wrapping experiments

api/asynccontextmanager.py

@@ -4,18 +4,27 @@ from contextlib import asynccontextmanager, contextmanager
 from io import BytesIO
 from typing import AsyncContextManager, AsyncIterator, ContextManager, Iterator
 
+from cache import AsyncLRU
+
+#
+# sync impl
+#
+
 
 def get_buf_sync() -> ContextManager[BytesIO]:
+    if getattr(get_buf_sync, "inner", None) is None:
+
         @functools.lru_cache
-    def inner() -> BytesIO:
+        def inner() -> bytes:
+            print("sync open")
             with open(__file__, "rb") as file:
-            return BytesIO(file.readline())
+                return file.readline()
+
+        setattr(get_buf_sync, "inner", inner)
 
     @contextmanager
     def ctx() -> Iterator[BytesIO]:
-        buf = inner()
-        buf.seek(0)
-        yield buf
+        yield BytesIO(get_buf_sync.inner())
 
     return ctx()
 
@@ -26,17 +35,25 @@ def main_sync() -> None:
             print(buffer.read())
 
 
+#
+# async impl
+#
+
+
 async def get_buf_async() -> AsyncContextManager[BytesIO]:
-    @functools.lru_cache
-    async def inner() -> BytesIO:
+    if getattr(get_buf_async, "inner", None) is None:
+
+        @AsyncLRU()
+        async def inner() -> bytes:
+            print("async open")
             with open(__file__, "rb") as file:
-            return BytesIO(file.readline())
+                return file.readline()
+
+        setattr(get_buf_async, "inner", inner)
 
     @asynccontextmanager
     async def ctx() -> AsyncIterator[BytesIO]:
-        buf = await inner()
-        buf.seek(0)
-        yield buf
+        yield BytesIO(await get_buf_async.inner())
 
     return ctx()