1 files changed, 35 insertions, 0 deletions
diff --git a/third_party/python/aiohttp/aiohttp/_helpers.pyx b/third_party/python/aiohttp/aiohttp/_helpers.pyx
new file mode 100644
index 0000000000..665f367c5d
--- /dev/null
+++ b/third_party/python/aiohttp/aiohttp/_helpers.pyx
@@ -0,0 +1,35 @@
+cdef class reify:
+    """Use as a class method decorator.  It operates almost exactly like
+    the Python `@property` decorator, but it puts the result of the
+    method it decorates into the instance dict after the first call,
+    effectively replacing the function it decorates with an instance
+    variable.  It is, in Python parlance, a data descriptor.
+
+    """
+
+    cdef object wrapped
+    cdef object name
+
+    def __init__(self, wrapped):
+        self.wrapped = wrapped
+        self.name = wrapped.__name__
+
+    @property
+    def __doc__(self):
+        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
+
+    def __set__(self, inst, value):
+        raise AttributeError("reified property is read-only")