[BACKEND] Optimize memory usage (#872)

Reduce memory usage significantly when pulling large channels all at once by
- Not loading entry script until it is being processed
- Deleting the entry memory once fully processed
- Disable yt-dlp from keeping entry info in memory since ytdl-sub reads it from file

src/ytdl_sub/config/overrides.py

@@ -56,7 +56,7 @@ class Overrides(DictFormatterValidator, Scriptable):
 
     def __init__(self, name, value):
         DictFormatterValidator.__init__(self, name, value)
-        Scriptable.__init__(self)
+        Scriptable.__init__(self, initialize_base_script=True)
 
         for key in self._keys:
             self.ensure_variable_name_valid(key)

src/ytdl_sub/downloaders/url/downloader.py

@@ -349,39 +349,43 @@ class MultiUrlDownloader(SourcePlugin[MultiUrlValidator]):
         )
 
     def _iterate_child_entries(
-        self, url_validator: UrlValidator, entries: List[Entry]
+        self, entries: List[Entry], download_reversed: bool
     ) -> Iterator[Entry]:
-        entries_to_iterate = entries
-        if url_validator.download_reverse:
-            entries_to_iterate = reversed(entries)
+        # Iterate a list of entries, and delete the entries after yielding
+        indices = list(range(len(entries)))
+        if download_reversed:
+            indices = reversed(indices)
 
-        for entry in entries_to_iterate:
+        for idx in indices:
             self._url_state.entries_downloaded += 1
 
-            if self._is_downloaded(entry):
+            if self._is_downloaded(entries[idx]):
                 download_logger.info(
                     "Already downloaded entry %d/%d: %s",
                     self._url_state.entries_downloaded,
                     self._url_state.entries_total,
-                    entry.title,
+                    entries[idx].title,
                 )
+                del entries[idx]
                 continue
 
-            yield entry
-            self._mark_downloaded(entry)
+            yield entries[idx]
+            self._mark_downloaded(entries[idx])
+
+            del entries[idx]
 
     def _iterate_parent_entry(
-        self, url_validator: UrlValidator, parent: EntryParent
+        self, parent: EntryParent, download_reversed: bool
     ) -> Iterator[Entry]:
         for entry_child in self._iterate_child_entries(
-            url_validator=url_validator, entries=parent.entry_children()
+            entries=parent.entry_children(), download_reversed=download_reversed
         ):
             yield entry_child
 
         # Recursion the parent's parent entries
         for parent_child in reversed(parent.parent_children()):
             for entry_child in self._iterate_parent_entry(
-                url_validator=url_validator, parent=parent_child
+                parent=parent_child, download_reversed=download_reversed
             ):
                 yield entry_child
 
@@ -415,9 +419,9 @@ class MultiUrlDownloader(SourcePlugin[MultiUrlValidator]):
 
     def _iterate_entries(
         self,
-        url_validator: UrlValidator,
         parents: List[EntryParent],
         orphans: List[Entry],
+        download_reversed: bool,
     ) -> Iterator[Entry]:
         """
         Downloads the leaf entries from EntryParent trees
@@ -426,11 +430,13 @@ class MultiUrlDownloader(SourcePlugin[MultiUrlValidator]):
         with self._separate_download_archives(clear_info_json_files=True):
             for parent in parents:
                 for entry_child in self._iterate_parent_entry(
-                    url_validator=url_validator, parent=parent
+                    parent=parent, download_reversed=download_reversed
                 ):
                     yield entry_child
 
-            for orphan in self._iterate_child_entries(url_validator=url_validator, entries=orphans):
+            for orphan in self._iterate_child_entries(
+                entries=orphans, download_reversed=download_reversed
+            ):
                 yield orphan
 
     def download_metadata(self) -> Iterable[Entry]:
@@ -454,7 +460,9 @@ class MultiUrlDownloader(SourcePlugin[MultiUrlValidator]):
                 "Beginning downloads for %s", self.overrides.apply_formatter(collection_url.url)
             )
             for entry in self._iterate_entries(
-                url_validator=collection_url, parents=parents, orphans=orphan_entries
+                parents=parents,
+                orphans=orphan_entries,
+                download_reversed=collection_url.download_reverse,
             ):
                 entry.initialize_script(self.overrides).add(
                     {v.ytdl_sub_input_url: self.overrides.apply_formatter(collection_url.url)}

src/ytdl_sub/entries/base_entry.py

@@ -116,23 +116,6 @@ class BaseEntry(ABC):
         """
         return self._working_directory
 
-    def add_kwargs(self, variables_to_add: Dict[str, Any]) -> "BaseEntry":
-        """
-        Adds variables to kwargs. Use with caution since yt-dlp data can be overwritten.
-        Plugins should use ``add_variables``.
-
-        Parameters
-        ----------
-        variables_to_add
-            Variables to add to kwargs
-
-        Returns
-        -------
-        self
-        """
-        self._kwargs = dict(self._kwargs, **variables_to_add)
-        return self
-
     def get_download_info_json_name(self) -> str:
         """
         Returns

src/ytdl_sub/entries/entry.py

@@ -44,12 +44,6 @@ class Entry(BaseEntry, Scriptable):
         BaseEntry.__init__(self, entry_dict=entry_dict, working_directory=working_directory)
         Scriptable.__init__(self)
 
-    def _add_entry_kwargs_to_script(self) -> None:
-        # Add entry metadata, but avoid the `.add()` helper since it also adds sanitized
-        self.unresolvable.remove(v.entry_metadata.variable_name)
-        self.script.add({v.entry_metadata.variable_name: ScriptUtils.to_script(self._kwargs)})
-        self.update_script()
-
     def initialize_script(self, other: Optional[Scriptable] = None) -> "Entry":
         """
         Initializes the entry script using the Overrides script, then adding
@@ -57,12 +51,20 @@ class Entry(BaseEntry, Scriptable):
         """
         # Overrides contains added variables that are unresolvable, add them here
         if other:
-            self.script = copy.deepcopy(other.script)
-            self.unresolvable = copy.deepcopy(other.unresolvable)
+            self._script = copy.deepcopy(other.script)
+            self._unresolvable = copy.deepcopy(other.unresolvable)
+        else:
+            self.initialize_base_script()
 
         self._add_entry_kwargs_to_script()
         return self
 
+    def _add_entry_kwargs_to_script(self) -> None:
+        # Add entry metadata, but avoid the `.add()` helper since it also adds sanitized
+        self.unresolvable.remove(v.entry_metadata.variable_name)
+        self.script.add({v.entry_metadata.variable_name: ScriptUtils.to_script(self._kwargs)})
+        self.update_script()
+
     def get(self, variable: Variable, expected_type: Type[TypeT]) -> TypeT:
         """
         Gets a variable of an expected type. Will error if it does not exist or is not resolved.

src/ytdl_sub/subscriptions/subscription_ytdl_options.py

@@ -81,6 +81,7 @@ class SubscriptionYTDLOptions:
             "skip_download": True,
             "writethumbnail": False,
             "writeinfojson": True,
+            "extract_flat": "discard",  # do not store info.json in mem since its in file
         }
 
     @property

src/ytdl_sub/utils/scriptable.py

@@ -2,6 +2,7 @@ import copy
 from abc import ABC
 from typing import Any
 from typing import Dict
+from typing import Optional
 from typing import Set
 
 from ytdl_sub.entries.script.function_scripts import CUSTOM_FUNCTION_SCRIPTS
@@ -13,21 +14,47 @@ from ytdl_sub.script.utils.exceptions import RuntimeException
 from ytdl_sub.utils.exceptions import StringFormattingException
 from ytdl_sub.utils.script import ScriptUtils
 
+_BASE_SCRIPT: Script = Script(
+    ScriptUtils.add_sanitized_variables(
+        dict(copy.deepcopy(VARIABLE_SCRIPTS), **copy.deepcopy(CUSTOM_FUNCTION_SCRIPTS))
+    )
+)
+
 
 class Scriptable(ABC):
     """
     Shared class between Entry and Overrides to manage their underlying Script.
     """
 
-    _BASE_SCRIPT: Script = Script(
-        ScriptUtils.add_sanitized_variables(
-            dict(copy.deepcopy(VARIABLE_SCRIPTS), **copy.deepcopy(CUSTOM_FUNCTION_SCRIPTS))
-        )
-    )
+    def __init__(self, initialize_base_script: bool = False):
+        self._script: Optional[Script] = None
+        self._unresolvable: Optional[Set[str]] = None
 
-    def __init__(self):
-        self.script = copy.deepcopy(Scriptable._BASE_SCRIPT)
-        self.unresolvable: Set[str] = copy.deepcopy(UNRESOLVED_VARIABLES)
+        if initialize_base_script:
+            self.initialize_base_script()
+
+    def initialize_base_script(self):
+        """
+        Initializes with base values
+        """
+        self._script = copy.deepcopy(_BASE_SCRIPT)
+        self._unresolvable = copy.deepcopy(UNRESOLVED_VARIABLES)
+
+    @property
+    def script(self) -> Script:
+        """
+        Initialized script
+        """
+        assert self._script is not None, "Not initialized"
+        return self._script
+
+    @property
+    def unresolvable(self) -> Set[str]:
+        """
+        Initialized unresolvable variables
+        """
+        assert self._unresolvable is not None, "Not initialized"
+        return self._unresolvable
 
     def update_script(self) -> None:
         """
@@ -45,7 +72,7 @@ class Scriptable(ABC):
             for var, definition in values.items()
         }
 
-        self.unresolvable -= set(list(values_as_str.keys()))
+        self._unresolvable -= set(list(values_as_str.keys()))
         self.script.add(
             ScriptUtils.add_sanitized_variables(
                 {

tools/docgen/plugins.py

@@ -39,6 +39,8 @@ def should_filter_property(property_name: str) -> bool:
         "dict_with_format_strings",
         "subscription_name",
         "list",
+        "script",
+        "unresolvable",
     )