[DO NOT MERGE]test API usage decorator

torchvision/ops/boxes.py

@@ -5,7 +5,7 @@
 from torch import Tensor
 from torchvision.extension import _assert_has_ops
 
-from ..utils import _log_api_usage_once
+from ..utils import _log_api_usage_once, log_api_usage_once_dec
 from ._box_convert import _box_cxcywh_to_xyxy, _box_xyxy_to_cxcywh, _box_xywh_to_xyxy, _box_xyxy_to_xywh
 
 
@@ -223,6 +223,7 @@ def _upcast(t: Tensor) -> Tensor:
         return t if t.dtype in (torch.int32, torch.int64) else t.int()
 
 
+@log_api_usage_once_dec
 def box_area(boxes: Tensor) -> Tensor:
     """
     Computes the area of a set of bounding boxes, which are specified by their
@@ -259,6 +260,7 @@ def _box_inter_union(boxes1: Tensor, boxes2: Tensor) -> Tuple[Tensor, Tensor]:
     return inter, union
 
 
+@log_api_usage_once_dec
 def box_iou(boxes1: Tensor, boxes2: Tensor) -> Tensor:
     """
     Return intersection-over-union (Jaccard index) between two sets of boxes.

torchvision/utils.py

@@ -1,8 +1,9 @@
 import math
 import pathlib
 import warnings
+from functools import wraps
 from types import FunctionType
-from typing import Any, BinaryIO, List, Optional, Tuple, Union
+from typing import Any, BinaryIO, List, Optional, Tuple, Union, TypeVar, Callable, cast
 
 import numpy as np
 import torch
@@ -547,3 +548,15 @@ def _log_api_usage_once(obj: Any) -> None:
     if isinstance(obj, FunctionType):
         name = obj.__name__
     torch._C._log_api_usage_once(f"{obj.__module__}.{name}")
+
+
+F = TypeVar("F", bound=Callable[..., Any])
+
+
+def log_api_usage_once_dec(fn: F) -> F:
+    @wraps(fn)
+    def wrapper(*args, **kwargs):
+        _log_api_usage_once(fn)
+        return fn(*args, **kwargs)
+
+    return cast(F, wrapper)