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mirror of https://codeberg.org/polarisfm/youtube-dl synced 2025-01-09 06:37:54 +01:00
youtube-dl/youtube_dl/archive.py
2020-04-18 00:12:41 +02:00

78 lines
2.7 KiB
Python

#!/usr/bin/env python
# coding: utf-8
import errno
import os
from youtube_dl.compat import compat_st_mtime
from youtube_dl.utils import locked_file
class Archive(object):
""" Class that manages the download Archive. Provides optimizations to avoid
excessive file parsing.
Initializing options:
filepath: str The filepath of the archive.
Properties:
_data: set Container for holding a cache of the archive
_disabled: bool When true, all functions are effectively void
filepath: str The filepath of the archive
_last_read: float The last modification date of the archive file
Methods:
__contains__ Checks a video id (archive id) exists in archive
_file_changed Checks if file has been modified since last read
_read_archive Reads archive from disk
record_download Adds a new download to archive
"""
def __init__(self, filepath):
""" Instantiate Archive
filepath: str or None. The filepath of the archive. If None is provided
instance can still be used but it's effectively
doing nothing."""
self.filepath = None if filepath == "" else filepath
self._disabled = self.filepath is None
self._data = set()
self._last_read = 0
def record_download(self, archive_id):
""" Records a new archive_id in the archive """
if self._disabled:
return
with locked_file(self.filepath, "a", encoding="utf-8") as file_out:
file_out.write(archive_id + "\n")
self._last_read = compat_st_mtime(self.filepath)
self._data.add(archive_id)
def _file_changed(self):
""" Checks if file has been modified, using system Modification Date """
if os.path.exists(self.filepath):
return self._last_read < compat_st_mtime(self.filepath)
return True
def _read_file(self):
""" Reads the data from archive file """
if self._disabled or not self._file_changed():
return
try:
with locked_file(self.filepath, "r", encoding="utf-8") as file_in:
self._data.update(line.strip() for line in file_in)
self._last_read = compat_st_mtime(self.filepath)
except IOError as err:
if err.errno != errno.ENOENT:
raise
def __contains__(self, item):
if not isinstance(item, str):
raise ValueError(
"An archive contains only strings. Provided {}".format(type(item))
)
if item not in self._data:
self._read_file()
return item in self._data