Desync auto-resync — client receives and loads state #7

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pbwraith · 2026-08-25T06:03:46+02:00

pbwraith commented

2026-08-25 06:03:46 +02:00

Repo: gopher64-netplay (fork of https://github.com/gopher64/gopher64)
Context: Full scope doc at upstream analysis — see commit history. Netplay uses GGRS over WebRTC (matchbox_socket), reliable channel carries NetplayMessage { name, data } in 16KB chunks. Savestates serialize full Device via postcard + compress.

Goal: The desynced peer receives resync_state, loads it, acks, and resumes.

Background:

Reliable-channel receive path already accumulates messages in process_reliable_messages → netplay.messages map (keyed by name)
Downstream of #1, #2, #6

Acceptance:

Poll for resync_state message key during the frame loop (in process_netplay — check the loop in netplay::process_requests)
On receipt:
- Client loads state via load_savestate_from_data
- Client sends resync_ready ack
- Client calls frame reset (#5) to match the host frame (frame travels inside the state message)
- Client resumes frame loop
State must swap device AND rdp_state AND ra_state (full parity with disk savestates)
Tests: mock host → client message flow, assert client loads state and frame matches host.

Verification: cargo test.

**Repo:** gopher64-netplay (fork of https://github.com/gopher64/gopher64) **Context:** Full scope doc at upstream analysis — see commit history. Netplay uses GGRS over WebRTC (matchbox_socket), reliable channel carries `NetplayMessage { name, data }` in 16KB chunks. Savestates serialize full Device via postcard + compress. **Goal:** The desynced peer receives `resync_state`, loads it, acks, and resumes. **Background:** - Reliable-channel receive path already accumulates messages in `process_reliable_messages` → `netplay.messages` map (keyed by name) - Downstream of #1, #2, #6 **Acceptance:** - Poll for `resync_state` message key during the frame loop (in `process_netplay` — check the loop in `netplay::process_requests`) - On receipt: - Client loads state via `load_savestate_from_data` - Client sends `resync_ready` ack - Client calls frame reset (#5) to match the host frame (frame travels inside the state message) - Client resumes frame loop - State must swap device AND rdp_state AND ra_state (full parity with disk savestates) - Tests: mock host → client message flow, assert client loads state and frame matches host. **Verification:** `cargo test`.

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2026-08-25 07:49:18 +02:00

Client receives and loads full state during desync resync (#7)

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