From 228b75a20dc68d0049592c5a2a0047236a754a6a Mon Sep 17 00:00:00 2001
From: Leo Vasanko <leo@git>
Date: Thu, 19 Oct 2023 20:54:33 +0300
Subject: [PATCH] Watching cleanup, debugging a problem case.

---
 cista/watching.py | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/cista/watching.py b/cista/watching.py
index 5e7a549..4457f9b 100755
--- a/cista/watching.py
+++ b/cista/watching.py
@@ -10,7 +10,6 @@ from watchdog.observers import Observer
 from . import config
 from .protocol import DirEntry, FileEntry, UpdateEntry
 
-secret = secrets.token_bytes(8)
 pubsub = {}
 
 def walk(path: Path) -> DirEntry | FileEntry | None:
@@ -33,7 +32,7 @@ def walk(path: Path) -> DirEntry | FileEntry | None:
         print("OS error walking path", path, e)
         return None
 
-tree = None
+tree = {"": None}
 tree_lock = threading.Lock()
 rootpath = None
 
@@ -43,14 +42,17 @@ def refresh():
         UpdateEntry(size=root.size, mtime=root.mtime, dir=root.dir)
     ]}).decode()
 
-def update(relpath: PurePosixPath, loop):
+def update(relpath: Path, loop):
+    """Called by inotify updates, check the filesystem and broadcast any changes."""
     new = walk(rootpath / relpath)
     with tree_lock:
-        msg = update_internal(relpath, new)
+        update = update_internal(relpath, new)
+        if not update: return  # No changes
+        msg = msgspec.json.encode({"update": update}).decode()
         print(msg)
         asyncio.run_coroutine_threadsafe(broadcast(msg), loop)
 
-def update_internal(relpath: PurePosixPath, new: DirEntry | FileEntry | None):
+def update_internal(relpath: PurePosixPath, new: DirEntry | FileEntry | None) -> list[UpdateEntry]:
     path = "", *relpath.parts
     old = tree
     elems = []
@@ -60,12 +62,19 @@ def update_internal(relpath: PurePosixPath, new: DirEntry | FileEntry | None):
             old = None
             elems.append((name, None))
             if len(elems) < len(path):
+                # We got a notify for an item whose parent is not in tree
+                print("Tree out of sync DEBUG", relpath)
+                print(elems)
+                print("Current tree:")
+                print(tree[""])
+                print("Walking all:")
+                print(walk(rootpath))
                 raise ValueError("Tree out of sync")
             break
         old = old[name]
         elems.append((name, old))
     if old == new:
-        return  # No changes
+        return []
     mt = new.mtime if new else 0
     szdiff = (new.size if new else 0) - (old.size if old else 0)
     # Update parents
@@ -93,7 +102,7 @@ def update_internal(relpath: PurePosixPath, new: DirEntry | FileEntry | None):
         del parent[name]
         u.deleted = True
     update.append(u)
-    return msgspec.json.encode({"update": update}).decode()
+    return update
 
 async def broadcast(msg):
     for queue in pubsub.values():
@@ -102,11 +111,11 @@ async def broadcast(msg):
 def register(app, url):
     @app.before_server_start
     async def start_watcher(app, loop):
-        global tree, rootpath
+        global rootpath
         config.load_config()
+        # Initialize the tree from filesystem
         rootpath = config.config.path
-        # Pseudo nameless root entry to ease updates
-        tree = {"": walk(rootpath)}
+        tree[""] = walk(rootpath)
         class Handler(FileSystemEventHandler):
             def on_any_event(self, event):
                 update(Path(event.src_path).relative_to(rootpath), loop)