yt_dlp/cache.py

   1 import contextlib
   2 import errno
   3 import json
   4 import os
   5 import re
   6 import shutil
   7 import traceback
   8
   9 from .utils import expand_path, traverse_obj, version_tuple, write_json_file
  10 from .version import __version__
  11
  12
  13 class Cache:
  14     def __init__(self, ydl):
  15         self._ydl = ydl
  16
  17     def _get_root_dir(self):
  18         res = self._ydl.params.get('cachedir')
  19         if res is None:
  20             cache_root = os.getenv('XDG_CACHE_HOME', '~/.cache')
  21             res = os.path.join(cache_root, 'yt-dlp')
  22         return expand_path(res)
  23
  24     def _get_cache_fn(self, section, key, dtype):
  25         assert re.match(r'^[a-zA-Z0-9_.-]+$', section), \
  26             'invalid section %r' % section
  27         assert re.match(r'^[a-zA-Z0-9_.-]+$', key), 'invalid key %r' % key
  28         return os.path.join(
  29             self._get_root_dir(), section, f'{key}.{dtype}')
  30
  31     @property
  32     def enabled(self):
  33         return self._ydl.params.get('cachedir') is not False
  34
  35     def store(self, section, key, data, dtype='json'):
  36         assert dtype in ('json',)
  37
  38         if not self.enabled:
  39             return
  40
  41         fn = self._get_cache_fn(section, key, dtype)
  42         try:
  43             try:
  44                 os.makedirs(os.path.dirname(fn))
  45             except OSError as ose:
  46                 if ose.errno != errno.EEXIST:
  47                     raise
  48             self._ydl.write_debug(f'Saving {section}.{key} to cache')
  49             write_json_file({'yt-dlp_version': __version__, 'data': data}, fn)
  50         except Exception:
  51             tb = traceback.format_exc()
  52             self._ydl.report_warning(f'Writing cache to {fn!r} failed: {tb}')
  53
  54     def _validate(self, data, min_ver):
  55         version = traverse_obj(data, 'yt-dlp_version')
  56         if not version:  # Backward compatibility
  57             data, version = {'data': data}, '2022.08.19'
  58         if not min_ver or version_tuple(version) >= version_tuple(min_ver):
  59             return data['data']
  60         self._ydl.write_debug(f'Discarding old cache from version {version} (needs {min_ver})')
  61
  62     def load(self, section, key, dtype='json', default=None, *, min_ver=None):
  63         assert dtype in ('json',)
  64
  65         if not self.enabled:
  66             return default
  67
  68         cache_fn = self._get_cache_fn(section, key, dtype)
  69         with contextlib.suppress(OSError):
  70             try:
  71                 with open(cache_fn, encoding='utf-8') as cachef:
  72                     self._ydl.write_debug(f'Loading {section}.{key} from cache')
  73                     return self._validate(json.load(cachef), min_ver)
  74             except (ValueError, KeyError):
  75                 try:
  76                     file_size = os.path.getsize(cache_fn)
  77                 except OSError as oe:
  78                     file_size = str(oe)
  79                 self._ydl.report_warning(f'Cache retrieval from {cache_fn} failed ({file_size})')
  80
  81         return default
  82
  83     def remove(self):
  84         if not self.enabled:
  85             self._ydl.to_screen('Cache is disabled (Did you combine --no-cache-dir and --rm-cache-dir?)')
  86             return
  87
  88         cachedir = self._get_root_dir()
  89         if not any((term in cachedir) for term in ('cache', 'tmp')):
  90             raise Exception('Not removing directory %s - this does not look like a cache dir' % cachedir)
  91
  92         self._ydl.to_screen(
  93             'Removing cache dir %s .' % cachedir, skip_eol=True)
  94         if os.path.exists(cachedir):
  95             self._ydl.to_screen('.', skip_eol=True)
  96             shutil.rmtree(cachedir)
  97         self._ydl.to_screen('.')