From b78e5d68a29c770b33ed60a840853cea4f3fa998 Mon Sep 17 00:00:00 2001
From: Kai Zhang <kaizh@fb.com>
Date: Wed, 16 Feb 2022 21:03:27 +0000
Subject: [PATCH 1/2] test API usage decorator

---
 torchvision/ops/boxes.py |  4 +++-
 torchvision/utils.py     | 15 +++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/torchvision/ops/boxes.py b/torchvision/ops/boxes.py
index 38cb4c1a836..7047db7096e 100644
--- a/torchvision/ops/boxes.py
+++ b/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.
diff --git a/torchvision/utils.py b/torchvision/utils.py
index 6d3293d103d..387b77269ea 100644
--- a/torchvision/utils.py
+++ b/torchvision/utils.py
@@ -1,6 +1,7 @@
 import math
 import pathlib
 import warnings
+from functools import wraps
 from types import FunctionType
 from typing import Any, BinaryIO, List, Optional, Tuple, Union
 
@@ -547,3 +548,17 @@ 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}")
+
+def log_api_usage_once_dec(f):
+    @wraps(f)
+    def wrapper(*args, **kwargs):
+        event = f.__module__
+        if f.__name__.endswith("__init__"):
+            # inside module instantiation
+            event += args[0].__class__.__name__
+        else:
+            event += f.__name__
+        torch._C._log_api_usage_once(event)
+        return f(*args, **kwargs)
+
+    return wrapper

From 146a2972a5b08f6d39395b51f70c72bc0d0564d6 Mon Sep 17 00:00:00 2001
From: Kai Zhang <kaizh@fb.com>
Date: Wed, 16 Feb 2022 23:42:00 +0000
Subject: [PATCH 2/2] use log api from #5424

---
 torchvision/utils.py | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/torchvision/utils.py b/torchvision/utils.py
index 387b77269ea..fa727307566 100644
--- a/torchvision/utils.py
+++ b/torchvision/utils.py
@@ -3,7 +3,7 @@
 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
@@ -549,16 +549,14 @@ def _log_api_usage_once(obj: Any) -> None:
         name = obj.__name__
     torch._C._log_api_usage_once(f"{obj.__module__}.{name}")
 
-def log_api_usage_once_dec(f):
-    @wraps(f)
+
+F = TypeVar("F", bound=Callable[..., Any])
+
+
+def log_api_usage_once_dec(fn: F) -> F:
+    @wraps(fn)
     def wrapper(*args, **kwargs):
-        event = f.__module__
-        if f.__name__.endswith("__init__"):
-            # inside module instantiation
-            event += args[0].__class__.__name__
-        else:
-            event += f.__name__
-        torch._C._log_api_usage_once(event)
-        return f(*args, **kwargs)
+        _log_api_usage_once(fn)
+        return fn(*args, **kwargs)
 
-    return wrapper
+    return cast(F, wrapper)