def data_loader_worker()

in data_loader.py [0:0]

• 53 lines of code
• 22 McCabe index (conditional complexity)

def data_loader_worker(tasks_queue, output_queue, quit_workers_event):
    """
    Worker for the data loader.
    """
    cursor_image = cv2.imread(CURSOR_FILE, cv2.IMREAD_UNCHANGED)
    # Assume 16x16
    cursor_image = cursor_image[:16, :16, :]
    cursor_alpha = cursor_image[:, :, 3:] / 255.0
    cursor_image = cursor_image[:, :, :3]

    while True:
        task = tasks_queue.get()
        if task is None:
            break
        trajectory_id, video_path, json_path = task
        video = cv2.VideoCapture(video_path)
        # NOTE: In some recordings, the game seems to start
        #       with attack always down from the beginning, which
        #       is stuck down until player actually presses attack
        # NOTE: It is uncertain if this was the issue with the original code.
        attack_is_stuck = False
        # Scrollwheel is allowed way to change items, but this is
        # not captured by the recorder.
        # Work around this by keeping track of selected hotbar item
        # and updating "hotbar.#" actions when hotbar selection changes.
        # NOTE: It is uncertain is this was/is an issue with the contractor data
        last_hotbar = 0

        with open(json_path) as json_file:
            json_lines = json_file.readlines()
            json_data = "[" + ",".join(json_lines) + "]"
            json_data = json.loads(json_data)
        for i in range(len(json_data)):
            if quit_workers_event.is_set():
                break
            step_data = json_data[i]

            if i == 0:
                # Check if attack will be stuck down
                if step_data["mouse"]["newButtons"] == [0]:
                    attack_is_stuck = True
            elif attack_is_stuck:
                # Check if we press attack down, then it might not be stuck
                if 0 in step_data["mouse"]["newButtons"]:
                    attack_is_stuck = False
            # If still stuck, remove the action
            if attack_is_stuck:
                step_data["mouse"]["buttons"] = [button for button in step_data["mouse"]["buttons"] if button != 0]

            action, is_null_action = json_action_to_env_action(step_data)

            # Update hotbar selection
            current_hotbar = step_data["hotbar"]
            if current_hotbar != last_hotbar:
                action["hotbar.{}".format(current_hotbar + 1)] = 1
            last_hotbar = current_hotbar

            # Read frame even if this is null so we progress forward
            ret, frame = video.read()
            if ret:
                # Skip null actions as done in the VPT paper
                # NOTE: in VPT paper, this was checked _after_ transforming into agent's action-space.
                #       We do this here as well to reduce amount of data sent over.
                if is_null_action:
                    continue
                if step_data["isGuiOpen"]:
                    camera_scaling_factor = frame.shape[0] / MINEREC_ORIGINAL_HEIGHT_PX
                    cursor_x = int(step_data["mouse"]["x"] * camera_scaling_factor)
                    cursor_y = int(step_data["mouse"]["y"] * camera_scaling_factor)
                    composite_images_with_alpha(frame, cursor_image, cursor_alpha, cursor_x, cursor_y)
                cv2.cvtColor(frame, code=cv2.COLOR_BGR2RGB, dst=frame)
                frame = np.asarray(np.clip(frame, 0, 255), dtype=np.uint8)
                frame = resize_image(frame, AGENT_RESOLUTION)
                output_queue.put((trajectory_id, frame, action), timeout=QUEUE_TIMEOUT)
            else:
                print(f"Could not read frame from video {video_path}")
        video.release()
        if quit_workers_event.is_set():
            break
    # Tell that we ended
    output_queue.put(None)