fix: use idb for elements and app state

excalidraw-app/App.tsx

@@ -112,7 +112,9 @@ import {
 import { updateStaleImageStatuses } from "./data/FileManager";
 import {
   importFromLocalStorage,
+  importFromIndexedDB,
   importUsernameFromLocalStorage,
+  migrateFromLocalStorageToIndexedDB,
 } from "./data/localStorage";
 
 import { loadFilesFromFirebase } from "./data/firebase";
@@ -218,7 +220,15 @@ const initializeScene = async (opts: {
   );
   const externalUrlMatch = window.location.hash.match(/^#url=(.*)$/);
 
-  const localDataState = importFromLocalStorage();
+  // migrate from localStorage to IndexedDB if needed
+  await migrateFromLocalStorageToIndexedDB();
+
+  // try to load from IndexedDB first, fallback to localStorage
+  let localDataState = await importFromIndexedDB();
+  if (!localDataState.elements.length && !localDataState.appState) {
+    // fallback to localStorage if IndexedDB is empty
+    localDataState = importFromLocalStorage();
+  }
 
   let scene: RestoredDataState & {
     scrollToContent?: boolean;
@@ -504,7 +514,7 @@ const ExcalidrawWrapper = () => {
       TITLE_TIMEOUT,
     );
 
-    const syncData = debounce(() => {
+    const syncData = debounce(async () => {
       if (isTestEnv()) {
         return;
       }
@@ -514,7 +524,12 @@ const ExcalidrawWrapper = () => {
       ) {
         // don't sync if local state is newer or identical to browser state
         if (isBrowserStorageStateNewer(STORAGE_KEYS.VERSION_DATA_STATE)) {
-          const localDataState = importFromLocalStorage();
+          // try to load from IndexedDB first, fallback to localStorage
+          let localDataState = await importFromIndexedDB();
+          if (!localDataState.elements.length && !localDataState.appState) {
+            // fallback to localStorage if IndexedDB is empty
+            localDataState = importFromLocalStorage();
+          }
           const username = importUsernameFromLocalStorage();
           setLangCode(getPreferredLanguage());
           excalidrawAPI.updateScene({

excalidraw-app/CustomStats.tsx

@@ -21,11 +21,23 @@ type StorageSizes = { scene: number; total: number };
 
 const STORAGE_SIZE_TIMEOUT = 500;
 
-const getStorageSizes = debounce((cb: (sizes: StorageSizes) => void) => {
+const getStorageSizes = debounce(async (cb: (sizes: StorageSizes) => void) => {
+  try {
+    const [scene, total] = await Promise.all([
+      getElementsStorageSize(),
+      getTotalStorageSize(),
+    ]);
     cb({
-    scene: getElementsStorageSize(),
-    total: getTotalStorageSize(),
+      scene,
+      total,
     });
+  } catch (error) {
+    console.error("Failed to get storage sizes:", error);
+    cb({
+      scene: 0,
+      total: 0,
+    });
+  }
 }, STORAGE_SIZE_TIMEOUT);
 
 type Props = {

excalidraw-app/data/LocalData.ts

@@ -65,7 +65,7 @@ class LocalFileManager extends FileManager {
   };
 }
 
-const saveDataStateToLocalStorage = (
+const saveDataStateToIndexedDB = async (
   elements: readonly ExcalidrawElement[],
   appState: AppState,
 ) => {
@@ -79,17 +79,15 @@ const saveDataStateToLocalStorage = (
       _appState.openSidebar = null;
     }
 
-    localStorage.setItem(
-      STORAGE_KEYS.LOCAL_STORAGE_ELEMENTS,
-      JSON.stringify(clearElementsForLocalStorage(elements)),
-    );
-    localStorage.setItem(
-      STORAGE_KEYS.LOCAL_STORAGE_APP_STATE,
-      JSON.stringify(_appState),
-    );
+    // save to IndexedDB
+    await Promise.all([
+      ElementsIndexedDBAdapter.save(clearElementsForLocalStorage(elements)),
+      AppStateIndexedDBAdapter.save(_appState),
+    ]);
+
     updateBrowserStateVersion(STORAGE_KEYS.VERSION_DATA_STATE);
   } catch (error: any) {
-    // Unable to access window.localStorage
+    // unable to access IndexedDB
     console.error(error);
   }
 };
@@ -104,7 +102,7 @@ export class LocalData {
       files: BinaryFiles,
       onFilesSaved: () => void,
     ) => {
-      saveDataStateToLocalStorage(elements, appState);
+      await saveDataStateToIndexedDB(elements, appState);
 
       await this.fileStorage.saveFiles({
         elements,
@@ -256,3 +254,63 @@ export class LibraryLocalStorageMigrationAdapter {
     localStorage.removeItem(STORAGE_KEYS.__LEGACY_LOCAL_STORAGE_LIBRARY);
   }
 }
+
+/** IndexedDB Adapter for storing app state */
+export class AppStateIndexedDBAdapter {
+  /** IndexedDB database and store name */
+  private static idb_name = "excalidraw-app-state";
+  /** app state data store key */
+  private static key = "appStateData";
+
+  private static store = createStore(
+    `${AppStateIndexedDBAdapter.idb_name}-db`,
+    `${AppStateIndexedDBAdapter.idb_name}-store`,
+  );
+
+  static async load() {
+    const IDBData = await get<Partial<AppState>>(
+      AppStateIndexedDBAdapter.key,
+      AppStateIndexedDBAdapter.store,
+    );
+
+    return IDBData || null;
+  }
+
+  static save(data: Partial<AppState>): MaybePromise<void> {
+    return set(
+      AppStateIndexedDBAdapter.key,
+      data,
+      AppStateIndexedDBAdapter.store,
+    );
+  }
+}
+
+/** IndexedDB Adapter for storing elements */
+export class ElementsIndexedDBAdapter {
+  /** IndexedDB database and store name */
+  private static idb_name = "excalidraw-elements";
+  /** elements data store key */
+  private static key = "elementsData";
+
+  private static store = createStore(
+    `${ElementsIndexedDBAdapter.idb_name}-db`,
+    `${ElementsIndexedDBAdapter.idb_name}-store`,
+  );
+
+  static async load() {
+    const IDBData = await get<ExcalidrawElement[]>(
+      ElementsIndexedDBAdapter.key,
+      ElementsIndexedDBAdapter.store,
+    );
+
+    return IDBData || null;
+  }
+
+  static save(data: ExcalidrawElement[]): MaybePromise<void> {
+    return set(
+      ElementsIndexedDBAdapter.key,
+      data,
+      ElementsIndexedDBAdapter.store,
+    );
+  }
+}

excalidraw-app/data/localStorage.ts

@@ -9,6 +9,11 @@ import type { AppState } from "@excalidraw/excalidraw/types";
 
 import { STORAGE_KEYS } from "../app_constants";
 
+import {
+  AppStateIndexedDBAdapter,
+  ElementsIndexedDBAdapter,
+} from "./LocalData";
+
 export const saveUsernameToLocalStorage = (username: string) => {
   try {
     localStorage.setItem(
@@ -74,28 +79,146 @@ export const importFromLocalStorage = () => {
   return { elements, appState };
 };
 
-export const getElementsStorageSize = () => {
+export const importFromIndexedDB = async () => {
+  let savedElements = null;
+  let savedState = null;
+
   try {
-    const elements = localStorage.getItem(STORAGE_KEYS.LOCAL_STORAGE_ELEMENTS);
-    const elementsSize = elements?.length || 0;
-    return elementsSize;
+    savedElements = await ElementsIndexedDBAdapter.load();
+    savedState = await AppStateIndexedDBAdapter.load();
+  } catch (error: any) {
+    // unable to access IndexedDB
+    console.error(error);
+  }
+
+  let elements: ExcalidrawElement[] = [];
+  if (savedElements) {
+    try {
+      elements = clearElementsForLocalStorage(savedElements);
     } catch (error: any) {
       console.error(error);
-    return 0;
+    }
+  }
+
+  let appState = null;
+  if (savedState) {
+    try {
+      appState = {
+        ...getDefaultAppState(),
+        ...clearAppStateForLocalStorage(savedState),
+      };
+    } catch (error: any) {
+      console.error(error);
+    }
+  }
+  return { elements, appState };
+};
+
+export const migrateFromLocalStorageToIndexedDB = async () => {
+  try {
+    // check if we have data in localStorage
+    const savedElements = localStorage.getItem(
+      STORAGE_KEYS.LOCAL_STORAGE_ELEMENTS,
+    );
+    const savedState = localStorage.getItem(
+      STORAGE_KEYS.LOCAL_STORAGE_APP_STATE,
+    );
+
+    if (savedElements || savedState) {
+      // parse and migrate elements
+      if (savedElements) {
+        try {
+          const elements = JSON.parse(savedElements);
+          await ElementsIndexedDBAdapter.save(elements);
+        } catch (error) {
+          console.error("Failed to migrate elements:", error);
+        }
+      }
+
+      // parse and migrate app state
+      if (savedState) {
+        try {
+          const appState = JSON.parse(savedState);
+          await AppStateIndexedDBAdapter.save(appState);
+        } catch (error) {
+          console.error("Failed to migrate app state:", error);
+        }
+      }
+
+      // clear localStorage after successful migration
+      localStorage.removeItem(STORAGE_KEYS.LOCAL_STORAGE_ELEMENTS);
+      localStorage.removeItem(STORAGE_KEYS.LOCAL_STORAGE_APP_STATE);
+    }
+  } catch (error) {
+    console.error("Migration failed:", error);
   }
 };
 
-export const getTotalStorageSize = () => {
+/**
+ * Get the size of elements stored in IndexedDB (with localStorage fallback)
+ * @returns Promise<number> - Size in bytes
+ */
+export const getElementsStorageSize = async () => {
   try {
-    const appState = localStorage.getItem(STORAGE_KEYS.LOCAL_STORAGE_APP_STATE);
+    const elements = await ElementsIndexedDBAdapter.load();
+    if (elements) {
+      // calculate size by stringifying the data
+      const elementsString = JSON.stringify(elements);
+      return elementsString.length;
+    }
+    return 0;
+  } catch (error: any) {
+    console.error("Failed to get elements size from IndexedDB:", error);
+    // fallback to localStorage
+    try {
+      const elements = localStorage.getItem(
+        STORAGE_KEYS.LOCAL_STORAGE_ELEMENTS,
+      );
+      return elements?.length || 0;
+    } catch (localStorageError: any) {
+      console.error(
+        "Failed to get elements size from localStorage:",
+        localStorageError,
+      );
+      return 0;
+    }
+  }
+};
+
+/**
+ * Get the total size of all data stored in IndexedDB and localStorage
+ * @returns Promise<number> - Size in bytes
+ */
+export const getTotalStorageSize = async () => {
+  try {
+    const appState = await AppStateIndexedDBAdapter.load();
+    const collab = localStorage.getItem(STORAGE_KEYS.LOCAL_STORAGE_COLLAB);
+
+    const appStateSize = appState ? JSON.stringify(appState).length : 0;
+    const collabSize = collab?.length || 0;
+
+    const elementsSize = await getElementsStorageSize();
+    return appStateSize + collabSize + elementsSize;
+  } catch (error: any) {
+    console.error("Failed to get total storage size from IndexedDB:", error);
+    // fallback to localStorage
+    try {
+      const appState = localStorage.getItem(
+        STORAGE_KEYS.LOCAL_STORAGE_APP_STATE,
+      );
       const collab = localStorage.getItem(STORAGE_KEYS.LOCAL_STORAGE_COLLAB);
 
       const appStateSize = appState?.length || 0;
       const collabSize = collab?.length || 0;
 
-    return appStateSize + collabSize + getElementsStorageSize();
-  } catch (error: any) {
-    console.error(error);
+      const elementsSize = await getElementsStorageSize();
+      return appStateSize + collabSize + elementsSize;
+    } catch (localStorageError: any) {
+      console.error(
+        "Failed to get total storage size from localStorage:",
+        localStorageError,
+      );
       return 0;
     }
+  }
 };