FlipperBackgroundPlugin

Summary:
Adds a new type of plugin: `FlipperBackgroundPlugin`
Background plugins are not torn down when the user switches to another plugin so they keep receiving messages in the background.

Background plugins need to use persistedState to keep their data. To handle the messages received in the background they need to implement a static method that merges a message with the current state from redux. The plugin doesn't need to call this method itself, it is called from `client.js`.

```static persistedStateReducer = (
    persistedState: PersistedState,
    data: Object,
  ): PersistedState
```

This method is used to handle messages in both foreground and background.

Reviewed By: danielbuechele

Differential Revision: D10256305

fbshipit-source-id: d86da9caa1b75178841a9a347eb427112141eaa3

src/Client.js

@@ -8,6 +8,7 @@
 import type {FlipperPlugin} from './plugin.js';
 import type {App} from './App.js';
 import type Logger from './fb-stubs/Logger.js';
+import type {Store} from './reducers/index.js';
 
 import {clientPlugins} from './plugins/index.js';
 import {ReactiveSocket, PartialResponder} from 'rsocket-core';
@@ -32,6 +33,7 @@ export default class Client extends EventEmitter {
     query: ClientQuery,
     conn: ReactiveSocket,
     logger: Logger,
+    store: Store,
   ) {
     super();
 
@@ -42,8 +44,8 @@ export default class Client extends EventEmitter {
     this.query = query;
     this.messageIdCounter = 0;
     this.logger = logger;
+    this.store = store;
 
-    this.bufferedMessages = new Map();
     this.broadcastCallbacks = new Map();
     this.requestCallbacks = new Map();
 
@@ -77,8 +79,8 @@ export default class Client extends EventEmitter {
   plugins: Plugins;
   connection: ReactiveSocket;
   responder: PartialResponder;
+  store: Store;
 
-  bufferedMessages: Map<string, Array<Object>>;
   broadcastCallbacks: Map<?string, Map<string, Set<Function>>>;
 
   requestCallbacks: Map<
@@ -159,22 +161,41 @@ export default class Client extends EventEmitter {
         const params = data.params;
         invariant(params, 'expected params');
 
+        const persistingPlugin: ?Class<FlipperPlugin<>> = clientPlugins.find(
+          (p: Class<FlipperPlugin<>>) =>
+            p.id === params.api && p.persistedStateReducer,
+        );
+
+        if (persistingPlugin) {
+          const pluginKey = `${this.id}#${params.api}`;
+          const persistedState = this.store.getState().pluginStates[pluginKey];
+          this.store.dispatch({
+            type: 'SET_PLUGIN_STATE',
+            payload: {
+              pluginKey,
+              // $FlowFixMe: We checked persistedStateReducer exists
+              state: persistingPlugin.persistedStateReducer(
+                persistedState,
+                params.params,
+              ),
+            },
+          });
+        } else {
           const apiCallbacks = this.broadcastCallbacks.get(params.api);
           if (!apiCallbacks) {
             return;
           }
 
-        const methodCallbacks: ?Set<Function> = apiCallbacks.get(params.method);
-        if (this.selectedPlugin != params.api) {
-          this.bufferMessage(params);
-          return;
-        }
-        if (methodCallbacks && methodCallbacks.size > 0) {
+          const methodCallbacks: ?Set<Function> = apiCallbacks.get(
+            params.method,
+          );
+          if (methodCallbacks) {
             for (const callback of methodCallbacks) {
               callback(params.params);
             }
           }
         }
+      }
       return;
     }
 
@@ -194,39 +215,6 @@ export default class Client extends EventEmitter {
     }
   }
 
-  readBufferedMessages(id: string) {
-    const paramsArray = this.bufferedMessages.get(id);
-    if (!paramsArray) {
-      return;
-    }
-    paramsArray.forEach((params, i) =>
-      setTimeout(() => {
-        const apiCallbacks = this.broadcastCallbacks.get(params.api);
-        if (!apiCallbacks) {
-          return;
-        }
-
-        const methodCallbacks: ?Set<Function> = apiCallbacks.get(params.method);
-        if (methodCallbacks) {
-          for (const callback of methodCallbacks) {
-            callback(params.params);
-          }
-        }
-      }, i * 20),
-    );
-    this.bufferedMessages.delete(id);
-  }
-
-  bufferMessage(msg: Object) {
-    const arr = this.bufferedMessages.get(msg.api);
-    if (arr) {
-      arr.push(msg);
-      this.bufferedMessages.set(msg.api, arr);
-    } else {
-      this.bufferedMessages.set(msg.api, [msg]);
-    }
-  }
-
   toJSON() {
     return `<Client#${this.id}>`;
   }

src/PluginContainer.js

@@ -6,6 +6,7 @@
  */
 import type {FlipperPlugin, FlipperBasePlugin} from './plugin.js';
 import type LogManager from './fb-stubs/Logger';
+import type Client from './Client.js';
 import type BaseDevice from './devices/BaseDevice.js';
 import type {Props as PluginProps} from './plugin';
 
@@ -19,7 +20,6 @@ import {
   styled,
 } from 'flipper';
 import React from 'react';
-import Client from './Client.js';
 import {connect} from 'react-redux';
 import {setPluginState} from './reducers/pluginStates.js';
 import {setActiveNotifications} from './reducers/notifications.js';
@@ -119,9 +119,6 @@ class PluginContainer extends Component<Props, State> {
     if (ref && target) {
       activateMenuItems(ref);
       ref._init();
-      if (target instanceof Client) {
-        target.readBufferedMessages(ref.constructor.id);
-      }
       this.props.logger.trackTimeSince(`activePlugin-${ref.constructor.id}`);
       this.plugin = ref;
     }

src/__tests__/server.electron.js

@@ -7,11 +7,14 @@
 
 import Server, {SECURE_PORT, INSECURE_PORT} from '../server.js';
 import LogManager from '../fb-stubs/Logger';
+import reducers from '../reducers/index.js';
+import configureStore from 'redux-mock-store';
 import path from 'path';
 import os from 'os';
 import fs from 'fs';
 
 let server;
+const mockStore = configureStore([])(reducers(undefined, {type: 'INIT'}));
 
 beforeAll(() => {
   // create config directory, which is usually created by static/index.js
@@ -20,7 +23,7 @@ beforeAll(() => {
     fs.mkdirSync(flipperDir);
   }
 
-  server = new Server(new LogManager());
+  server = new Server(new LogManager(), mockStore);
 });
 
 test('servers starting at ports', done => {

src/dispatcher/server.js

@@ -12,13 +12,8 @@ import type Logger from '../fb-stubs/Logger.js';
 import type Client from '../Client.js';
 
 export default (store: Store, logger: Logger) => {
-  const server = new Server(logger);
-  store.subscribe(() => {
-    let currentState = store.getState();
-    currentState.connections.clients.forEach((client: Client) => {
-      client.selectedPlugin = currentState.connections.selectedPlugin;
-    });
-  });
+  const server = new Server(logger, store);
+
   server.addListener('new-client', (client: Client) => {
     store.dispatch({
       type: 'NEW_CLIENT',

src/plugin.js

@@ -113,6 +113,8 @@ export class FlipperPlugin<S = *, A = *, P = *> extends FlipperBasePlugin<
   A,
   P,
 > {
+  static persistedStateReducer: ?(persistedState: P, data: Object) => $Shape<P>;
+
   constructor(props: Props<*>) {
     super(props);
     const {id} = this.constructor;
@@ -163,6 +165,10 @@ export class FlipperPlugin<S = *, A = *, P = *> extends FlipperBasePlugin<
   }
 
   _teardown() {
+    if (this.constructor.persistedStateReducer) {
+      // do not tear down when persistedStateReducer is set
+      return;
+    }
     // automatically unsubscribe subscriptions
     for (const {method, callback} of this.subscriptions) {
       this.realClient.unsubscribe(this.constructor.id, method, callback);

src/server.js

@@ -8,6 +8,7 @@
 import type {SecureServerConfig} from './utils/CertificateProvider';
 import type Logger from './fb-stubs/Logger';
 import type {ClientQuery} from './Client.js';
+import type {Store} from './reducers/index.js';
 
 import CertificateProvider from './utils/CertificateProvider';
 import {RSocketServer, ReactiveSocket} from 'rsocket-core';
@@ -42,13 +43,15 @@ export default class Server extends EventEmitter {
   certificateProvider: CertificateProvider;
   connectionTracker: ConnectionTracker;
   logger: Logger;
+  store: Store;
 
-  constructor(logger: Logger) {
+  constructor(logger: Logger, store: Store) {
     super();
     this.logger = logger;
     this.connections = new Map();
     this.certificateProvider = new CertificateProvider(this, logger);
     this.connectionTracker = new ConnectionTracker(logger);
+    this.store = store;
     this.init();
   }
 
@@ -244,7 +247,7 @@ export default class Server extends EventEmitter {
     const id = `${query.app}-${query.os}-${query.device}-${query.device_id}`;
     console.debug(`Device connected: ${id}`, 'server');
 
-    const client = new Client(id, query, conn, this.logger);
+    const client = new Client(id, query, conn, this.logger, this.store);
 
     const info = {
       client,