1 files changed, 193 insertions, 0 deletions
diff --git a/cli/js/workers.ts b/cli/js/workers.ts
new file mode 100644
index 000000000..281fe619f
--- /dev/null
+++ b/cli/js/workers.ts
@@ -0,0 +1,193 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import * as dispatch from "./dispatch.ts";
+import { sendAsync, sendSync } from "./dispatch_json.ts";
+import { log } from "./util.ts";
+import { TextDecoder, TextEncoder } from "./text_encoding.ts";
+import { window } from "./window.ts";
+import { blobURLMap } from "./url.ts";
+import { blobBytesWeakMap } from "./blob.ts";
+
+const encoder = new TextEncoder();
+const decoder = new TextDecoder();
+
+export function encodeMessage(data: any): Uint8Array {
+  const dataJson = JSON.stringify(data);
+  return encoder.encode(dataJson);
+}
+
+export function decodeMessage(dataIntArray: Uint8Array): any {
+  const dataJson = decoder.decode(dataIntArray);
+  return JSON.parse(dataJson);
+}
+
+function createWorker(
+  specifier: string,
+  includeDenoNamespace: boolean,
+  hasSourceCode: boolean,
+  sourceCode: Uint8Array
+): number {
+  return sendSync(dispatch.OP_CREATE_WORKER, {
+    specifier,
+    includeDenoNamespace,
+    hasSourceCode,
+    sourceCode: new TextDecoder().decode(sourceCode)
+  });
+}
+
+async function hostGetWorkerClosed(rid: number): Promise<void> {
+  await sendAsync(dispatch.OP_HOST_GET_WORKER_CLOSED, { rid });
+}
+
+function hostPostMessage(rid: number, data: any): void {
+  const dataIntArray = encodeMessage(data);
+  sendSync(dispatch.OP_HOST_POST_MESSAGE, { rid }, dataIntArray);
+}
+
+async function hostGetMessage(rid: number): Promise<any> {
+  const res = await sendAsync(dispatch.OP_HOST_GET_MESSAGE, { rid });
+
+  if (res.data != null) {
+    return decodeMessage(new Uint8Array(res.data));
+  } else {
+    return null;
+  }
+}
+
+// Stuff for workers
+export const onmessage: (e: { data: any }) => void = (): void => {};
+
+export function postMessage(data: any): void {
+  const dataIntArray = encodeMessage(data);
+  sendSync(dispatch.OP_WORKER_POST_MESSAGE, {}, dataIntArray);
+}
+
+export async function getMessage(): Promise<any> {
+  log("getMessage");
+  const res = await sendAsync(dispatch.OP_WORKER_GET_MESSAGE);
+
+  if (res.data != null) {
+    return decodeMessage(new Uint8Array(res.data));
+  } else {
+    return null;
+  }
+}
+
+export let isClosing = false;
+
+export function workerClose(): void {
+  isClosing = true;
+}
+
+export async function workerMain(): Promise<void> {
+  log("workerMain");
+
+  while (!isClosing) {
+    const data = await getMessage();
+    if (data == null) {
+      log("workerMain got null message. quitting.");
+      break;
+    }
+
+    if (window["onmessage"]) {
+      const event = { data };
+      const result: void | Promise<void> = window.onmessage(event);
+      if (result && "then" in result) {
+        await result;
+      }
+    }
+
+    if (!window["onmessage"]) {
+      break;
+    }
+  }
+}
+
+export interface Worker {
+  onerror?: () => void;
+  onmessage?: (e: { data: any }) => void;
+  onmessageerror?: () => void;
+  postMessage(data: any): void;
+  closed: Promise<void>;
+}
+
+// TODO(kevinkassimo): Maybe implement reasonable web worker options?
+// eslint-disable-next-line @typescript-eslint/no-empty-interface
+export interface WorkerOptions {}
+
+/** Extended Deno Worker initialization options.
+ * `noDenoNamespace` hides global `window.Deno` namespace for
+ * spawned worker and nested workers spawned by it (default: false).
+ */
+export interface DenoWorkerOptions extends WorkerOptions {
+  noDenoNamespace?: boolean;
+}
+
+export class WorkerImpl implements Worker {
+  private readonly rid: number;
+  private isClosing = false;
+  private readonly isClosedPromise: Promise<void>;
+  public onerror?: () => void;
+  public onmessage?: (data: any) => void;
+  public onmessageerror?: () => void;
+
+  constructor(specifier: string, options?: DenoWorkerOptions) {
+    let hasSourceCode = false;
+    let sourceCode = new Uint8Array();
+
+    let includeDenoNamespace = true;
+    if (options && options.noDenoNamespace) {
+      includeDenoNamespace = false;
+    }
+    // Handle blob URL.
+    if (specifier.startsWith("blob:")) {
+      hasSourceCode = true;
+      const b = blobURLMap.get(specifier);
+      if (!b) {
+        throw new Error("No Blob associated with the given URL is found");
+      }
+      const blobBytes = blobBytesWeakMap.get(b!);
+      if (!blobBytes) {
+        throw new Error("Invalid Blob");
+      }
+      sourceCode = blobBytes!;
+    }
+
+    this.rid = createWorker(
+      specifier,
+      includeDenoNamespace,
+      hasSourceCode,
+      sourceCode
+    );
+    this.run();
+    this.isClosedPromise = hostGetWorkerClosed(this.rid);
+    this.isClosedPromise.then(
+      (): void => {
+        this.isClosing = true;
+      }
+    );
+  }
+
+  get closed(): Promise<void> {
+    return this.isClosedPromise;
+  }
+
+  postMessage(data: any): void {
+    hostPostMessage(this.rid, data);
+  }
+
+  private async run(): Promise<void> {
+    while (!this.isClosing) {
+      const data = await hostGetMessage(this.rid);
+      if (data == null) {
+        log("worker got null message. quitting.");
+        break;
+      }
+      // TODO(afinch7) stop this from eating messages before onmessage has been assigned
+      if (this.onmessage) {
+        const event = { data };
+        this.onmessage(event);
+      }
+    }
+  }
+}