From 0b9eb7fdf100d62640dd2308eb904a2b2dbea9df Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sat, 7 Sep 2024 11:53:17 -0500
Subject: [PATCH 1/2] Optimize cython cached_property implementation

---
 yarl/_helpers_c.pyx | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/yarl/_helpers_c.pyx b/yarl/_helpers_c.pyx
index c428753d2..e6eec3754 100644
--- a/yarl/_helpers_c.pyx
+++ b/yarl/_helpers_c.pyx
@@ -1,5 +1,7 @@
 # cython: language_level=3
 
+cdef _sentinel = object()
+
 cdef class cached_property:
     """Use as a class method decorator.  It operates almost exactly like
     the Python `@property` decorator, but it puts the result of the
@@ -21,17 +23,14 @@ cdef class cached_property:
         return self.wrapped.__doc__
 
     def __get__(self, inst, owner):
-        try:
-            try:
-                return inst._cache[self.name]
-            except KeyError:
-                val = self.wrapped(inst)
-                inst._cache[self.name] = val
-                return val
-        except AttributeError:
-            if inst is None:
-                return self
-            raise
+        if inst is None:
+            return self
+        cdef dict cache = inst._cache
+        val = cache.get(self.name, _sentinel)
+        if val is _sentinel:
+            val = self.wrapped(inst)
+            cache[self.name] = val
+        return val
 
     def __set__(self, inst, value):
         raise AttributeError("cached property is read-only")

From e8eea5cabc37088cd7df74a61e326af0a216204a Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sat, 7 Sep 2024 14:37:38 -0500
Subject: [PATCH 2/2] changelog

---
 CHANGES/1122.misc.rst | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 CHANGES/1122.misc.rst

diff --git a/CHANGES/1122.misc.rst b/CHANGES/1122.misc.rst
new file mode 100644
index 000000000..a911c35e9
--- /dev/null
+++ b/CHANGES/1122.misc.rst
@@ -0,0 +1 @@
+Improved performance of the Cython ``cached_property`` implementation -- by :user:`bdraco`.