Function transform

apps/cloud/src/observability/memory-metrics.ts:224–233

(chunk, controller)

  const counting = new TransformStream<unknown, unknown>({
    transform(chunk, controller) {
      const written = byteLengthOf(chunk);
      const writeAt = Date.now();
      connection.chunks += 1;
      connection.bytes += written;
      connection.lastWriteAt = writeAt;
      totalBytesForwarded += written;
      maybeEmitPeriodicSnapshot(writeAt, OTEL_MAX_SPAN_QUEUE_SIZE);
      controller.enqueue(chunk);
    },
    flush() {
      closeConnection(connection, "normal", OTEL_MAX_SPAN_QUEUE_SIZE);
    },