Cache supported tags for wheels.

This fixes #3804

changelog.d/3804.change.rst

@@ -0,0 +1 @@
+Cache supported tags for wheels.

setuptools/tests/test_wheel.py

@@ -612,6 +612,7 @@ def sys_tags():
         for t in parse_tag('cp36-cp36m-manylinux1_x86_64'):
             yield t
     monkeypatch.setattr('setuptools.wheel.sys_tags', sys_tags)
+    monkeypatch.setattr('setuptools.wheel._supported_tags', None)
     assert Wheel(
         'onnxruntime-0.1.2-cp36-cp36m-manylinux1_x86_64.whl').is_compatible()
 

setuptools/wheel.py

@@ -28,6 +28,8 @@
 NAMESPACE_PACKAGE_INIT = \
     "__import__('pkg_resources').declare_namespace(__name__)\n"
 
+_supported_tags = None
+
 
 def unpack(src_dir, dst_dir):
     '''Move everything under `src_dir` to `dst_dir`, and delete the former.'''
@@ -83,10 +85,15 @@ def tags(self):
         )
 
     def is_compatible(self):
-        '''Is the wheel is compatible with the current platform?'''
-        supported_tags = set(
-            (t.interpreter, t.abi, t.platform) for t in sys_tags())
-        return next((True for t in self.tags() if t in supported_tags), False)
+        '''Is the wheel compatible with the current platform?'''
+        global _supported_tags
+        if _supported_tags is None:
+            # We calculate the supported tags only once, otherwise calling
+            # this method on thousands of wheels takes seconds instead of
+            # milliseconds.
+            _supported_tags = set(
+                (t.interpreter, t.abi, t.platform) for t in sys_tags())
+        return next((True for t in self.tags() if t in _supported_tags), False)
 
     def egg_name(self):
         return pkg_resources.Distribution(