CHORE refactor again (#4169)

* CHORE refactor again

* REFACTOR the `electron` plugin to improve ipcRenderer communications

* FIX typo

CHANGELOG.md

@@ -2,6 +2,7 @@
 # RxDB Changelog
 
 <!-- CHANGELOG NEWEST -->
+- REFACTOR the `electron` plugin to improve ipcRenderer communications.
 - REMOVE `is-electron` dependency.
 <!-- ADD new changes here! -->
 

examples/electron/main.js

@@ -7,6 +7,11 @@ const { exposeIpcMainRxStorage } = require('rxdb/plugins/electron');
 
 const { getDatabase } = require('./shared');
 
+/**
+ * @link https://github.com/electron/electron/issues/19775#issuecomment-834649057
+ */
+process.env['ELECTRON_DISABLE_SECURITY_WARNINGS'] = 'true';
+
 const app = electron.app;
 const BrowserWindow = electron.BrowserWindow;
 
@@ -32,7 +37,7 @@ function createWindow() {
     w.setPosition(x, y);
     windows.push(w);
 
-    // use this to debug
+    // use this to debug by automatically opening the devtools.
     // w.webContents.openDevTools();
 }
 

src/plugins/electron/rx-storage-ipc-main.ts

@@ -3,62 +3,52 @@
  * that is supposed to run inside of the electron main process
  */
 import type {
-    RxStorage,
-    RxStorageInstanceCreationParams
+    RxStorage
 } from '../../types';
-import {
-    ensureNotFalsy,
-    getFromMapOrThrow
-} from '../../util';
 import { Subject } from 'rxjs';
 import {
-    IPC_RENDERER_KEY_PREFIX,
-    IPC_RENDERER_TO_MAIN
+    IPC_RENDERER_KEY_PREFIX
 } from './electron-helper';
 import {
     exposeRxStorageMessageChannel,
+    RxMessageChannelExposeSettings,
     RxStorageMessageToRemote
 } from '../../rx-storage-message-channel';
-
 export function exposeIpcMainRxStorage<T, D>(
     args: {
         key: string;
         storage: RxStorage<T, D>;
         ipcMain: any;
     }
 ) {
-
-    const onCreateRemoteStorage$ = new Subject<{
-        port: MessagePort;
-        params: RxStorageInstanceCreationParams<any, any>;
-    }>;
-    const portByDatabaseInstanceToken = new Map<string, MessagePort>();
+    const channelId = [
+        IPC_RENDERER_KEY_PREFIX,
+        args.key,
+    ].join('|');
+    const messages$ = new Subject<RxStorageMessageToRemote>();
+    const openRenderers: Set<any> = new Set();
     args.ipcMain.on(
-        [
-            IPC_RENDERER_KEY_PREFIX,
-            'postMessage',
-            args.key,
-            'createStorageInstance'
-        ].join('|'),
-        (event: any, params: RxStorageInstanceCreationParams<any, any>) => {
-            const [port] = event.ports;
-            portByDatabaseInstanceToken.set(params.databaseInstanceToken, port);
-            onCreateRemoteStorage$.next({
-                params,
-                port
-            });
+        channelId,
+        (event: any, message: any) => {
+            openRenderers.add(event.sender);
+            if (message) {
+                messages$.next(message);
+            }
+        }
+    );
+    const send: RxMessageChannelExposeSettings['send'] = (msg) => {
+        /**
+         * TODO we could improve performance
+         * by only sending the message to the 'correct' sender
+         * and removing senders whose browser window is closed.
+         */
+        openRenderers.forEach(sender => {
+            sender.send(channelId, msg);
         });
-
+    };
     exposeRxStorageMessageChannel({
         storage: args.storage,
-        onCreateRemoteStorage$
-    });
-
-
-    args.ipcMain.on(IPC_RENDERER_TO_MAIN, (_event: any, message: RxStorageMessageToRemote) => {
-        const port = getFromMapOrThrow(portByDatabaseInstanceToken, message.instanceId);
-        ensureNotFalsy(port.onmessage as any)({
-            data: message
-        });
+        messages$,
+        send
     });
 }

src/plugins/electron/rx-storage-ipc-renderer.ts

@@ -1,18 +1,23 @@
+import { Subject } from 'rxjs';
 import {
     getRxStorageMessageChannel,
     RxStorageMessageChannel,
-    RxStorageMessageToRemote
+    RxStorageMessageChannelSettings,
+    RxStorageMessageFromRemote
 } from '../../rx-storage-message-channel';
 import type {
     RxStorageStatics
 } from '../../types';
-import { getFromMapOrThrow } from '../../util';
 import {
-    IPC_RENDERER_KEY_PREFIX,
-    IPC_RENDERER_TO_MAIN
+    IPC_RENDERER_KEY_PREFIX
 } from './electron-helper';
 
 export type RxStorageIpcRendererSettings = {
+    /**
+     * Set the same key on both sides
+     * to ensure that messages do not get mixed
+     * up when you use more then one storage.
+     */
     key: string;
     statics: RxStorageStatics;
     ipcRenderer: any;
@@ -22,38 +27,33 @@ export type RxStorageIpcRenderer = RxStorageMessageChannel;
 export function getRxStorageIpcRenderer(
     settings: RxStorageIpcRendererSettings
 ): RxStorageIpcRenderer {
+    const channelId = [
+        IPC_RENDERER_KEY_PREFIX,
+        settings.key
+    ].join('|');
 
+    const messages$ = new Subject<RxStorageMessageFromRemote>();
+    settings.ipcRenderer.on(channelId, (_event: any, message: any) => {
+        messages$.next(message);
+    });
+
+
+    settings.ipcRenderer.postMessage(
+        channelId,
+        false
+    );
+
+    const send: RxStorageMessageChannelSettings['send'] = (msg) => {
+        settings.ipcRenderer.postMessage(
+            channelId,
+            msg
+        );
+    };
     const storage = getRxStorageMessageChannel({
         name: 'ipc-renderer',
         statics: settings.statics,
-        createRemoteStorage: (
-            port,
-            params
-        ) => {
-
-            /**
-             * Electron does not allow to send messages
-             * via ports from ipcRenderer->ipcMain.
-             * Therefore we have to overwrite the port1.postMessage()
-             * so that it works over args.ipcMain.on() messages.
-             */
-            const messageChannel = getFromMapOrThrow(storage.messageChannelByPort, port);
-            const otherPort = messageChannel.port1;
-            otherPort.postMessage = function (message: RxStorageMessageToRemote) {
-                settings.ipcRenderer.send(IPC_RENDERER_TO_MAIN, message);
-            };
-
-            settings.ipcRenderer.postMessage(
-                [
-                    IPC_RENDERER_KEY_PREFIX,
-                    'postMessage',
-                    settings.key,
-                    'createStorageInstance'
-                ].join('|'),
-                params,
-                [port]
-            );
-        }
+        messages$,
+        send
     });
     return storage;
 }