Module server 

WebSocket dev server.

whisker run opens a TCP listener, exposes a single GET /whisker-dev route that upgrades to WebSocket, and pushes patch messages to every connected client. The on-device whisker-dev-runtime is the canonical client.

Wire format

Two frame types:

Patches — binary frames laid out as:

[8 bytes: u64 BE — JSON header length]
[N bytes:        JSON header { "kind": "patch", "table": {...} } ]
[rest:           raw patch dylib bytes (no encoding) ]

No base64. The dylib lands on the device with the original byte count, ~30 % smaller on the wire than the previous JSON-with- base64-string protocol.

Hello — text frame, {"kind":"hello","aslr_reference":<u64>}. The device sends this on connect; the server stores the value and the patcher uses it to compute the ASLR slide.

Architecture

A single tokio::sync::broadcast channel: every connected socket has its own subscriber receiver, so one PatchSender::send reaches all clients. New connections see only payloads sent after they subscribe — the receiver is at the tail end of the broadcast buffer, not replayed.

Modules

wire_jump_table

Shared serde adapter used by whisker-dev-runtime::hot_reload too — both sides must agree on the JSON shape. Kept inline (not a shared crate) because the type is tiny and the duplication burden is one ~30-line module.

Structs

Patch

Cheap-to-clone broadcast payload. The dylib bytes are held by Arc so cloning into each subscribed client’s receive queue is just a refcount bump.

PatchSender

Cheap-to-clone handle for sending patches from the rest of the dev server (file watcher / builder / etc.) to every connected client.

Functions

serve

Bind on addr, spawn the axum server on the current tokio runtime, and return: