[cache] Add cache validation by program version, based on yt-dlp

This commit is contained in:
dirkf 2022-09-01 13:28:30 +01:00
parent 55c823634d
commit 218c423bc0
2 changed files with 37 additions and 7 deletions

View file

@ -3,17 +3,18 @@
from __future__ import unicode_literals
import shutil
# Allow direct execution
import os
import sys
import unittest
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
import shutil
from test.helper import FakeYDL
from youtube_dl.cache import Cache
from youtube_dl.utils import version_tuple
from youtube_dl.version import __version__
def _is_empty(d):
@ -54,6 +55,17 @@ class TestCache(unittest.TestCase):
self.assertFalse(os.path.exists(self.test_dir))
self.assertEqual(c.load('test_cache', 'k.'), None)
def test_cache_validation(self):
ydl = FakeYDL({
'cachedir': self.test_dir,
})
c = Cache(ydl)
obj = {'x': 1, 'y': ['ä', '\\a', True]}
c.store('test_cache', 'k.', obj)
self.assertEqual(c.load('test_cache', 'k.', min_ver='1970.01.01'), obj)
new_version = '.'.join(('%d' % ((v + 1) if i == 0 else v, )) for i, v in enumerate(version_tuple(__version__)))
self.assertIs(c.load('test_cache', 'k.', min_ver=new_version), None)
if __name__ == '__main__':
unittest.main()

View file

@ -10,12 +10,21 @@ import traceback
from .compat import compat_getenv
from .utils import (
error_to_compat_str,
expand_path,
is_outdated_version,
try_get,
write_json_file,
)
from .version import __version__
class Cache(object):
_YTDL_DIR = 'youtube-dl'
_VERSION_KEY = _YTDL_DIR + '_version'
_DEFAULT_VERSION = '2021.12.17'
def __init__(self, ydl):
self._ydl = ydl
@ -23,7 +32,7 @@ class Cache(object):
res = self._ydl.params.get('cachedir')
if res is None:
cache_root = compat_getenv('XDG_CACHE_HOME', '~/.cache')
res = os.path.join(cache_root, 'youtube-dl')
res = os.path.join(cache_root, self._YTDL_DIR)
return expand_path(res)
def _get_cache_fn(self, section, key, dtype):
@ -50,13 +59,22 @@ class Cache(object):
except OSError as ose:
if ose.errno != errno.EEXIST:
raise
write_json_file(data, fn)
write_json_file({self._VERSION_KEY: __version__, 'data': data}, fn)
except Exception:
tb = traceback.format_exc()
self._ydl.report_warning(
'Writing cache to %r failed: %s' % (fn, tb))
def load(self, section, key, dtype='json', default=None):
def _validate(self, data, min_ver):
version = try_get(data, lambda x: x[self._VERSION_KEY])
if not version: # Backward compatibility
data, version = {'data': data}, self._DEFAULT_VERSION
if not is_outdated_version(version, min_ver or '0', assume_new=False):
return data['data']
self._ydl.to_screen(
'Discarding old cache from version {version} (needs {min_ver})'.format(**locals()))
def load(self, section, key, dtype='json', default=None, min_ver=None):
assert dtype in ('json',)
if not self.enabled:
@ -66,12 +84,12 @@ class Cache(object):
try:
try:
with io.open(cache_fn, 'r', encoding='utf-8') as cachef:
return json.load(cachef)
return self._validate(json.load(cachef), min_ver)
except ValueError:
try:
file_size = os.path.getsize(cache_fn)
except (OSError, IOError) as oe:
file_size = str(oe)
file_size = error_to_compat_str(oe)
self._ydl.report_warning(
'Cache retrieval from %s failed (%s)' % (cache_fn, file_size))
except IOError: