youtube_dl/cache.py

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