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Diffstat (limited to 'VNLib.Plugins.Extensions.Loading/LoadingExtensions.cs')
| -rw-r--r-- | VNLib.Plugins.Extensions.Loading/LoadingExtensions.cs | 334 |
1 files changed, 0 insertions, 334 deletions
diff --git a/VNLib.Plugins.Extensions.Loading/LoadingExtensions.cs b/VNLib.Plugins.Extensions.Loading/LoadingExtensions.cs deleted file mode 100644 index c23f5e2..0000000 --- a/VNLib.Plugins.Extensions.Loading/LoadingExtensions.cs +++ /dev/null @@ -1,334 +0,0 @@ -/* -* Copyright (c) 2022 Vaughn Nugent -* -* Library: VNLib -* Package: VNLib.Plugins.Extensions.Loading -* File: LoadingExtensions.cs -* -* LoadingExtensions.cs is part of VNLib.Plugins.Extensions.Loading which is part of the larger -* VNLib collection of libraries and utilities. -* -* VNLib.Plugins.Extensions.Loading is free software: you can redistribute it and/or modify -* it under the terms of the GNU General Public License as published -* by the Free Software Foundation, either version 2 of the License, -* or (at your option) any later version. -* -* VNLib.Plugins.Extensions.Loading is distributed in the hope that it will be useful, -* but WITHOUT ANY WARRANTY; without even the implied warranty of -* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -* General Public License for more details. -* -* You should have received a copy of the GNU General Public License -* along with VNLib.Plugins.Extensions.Loading. If not, see http://www.gnu.org/licenses/. -*/ - -using System; -using System.IO; -using System.Linq; -using System.Text.Json; -using System.Threading.Tasks; -using System.Collections.Generic; -using System.Security.Cryptography; -using System.Runtime.CompilerServices; - -using VNLib.Utils; -using VNLib.Utils.Logging; -using VNLib.Utils.Extensions; -using VNLib.Plugins.Essentials.Accounts; - -namespace VNLib.Plugins.Extensions.Loading -{ - /// <summary> - /// Provides common loading (and unloading when required) extensions for plugins - /// </summary> - public static class LoadingExtensions - { - public const string DEBUG_CONFIG_KEY = "debug"; - public const string SECRETS_CONFIG_KEY = "secrets"; - public const string PASSWORD_HASHING_KEY = "passwords"; - - /* - * Plugin local cache used for storing singletons for a plugin instance - */ - private static readonly ConditionalWeakTable<PluginBase, PluginLocalCache> _localCache = new(); - - /// <summary> - /// Gets a previously cached service singleton for the desired plugin - /// </summary> - /// <param name="serviceType">The service instance type</param> - /// <param name="plugin">The plugin to obtain or build the singleton for</param> - /// <param name="serviceFactory">The method to produce the singleton</param> - /// <returns>The cached or newly created singleton</returns> - public static object GetOrCreateSingleton(PluginBase plugin, Type serviceType, Func<PluginBase, object> serviceFactory) - { - Lazy<object>? service; - //Get local cache - PluginLocalCache pc = _localCache.GetValue(plugin, PluginLocalCache.Create); - //Hold lock while get/set the singleton - lock (pc.SyncRoot) - { - //Check if service already exists - service = pc.GetService(serviceType); - //publish the service if it isnt loaded yet - service ??= pc.AddService(serviceType, serviceFactory); - } - //Deferred load of the service - return service.Value; - } - - /// <summary> - /// Gets a previously cached service singleton for the desired plugin - /// or creates a new singleton instance for the plugin - /// </summary> - /// <typeparam name="T"></typeparam> - /// <param name="plugin">The plugin to obtain or build the singleton for</param> - /// <param name="serviceFactory">The method to produce the singleton</param> - /// <returns>The cached or newly created singleton</returns> - public static T GetOrCreateSingleton<T>(PluginBase plugin, Func<PluginBase, T> serviceFactory) - => (T)GetOrCreateSingleton(plugin, typeof(T), p => serviceFactory(p)!); - - - /// <summary> - /// Gets the plugins ambient <see cref="PasswordHashing"/> if loaded, or loads it if required. This class will - /// be unloaded when the plugin us unloaded. - /// </summary> - /// <param name="plugin"></param> - /// <returns>The ambient <see cref="PasswordHashing"/></returns> - /// <exception cref="OverflowException"></exception> - /// <exception cref="KeyNotFoundException"></exception> - /// <exception cref="ObjectDisposedException"></exception> - public static PasswordHashing GetPasswords(this PluginBase plugin) - { - plugin.ThrowIfUnloaded(); - //Get/load the passwords one time only - return GetOrCreateSingleton(plugin, LoadPasswords); - } - - private static PasswordHashing LoadPasswords(PluginBase plugin) - { - PasswordHashing Passwords; - //Get the global password system secret (pepper) - byte[] pepper = plugin.TryGetSecretAsync(PASSWORD_HASHING_KEY) - .ToBase64Bytes().Result ?? throw new KeyNotFoundException($"Missing required key '{PASSWORD_HASHING_KEY}' in secrets"); - - ERRNO cb(Span<byte> buffer) - { - //No longer valid peper if plugin is unloaded as its set to zero, so we need to protect it - plugin.ThrowIfUnloaded(); - - pepper.CopyTo(buffer); - return pepper.Length; - } - - //See hashing params are defined - IReadOnlyDictionary<string, JsonElement>? hashingArgs = plugin.TryGetConfig(PASSWORD_HASHING_KEY); - if (hashingArgs != null) - { - //Get hashing arguments - uint saltLen = hashingArgs["salt_len"].GetUInt32(); - uint hashLen = hashingArgs["hash_len"].GetUInt32(); - uint timeCost = hashingArgs["time_cost"].GetUInt32(); - uint memoryCost = hashingArgs["memory_cost"].GetUInt32(); - uint parallelism = hashingArgs["parallelism"].GetUInt32(); - //Load passwords - Passwords = new(cb, pepper.Length, (int)saltLen, timeCost, memoryCost, parallelism, hashLen); - } - else - { - //Init default password hashing - Passwords = new(cb, pepper.Length); - } - - //Register event to cleanup the password class - _ = plugin.RegisterForUnload(() => - { - //Zero the pepper - CryptographicOperations.ZeroMemory(pepper); - }); - //return - return Passwords; - } - - - /// <summary> - /// Loads an assembly into the current plugins AppDomain and will unload when disposed - /// or the plugin is unloaded from the host application. - /// </summary> - /// <typeparam name="T">The desired exported type to load from the assembly</typeparam> - /// <param name="plugin"></param> - /// <param name="assemblyName">The name of the assembly (ex: 'file.dll') to search for</param> - /// <param name="dirSearchOption">Directory/file search option</param> - /// <returns>The <see cref="AssemblyLoader{T}"/> managing the loaded assmbly in the current AppDomain</returns> - /// <exception cref="ArgumentNullException"></exception> - /// <exception cref="FileNotFoundException"></exception> - /// <exception cref="EntryPointNotFoundException"></exception> - public static AssemblyLoader<T> LoadAssembly<T>(this PluginBase plugin, string assemblyName, SearchOption dirSearchOption = SearchOption.AllDirectories) - { - plugin.ThrowIfUnloaded(); - _ = assemblyName ?? throw new ArgumentNullException(nameof(assemblyName)); - - //get plugin directory from config - IReadOnlyDictionary<string, JsonElement> config = plugin.GetConfig("plugins"); - string? pluginsBaseDir = config["path"].GetString(); - - /* - * This should never happen since this method can only be called from a - * plugin context, which means this path was used to load the current plugin - */ - _ = pluginsBaseDir ?? throw new ArgumentNullException("path", "No plugin path is defined for the current host configuration, this is likely a bug"); - - //Get the first file that matches the search file - string? asmFile = Directory.EnumerateFiles(pluginsBaseDir, assemblyName, dirSearchOption).FirstOrDefault(); - _ = asmFile ?? throw new FileNotFoundException($"Failed to load custom assembly {assemblyName} from plugin directory"); - - //Load the assembly - return AssemblyLoader<T>.Load(asmFile, plugin.UnloadToken); - } - - - /// <summary> - /// Determintes if the current plugin config has a debug propety set - /// </summary> - /// <param name="plugin"></param> - /// <returns>True if debug mode is enabled, false otherwise</returns> - /// <exception cref="ObjectDisposedException"></exception> - public static bool IsDebug(this PluginBase plugin) - { - plugin.ThrowIfUnloaded(); - //Check for debug element - return plugin.PluginConfig.TryGetProperty(DEBUG_CONFIG_KEY, out JsonElement dbgEl) && dbgEl.GetBoolean(); - } - - /// <summary> - /// Internal exception helper to raise <see cref="ObjectDisposedException"/> if the plugin has been unlaoded - /// </summary> - /// <param name="plugin"></param> - /// <exception cref="ObjectDisposedException"></exception> - public static void ThrowIfUnloaded(this PluginBase plugin) - { - //See if the plugin was unlaoded - if (plugin.UnloadToken.IsCancellationRequested) - { - throw new ObjectDisposedException("The plugin has been unloaded"); - } - } - - /// <summary> - /// Schedules an asynchronous callback function to run and its results will be observed - /// when the operation completes, or when the plugin is unloading - /// </summary> - /// <param name="plugin"></param> - /// <param name="asyncTask">The asynchronous operation to observe</param> - /// <param name="delayMs">An optional startup delay for the operation</param> - /// <returns>A task that completes when the deferred task completes </returns> - /// <exception cref="ObjectDisposedException"></exception> - public static async Task DeferTask(this PluginBase plugin, Func<Task> asyncTask, int delayMs = 0) - { - /* - * Motivation: - * Sometimes during plugin loading, a plugin may want to asynchronously load - * data, where the results are not required to be observed during loading, but - * should not be pending after the plugin is unloaded, as the assembly may be - * unloaded and referrences collected by the GC. - * - * So we can use the plugin's unload cancellation token to observe the results - * of a pending async operation - */ - - //Test status - plugin.ThrowIfUnloaded(); - - //Optional delay - await Task.Delay(delayMs); - - //Run on ts - Task deferred = Task.Run(asyncTask); - - //Add task to deferred list - plugin.ObserveTask(deferred); - try - { - //Await the task results - await deferred.ConfigureAwait(false); - } - catch(Exception ex) - { - //Log errors - plugin.Log.Error(ex, "Error occured while observing deferred task"); - } - finally - { - //Remove task when complete - plugin.RemoveObservedTask(deferred); - } - } - - /// <summary> - /// Registers an event to occur when the plugin is unloaded on a background thread - /// and will cause the Plugin.Unload() method to block until the event completes - /// </summary> - /// <param name="pbase"></param> - /// <param name="callback">The method to call when the plugin is unloaded</param> - /// <returns>A task that represents the registered work</returns> - /// <exception cref="ArgumentNullException"></exception> - /// <exception cref="ObjectDisposedException"></exception> - public static Task RegisterForUnload(this PluginBase pbase, Action callback) - { - //Test status - pbase.ThrowIfUnloaded(); - _ = callback ?? throw new ArgumentNullException(nameof(callback)); - - //Wait method - static async Task WaitForUnload(PluginBase pb, Action callback) - { - //Wait for unload as a task on the threadpool to avoid deadlocks - await pb.UnloadToken.WaitHandle.WaitAsync() - .ConfigureAwait(false); - - callback(); - } - - //Registaer the task to cause the plugin to wait - return pbase.DeferTask(() => WaitForUnload(pbase, callback)); - } - - - private sealed class PluginLocalCache - { - private readonly PluginBase _plugin; - - private readonly Dictionary<Type, Lazy<object>> _store; - - public object SyncRoot { get; } = new(); - - private PluginLocalCache(PluginBase plugin) - { - _plugin = plugin; - _store = new(); - //Register cleanup on unload - _ = _plugin.RegisterForUnload(() => _store.Clear()); - } - - public static PluginLocalCache Create(PluginBase plugin) => new(plugin); - - - public Lazy<object>? GetService(Type serviceType) - { - Lazy<object>? t = _store.Where(t => t.Key.IsAssignableTo(serviceType)) - .Select(static tk => tk.Value) - .FirstOrDefault(); - return t; - } - - public Lazy<object> AddService(Type serviceType, Func<PluginBase, object> factory) - { - //Get lazy loader to invoke factory outside of cache lock - Lazy<object> lazyFactory = new(() => factory(_plugin), true); - //Store lazy factory - _store.Add(serviceType, lazyFactory); - //Pass the lazy factory back - return lazyFactory; - } - } - } -} |