rssVideos: Now thread-safe (kinda)

config/scripts/rssVideos

@@ -9,6 +9,7 @@ with the unread items (non-video links are ignored).
 """
 
 import datetime
+import filelock
 import functools
 import logging
 import os
@@ -26,8 +27,6 @@ import yt_dlp
 
 log = logging.getLogger(__name__)
 
-# TODO Lockfile, or a way to parallel watch and download
-
 
 def configure_logging(args: configargparse.Namespace) -> None:
     # Configure logging
@@ -107,17 +106,33 @@ def format_duration(duration: int) -> str:
 class RVElement:
     parent: "RVDatabase"
     item: dict
-    downloaded_filepath: typing.Optional[str]
+
+    RERESEARCH_AFTER = datetime.timedelta(hours=1)
 
     def __init__(self, parent: "RVDatabase", item: dict) -> None:
         self.parent = parent
         self.item = item
-        self.downloaded_filepath = None
 
     @property
     def id(self) -> str:
         return self.item["id"]
 
+    @property
+    def sid(self) -> str:
+        return self.id.split("/")[-1]
+
+    def metafile(self, extension: str) -> str:
+        return os.path.join(self.parent.METADATA_FOLDER, f"{self.sid}.{extension}")
+
+    def metafile_read(self, extension: str) -> typing.Any:
+        return self.parent.metafile_read(f"{self.sid}.{extension}")
+
+    def metafile_write(self, extension: str, data: typing.Any) -> None:
+        return self.parent.metafile_write(f"{self.sid}.{extension}", data)
+
+    def save(self) -> None:
+        self.metafile_write("item", self.item)
+
     @property
     def title(self) -> str:
         return self.item["title"]
@@ -136,14 +151,8 @@ class RVElement:
 
     @property
     def is_researched(self) -> bool:
-        return "ytdl_infos" in self.__dict__
+        metafile = self.metafile("ytdl")
-
+        return os.path.isfile(metafile)
-    def salvage_cache(self, cache: "RVElement") -> None:
-        if cache.is_researched:
-            self.__dict__["ytdl_infos"] = cache.__dict__["ytdl_infos"]
-            log.debug(f"From cache: {self}")
-        if cache.downloaded_filepath:
-            self.downloaded_filepath = cache.downloaded_filepath
 
     def __str__(self) -> str:
         str = f"{self.date.strftime('%y-%m-%d %H:%M')} ("
@@ -169,6 +178,14 @@ class RVElement:
 
     @functools.cached_property
     def ytdl_infos(self) -> typing.Optional[dict]:
+        try:
+            return self.metafile_read("ytdl")
+        except (FileNotFoundError, TypeError, AttributeError, EOFError):
+            infos = self._ytdl_infos()
+            self.metafile_write("ytdl", infos)
+        return infos
+
+    def _ytdl_infos(self) -> typing.Optional[dict]:
         log.info(f"Researching: {self}")
         try:
             infos = self.parent.ytdl_dry.extract_info(self.link, download=False)
@@ -180,9 +197,6 @@ class RVElement:
             infos = None
         if infos:
             infos = self.parent.ytdl_dry.sanitize_info(infos)
-        # Save database once it's been computed
-        self.__dict__["ytdl_infos"] = infos
-        self.parent.save()
         return infos
 
     @property
@@ -196,6 +210,18 @@ class RVElement:
         # Duration might be missing in playlists and stuff
         return self.ytdl_infos is not None and "duration" in self.ytdl_infos
 
+    @functools.cached_property
+    def downloaded_filepath(self) -> typing.Optional[str]:
+        try:
+            return self.metafile_read("path")
+        except FileNotFoundError:
+            return None
+
+    @property
+    def was_downloaded(self) -> bool:
+        metafile = self.metafile("path")
+        return os.path.exists(metafile)
+
     @property
     def filepath(self) -> str:
         assert self.is_video
@@ -204,37 +230,36 @@ class RVElement:
         return self.parent.ytdl_dry.prepare_filename(self.ytdl_infos)
 
     @property
-    def filename(self) -> str:
+    def basename(self) -> str:
         assert self.is_video
         return os.path.splitext(self.filepath)[0]
 
+    def expire_info(self) -> None:
+        metafile = self.metafile("ytdl")
+        if os.path.isfile(metafile):
+            stat = os.stat(metafile)
+            mtime = datetime.datetime.fromtimestamp(stat.st_mtime)
+            diff = datetime.datetime.now() - mtime
+            if diff > self.RERESEARCH_AFTER:
+                os.unlink(metafile)
+                del self.ytdl_infos
+
     def download(self) -> None:
         assert self.is_video
+        if self.downloaded:
+            return
+        self.expire_info()
         log.info(f"Downloading: {self}")
-        if self.parent.args.research:
+        lockfile = self.metafile("lock")
-            del self.ytdl_infos
+        with filelock.FileLock(lockfile):
             if not self.parent.args.dryrun:
                 with yt_dlp.YoutubeDL(self.parent.ytdl_opts) as ydl:
                     ydl.add_post_processor(SaveInfoPP(self))
                     ydl.process_ie_result(self.ytdl_infos, download=True)
-        self.parent.save()
 
     def update_post_download(self, info: dict) -> None:
         self.downloaded_filepath = self.parent.ytdl_dry.prepare_filename(info)
-
+        self.metafile_write("path", self.downloaded_filepath)
-    @property
-    def was_downloaded(self) -> bool:
-        return self.downloaded_filepath is not None
-
-    def preload(self) -> None:
-        assert self.is_video
-        if self.downloaded:
-            log.debug(f"Currently downloaded: {self}")
-            return
-        if self.was_downloaded:
-            log.debug(f"Downloaded previously: {self}")
-            return
-        self.download()
 
     @property
     def watched(self) -> bool:
@@ -270,7 +295,6 @@ class RVElement:
         return True
 
     def watch(self) -> None:
-        if not self.downloaded:
         self.download()
 
         cmd = ["mpv", self.filepath]
@@ -279,17 +303,27 @@ class RVElement:
             proc = subprocess.run(cmd)
             proc.check_returncode()
 
-        self.clean()
+        self.undownload()
         self.try_mark_read()
 
-    def clean(self) -> None:
+    def clean_file(self, folder: str, basename: str) -> None:
-        assert self.is_video
+        for file in os.listdir(folder):
-        log.info(f"Removing gone video: {self.filename}*")
+            if file.startswith(basename):
-        for file in os.listdir():
+                path = os.path.join(folder, file)
-            if file.startswith(self.filename):
+                log.debug(f"Removing file: {path}")
-                log.debug(f"Removing file: {file}")
                 if not self.parent.args.dryrun:
-                    os.unlink(file)
+                    os.unlink(path)
+
+    def undownload(self) -> None:
+        assert self.is_video
+        log.info(f"Removing gone video: {self.basename}*")
+        self.clean_file(".", self.basename)
+
+    def clean(self) -> None:
+        if self.is_video:
+            self.undownload()
+        log.info(f"Removing gone metadata: {self.sid}*")
+        self.clean_file(self.parent.METADATA_FOLDER, self.sid)
 
     def mark_read(self) -> None:
         log.debug(f"Marking {self} read")
@@ -309,7 +343,7 @@ class RVElement:
         if r.text.strip() != "OK":
             raise RuntimeError(f"Couldn't mark {self} as read: {r.text}")
         log.info(f"Marked {self} as read")
-        self.parent.elements.remove(self)
+        self.clean()
 
     def try_mark_read(self) -> None:
         try:
@@ -319,7 +353,7 @@ class RVElement:
 
 
 class RVDatabase:
-    SAVE_FILE = ".cache.p"
+    METADATA_FOLDER = ".metadata"
 
     args: configargparse.Namespace
     elements: list[RVElement]
@@ -327,53 +361,27 @@ class RVDatabase:
     def __init__(self, args: configargparse.Namespace) -> None:
         self.args = args
 
-    def save(self) -> None:
+    def metafile_read(self, name: str) -> typing.Any:
-        log.debug("Saving cache")
+        path = os.path.join(self.METADATA_FOLDER, name)
-        if self.args.dryrun:
+        log.debug(f"Reading {path}")
-            return
+        with open(path, "rb") as mf:
-        with open(self.SAVE_FILE, "wb") as save_file:
+            return pickle.load(mf)
-            pickle.dump(self, save_file)
 
-    @classmethod
+    def metafile_write(self, name: str, data: typing.Any) -> None:
-    def load(cls) -> typing.Optional["RVDatabase"]:
+        path = os.path.join(self.METADATA_FOLDER, name)
-        try:
+        log.debug(f"Writing {path}")
-            with open(cls.SAVE_FILE, "rb") as save_file:
+        if not self.args.dryrun:
-                return pickle.load(save_file)
+            with open(path, "wb") as mf:
-        except (TypeError, AttributeError, EOFError):
+                pickle.dump(data, mf)
-            log.warning("Corrupt / outdated cache, it will be rebuilt.")
-        except FileNotFoundError:
-            pass
-        return None
-
-    def salvage_cache_pre(self, cache: "RVDatabase") -> None:
-        if "auth_headers" in cache.__dict__:
-            self.auth_headers = cache.auth_headers
-
-    def salvage_cache(self, cache: "RVDatabase") -> None:
-        log.debug("Salvaging cache")
-        cache_els = dict()
-        for cache_el in cache.elements:
-            cache_els[cache_el.id] = cache_el
-        for el in self.elements:
-            if el.id in cache_els:
-                el.salvage_cache(cache_els[el.id])
 
     def clean_cache(self, cache: "RVDatabase") -> None:
         log.debug("Cleaning cache")
-        self_els = dict()
+        fresh_ids = set(el.id for el in self.elements)
-        for self_el in self.elements:
-            self_els[self_el.id] = self_el
         for el in cache.elements:
-            if el.id not in self_els:
+            if el.id not in fresh_ids:
-                if el.is_researched and el.is_video:
                 el.clean()
 
-    def import_cache(self, cache: "RVDatabase") -> None:
+    def _auth_headers(self) -> dict[str, str]:
-        log.debug("Importing cache")
-        self.build_list([element.item for element in cache.elements])
-
-    @functools.cached_property
-    def auth_headers(self) -> dict[str, str]:
         r = requests.get(
             f"{self.args.url}/accounts/ClientLogin",
             params={"Email": self.args.email, "Passwd": self.args.passwd},
@@ -385,6 +393,15 @@ class RVDatabase:
                 return {"Authorization": f"GoogleLogin auth={val}"}
         raise RuntimeError("Couldn't find auth= key")
 
+    @functools.cached_property
+    def auth_headers(self) -> dict[str, str]:
+        try:
+            return self.metafile_read(".auth_headers")
+        except FileNotFoundError:
+            headers = self._auth_headers()
+            self.metafile_write(".auth_headers", headers)
+            return headers
+
     def fetch_feed_elements(self) -> typing.Generator[dict, None, None]:
         log.info("Fetching RSS feed")
         continuation: typing.Optional[str] = None
@@ -409,45 +426,47 @@ class RVDatabase:
             while continuation:
                 yield from next_page()
 
-    def build_list(self, items: typing.Iterable[dict]) -> None:
+    def fetch_cache_elements(self) -> typing.Generator[dict, None, None]:
+        log.info("Fetching from cache")
+        for file in os.listdir(self.METADATA_FOLDER):
+            if not file.endswith(".item"):
+                continue
+            yield self.metafile_read(file)
+
+    def build_list(self, items: typing.Iterable[dict], save: bool = False) -> None:
         self.elements = []
         for item in items:
             element = RVElement(self, item)
             self.elements.insert(0, element)
             log.debug(f"Known: {element}")
+            if save:
+                element.save()
 
     def read_feed(self) -> None:
-        self.build_list(self.fetch_feed_elements())
+        self.build_list(self.fetch_feed_elements(), save=True)
+
+    def read_cache(self) -> None:
+        self.build_list(self.fetch_cache_elements())
+
+    def clean_folder(self, folder: str, basenames: set[str]) -> None:
+        for file in os.listdir(folder):
+            path = os.path.join(folder, file)
+            if not os.path.isfile(path) or file[0] == ".":
+                continue
+            for basename in basenames:
+                if file.startswith(basename):
+                    break
+            else:
+                log.info(f"Removing unknown file: {path}")
+                if not self.args.dryrun:
+                    os.unlink(path)
 
     def clean(self) -> None:
         log.debug("Cleaning")
-        filenames = set()
+        filenames = set(el.basename for el in self.elements if el.is_video)
-        for element in self.elements:
+        self.clean_folder(".", filenames)
-            if element.is_video:
+        ids = set(el.sid for el in self.elements)
-                filenames.add(element.filename)
+        self.clean_folder(self.METADATA_FOLDER, ids)
-        for file in os.listdir():
-            if file == RVDatabase.SAVE_FILE:
-                continue
-            if not os.path.isfile(file):
-                continue
-            for filename in filenames:
-                if file.startswith(filename):
-                    break
-            else:
-                log.info(f"Removing unknown file: {file}")
-                if not self.args.dryrun:
-                    os.unlink(file)
-
-    @property
-    def all_researched(self) -> bool:
-        for element in self.elements:
-            if not element.is_researched:
-                return False
-        return True
-
-    def attempt_clean(self) -> None:
-        if self.all_researched:
-            self.clean()
 
     @property
     def ytdl_opts(self) -> dict:
@@ -468,7 +487,9 @@ class RVDatabase:
         elements: typing.Iterable[RVElement]
         # Inexpensive sort
         if args.order == "new":
-            elements = reversed(elements_src)
+            elements = sorted(elements_src, key=lambda el: el.date, reverse=True)
+        elif args.order == "old":
+            elements = sorted(elements_src, key=lambda el: el.date)
         elif args.order == "title":
             elements = sorted(elements_src, key=lambda el: el.title)
         elif args.order == "creator":
@@ -478,8 +499,6 @@ class RVDatabase:
         elif args.order == "random":
             elements = elements_src
             random.shuffle(elements)
-        else:
-            elements = elements_src
 
         # Possibly expensive filtering
         elements = filter(lambda el: el.matches_filter(args), elements)
@@ -575,11 +594,6 @@ def get_args() -> configargparse.Namespace:
         env_var="RSS_VIDEOS_PASSWD",
         required=True,
     )
-    parser.add(
-        "--research",
-        help="Fetch video info again",
-        action="store_true",
-    )
     parser.add(
         "--no-refresh",
         dest="refresh",
@@ -641,67 +655,46 @@ def get_args() -> configargparse.Namespace:
             "list",
             "watch",
             "binge",
-            "clean",
         ),
         default="download",
     )
 
     args = parser.parse_args()
     args.videos = os.path.realpath(os.path.expanduser(args.videos))
-    if not args.duration and args.max_duration:
-        args.duration = str(args.max_duration)
 
     return args
 
 
 def get_database(args: configargparse.Namespace) -> RVDatabase:
-    database = RVDatabase(args)
+    cache = RVDatabase(args)
-    cache = RVDatabase.load()
+    cache.read_cache()
-    feed_fetched = False
+    if not args.refresh:
-    if cache:
+        return cache
-        database.salvage_cache_pre(cache)
-    if args.refresh:
-        try:
-            database.read_feed()
-            feed_fetched = True
-        except requests.ConnectionError as err:
-            if args.action == "download":
-                raise RuntimeError("Couldn't fetch feed, refusing to download")
-                # This is a quirky failsafe in case of no internet connection,
-                # so the script doesn't go noting that no element is a video.
-            log.warning(f"Couldn't fetch feed: {err}")
-    if not feed_fetched:
-        if cache:
-            log.warning("Using cached feed.")
-            database.import_cache(cache)
-        else:
-            raise FileNotFoundError("Feed not fetched and no cached feed.")
-    if cache:
-        database.salvage_cache(cache)
-        database.clean_cache(cache)
-        database.save()
 
-    return database
+    fresh = RVDatabase(args)
+    fresh.read_feed()
+    fresh.clean_cache(cache)
+    return fresh
 
 
 def main() -> None:
     args = get_args()
     configure_logging(args)
 
-    os.makedirs(args.videos, exist_ok=True)
+    metadata_dir = os.path.join(args.videos, RVDatabase.METADATA_FOLDER)
+    for dir in (args.videos, metadata_dir):
+        os.makedirs(dir, exist_ok=True)
     os.chdir(args.videos)
 
     database = get_database(args)
+    database.clean()
 
     log.debug("Running action")
-    if args.action == "clean":
-        database.clean()
-    else:
     duration = 0
     for element in database.filter(args):
         duration += element.duration if element.is_video else 0
         if args.action == "download":
-                element.preload()
+            element.download()
         elif args.action == "list":
             print(element)
         elif args.action in ("watch", "binge"):
@@ -711,9 +704,7 @@ def main() -> None:
         else:
             raise NotImplementedError(f"Unimplemented action: {args.action}")
     log.info(f"Total duration: {format_duration(duration)}")
-        database.attempt_clean()
     database.try_mark_watched_read()
-    database.save()
 
 
 if __name__ == "__main__":