madbase/.trae/documents/plan_20260311_223953.md

Implement Missing Roadmap Features (Phase 2)

I will implement the key missing features from Phase 2 of the roadmap to improve compatibility with the Supabase client SDK.

1. Realtime Presence (realtime crate)

Goal: Enable user state tracking (online/offline, custom status) compatible with supabase-js.

• Dependencies: Add dashmap for thread-safe concurrent state management.
• State Management: Update RealtimeState to store presence data in memory: Arc<DashMap<Topic, DashMap<ClientID, PresenceData>>>.
• WebSocket Logic:
  • Handle presence events (join, leave, sync).
  • Implement track (user joins/updates state) and untrack (user leaves).
  • Broadcast presence_diff events to all subscribers on a topic when state changes.

2. Storage Image Transformations (storage crate)

Goal: Support on-the-fly image resizing and formatting via query parameters.

• Dependencies: Add image crate (with jpeg, png, webp support).
• Handler Update: Modify download_object to parse query parameters:
  • w / width: Target width.
  • h / height: Target height.
  • q / quality: Compression quality.
  • f / format: Output format (e.g., webp, png).
• Processing Logic:
  • If parameters are present, decode the downloaded image bytes.
  • Apply resizing (using Lanczos3 filter for quality).
  • Encode to the target format/quality.
  • Return the processed image with correct Content-Type.

Execution Steps

1. Update Dependencies: Add dashmap to realtime/Cargo.toml and image to storage/Cargo.toml.
2. Refactor Realtime: Modify RealtimeState and ws.rs to implement the Presence protocol.
3. Refactor Storage: Modify handlers.rs to implement the Image Transformation pipeline.
4. Verification: Verify compilation and basic functionality (via cargo check and manual review of the logic).