fix bug with transaction

Author: silesky

packages/signals/signals/src/core/buffer/index.ts

@@ -18,29 +18,22 @@ export interface SignalPersistentStorage {
 export class SignalStore implements SignalPersistentStorage {
   static readonly DB_NAME = 'Segment Signals Buffer'
   static readonly STORE_NAME = 'signals'
-  private signalStore: Promise<IDBPDatabase<SignalDatabase>>
-  private signalCount = 0
+  private db: Promise<IDBPDatabase<SignalDatabase>>
   private maxBufferSize: number
-
-  public length() {
-    return this.signalCount
-  }
-
   static deleteDatabase() {
     return indexedDB.deleteDatabase(SignalStore.DB_NAME)
   }
 
   constructor(settings: { maxBufferSize?: number } = {}) {
     this.maxBufferSize = settings.maxBufferSize ?? 50
-    this.signalStore = this.createSignalStore()
-    void this.initializeSignalCount()
+    this.db = this.initSignalDB()
   }
 
   private getStore() {
-    return this.signalStore
+    return this.db
   }
 
-  private async createSignalStore() {
+  private async initSignalDB() {
     const db = await openDB<SignalDatabase>(SignalStore.DB_NAME, 1, {
       upgrade(db) {
         db.createObjectStore(SignalStore.STORE_NAME, { autoIncrement: true })
@@ -50,31 +43,28 @@ export class SignalStore implements SignalPersistentStorage {
     return db
   }
 
-  private async initializeSignalCount() {
-    const store = await this.signalStore
-    this.signalCount = await store.count(SignalStore.STORE_NAME)
-    logger.debug(
-      `Signal count initialized with ${this.signalCount} signals (max: ${this.maxBufferSize})`
-    )
+  async add(signal: Signal): Promise<void> {
+    const db = await this.db
+    await this.countAndDeleteOldestIfNeeded(db, this.maxBufferSize)
+    await db.add(SignalStore.STORE_NAME, signal)
   }
 
-  async add(signal: Signal): Promise<void> {
-    const store = await this.signalStore
-    if (this.signalCount >= this.maxBufferSize) {
-      // Get the key of the oldest signal and delete it
-      const oldestKey = await store
-        .transaction(SignalStore.STORE_NAME)
-        .store.getKey(IDBKeyRange.lowerBound(0))
-      if (oldestKey !== undefined) {
-        await store.delete(SignalStore.STORE_NAME, oldestKey)
-      } else {
-        this.signalCount--
+  private async countAndDeleteOldestIfNeeded(
+    db: IDBPDatabase<SignalDatabase>,
+    maxItems: number
+  ) {
+    const transaction = db.transaction('signals', 'readwrite')
+    const store = transaction.objectStore('signals')
+    const count = await store.count()
+    if (count >= maxItems) {
+      const cursor = await store.openCursor()
+      if (cursor) {
+        await cursor.delete()
+        logger.debug('Deleted item', { count: count - 1, key: cursor.key })
       }
     }
-    await store.add(SignalStore.STORE_NAME, signal)
-    this.signalCount++
+    return await transaction.done
   }
-
   /**
    * Get list of signals from the store, with the newest signals first.
    */