Measure how many bytes are received per plugin

Summary:
Measure how many byte we receive per plugin, and add this to the plugin stats that are collected

Will add a graph to the flipper dashboard, and probably a small visualization in a next diff as well.

Reviewed By: priteshrnandgaonkar

Differential Revision: D20917583

fbshipit-source-id: bb341531ecf8492080af82c56e73c0ec608f7b36

desktop/app/src/Client.tsx

@@ -27,6 +27,7 @@ import {flipperRecorderAddEvent} from './utils/pluginStateRecorder';
 import {getPluginKey} from './utils/pluginUtils';
 import {processMessageLater} from './utils/messageQueue';
 import {sideEffect} from './utils/sideEffect';
+import {emitBytesReceived} from './dispatcher/tracking';
 
 type Plugins = Array<string>;
 
@@ -321,6 +322,8 @@ export default class Client extends EventEmitter {
       } else if (method === 'execute') {
         invariant(data.params, 'expected params');
         const params: Params = data.params;
+        const bytes = msg.length * 2; // string lengths are measured in UTF-16 units (not characters), so 2 bytes per char
+        emitBytesReceived(params.api, bytes);
 
         const persistingPlugin:
           | typeof FlipperPlugin
@@ -459,10 +462,15 @@ export default class Client extends EventEmitter {
                 if (!fromPlugin || this.isAcceptingMessagesFromPlugin(plugin)) {
                   const logEventName = this.getLogEventName(data);
                   this.logger.trackTimeSince(mark, logEventName);
+                  emitBytesReceived(
+                    plugin || 'unknown',
+                    payload.data.length * 2,
+                  );
                   const response: {
                     success?: Object;
                     error?: ErrorType;
                   } = JSON.parse(payload.data);
+
                   this.onResponse(response, resolve, reject);
                 }
               },

desktop/app/src/dispatcher/tracking.tsx

@@ -42,6 +42,28 @@ export type UsageSummary = {
 
 export const fpsEmitter = new EventEmitter();
 
+// var is fine, let doesn't have the correct hoisting semantics
+// eslint-disable-next-line no-var
+var bytesReceivedEmitter: EventEmitter;
+
+export function onBytesReceived(
+  callback: (plugin: string, bytes: number) => void,
+): () => void {
+  if (!bytesReceivedEmitter) {
+    bytesReceivedEmitter = new EventEmitter();
+  }
+  bytesReceivedEmitter.on('bytesReceived', callback);
+  return () => {
+    bytesReceivedEmitter.off('bytesReceived', callback);
+  };
+}
+
+export function emitBytesReceived(plugin: string, bytes: number) {
+  if (bytesReceivedEmitter) {
+    bytesReceivedEmitter.emit('bytesReceived', plugin, bytes);
+  }
+}
+
 export default (store: Store, logger: Logger) => {
   let droppedFrames: number = 0;
   let largeFrameDrops: number = 0;

desktop/app/src/utils/messageQueue.tsx

@@ -19,6 +19,7 @@ import {
 import {Idler, BaseIdler} from './Idler';
 import {pluginIsStarred, getSelectedPluginKey} from '../reducers/connections';
 import {deconstructPluginKey} from './clientUtils';
+import {onBytesReceived} from '../dispatcher/tracking';
 
 const MAX_BACKGROUND_TASK_TIME = 25;
 
@@ -28,6 +29,8 @@ type StatEntry = {
   messageCountTotal: number; // amount of message received for this plugin
   messageCountDelta: number; // amout of messages received since previous tracking tick
   maxTime: number; // maximum time spend in a single reducer call
+  bytesReceivedTotal: number; // Bytes received
+  bytesReceivedDelta: number; // Bytes received since last tick
 };
 
 const pluginBackgroundStats = new Map<string, StatEntry>();
@@ -36,9 +39,19 @@ export function resetPluginBackgroundStatsDelta() {
   pluginBackgroundStats.forEach((stat) => {
     stat.cpuTimeDelta = 0;
     stat.messageCountDelta = 0;
+    stat.bytesReceivedDelta = 0;
   });
 }
 
+onBytesReceived((plugin: string, bytes: number) => {
+  if (!pluginBackgroundStats.has(plugin)) {
+    pluginBackgroundStats.set(plugin, createEmptyStat());
+  }
+  const stat = pluginBackgroundStats.get(plugin)!;
+  stat.bytesReceivedTotal += bytes;
+  stat.bytesReceivedDelta += bytes;
+});
+
 export function getPluginBackgroundStats(): {
   cpuTime: number; // amount of ms cpu used since the last stats (typically every minute)
   byPlugin: {[plugin: string]: StatEntry};
@@ -71,6 +84,8 @@ if (window) {
             messageCountDelta,
             messageCountTotal,
             maxTime,
+            bytesReceivedTotal,
+            bytesReceivedDelta,
           },
         ]) => ({
           plugin,
@@ -79,21 +94,29 @@ if (window) {
           cpuTimeDelta,
           messageCountDelta,
           maxTime,
+          bytesReceivedTotal,
+          bytesReceivedDelta,
         }),
       ),
     );
   };
 }
 
+function createEmptyStat(): StatEntry {
+  return {
+    cpuTimeDelta: 0,
+    cpuTimeTotal: 0,
+    messageCountDelta: 0,
+    messageCountTotal: 0,
+    maxTime: 0,
+    bytesReceivedTotal: 0,
+    bytesReceivedDelta: 0,
+  };
+}
+
 function addBackgroundStat(plugin: string, cpuTime: number) {
   if (!pluginBackgroundStats.has(plugin)) {
-    pluginBackgroundStats.set(plugin, {
-      cpuTimeDelta: 0,
-      cpuTimeTotal: 0,
-      messageCountDelta: 0,
-      messageCountTotal: 0,
-      maxTime: 0,
-    });
+    pluginBackgroundStats.set(plugin, createEmptyStat());
   }
   const stat = pluginBackgroundStats.get(plugin)!;
   stat.cpuTimeDelta += cpuTime;