1 files changed, 136 insertions, 0 deletions
diff --git a/packages/taler-wallet-core/src/crypto/workers/synchronousWorker.ts b/packages/taler-wallet-core/src/crypto/workers/synchronousWorker.ts
new file mode 100644
index 000000000..5327670bd
--- /dev/null
+++ b/packages/taler-wallet-core/src/crypto/workers/synchronousWorker.ts
@@ -0,0 +1,136 @@
+/*
+ This file is part of GNU Taler
+ (C) 2019 GNUnet e.V.
+
+ GNU Taler is free software; you can redistribute it and/or modify it under the
+ terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 3, or (at your option) any later version.
+
+ GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+import { CryptoImplementation } from "./cryptoImplementation";
+
+import { CryptoWorkerFactory } from "./cryptoApi";
+import { CryptoWorker } from "./cryptoWorker";
+
+/**
+ * The synchronous crypto worker produced by this factory doesn't run in the
+ * background, but actually blocks the caller until the operation is done.
+ */
+export class SynchronousCryptoWorkerFactory implements CryptoWorkerFactory {
+  startWorker(): CryptoWorker {
+    if (typeof require === "undefined") {
+      throw Error("cannot make worker, require(...) not defined");
+    }
+    return new SynchronousCryptoWorker();
+  }
+
+  getConcurrency(): number {
+    return 1;
+  }
+}
+
+/**
+ * Worker implementation that uses node subprocesses.
+ */
+export class SynchronousCryptoWorker {
+  /**
+   * Function to be called when we receive a message from the worker thread.
+   */
+  onmessage: undefined | ((m: any) => void);
+
+  /**
+   * Function to be called when we receive an error from the worker thread.
+   */
+  onerror: undefined | ((m: any) => void);
+
+  constructor() {
+    this.onerror = undefined;
+    this.onmessage = undefined;
+  }
+
+  /**
+   * Add an event listener for either an "error" or "message" event.
+   */
+  addEventListener(event: "message" | "error", fn: (x: any) => void): void {
+    switch (event) {
+      case "message":
+        this.onmessage = fn;
+        break;
+      case "error":
+        this.onerror = fn;
+        break;
+    }
+  }
+
+  private dispatchMessage(msg: any): void {
+    if (this.onmessage) {
+      this.onmessage({ data: msg });
+    }
+  }
+
+  private async handleRequest(
+    operation: string,
+    id: number,
+    args: string[],
+  ): Promise<void> {
+    const impl = new CryptoImplementation();
+
+    if (!(operation in impl)) {
+      console.error(`crypto operation '${operation}' not found`);
+      return;
+    }
+
+    let result: any;
+    try {
+      result = (impl as any)[operation](...args);
+    } catch (e) {
+      console.log("error during operation", e);
+      return;
+    }
+
+    try {
+      setTimeout(() => this.dispatchMessage({ result, id }), 0);
+    } catch (e) {
+      console.log("got error during dispatch", e);
+    }
+  }
+
+  /**
+   * Send a message to the worker thread.
+   */
+  postMessage(msg: any): void {
+    const args = msg.args;
+    if (!Array.isArray(args)) {
+      console.error("args must be array");
+      return;
+    }
+    const id = msg.id;
+    if (typeof id !== "number") {
+      console.error("RPC id must be number");
+      return;
+    }
+    const operation = msg.operation;
+    if (typeof operation !== "string") {
+      console.error("RPC operation must be string");
+      return;
+    }
+
+    this.handleRequest(operation, id, args).catch((e) => {
+      console.error("Error while handling crypto request:", e);
+    });
+  }
+
+  /**
+   * Forcibly terminate the worker thread.
+   */
+  terminate(): void {
+    // This is a no-op.
+  }
+}