godot/modules/mono/glue/GodotSharp/GodotPlugins/PluginLoadContext.cs
2023-02-04 14:35:11 +01:00

85 lines
3.4 KiB
C#

using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;
using System.Runtime.Loader;
namespace GodotPlugins
{
public class PluginLoadContext : AssemblyLoadContext
{
private readonly AssemblyDependencyResolver _resolver;
private readonly ICollection<string> _sharedAssemblies;
private readonly AssemblyLoadContext _mainLoadContext;
public string? AssemblyLoadedPath { get; private set; }
public PluginLoadContext(string pluginPath, ICollection<string> sharedAssemblies,
AssemblyLoadContext mainLoadContext, bool isCollectible)
: base(isCollectible)
{
_resolver = new AssemblyDependencyResolver(pluginPath);
_sharedAssemblies = sharedAssemblies;
_mainLoadContext = mainLoadContext;
if (string.IsNullOrEmpty(AppContext.BaseDirectory))
{
// See https://github.com/dotnet/runtime/blob/v6.0.0/src/libraries/System.Private.CoreLib/src/System/AppContext.AnyOS.cs#L17-L35
// but Assembly.Location is unavailable, because we load assemblies from memory.
string? baseDirectory = Path.GetDirectoryName(pluginPath);
if (baseDirectory != null)
{
if (!Path.EndsInDirectorySeparator(baseDirectory))
baseDirectory += Path.DirectorySeparatorChar;
// This SetData call effectively sets AppContext.BaseDirectory
// See https://github.com/dotnet/runtime/blob/v6.0.0/src/libraries/System.Private.CoreLib/src/System/AppContext.cs#L21-L25
AppDomain.CurrentDomain.SetData("APP_CONTEXT_BASE_DIRECTORY", baseDirectory);
}
else
{
// TODO: How to log from GodotPlugins? (delegate pointer?)
Console.Error.WriteLine("Failed to set AppContext.BaseDirectory. Dynamic loading of libraries may fail.");
}
}
}
protected override Assembly? Load(AssemblyName assemblyName)
{
if (assemblyName.Name == null)
return null;
if (_sharedAssemblies.Contains(assemblyName.Name))
return _mainLoadContext.LoadFromAssemblyName(assemblyName);
string? assemblyPath = _resolver.ResolveAssemblyToPath(assemblyName);
if (assemblyPath != null)
{
AssemblyLoadedPath = assemblyPath;
// Load in memory to prevent locking the file
using var assemblyFile = File.Open(assemblyPath, FileMode.Open, FileAccess.Read, FileShare.Read);
string pdbPath = Path.ChangeExtension(assemblyPath, ".pdb");
if (File.Exists(pdbPath))
{
using var pdbFile = File.Open(pdbPath, FileMode.Open, FileAccess.Read, FileShare.Read);
return LoadFromStream(assemblyFile, pdbFile);
}
return LoadFromStream(assemblyFile);
}
return null;
}
protected override IntPtr LoadUnmanagedDll(string unmanagedDllName)
{
string? libraryPath = _resolver.ResolveUnmanagedDllToPath(unmanagedDllName);
if (libraryPath != null)
return LoadUnmanagedDllFromPath(libraryPath);
return IntPtr.Zero;
}
}
}