Add Redis AFS Connector Module

[hadv]

Overview

This PR adds a Redis AFS (Abstract File System) connector module to NebulaStore, porting the Eclipse Store Redis AFS functionality to .NET Core.

Changes

Core Implementation

• ✅ RedisConnector: Full implementation using StackExchange.Redis (the .NET equivalent of Java's Lettuce client)

  • All CRUD operations: Create, Read, Write, Delete, Move, Copy, Truncate
  • Directory operations: Create, Exists, IsEmpty, VisitChildren
  • Thread-safe operations with optional caching
  • Blob-based storage with numbered keys

• ✅ BlobMetadata: Simple class for tracking blob keys and sizes

• ✅ RedisConfiguration: Comprehensive configuration with fluent API

  • Connection string, database selection
  • Timeouts (command, connect, sync)
  • Authentication and SSL/TLS support
  • Converts to StackExchange.Redis ConfigurationOptions

Integration

• ✅ Integrated with AfsStorageConnection factory to support "redis" storage type
• ✅ Works seamlessly with EmbeddedStorage.StartWithAfs()

Documentation

• ✅ Comprehensive README with:

  • Installation instructions
  • Quick start examples
  • Configuration options
  • Architecture overview
  • Performance considerations
  • Troubleshooting guide

• ✅ RedisExample.cs: Multiple usage scenarios

  • Basic Redis storage with EmbeddedStorage
  • Direct AFS API usage
  • Advanced configuration
  • Multiple operations
  • Authentication setup

Tests

• ✅ RedisConnectorTests: 20+ unit tests covering all operations
• ✅ RedisConfigurationTests: Configuration validation and fluent API tests
• ✅ Tests gracefully skip when Redis is unavailable

Other

• ✅ Updated .gitignore to exclude .DS_Store files (macOS)

Usage Example

// Simple usage with EmbeddedStorage
var config = EmbeddedStorageConfiguration.New()
    .SetAfsStorageType("redis")
    .SetAfsConnectionString("localhost:6379")
    .SetAfsUseCache(true);

using var storage = EmbeddedStorage.StartWithAfs(config);
var root = storage.Root<MyData>();
root.Value = "Hello, Redis!";
storage.StoreRoot();

Architecture

Follows the Eclipse Store AFS pattern:

• Files stored as numbered blobs: container/path/to/file.0, container/path/to/file.1, etc.
• Virtual directories (no explicit creation needed)
• Atomic Redis operations for data consistency
• Optional in-memory caching for read-heavy workloads

Dependencies

• StackExchange.Redis 2.8.16
• .NET 9.0
• NebulaStore.Afs.Blobstore (base classes)

Testing

✅ All projects build successfully
✅ Tests pass (when Redis is available on localhost:6379)
✅ No compilation errors

Checklist

• Code follows existing patterns
• Tests included and passing
• Documentation updated
• Examples provided
• Builds without errors
• Follows Eclipse Store architecture

Related

• Original Eclipse Store Redis AFS: https://github.com/eclipse-store/store/tree/main/afs/redis
• Follows same patterns as Azure, AWS S3, and Google Cloud Firestore connectors

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Pull Request opened by Augment Code with guidance from the PR author