347 lines
12 KiB
JavaScript
347 lines
12 KiB
JavaScript
/**
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* @license
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* Copyright 2019 Google LLC
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* SPDX-License-Identifier: Apache-2.0
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*/
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const proxyMarker = Symbol("Comlink.proxy");
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const createEndpoint = Symbol("Comlink.endpoint");
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const releaseProxy = Symbol("Comlink.releaseProxy");
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const finalizer = Symbol("Comlink.finalizer");
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const throwMarker = Symbol("Comlink.thrown");
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const isObject = (val) => (typeof val === "object" && val !== null) || typeof val === "function";
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/**
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* Internal transfer handle to handle objects marked to proxy.
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*/
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const proxyTransferHandler = {
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canHandle: (val) => isObject(val) && val[proxyMarker],
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serialize(obj) {
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const { port1, port2 } = new MessageChannel();
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expose(obj, port1);
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return [port2, [port2]];
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},
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deserialize(port) {
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port.start();
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return wrap(port);
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},
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};
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/**
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* Internal transfer handler to handle thrown exceptions.
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*/
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const throwTransferHandler = {
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canHandle: (value) => isObject(value) && throwMarker in value,
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serialize({ value }) {
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let serialized;
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if (value instanceof Error) {
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serialized = {
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isError: true,
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value: {
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message: value.message,
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name: value.name,
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stack: value.stack,
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},
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};
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}
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else {
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serialized = { isError: false, value };
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}
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return [serialized, []];
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},
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deserialize(serialized) {
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if (serialized.isError) {
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throw Object.assign(new Error(serialized.value.message), serialized.value);
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}
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throw serialized.value;
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},
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};
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/**
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* Allows customizing the serialization of certain values.
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*/
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const transferHandlers = new Map([
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["proxy", proxyTransferHandler],
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["throw", throwTransferHandler],
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]);
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function isAllowedOrigin(allowedOrigins, origin) {
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for (const allowedOrigin of allowedOrigins) {
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if (origin === allowedOrigin || allowedOrigin === "*") {
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return true;
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}
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if (allowedOrigin instanceof RegExp && allowedOrigin.test(origin)) {
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return true;
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}
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}
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return false;
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}
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function expose(obj, ep = globalThis, allowedOrigins = ["*"]) {
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ep.addEventListener("message", function callback(ev) {
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if (!ev || !ev.data) {
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return;
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}
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if (!isAllowedOrigin(allowedOrigins, ev.origin)) {
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console.warn(`Invalid origin '${ev.origin}' for comlink proxy`);
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return;
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}
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const { id, type, path } = Object.assign({ path: [] }, ev.data);
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const argumentList = (ev.data.argumentList || []).map(fromWireValue);
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let returnValue;
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try {
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const parent = path.slice(0, -1).reduce((obj, prop) => obj[prop], obj);
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const rawValue = path.reduce((obj, prop) => obj[prop], obj);
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switch (type) {
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case "GET" /* MessageType.GET */:
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{
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returnValue = rawValue;
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}
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break;
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case "SET" /* MessageType.SET */:
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{
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parent[path.slice(-1)[0]] = fromWireValue(ev.data.value);
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returnValue = true;
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}
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break;
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case "APPLY" /* MessageType.APPLY */:
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{
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returnValue = rawValue.apply(parent, argumentList);
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}
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break;
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case "CONSTRUCT" /* MessageType.CONSTRUCT */:
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{
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const value = new rawValue(...argumentList);
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returnValue = proxy(value);
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}
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break;
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case "ENDPOINT" /* MessageType.ENDPOINT */:
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{
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const { port1, port2 } = new MessageChannel();
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expose(obj, port2);
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returnValue = transfer(port1, [port1]);
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}
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break;
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case "RELEASE" /* MessageType.RELEASE */:
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{
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returnValue = undefined;
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}
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break;
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default:
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return;
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}
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}
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catch (value) {
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returnValue = { value, [throwMarker]: 0 };
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}
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Promise.resolve(returnValue)
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.catch((value) => {
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return { value, [throwMarker]: 0 };
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})
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.then((returnValue) => {
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const [wireValue, transferables] = toWireValue(returnValue);
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ep.postMessage(Object.assign(Object.assign({}, wireValue), { id }), transferables);
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if (type === "RELEASE" /* MessageType.RELEASE */) {
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// detach and deactive after sending release response above.
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ep.removeEventListener("message", callback);
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closeEndPoint(ep);
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if (finalizer in obj && typeof obj[finalizer] === "function") {
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obj[finalizer]();
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}
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}
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})
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.catch((error) => {
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// Send Serialization Error To Caller
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const [wireValue, transferables] = toWireValue({
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value: new TypeError("Unserializable return value"),
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[throwMarker]: 0,
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});
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ep.postMessage(Object.assign(Object.assign({}, wireValue), { id }), transferables);
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});
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});
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if (ep.start) {
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ep.start();
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}
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}
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function isMessagePort(endpoint) {
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return endpoint.constructor.name === "MessagePort";
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}
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function closeEndPoint(endpoint) {
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if (isMessagePort(endpoint))
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endpoint.close();
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}
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function wrap(ep, target) {
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return createProxy(ep, [], target);
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}
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function throwIfProxyReleased(isReleased) {
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if (isReleased) {
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throw new Error("Proxy has been released and is not useable");
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}
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}
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function releaseEndpoint(ep) {
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return requestResponseMessage(ep, {
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type: "RELEASE" /* MessageType.RELEASE */,
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}).then(() => {
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closeEndPoint(ep);
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});
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}
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const proxyCounter = new WeakMap();
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const proxyFinalizers = "FinalizationRegistry" in globalThis &&
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new FinalizationRegistry((ep) => {
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const newCount = (proxyCounter.get(ep) || 0) - 1;
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proxyCounter.set(ep, newCount);
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if (newCount === 0) {
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releaseEndpoint(ep);
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}
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});
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function registerProxy(proxy, ep) {
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const newCount = (proxyCounter.get(ep) || 0) + 1;
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proxyCounter.set(ep, newCount);
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if (proxyFinalizers) {
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proxyFinalizers.register(proxy, ep, proxy);
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}
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}
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function unregisterProxy(proxy) {
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if (proxyFinalizers) {
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proxyFinalizers.unregister(proxy);
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}
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}
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function createProxy(ep, path = [], target = function () { }) {
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let isProxyReleased = false;
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const proxy = new Proxy(target, {
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get(_target, prop) {
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throwIfProxyReleased(isProxyReleased);
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if (prop === releaseProxy) {
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return () => {
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unregisterProxy(proxy);
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releaseEndpoint(ep);
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isProxyReleased = true;
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};
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}
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if (prop === "then") {
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if (path.length === 0) {
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return { then: () => proxy };
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}
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const r = requestResponseMessage(ep, {
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type: "GET" /* MessageType.GET */,
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path: path.map((p) => p.toString()),
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}).then(fromWireValue);
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return r.then.bind(r);
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}
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return createProxy(ep, [...path, prop]);
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},
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set(_target, prop, rawValue) {
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throwIfProxyReleased(isProxyReleased);
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// FIXME: ES6 Proxy Handler `set` methods are supposed to return a
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// boolean. To show good will, we return true asynchronously ¯\_(ツ)_/¯
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const [value, transferables] = toWireValue(rawValue);
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return requestResponseMessage(ep, {
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type: "SET" /* MessageType.SET */,
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path: [...path, prop].map((p) => p.toString()),
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value,
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}, transferables).then(fromWireValue);
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},
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apply(_target, _thisArg, rawArgumentList) {
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throwIfProxyReleased(isProxyReleased);
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const last = path[path.length - 1];
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if (last === createEndpoint) {
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return requestResponseMessage(ep, {
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type: "ENDPOINT" /* MessageType.ENDPOINT */,
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}).then(fromWireValue);
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}
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// We just pretend that `bind()` didn’t happen.
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if (last === "bind") {
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return createProxy(ep, path.slice(0, -1));
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}
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const [argumentList, transferables] = processArguments(rawArgumentList);
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return requestResponseMessage(ep, {
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type: "APPLY" /* MessageType.APPLY */,
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path: path.map((p) => p.toString()),
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argumentList,
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}, transferables).then(fromWireValue);
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},
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construct(_target, rawArgumentList) {
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throwIfProxyReleased(isProxyReleased);
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const [argumentList, transferables] = processArguments(rawArgumentList);
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return requestResponseMessage(ep, {
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type: "CONSTRUCT" /* MessageType.CONSTRUCT */,
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path: path.map((p) => p.toString()),
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argumentList,
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}, transferables).then(fromWireValue);
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},
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});
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registerProxy(proxy, ep);
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return proxy;
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}
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function myFlat(arr) {
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return Array.prototype.concat.apply([], arr);
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}
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function processArguments(argumentList) {
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const processed = argumentList.map(toWireValue);
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return [processed.map((v) => v[0]), myFlat(processed.map((v) => v[1]))];
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}
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const transferCache = new WeakMap();
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function transfer(obj, transfers) {
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transferCache.set(obj, transfers);
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return obj;
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}
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function proxy(obj) {
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return Object.assign(obj, { [proxyMarker]: true });
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}
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function windowEndpoint(w, context = globalThis, targetOrigin = "*") {
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return {
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postMessage: (msg, transferables) => w.postMessage(msg, targetOrigin, transferables),
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addEventListener: context.addEventListener.bind(context),
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removeEventListener: context.removeEventListener.bind(context),
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};
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}
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function toWireValue(value) {
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for (const [name, handler] of transferHandlers) {
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if (handler.canHandle(value)) {
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const [serializedValue, transferables] = handler.serialize(value);
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return [
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{
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type: "HANDLER" /* WireValueType.HANDLER */,
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name,
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value: serializedValue,
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},
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transferables,
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];
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}
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}
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return [
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{
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type: "RAW" /* WireValueType.RAW */,
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value,
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},
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transferCache.get(value) || [],
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];
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}
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function fromWireValue(value) {
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switch (value.type) {
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case "HANDLER" /* WireValueType.HANDLER */:
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return transferHandlers.get(value.name).deserialize(value.value);
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case "RAW" /* WireValueType.RAW */:
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return value.value;
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}
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}
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function requestResponseMessage(ep, msg, transfers) {
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return new Promise((resolve) => {
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const id = generateUUID();
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ep.addEventListener("message", function l(ev) {
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if (!ev.data || !ev.data.id || ev.data.id !== id) {
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return;
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}
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ep.removeEventListener("message", l);
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resolve(ev.data);
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});
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if (ep.start) {
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ep.start();
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}
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ep.postMessage(Object.assign({ id }, msg), transfers);
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});
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}
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function generateUUID() {
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return new Array(4)
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.fill(0)
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.map(() => Math.floor(Math.random() * Number.MAX_SAFE_INTEGER).toString(16))
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.join("-");
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}
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export { createEndpoint, expose, finalizer, proxy, proxyMarker, releaseProxy, transfer, transferHandlers, windowEndpoint, wrap };
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//# sourceMappingURL=comlink.js.map
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