create @mercuryworkshop/rpc package

Author: velzie

packages/scramjet/packages/rpc/index.ts

@@ -0,0 +1,112 @@
+type Serverbound = {
+	method1: [{ paramA: string; paramB: number }, boolean];
+	method2: [string, number];
+};
+
+type Clientbound = {
+	method1: [number];
+	method2: [boolean, string];
+};
+
+export type RpcDescription = {
+	[method: string]: [args: any, returnType: any] | [args: any] | [];
+};
+
+export type MethodsDefinition<Description extends RpcDescription, Meta> = {
+	[Method in keyof Description]: (
+		...args: Description[Method] extends [infer A, ...any[]]
+			? [Meta, A]
+			: [Meta]
+	) => Description[Method] extends [...any[], infer R]
+		? Promise<[R, Transferable[]]>
+		: Promise<void>;
+};
+
+class RpcHelper<
+	Local extends RpcDescription,
+	Remote extends RpcDescription,
+	Meta,
+> {
+	counter: number = 0;
+	promiseCallbacks: Map<
+		number,
+		{ resolve: (value: any) => void; reject: (reason?: any) => void }
+	> = new Map();
+	constructor(
+		private methods: MethodsDefinition<Local, Meta>,
+		private id: string,
+		private sendRaw: (data: any, transfer: Transferable[]) => void
+	) {}
+
+	recieve(data: any, meta: Meta) {
+		if (data === undefined || data === null || typeof data !== "object") return;
+		const dt = data[this.id];
+		if (dt === undefined || dt === null || typeof dt !== "object") return;
+
+		const type = dt.$type;
+
+		if (type === "response") {
+			const token = dt.$token;
+			const data = dt.$data;
+			const error = dt.$error;
+			const cb = this.promiseCallbacks.get(token);
+			if (!cb) return;
+			this.promiseCallbacks.delete(token);
+			if (error !== undefined) {
+				cb.reject(new Error(error));
+			} else {
+				cb.resolve(data);
+			}
+		} else if (type === "request") {
+			const method = dt.$method as keyof Local;
+			const args = dt.$args as Local[typeof method][0];
+			(this.methods[method] as any)(meta, args)
+				.then(([res, transfer]) => {
+					this.sendRaw(
+						{
+							[this.id]: {
+								$type: "response",
+								$token: dt.$token,
+								$data: res,
+							},
+						},
+						transfer
+					);
+				})
+				.catch((err: any) => {
+					this.sendRaw(
+						{
+							[this.id]: {
+								$type: "response",
+								$token: dt.$token,
+								$error: err?.toString() || "Unknown error",
+							},
+						},
+						[]
+					);
+				});
+		}
+	}
+
+	call<Method extends keyof Remote>(
+		method: Method,
+		args: Remote[Method][0],
+		transfer: Transferable[]
+	): Promise<Remote[Method][1]> {
+		let token = this.counter++;
+		return new Promise((resolve, reject) => {
+			this.promiseCallbacks.set(token, { resolve, reject });
+			this.sendRaw(
+				{
+					[this.id]: {
+						$type: "request",
+						$method: method,
+						$args: args,
+						$token: token,
+					},
+				},
+				transfer
+			);
+		});
+	}
+}

packages/scramjet/packages/rpc/package.json

@@ -0,0 +1,6 @@
+{
+	"name": "@mercuryworkshop/rpc",
+	"version": "0.0.1",
+	"type": "module",
+	"packageManager": "[email protected]"
+}

packages/scramjet/pnpm-workspace.yaml

@@ -8,3 +8,4 @@ packages:
   - "packages/libcurl-transport"
   - "packages/demo"
   - "packages/rewriter_demo"
+  - "packages/rpc"

pnpm-workspace.yaml

@@ -18,3 +18,4 @@ packages:
   - "packages/scramjet/packages/libcurl-transport"
   - "packages/scramjet/packages/demo"
   - "packages/scramjet/packages/rewriter_demo"
+  - "packages/scramjet/packages/rpc"