also make shadow file ops async

Author: bollwyvl

py_src/jupyter_lsp/tests/test_virtual_documents_shadow.py

@@ -11,32 +11,46 @@
 )
 
 
-def test_read(tmp_path):
+@pytest.mark.asyncio
+async def test_read(tmp_path):
     path = tmp_path / "existing.py"
     path.write_text("a\ntest")
-    file = EditableFile(path)
-    assert file.lines == ["a", "test"]
 
+    editable_file = EditableFile(path)
+
+    await editable_file.read()
+
+    assert editable_file.lines == ["a", "test"]
+
+
+@pytest.mark.asyncio
+async def test_read_missing(tmp_path):
     path = tmp_path / "missing.py"
-    file = EditableFile(path)
-    assert file.lines == [""]
+    missing_file = EditableFile(path)
+
+    await missing_file.read()
+
+    assert missing_file.lines == [""]
 
 
-def test_apply_change(tmp_path):
+@pytest.mark.asyncio
+async def test_apply_change(tmp_path):
     # inserting text
     path = tmp_path / "test.py"
-    file = EditableFile(path)
-    file.apply_change("new\ntext", **file.full_range)
-    assert file.lines == ["new", "text"]
+    editable_file = EditableFile(path)
+    await editable_file.read()
+
+    editable_file.apply_change("new\ntext", **editable_file.full_range)
+    assert editable_file.lines == ["new", "text"]
 
     # modifying a range
-    file.apply_change(
+    editable_file.apply_change(
         "ves", start={"line": 1, "character": 0}, end={"line": 1, "character": 3}
     )
-    assert file.lines == ["new", "vest"]
+    assert editable_file.lines == ["new", "vest"]
 
-    file.apply_change("", **file.full_range)
-    assert file.lines == [""]
+    editable_file.apply_change("", **editable_file.full_range)
+    assert editable_file.lines == [""]
 
 
 def test_extract_or_none():

py_src/jupyter_lsp/virtual_documents_shadow.py

@@ -1,10 +1,17 @@
 # flake8: noqa: W503
+from concurrent.futures import ThreadPoolExecutor
 from pathlib import Path
 from shutil import rmtree
 
+from tornado.concurrent import run_on_executor
+from tornado.gen import convert_yielded
+
 from .manager import lsp_message_listener
 from .paths import file_uri_to_path
 
+# TODO: make configurable
+MAX_WORKERS = 4
+
 
 def extract_or_none(obj, path):
     for crumb in path:
@@ -16,11 +23,19 @@ def extract_or_none(obj, path):
 
 
 class EditableFile:
+    executor = ThreadPoolExecutor(max_workers=MAX_WORKERS)
+
     def __init__(self, path):
         # Python 3.5 relict:
         self.path = Path(path) if isinstance(path, str) else path
-        self.lines = self.read_lines()
 
+    async def read(self):
+        self.lines = await convert_yielded(self.read_lines())
+
+    async def write(self):
+        return await convert_yielded(self.write_lines())
+
+    @run_on_executor
     def read_lines(self):
         # empty string required by the assumptions of the gluing algorithm
         lines = [""]
@@ -30,6 +45,11 @@ def read_lines(self):
             pass
         return lines
 
+    @run_on_executor
+    def write_lines(self):
+        self.path.parent.mkdir(parents=True, exist_ok=True)
+        self.path.write_text("\n".join(self.lines))
+
     @staticmethod
     def trim(lines: list, character: int, side: int):
         needs_glue = False
@@ -63,10 +83,6 @@ def apply_change(self, text: str, start, end):
             + after[1 if needs_glue_right else None :]
         ) or [""]
 
-    def write(self):
-        self.path.parent.mkdir(parents=True, exist_ok=True)
-        self.path.write_text("\n".join(self.lines))
-
     @property
     def full_range(self):
         start = {"line": 0, "character": 0}
@@ -125,7 +141,9 @@ async def shadow_virtual_documents(scope, message, language_server, manager):
             return
 
         path = file_uri_to_path(uri)
-        file = EditableFile(path)
+        editable_file = EditableFile(path)
+
+        await editable_file.read()
 
         text = extract_or_none(document, ["text"])
 
@@ -148,10 +166,10 @@ async def shadow_virtual_documents(scope, message, language_server, manager):
             )
 
         for change in changes[:1]:
-            change_range = change.get("range", file.full_range)
-            file.apply_change(change["text"], **change_range)
+            change_range = change.get("range", editable_file.full_range)
+            editable_file.apply_change(change["text"], **change_range)
 
-        file.write()
+        await editable_file.write()
 
         return path