From 16576a566debbbc1e6afe8e7a39e71dd6704fa46 Mon Sep 17 00:00:00 2001
From: Nathan Bierema <nbierema@gmail.com>
Date: Sun, 4 Aug 2024 12:41:15 -0400
Subject: [PATCH] Split messages sent to devpanel

---
 .../src/background/store/apiMiddleware.ts     | 63 +++++++++++++++++--
 extension/src/contentScript/index.ts          |  1 +
 extension/src/devpanel/index.tsx              | 37 ++++++++++-
 3 files changed, 93 insertions(+), 8 deletions(-)

diff --git a/extension/src/background/store/apiMiddleware.ts b/extension/src/background/store/apiMiddleware.ts
index 480f6682..8e487582 100644
--- a/extension/src/background/store/apiMiddleware.ts
+++ b/extension/src/background/store/apiMiddleware.ts
@@ -229,21 +229,72 @@ type MonitorAction<S, A extends Action<string>> =
   | UpdateStateAction<S, A>
   | SetPersistAction;
 
+// Chrome message limit is 64 MB, but we're using 32 MB to include other object's parts
+const maxChromeMsgSize = 32 * 1024 * 1024;
+
 function toMonitors<S, A extends Action<string>>(
   action: MonitorAction<S, A>,
   tabId?: string | number,
   verbose?: boolean,
 ) {
-  Object.keys(connections.monitor).forEach((id) => {
-    connections.monitor[id].postMessage(
+  for (const monitorPort of Object.values(connections.monitor)) {
+    monitorPort.postMessage(
       verbose || action.type === 'ERROR' || action.type === SET_PERSIST
         ? action
         : { type: UPDATE_STATE },
     );
-  });
-  Object.keys(connections.panel).forEach((id) => {
-    connections.panel[id].postMessage(action);
-  });
+  }
+
+  for (const panelPort of Object.values(connections.panel)) {
+    try {
+      panelPort.postMessage(action);
+    } catch (err) {
+      if (
+        action.type !== UPDATE_STATE ||
+        err == null ||
+        (err as Error).message !==
+          'Message length exceeded maximum allowed length.'
+      ) {
+        throw err;
+      }
+
+      const splitMessageStart = { split: 'start' };
+      const toSplit: [string, string][] = [];
+      let size = 0;
+      for (const [key, value] of Object.entries(
+        action.request as unknown as Record<string, unknown>,
+      )) {
+        if (typeof value === 'string') {
+          size += value.length;
+          if (size > maxChromeMsgSize) {
+            toSplit.push([key, value]);
+            continue;
+          }
+        }
+
+        splitMessageStart[key] = value;
+      }
+
+      panelPort.postMessage({ ...action, request: splitMessageStart });
+
+      for (let i = 0; i < toSplit.length; i++) {
+        for (let j = 0; j < toSplit[i][1].length; j += maxChromeMsgSize) {
+          panelPort.postMessage({
+            ...action,
+            request: {
+              split: 'chunk',
+              chunk: [
+                toSplit[i][0],
+                toSplit[i][1].substring(j, j + maxChromeMsgSize),
+              ],
+            },
+          });
+        }
+      }
+
+      panelPort.postMessage({ ...action, request: { split: 'end' } });
+    }
+  }
 }
 
 interface ImportMessage {
diff --git a/extension/src/contentScript/index.ts b/extension/src/contentScript/index.ts
index b9894ab3..123bd3a3 100644
--- a/extension/src/contentScript/index.ts
+++ b/extension/src/contentScript/index.ts
@@ -16,6 +16,7 @@ import {
   DispatchAction as AppDispatchAction,
 } from '@redux-devtools/app';
 import { LiftedState } from '@redux-devtools/instrument';
+
 const source = '@devtools-extension';
 const pageSource = '@devtools-page';
 // Chrome message limit is 64 MB, but we're using 32 MB to include other object's parts
diff --git a/extension/src/devpanel/index.tsx b/extension/src/devpanel/index.tsx
index 546aa3a6..e894c2a9 100644
--- a/extension/src/devpanel/index.tsx
+++ b/extension/src/devpanel/index.tsx
@@ -3,7 +3,11 @@ import React, { CSSProperties, ReactNode } from 'react';
 import { createRoot, Root } from 'react-dom/client';
 import { Provider } from 'react-redux';
 import { Persistor } from 'redux-persist';
-import { REMOVE_INSTANCE, StoreAction } from '@redux-devtools/app';
+import {
+  REMOVE_INSTANCE,
+  StoreAction,
+  UPDATE_STATE,
+} from '@redux-devtools/app';
 import App from '../app/App';
 import configureStore from './store/panelStore';
 
@@ -90,6 +94,8 @@ function renderNA() {
   }, 3500);
 }
 
+let splitMessage;
+
 function init(id: number) {
   renderNA();
   bgConnection = chrome.runtime.connect({
@@ -102,7 +108,34 @@ function init(id: number) {
         else store!.dispatch({ type: REMOVE_INSTANCE, id: message.id });
       } else {
         if (!rendered) renderDevTools();
-        store!.dispatch(message);
+
+        if (message.type === UPDATE_STATE && message.request.split) {
+          if (message.request.split === 'start') {
+            splitMessage = message.request;
+            return;
+          }
+
+          if (message.request.split === 'chunk') {
+            if (splitMessage[message.request.chunk[0]]) {
+              splitMessage[message.request.chunk[0]] +=
+                message.request.chunk[1];
+            } else {
+              splitMessage[message.request.chunk[0]] = message.request.chunk[1];
+            }
+            return;
+          }
+
+          if (message.request.split === 'end') {
+            store!.dispatch({ ...message, request: splitMessage });
+            return;
+          }
+
+          throw new Error(
+            `Unable to process split message with type: ${message.request.split}`,
+          );
+        } else {
+          store!.dispatch(message);
+        }
       }
     },
   );