get "cats" up there

1 files changed, 46 insertions, 0 deletions

diff --git a/static/src/engine/debounce_publisher.ts b/static/src/engine/debounce_publisher.ts
new file mode 100644
index 0000000..8ee4bb0
--- /dev/null
+++ b/static/src/engine/debounce_publisher.ts
@@ -0,0 +1,46 @@
+export class DebouncePublisher<T> {
+  private last_event_time = Date.now();
+  private unpublished_data: T | undefined;
+  private interval_id: number | undefined;
+
+  constructor(
+    private readonly publisher: (data: T) => void | Promise<void>,
+    private readonly debounce_ms = 100,
+  ) {}
+
+  public start() {
+    if (typeof this.interval_id !== "undefined") {
+      return;
+    }
+    this.interval_id = setInterval(
+      () => this.debounce_publish(),
+      this.debounce_ms,
+    );
+  }
+
+  public stop() {
+    if (this.interval_id === null) {
+      return;
+    }
+    clearInterval(this.interval_id);
+    delete this.interval_id;
+  }
+
+  public update(data: T) {
+    this.unpublished_data = data;
+    this.debounce_publish();
+  }
+
+  private debounce_publish() {
+    if (
+      Date.now() - this.last_event_time < this.debounce_ms ||
+      typeof this.unpublished_data === "undefined"
+    ) {
+      return;
+    }
+
+    this.last_event_time = Date.now();
+    this.publisher(this.unpublished_data);
+    this.unpublished_data = undefined;
+  }
+}