Kill off olm-loader

Now that Olm needs to be inited asynchronously anyway, we can just
pass the options to Olm.init(), and as long as we do that before we
start the js-sdk, we're all good.

This will means the olm js is now part of the main bundle but since
it's now just a wrapper around the wasm, this is probably faster.

Also add the directwatch flag to olm.wasm because otherwise it
doesn't seem to copy the file in watch mode...

scripts/copy-res.js

@@ -60,7 +60,7 @@ const COPY_LIST = [
     // XXX: This is tied quite heavily to the matching olm.js so it really should be
     // in the bundle dir with the js to avoid caching issues giving us wasm that
     // doesn't match our js, but I cannot find any way to get webpack to do this.
-    ["node_modules/olm/olm.wasm", "webapp"],
+    ["node_modules/olm/olm.wasm", "webapp", { directwatch: 1 }],
     ["./config.json", "webapp", { directwatch: 1 }],
 ];
 

src/vector/index.js

@@ -54,6 +54,8 @@ import SettingsStore, {SettingLevel} from "matrix-react-sdk/lib/settings/Setting
 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';
@@ -227,6 +229,20 @@ async function loadApp() {
 
     window.addEventListener('hashchange', onHashChange);
 
+    /* Start loading Olm. Note that we *don't* wait for this to load: the
+     * js-sdk will also call this and actually wait on the promise before it
+     * tries to use the library. It can be loading its wasm while the rest of
+     * the app loads though.
+     *
+     * 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.
+     */
+    Olm.init({
+        locateFile: () => 'olm.wasm',
+    });
+
     await loadLanguage();
 
     const fragparts = parseQsFromFragment(window.location);

src/vector/olm-loader.js

@@ -1,39 +0,0 @@
-/*
-Copyright 2016 OpenMarket Ltd
-Copyright 2018 New Vector Ltd
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-import olm from 'olm/olm.js';
-
-/* a very thin shim for loading olm.js: just sets the global OLM_OPTIONS and
- * requires the actual olm.js library.
- *
- * olm.js reads global.OLM_OPTIONS and defines global.Olm. The latter is fine for us,
- * but we need to prepare the former.
- *
- * We can't use webpack's definePlugin to do this, because we tell webpack not
- * to parse olm.js. We also can't put this code in index.js, because olm and
- * index.js are loaded in parallel, and we need to make sure OLM_OPTIONS is set
- * before olm.js is loaded.
- */
-
-/* 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.
- */
-global.OLM_OPTIONS = {
-    locateFile: () => 'olm.wasm',
-};

webpack.config.js

@@ -15,15 +15,6 @@ module.exports = {
 
         "mobileguide": "./src/vector/mobile_guide/index.js",
 
-        // We ship olm.js as a separate lump of javascript. This makes it get
-        // loaded via a separate <script/> tag in index.html (which loads it
-        // into the browser global `Olm`, where js-sdk expects to find it).
-        //
-        // (we should probably make js-sdk load it asynchronously at some
-        // point, so that it doesn't block the pageload, but that is a separate
-        // problem)
-        "olm": "./src/vector/olm-loader.js",
-
         // CSS themes
         "theme-light":  "./node_modules/matrix-react-sdk/res/themes/light/css/light.scss",
         "theme-dark":   "./node_modules/matrix-react-sdk/res/themes/dark/css/dark.scss",
@@ -154,12 +145,3 @@ module.exports = {
         },
     },
 };
-
-// olm is an optional dependency. Ignore it if it's not installed, to avoid a
-// scary-looking error.
-try {
-    require('olm');
-} catch (e) {
-    console.log("Olm is not installed; not shipping it");
-    delete(module.exports.entry["olm"]);
-}