From 50341152811fb39b3d9b10b9328989d4da049f34 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rn-Michael=20Miehe?=
 <40151420+ldericher@users.noreply.github.com>
Date: Sat, 3 Sep 2022 15:40:46 +0000
Subject: [PATCH] wip/experiments

---
 api/ovdashboard_api/__init__.py        | 19 +++++++++++++++++++
 api/ovdashboard_api/dav_file.py        | 23 ++---------------------
 api/ovdashboard_api/routers/_common.py | 26 ++++++++++++++++----------
 3 files changed, 37 insertions(+), 31 deletions(-)

diff --git a/api/ovdashboard_api/__init__.py b/api/ovdashboard_api/__init__.py
index 66b70fc..4fa6c6e 100644
--- a/api/ovdashboard_api/__init__.py
+++ b/api/ovdashboard_api/__init__.py
@@ -1,3 +1,4 @@
+import asyncio
 import functools
 from typing import Any
 
@@ -13,11 +14,29 @@ _WEBDAV_CLIENT = WebDAVclient.Client({
 })
 
 
+def run_in_executor(f):
+    """
+    Decorator to make blocking function call asyncio compatible
+    https://stackoverflow.com/questions/41063331/how-to-use-asyncio-with-existing-blocking-library/
+    """
+
+    @functools.wraps(f)
+    def inner(*args, **kwargs):
+        loop = asyncio.get_running_loop()
+        return loop.run_in_executor(
+            None,
+            functools.partial(f, *args, **kwargs),
+        )
+
+    return inner
+
+
 @functools.lru_cache
 def webdav_resource(remote_path: Any) -> WebDAVclient.Resource:
     return _WEBDAV_CLIENT.resource(remote_path)
 
 
+@run_in_executor
 def webdav_list(remote_path: str) -> list:
     return _WEBDAV_CLIENT.list(remote_path)
 
diff --git a/api/ovdashboard_api/dav_file.py b/api/ovdashboard_api/dav_file.py
index ac966ed..5a07fe7 100644
--- a/api/ovdashboard_api/dav_file.py
+++ b/api/ovdashboard_api/dav_file.py
@@ -1,5 +1,3 @@
-import asyncio
-import functools
 import logging
 import time
 from io import BytesIO
@@ -8,28 +6,11 @@ from typing import Any, Optional
 from async_lru import alru_cache
 from webdav3.client import Resource
 
-from . import webdav_resource
+from . import run_in_executor, webdav_resource
 
 _logger = logging.getLogger(__name__)
 
 
-def _run_in_executor(f):
-    """
-    Decorator to make blocking function call asyncio compatible
-    https://stackoverflow.com/questions/41063331/how-to-use-asyncio-with-existing-blocking-library/
-    """
-
-    @functools.wraps(f)
-    def inner(*args, **kwargs):
-        loop = asyncio.get_running_loop()
-        return loop.run_in_executor(
-            None,
-            functools.partial(f, *args, **kwargs),
-        )
-
-    return inner
-
-
 def _get_ttl_hash(seconds: int = 20) -> int:
     """
     Return the same value within `seconds` time period
@@ -45,7 +26,7 @@ async def _get_buffer(
 ) -> BytesIO:
     del ttl_hash
 
-    @_run_in_executor
+    @run_in_executor
     def buffer_inner(resource: Resource) -> BytesIO:
         _logger.info(f"updating {resource}")
         print(f"updating {resource}")
diff --git a/api/ovdashboard_api/routers/_common.py b/api/ovdashboard_api/routers/_common.py
index 63f1a54..9c36bd1 100644
--- a/api/ovdashboard_api/routers/_common.py
+++ b/api/ovdashboard_api/routers/_common.py
@@ -1,6 +1,6 @@
 import re
 from dataclasses import dataclass
-from typing import Iterator
+from typing import Iterator, Protocol
 
 from fastapi import HTTPException, status
 from webdav3.exceptions import RemoteResourceNotFound
@@ -9,14 +9,20 @@ from .. import webdav_list
 from ..dav_file import DavFile
 
 
+@dataclass(frozen=True)
+class NameLister(Protocol):
+    def __call__(self) -> Iterator[str]:
+        ...
+
+
 @dataclass(frozen=True)
 class FileNameLister:
     remote_path: str
     re: re.Pattern[str]
 
-    def __call__(self) -> Iterator[str]:
+    async def __call__(self) -> Iterator[str]:
         try:
-            file_names = webdav_list(self.remote_path)
+            file_names = await webdav_list(self.remote_path)
 
             return (
                 name
@@ -29,20 +35,20 @@ class FileNameLister:
 
 
 @dataclass(frozen=True)
-class FilePrefixFinder:
-    lister: FileNameLister
+class PrefixFinder:
+    lister: NameLister
 
-    def __call__(self, prefix: str) -> Iterator[str]:
+    async def __call__(self, prefix: str) -> Iterator[str]:
         return (
             file_name
-            for file_name in self.lister()
+            for file_name in (await self.lister())
             if file_name.lower().startswith(prefix.lower())
         )
 
 
 @dataclass(frozen=True)
 class FilePrefixLoader:
-    finder: FilePrefixFinder
+    finder: PrefixFinder
 
     @property
     def responses(self) -> dict:
@@ -62,8 +68,8 @@ class FilePrefixLoader:
             },
         }
 
-    def __call__(self, prefix: str) -> DavFile:
-        file_names = list(self.finder(prefix))
+    async def __call__(self, prefix: str) -> DavFile:
+        file_names = list(await self.finder(prefix))
 
         if not (file_names):
             raise HTTPException(status_code=status.HTTP_404_NOT_FOUND)