rewrite mod assembly loading (#229)

This greatly simplifies mod loading, eliminates the .cache folders by loading assemblies in memory, ensures DLLs are loaded in leaf-to-root order, and reduces log verbosity. These changes should address a range of issues, notably #221 and #226.

1 files changed, 0 insertions, 143 deletions

diff --git a/src/StardewModdingAPI/Framework/ModAssemblyLoader.cs b/src/StardewModdingAPI/Framework/ModAssemblyLoader.cs
deleted file mode 100644
index e4760398..00000000
--- a/src/StardewModdingAPI/Framework/ModAssemblyLoader.cs
+++ /dev/null
@@ -1,143 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Reflection;
-using System.Security.Cryptography;
-using Mono.Cecil;
-using Newtonsoft.Json;
-using StardewModdingAPI.AssemblyRewriters;
-using StardewModdingAPI.Framework.AssemblyRewriting;
-
-namespace StardewModdingAPI.Framework
-{
-    /// <summary>Preprocesses and loads mod assemblies.</summary>
-    internal class ModAssemblyLoader
-    {
-        /*********
-        ** Properties
-        *********/
-        /// <summary>The name of the directory containing a mod's cached data.</summary>
-        private readonly string CacheDirName;
-
-        /// <summary>Metadata for mapping assemblies to the current <see cref="Platform"/>.</summary>
-        private readonly PlatformAssemblyMap AssemblyMap;
-
-        /// <summary>Rewrites assembly types to match the current platform.</summary>
-        private readonly AssemblyTypeRewriter AssemblyTypeRewriter;
-
-        /// <summary>Encapsulates monitoring and logging.</summary>
-        private readonly IMonitor Monitor;
-
-        /// <summary>The current game platform.</summary>
-        private readonly Platform TargetPlatform;
-
-        /*********
-        ** Public methods
-        *********/
-        /// <summary>Construct an instance.</summary>
-        /// <param name="cacheDirName">The name of the directory containing a mod's cached data.</param>
-        /// <param name="targetPlatform">The current game platform.</param>
-        /// <param name="monitor">Encapsulates monitoring and logging.</param>
-        public ModAssemblyLoader(string cacheDirName, Platform targetPlatform, IMonitor monitor)
-        {
-            this.CacheDirName = cacheDirName;
-            this.TargetPlatform = targetPlatform;
-            this.Monitor = monitor;
-            this.AssemblyMap = Constants.GetAssemblyMap(targetPlatform);
-            this.AssemblyTypeRewriter = new AssemblyTypeRewriter(this.AssemblyMap, monitor);
-        }
-
-        /// <summary>Preprocess an assembly unless the cache is up to date.</summary>
-        /// <param name="assemblyPath">The assembly file path.</param>
-        /// <returns>Returns the rewrite metadata for the preprocessed assembly.</returns>
-        public RewriteResult ProcessAssemblyUnlessCached(string assemblyPath)
-        {
-            // read assembly data
-            byte[] assemblyBytes = File.ReadAllBytes(assemblyPath);
-            string hash = string.Join("", MD5.Create().ComputeHash(assemblyBytes).Select(p => p.ToString("X2")));
-
-            // get cached result if current
-            CachePaths cachePaths = this.GetCachePaths(assemblyPath);
-            {
-                CacheEntry cacheEntry = File.Exists(cachePaths.Metadata) ? JsonConvert.DeserializeObject<CacheEntry>(File.ReadAllText(cachePaths.Metadata)) : null;
-                if (cacheEntry != null && cacheEntry.IsUpToDate(cachePaths, hash, Constants.ApiVersion, this.TargetPlatform, Environment.MachineName))
-                    return new RewriteResult(assemblyPath, cachePaths, assemblyBytes, cacheEntry.Hash, cacheEntry.UseCachedAssembly, isNewerThanCache: false); // no rewrite needed
-            }
-            this.Monitor.Log($"Preprocessing {Path.GetFileName(assemblyPath)} for compatibility...", LogLevel.Trace);
-
-            // rewrite assembly
-            AssemblyDefinition assembly;
-            using (Stream readStream = new MemoryStream(assemblyBytes))
-                assembly = AssemblyDefinition.ReadAssembly(readStream);
-            bool modified = this.AssemblyTypeRewriter.RewriteAssembly(assembly);
-            using (MemoryStream outStream = new MemoryStream())
-            {
-                assembly.Write(outStream);
-                byte[] outBytes = outStream.ToArray();
-                return new RewriteResult(assemblyPath, cachePaths, outBytes, hash, useCachedAssembly: modified, isNewerThanCache: true);
-            }
-        }
-
-        /// <summary>Write rewritten assembly metadata to the cache for a mod.</summary>
-        /// <param name="results">The rewrite results.</param>
-        /// <param name="forceCacheAssemblies">Whether to write all assemblies to the cache, even if they weren't modified.</param>
-        /// <exception cref="InvalidOperationException">There are no results to write, or the results are not all for the same directory.</exception>
-        public void WriteCache(IEnumerable<RewriteResult> results, bool forceCacheAssemblies)
-        {
-            results = results.ToArray();
-
-            // get cache directory
-            if (!results.Any())
-                throw new InvalidOperationException("There are no assemblies to cache.");
-            if (results.Select(p => p.CachePaths.Directory).Distinct().Count() > 1)
-                throw new InvalidOperationException("The assemblies can't be cached together because they have different source directories.");
-            string cacheDir = results.Select(p => p.CachePaths.Directory).First();
-
-            // reset cache
-            if (Directory.Exists(cacheDir))
-                Directory.Delete(cacheDir, recursive: true);
-            Directory.CreateDirectory(cacheDir);
-
-            // cache all results
-            foreach (RewriteResult result in results)
-            {
-                CacheEntry cacheEntry = new CacheEntry(result.Hash, Constants.ApiVersion.ToString(), this.TargetPlatform, Environment.MachineName, forceCacheAssemblies || result.UseCachedAssembly);
-                File.WriteAllText(result.CachePaths.Metadata, JsonConvert.SerializeObject(cacheEntry));
-                if (forceCacheAssemblies || result.UseCachedAssembly)
-                    File.WriteAllBytes(result.CachePaths.Assembly, result.AssemblyBytes);
-            }
-        }
-
-        /// <summary>Resolve an assembly from its name.</summary>
-        /// <param name="name">The assembly name.</param>
-        /// <remarks>
-        /// This implementation returns the first loaded assembly which matches the short form of
-        /// the assembly name, to resolve assembly resolution issues when rewriting
-        /// assemblies (especially with Mono). Since this is meant to be called on <see cref="AppDomain.AssemblyResolve"/>,
-        /// the implicit assumption is that loading the exact assembly failed.
-        /// </remarks>
-        public Assembly ResolveAssembly(string name)
-        {
-            string shortName = name.Split(new[] { ',' }, 2).First(); // get simple name (without version and culture)
-            return AppDomain.CurrentDomain
-                .GetAssemblies()
-                .FirstOrDefault(p => p.GetName().Name == shortName);
-        }
-
-
-        /*********
-        ** Private methods
-        *********/
-        /// <summary>Get the cache details for an assembly.</summary>
-        /// <param name="assemblyPath">The assembly file path.</param>
-        private CachePaths GetCachePaths(string assemblyPath)
-        {
-            string fileName = Path.GetFileName(assemblyPath);
-            string dirPath = Path.Combine(Path.GetDirectoryName(assemblyPath), this.CacheDirName);
-            string cacheAssemblyPath = Path.Combine(dirPath, fileName);
-            string metadataPath = Path.Combine(dirPath, $"{fileName}.json");
-            return new CachePaths(dirPath, cacheAssemblyPath, metadataPath);
-        }
-    }
-}