Add comments to the opendal packages

packages/jumpstarter-driver-opendal/jumpstarter_driver_opendal/adapter.py

@@ -13,6 +13,10 @@
 
 @dataclass(frozen=True, kw_only=True, slots=True)
 class AsyncFileStream(ObjectStream[bytes]):
+    """
+    wrapper type for opendal.AsyncFile to make it compatible with anyio streams
+    """
+
     file: AsyncFile
 
     async def send(self, item: bytes):
@@ -42,21 +46,22 @@ async def aclose(self):
 
 @dataclass(kw_only=True)
 class OpendalAdapter(ClientAdapter):
-    operator: Operator
-    path: str
-    mode: Literal["rb", "wb"] = "rb"
+    operator: Operator  # opendal.Operator for the storage backend
+    path: str  # file path in storage backend relative to the storage root
+    mode: Literal["rb", "wb"] = "rb"  # binary read or binary write mode
 
     async def __aenter__(self):
+        # if the access mode is binary read, and the storage backend supports presigned read requests
         if self.mode == "rb" and self.operator.capability().presign_read:
+            # create presigned url for the specified file with a 60 second expiration
             presigned = await self.operator.to_async_operator().presign_read(self.path, expire_second=60)
             return PresignedRequestResource(
                 headers=presigned.headers, url=presigned.url, method=presigned.method
             ).model_dump(mode="json")
+        # otherwise stream the file content from the client to the exporter
         else:
             file = await self.operator.to_async_operator().open(self.path, self.mode)
-
             self.resource = self.client.resource_async(AsyncFileStream(file=file))
-
             return await self.resource.__aenter__()
 
     async def __aexit__(self, exc_type, exc_value, traceback):

packages/jumpstarter-driver-opendal/jumpstarter_driver_opendal/driver_test.py

@@ -14,16 +14,23 @@
 def test_drivers_mock_storage_mux_fs(monkeypatch: pytest.MonkeyPatch):
     with serve(MockStorageMux()) as client:
         with TemporaryDirectory() as tempdir:
+            # original file on the client to be pushed to the exporter
             original = Path(tempdir) / "original"
+            # new file read back from the exporter to the client
             readback = Path(tempdir) / "readback"
 
-            # absolute path
+            # test accessing files with absolute path
+
+            # fill the original file with random bytes
             original.write_bytes(randbytes(1024 * 1024 * 10))
+            # write the file to the storage on the exporter
             client.write_local_file(str(original))
+            # read the storage on the exporter to a local file
             client.read_local_file(str(readback))
+            # ensure the contents are equal
             assert original.read_bytes() == readback.read_bytes()
 
-            # relative path
+            # test accessing files with relative path
             with monkeypatch.context() as m:
                 m.chdir(tempdir)
 
@@ -39,6 +46,7 @@ def test_drivers_mock_storage_mux_fs(monkeypatch: pytest.MonkeyPatch):
 
 
 def test_drivers_mock_storage_mux_http():
+    # dummy HTTP server returning static test content
     class StaticHandler(BaseHTTPRequestHandler):
         def do_HEAD(self):
             self.send_response(200)
@@ -52,11 +60,13 @@ def do_GET(self):
             self.wfile.write(b"testcontent" * 1000)
 
     with serve(MockStorageMux()) as client:
+        # start the HTTP server
         server = HTTPServer(("127.0.0.1", 8080), StaticHandler)
         server_thread = Thread(target=server.serve_forever)
         server_thread.daemon = True
         server_thread.start()
 
+        # write a remote file from the http server to the exporter
         fs = Operator("http", endpoint="http://127.0.0.1:8080")
         client.write_file(fs, "test")