fix(core): update

ts/classes.backpressuredarray.ts

@@ -0,0 +1,62 @@
+import * as plugins from './classes.plugins.js';
+
+export class BackpressuredArray<T> {
+  public data: T[];
+  private highWaterMark: number;
+  public hasSpace = new plugins.smartrx.rxjs.Subject<'hasSpace'>();
+  private itemsAvailable = new plugins.smartrx.rxjs.Subject<'itemsAvailable'>();
+
+  constructor(highWaterMark: number = 16) {
+    this.data = [];
+    this.highWaterMark = highWaterMark;
+  }
+
+  push(item: T): boolean {
+    this.data.push(item);
+    this.itemsAvailable.next('itemsAvailable');
+    
+    const spaceAvailable = this.checkSpaceAvailable();
+    if (spaceAvailable) {
+      this.hasSpace.next('hasSpace');
+    }
+    return spaceAvailable;
+  }
+
+  shift(): T | undefined {
+    const item = this.data.shift();
+    if (this.checkSpaceAvailable()) {
+      this.hasSpace.next('hasSpace');
+    }
+    return item;
+  }
+
+  checkSpaceAvailable(): boolean {
+    return this.data.length < this.highWaterMark;
+  }
+
+  waitForSpace(): Promise<void> {
+    return new Promise<void>((resolve) => {
+      if (this.checkSpaceAvailable()) {
+        resolve();
+      } else {
+        const subscription = this.hasSpace.subscribe(() => {
+          subscription.unsubscribe();
+          resolve();
+        });
+      }
+    });
+  }
+
+  waitForItems(): Promise<void> {
+    return new Promise<void>((resolve) => {
+      if (this.data.length > 0) {
+        resolve();
+      } else {
+        const subscription = this.itemsAvailable.subscribe(() => {
+          subscription.unsubscribe();
+          resolve();
+        });
+      }
+    });
+  }
+}