Class IDBChatHistoryStore

ui/src/chat/chatHistory.ts:77–330

 * Stores conversations entirely in the user's browser.
 */
export class IDBChatHistoryStore implements ChatHistoryStore {
  private dbPromise: Promise<IDBPDatabase> | null = null;

  private getDB(): Promise<IDBPDatabase> {
    if (!this.dbPromise) {
      this.dbPromise = openDB(DB_NAME, DB_VERSION, {
        upgrade(db, oldVersion, _newVersion, transaction) {
          if (!db.objectStoreNames.contains(STORE_NAME)) {
            const store = db.createObjectStore(STORE_NAME, { keyPath: 'id' });
            store.createIndex('updatedAt', 'updatedAt');
            store.createIndex('projectKey', 'projectKey');
          } else if (oldVersion < 2) {
            const store = transaction.objectStore(STORE_NAME);
            if (!store.indexNames.contains('projectKey')) {
              store.createIndex('projectKey', 'projectKey');
            }
          }
          // v3: separate blob store for image attachments
          if (oldVersion < 3) {
            if (!db.objectStoreNames.contains(BLOB_STORE)) {
              const blobStore = db.createObjectStore(BLOB_STORE, {
                keyPath: 'id',
              });
              blobStore.createIndex('conversationId', 'conversationId');
            }
            // Note: we intentionally skip migrating existing inline images here.
            // Using async operations (.then/.getAll) inside the upgrade callback
            // can cause TransactionInactiveError. Inline images from before v3
            // will continue to work as-is; new images use the blob store.
          }
        },
      }).catch((err) => {
        this.dbPromise = null;
        throw err;
      });
    }
    return this.dbPromise;
  }

  /**
   * Extract blobs from messages and return stripped messages + blobs.
   */
  private stripBlobs(
    convId: string,
    messages: ChatMessage[],
  ): { stripped: ChatMessage[]; blobs: StoredBlob[] } {
    const blobs: StoredBlob[] = [];
    const stripped = messages.map((m) => {
      if (m.role !== 'user') return m;
      let result = m;

      // Strip legacy image blobs
      if (m.images?.length) {
        result = {
          ...result,
          images: m.images.map((img) => {
            if (img.dataUrl) {
              blobs.push({