnumerateFiles(options.Directory))
-            {
-                if (Path.GetExtension(file).ToLower().Equals(".dll") && !(options.Disabled != null && options.Disabled.Contains(Path.GetFileNameWithoutExtension(file)))) {
-                    moduleNames.Add(Path.GetFileNameWithoutExtension(file));
-                }
-            }
-            return Ok(moduleNames);
-        }
-
-
-        [HttpGet]
-        [Route("{shopModuleName}")]
-        public IActionResult GetModule(string shopModuleName) {
-            ShopOptions options = configuration.GetSection(ShopOptions.Shop).Get<ShopOptions>();
-            string shopPath = Path.Join(options.Directory, shopModuleName);
-            shopPath += ".dll";
-            if (!System.IO.File.Exists(shopPath)) return NotFound();
-            if (options.Disabled != null && options.Disabled.Contains(shopModuleName)) return Forbid();
-            return File(new FileStream(shopPath, FileMode.Open), "application/shop-dll");
-        }
-    }
-}

src/MultiShop/Server/Options/ShopModulesOptions.cs

@@ -3,9 +3,9 @@ using System.Collections.Generic;
 namespace MultiShop.Server.Options
 {
     //https://docs.microsoft.com/en-us/aspnet/core/fundamentals/configuration/?view=aspnetcore-5.0#bind-hierarchical-configuration-data-using-the-options-pattern
-    public class ShopOptions
+    public class ShopModulesOptions
     {
-        public const string Shop = "Shops";
+        public const string ShopModules = "ShopModules";
         public string Directory { get; set; }
         public IList<string> Disabled { get; set; }
     }

src/MultiShop/Server/appsettings.json

@@ -1,5 +1,5 @@
 {
-  "Shops": {
+  "ShopModules": {
     "Directory": "modules",
     "Disabled": [
     ]