RuntimePluggableClassFactory - TDS Implementation

A comprehensive .NET library for dynamic plugin loading, execution, and management with enhanced stability, type safety, and security features.

RuntimePluggableClassFactory - TDS Implementation

Overview

This document describes the complete implementation of the Technical Design Specification (TDS) for the RuntimePluggableClassFactory tool. The implementation enhances the original plugin system with dynamic loading/unloading, enhanced stability, type safety, security hardening, and comprehensive testing.

TDS Requirements Implementation Status

✅ 1. Dynamic Plugin Loading/Unloading

Requirement: Implement dynamic plugin loading and unloading capabilities using AssemblyLoadContext

Implementation:

Key Features:

✅ 2. Enhanced Stability and Error Handling

Requirement: Improve system stability with comprehensive error handling and recovery mechanisms

Implementation:

Key Features:

✅ 3. API Redesign with Type Safety

Requirement: Replace string-based approach with strongly-typed DTOs and generic interfaces

Implementation:

Key Features:

✅ 4. Security Hardening

Requirement: Implement comprehensive security validation and plugin sandboxing

Implementation:

Key Features:

✅ 5. Comprehensive Testing Strategy

Requirement: Implement thorough testing coverage across all system aspects

Implementation:

Performance Benchmarks:

Architecture Overview

Core Components

  1. Plugin Loading System
    • PluginLoadContext: Collectible AssemblyLoadContext for proper unloading
    • FilePluginLoader<T>: File-based plugin discovery and loading
    • PluginWatcher: Runtime plugin detection and monitoring
  2. Plugin Execution System
    • PluginClassFactory<T>: Core plugin factory with error handling
    • TypedPluginClassFactory<TPlugin, TInput, TOutput>: Type-safe plugin execution
    • PluginExecutionSandbox: Isolated execution environment
  3. Security System
    • IPluginSecurityValidator: Security validation interface
    • DefaultPluginSecurityValidator: Comprehensive security implementation
    • PluginSecuritySettings: Configurable security policies
  4. Type Safety System
    • ITypedPluginClass<TInput, TOutput>: Generic plugin interface
    • PluginExecutionContext: Functional execution context
    • PluginExecutionResult<T>: Strongly-typed execution results

Key Interfaces

// Core plugin interface (provides metadata only)
public interface IPluginClass
{
    IdentifierString Name { get; }
    NamespaceString Module { get; }
    string Description { get; }
    SemanticVersionNumber Version { get; }
}

// Type-safe plugin interface
public interface ITypedPluginClass<TInput, TOutput> : IPluginClass
{
    PluginExecutionResult<TOutput> Execute(IPluginExecutionContext context, TInput input);
}

// Plugin loader interface
public interface IPluginLoader<T> where T : IPluginClass
{
    Task<IEnumerable<(NamespaceString, IdentifierString, SemanticVersionNumber, string, Type)>> ListAllPossiblePluginsAsync();
    Task<IEnumerable<(NamespaceString ModuleName, IdentifierString PluginName, SemanticVersionNumber Version, string Description, Type Type)>> LoadPluginsAsync(List<(NamespaceString ModuleName, IdentifierString Name, SemanticVersionNumber Version)> allowedPlugins);
    bool UnloadPlugin(string pluginPath);
    void UnloadAllPlugins();
}

// Security validator interface
public interface IPluginSecurityValidator
{
    Task<PluginSecurityValidationResult> ValidateAssemblyAsync(string assemblyPath);
}

Usage Examples

Basic Plugin Usage

// Create plugin loader with security validation
var securityValidator = new DefaultPluginSecurityValidator(PluginSecuritySettings.CreateDefault());
var pluginLoader = new FilePluginLoader<ISpecificInterface>(pluginDirectory, securityValidator);
var pluginFactory = new PluginClassFactory<ISpecificInterface>(pluginLoader);

// Load and execute plugin
await pluginFactory.RefreshPluginsAsync();
var plugin = pluginFactory.GetInstance("MyModule", "MyPlugin");
var result = plugin.Execute("input data");

// Unload plugins when done
pluginLoader.UnloadAllPlugins();

Type-Safe Plugin Usage

// Create typed plugin factory
var typedFactory = new TypedPluginClassFactory<ITypedInterface, MyInput, MyOutput>(pluginLoader);

// Execute with strong typing
var input = new MyInput { Data = "test" };
var result = typedFactory.ExecutePlugin("MyModule", "MyPlugin", input);

if (result.Success)
{
    Console.WriteLine($"Result: {result.Data.ProcessedData}");
}

Security Configuration

// Configure security settings
var strictSettings = PluginSecuritySettings.CreateStrict();
strictSettings.MaxAssemblySizeBytes = 1024 * 1024; // 1MB limit
strictSettings.RequireDigitalSignature = true;
strictSettings.ProhibitedNamespaces.Add("System.IO");

var validator = new DefaultPluginSecurityValidator(strictSettings);

Migration Guide

From Original Implementation

  1. Plugin Interfaces: Existing IPluginClass implementations remain compatible
  2. Plugin Loading: Replace direct assembly loading with FilePluginLoader<T>
  3. Error Handling: Subscribe to error events for comprehensive error management
  4. Security: Add security validation to plugin loading process
  5. Type Safety: Optionally migrate to ITypedPluginClass<TInput, TOutput> for type safety

Breaking Changes

  1. Assembly Loading: Direct Assembly.LoadFrom() replaced with AssemblyLoadContext
  2. Plugin Discovery: Plugin enumeration now async (ListAllPossiblePluginsAsync())
  3. Error Handling: Exceptions now wrapped in events for better error management
  4. Security: Plugin loading now includes security validation by default

Performance Characteristics

Benchmarks (Validated by Performance Tests)

Operation Performance Target Actual Performance
Plugin Discovery < 5 seconds ✅ Validated
Plugin Instantiation (Avg) < 100ms ✅ Validated
Plugin Instantiation (Max) < 500ms ✅ Validated
Plugin Execution < 10ms average ✅ Validated
Concurrent Throughput > 100 exec/sec ✅ Validated
Security Validation < 500ms average ✅ Validated
Memory Growth < 50MB under load ✅ Validated
Load/Unload Cycle < 2 seconds ✅ Validated

Scalability

Security Features

Assembly-Level Security

Type-Level Security

Method-Level Security

Configurable Security Policies

Testing Coverage

Test Categories

  1. Unit Tests (RuntimeTests.cs) - 4 tests
    • Core plugin loading and execution
    • Version handling and plugin metadata
    • Basic error scenarios
  2. Stability Tests (StabilityTests.cs) - 5 tests
    • Plugin loading failure handling
    • Error event propagation
    • System recovery scenarios
  3. Unloading Tests (UnloadingTests.cs) - 2 tests
    • Individual plugin unloading
    • Bulk plugin unloading with memory cleanup
  4. Typed Plugin Tests (TypedPluginTests.cs) - 8 tests
    • Type-safe plugin discovery and execution
    • Execution context functionality
    • Async execution with timeout
  5. Security Tests (SecurityTests.cs) - 13 tests
    • Security settings configuration
    • Plugin security validation
    • Security event handling
  6. Integration Tests (IntegrationTests.cs) - 8 tests
    • End-to-end plugin workflows
    • Concurrent execution scenarios
    • Memory management validation
  7. Performance Tests (PerformanceTests.cs) - 8 tests
    • Performance benchmark validation
    • Scalability testing
    • Resource usage monitoring

Test Execution

# Run all tests
dotnet test RuntimePluggableClassFactory.Test/RuntimePluggableClassFactory.Test.csproj

# Expected result: 48 tests passing

Deployment and Integration

Prerequisites

Build and Deploy

# Clone repository
git clone https://github.com/DevelApp-ai/RuntimePluggableClassFactory.git
cd RuntimePluggableClassFactory

# Build solution
dotnet build RuntimePluggableClassFactory.sln

# Run tests
dotnet test

# Create NuGet package
dotnet pack RuntimePluggableClassFactory/RuntimePluggableClassFactory.csproj

Integration Steps

  1. Add NuGet Reference: Reference the RuntimePluggableClassFactory package
  2. Implement Plugin Interface: Create plugins implementing IPluginClass or ITypedPluginClass<TInput, TOutput>
  3. Configure Security: Set up appropriate security validation
  4. Initialize Factory: Create plugin loader and factory instances
  5. Load and Execute: Discover, load, and execute plugins
  6. Cleanup: Properly unload plugins when done

Conclusion

The TDS implementation successfully enhances the RuntimePluggableClassFactory with:

The implementation maintains backward compatibility while providing significant enhancements in functionality, security, and reliability. All TDS requirements have been fully implemented and validated through comprehensive testing.

Support and Maintenance

For questions or support, refer to the comprehensive test suite and documentation provided in this implementation.