refactor: Rename runtime/rt to runtime/js (#8806)

runtime/js/11_workers.js

@@ -0,0 +1,206 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+((window) => {
+  const core = window.Deno.core;
+  const { Window } = window.__bootstrap.globalInterfaces;
+  const { log } = window.__bootstrap.util;
+  const { defineEventHandler } = window.__bootstrap.webUtil;
+
+  function createWorker(
+    specifier,
+    hasSourceCode,
+    sourceCode,
+    useDenoNamespace,
+    name,
+  ) {
+    return core.jsonOpSync("op_create_worker", {
+      specifier,
+      hasSourceCode,
+      sourceCode,
+      name,
+      useDenoNamespace,
+    });
+  }
+
+  function hostTerminateWorker(id) {
+    core.jsonOpSync("op_host_terminate_worker", { id });
+  }
+
+  function hostPostMessage(id, data) {
+    core.jsonOpSync("op_host_post_message", { id }, data);
+  }
+
+  function hostGetMessage(id) {
+    return core.jsonOpAsync("op_host_get_message", { id });
+  }
+
+  const encoder = new TextEncoder();
+  const decoder = new TextDecoder();
+
+  function encodeMessage(data) {
+    const dataJson = JSON.stringify(data);
+    return encoder.encode(dataJson);
+  }
+
+  function decodeMessage(dataIntArray) {
+    const dataJson = decoder.decode(dataIntArray);
+    return JSON.parse(dataJson);
+  }
+
+  class Worker extends EventTarget {
+    #id = 0;
+    #name = "";
+    #terminated = false;
+
+    constructor(specifier, options) {
+      super();
+      const { type = "classic", name = "unknown" } = options ?? {};
+
+      if (type !== "module") {
+        throw new Error(
+          'Not yet implemented: only "module" type workers are supported',
+        );
+      }
+
+      this.#name = name;
+      const hasSourceCode = false;
+      const sourceCode = decoder.decode(new Uint8Array());
+
+      const useDenoNamespace = options ? !!options.deno : false;
+
+      const { id } = createWorker(
+        specifier,
+        hasSourceCode,
+        sourceCode,
+        useDenoNamespace,
+        options?.name,
+      );
+      this.#id = id;
+      this.#poll();
+    }
+
+    #handleMessage = (msgData) => {
+      let data;
+      try {
+        data = decodeMessage(new Uint8Array(msgData));
+      } catch (e) {
+        const msgErrorEvent = new MessageEvent("messageerror", {
+          cancelable: false,
+          data,
+        });
+        return;
+      }
+
+      const msgEvent = new MessageEvent("message", {
+        cancelable: false,
+        data,
+      });
+
+      this.dispatchEvent(msgEvent);
+    };
+
+    #handleError = (e) => {
+      const event = new ErrorEvent("error", {
+        cancelable: true,
+        message: e.message,
+        lineno: e.lineNumber ? e.lineNumber + 1 : undefined,
+        colno: e.columnNumber ? e.columnNumber + 1 : undefined,
+        filename: e.fileName,
+        error: null,
+      });
+
+      let handled = false;
+
+      this.dispatchEvent(event);
+      if (event.defaultPrevented) {
+        handled = true;
+      }
+
+      return handled;
+    };
+
+    #poll = async () => {
+      while (!this.#terminated) {
+        const event = await hostGetMessage(this.#id);
+
+        // If terminate was called then we ignore all messages
+        if (this.#terminated) {
+          return;
+        }
+
+        const type = event.type;
+
+        if (type === "terminalError") {
+          this.#terminated = true;
+          if (!this.#handleError(event.error)) {
+            if (globalThis instanceof Window) {
+              throw new Error("Unhandled error event reached main worker.");
+            } else {
+              core.jsonOpSync(
+                "op_host_unhandled_error",
+                { message: event.error.message },
+              );
+            }
+          }
+          continue;
+        }
+
+        if (type === "msg") {
+          this.#handleMessage(event.data);
+          continue;
+        }
+
+        if (type === "error") {
+          if (!this.#handleError(event.error)) {
+            if (globalThis instanceof Window) {
+              throw new Error("Unhandled error event reached main worker.");
+            } else {
+              core.jsonOpSync(
+                "op_host_unhandled_error",
+                { message: event.error.message },
+              );
+            }
+          }
+          continue;
+        }
+
+        if (type === "close") {
+          log(`Host got "close" message from worker: ${this.#name}`);
+          this.#terminated = true;
+          return;
+        }
+
+        throw new Error(`Unknown worker event: "${type}"`);
+      }
+    };
+
+    postMessage(message, transferOrOptions) {
+      if (transferOrOptions) {
+        throw new Error(
+          "Not yet implemented: `transfer` and `options` are not supported.",
+        );
+      }
+
+      if (this.#terminated) {
+        return;
+      }
+
+      hostPostMessage(this.#id, encodeMessage(message));
+    }
+
+    terminate() {
+      if (!this.#terminated) {
+        this.#terminated = true;
+        hostTerminateWorker(this.#id);
+      }
+    }
+  }
+
+  defineEventHandler(Worker.prototype, "error");
+  defineEventHandler(Worker.prototype, "message");
+  defineEventHandler(Worker.prototype, "messageerror");
+
+  window.__bootstrap.worker = {
+    Worker,
+  };
+})(this);