Merge branch 'develop' into lint

src/vector/index.js

@@ -51,6 +51,8 @@ import SettingsStore from "matrix-react-sdk/lib/settings/SettingsStore";
 import Tinter from 'matrix-react-sdk/lib/Tinter';
 import SdkConfig from "matrix-react-sdk/lib/SdkConfig";
 
+import Olm from 'olm';
+
 import rageshake from "matrix-react-sdk/lib/rageshake/rageshake";
 
 import CallHandler from 'matrix-react-sdk/lib/CallHandler';
@@ -226,6 +228,8 @@ async function loadApp() {
 
     window.addEventListener('hashchange', onHashChange);
 
+    await loadOlm();
+
     await loadLanguage();
 
     const fragparts = parseQsFromFragment(window.location);
@@ -358,6 +362,42 @@ async function loadApp() {
     }
 }
 
+function loadOlm() {
+    /* Load Olm. We try the WebAssembly version first, and then the legacy,
+     * asm.js version if that fails. For this reason we need to wait for this
+     * to finish before continuing to load the rest of the app. In future
+     * we could somehow pass a promise down to react-sdk and have it wait on
+     * that so olm can be loading in parallel with the rest of the app.
+     *
+     * We also need to tell the Olm js to look for its wasm file at the same
+     * level as index.html. It really should be in the same place as the js,
+     * ie. in the bundle directory, to avoid caching issues, but as far as I
+     * can tell this is completely impossible with webpack.
+     */
+    return Olm.init({
+        locateFile: () => 'olm.wasm',
+    }).then(() => {
+        console.log("Using WebAssembly Olm");
+    }).catch((e) => {
+        console.log("Failed to load Olm: trying legacy version");
+        return new Promise((resolve, reject) => {
+            const s = document.createElement('script');
+            s.src = 'olm_legacy.js';
+            s.onload = resolve;
+            s.onerror = reject;
+            document.body.appendChild(s);
+        }).then(() => {
+            // Init window.Olm, ie. the one just loaded by the script tag,
+            // not 'Olm' which is still the failed wasm version.
+            return window.Olm.init();
+        }).then(() => {
+            console.log("Using legacy Olm");
+        }).catch((e) => {
+            console.log("Both WebAssembly and asm.js Olm failed!", e);
+        });
+    });
+}
+
 async function loadLanguage() {
     const prefLang = SettingsStore.getValue("language", null, /*excludeDefault=*/true);
     let langs = [];