1 files changed, 91 insertions, 0 deletions
diff --git a/yt_dlp/cache.py b/yt_dlp/cache.py
new file mode 100644
index 0000000..9dd4f2f
--- /dev/null
+++ b/yt_dlp/cache.py
@@ -0,0 +1,91 @@
+import contextlib
+import json
+import os
+import re
+import shutil
+import traceback
+import urllib.parse
+
+from .utils import expand_path, traverse_obj, version_tuple, write_json_file
+from .version import __version__
+
+
+class Cache:
+    def __init__(self, ydl):
+        self._ydl = ydl
+
+    def _get_root_dir(self):
+        res = self._ydl.params.get('cachedir')
+        if res is None:
+            cache_root = os.getenv('XDG_CACHE_HOME', '~/.cache')
+            res = os.path.join(cache_root, 'yt-dlp')
+        return expand_path(res)
+
+    def _get_cache_fn(self, section, key, dtype):
+        assert re.match(r'^[\w.-]+$', section), f'invalid section {section!r}'
+        key = urllib.parse.quote(key, safe='').replace('%', ',')  # encode non-ascii characters
+        return os.path.join(self._get_root_dir(), section, f'{key}.{dtype}')
+
+    @property
+    def enabled(self):
+        return self._ydl.params.get('cachedir') is not False
+
+    def store(self, section, key, data, dtype='json'):
+        assert dtype in ('json',)
+
+        if not self.enabled:
+            return
+
+        fn = self._get_cache_fn(section, key, dtype)
+        try:
+            os.makedirs(os.path.dirname(fn), exist_ok=True)
+            self._ydl.write_debug(f'Saving {section}.{key} to cache')
+            write_json_file({'yt-dlp_version': __version__, 'data': data}, fn)
+        except Exception:
+            tb = traceback.format_exc()
+            self._ydl.report_warning(f'Writing cache to {fn!r} failed: {tb}')
+
+    def _validate(self, data, min_ver):
+        version = traverse_obj(data, 'yt-dlp_version')
+        if not version:  # Backward compatibility
+            data, version = {'data': data}, '2022.08.19'
+        if not min_ver or version_tuple(version) >= version_tuple(min_ver):
+            return data['data']
+        self._ydl.write_debug(f'Discarding old cache from version {version} (needs {min_ver})')
+
+    def load(self, section, key, dtype='json', default=None, *, min_ver=None):
+        assert dtype in ('json',)
+
+        if not self.enabled:
+            return default
+
+        cache_fn = self._get_cache_fn(section, key, dtype)
+        with contextlib.suppress(OSError):
+            try:
+                with open(cache_fn, encoding='utf-8') as cachef:
+                    self._ydl.write_debug(f'Loading {section}.{key} from cache')
+                    return self._validate(json.load(cachef), min_ver)
+            except (ValueError, KeyError):
+                try:
+                    file_size = os.path.getsize(cache_fn)
+                except OSError as oe:
+                    file_size = str(oe)
+                self._ydl.report_warning(f'Cache retrieval from {cache_fn} failed ({file_size})')
+
+        return default
+
+    def remove(self):
+        if not self.enabled:
+            self._ydl.to_screen('Cache is disabled (Did you combine --no-cache-dir and --rm-cache-dir?)')
+            return
+
+        cachedir = self._get_root_dir()
+        if not any((term in cachedir) for term in ('cache', 'tmp')):
+            raise Exception('Not removing directory %s - this does not look like a cache dir' % cachedir)
+
+        self._ydl.to_screen(
+            'Removing cache dir %s .' % cachedir, skip_eol=True)
+        if os.path.exists(cachedir):
+            self._ydl.to_screen('.', skip_eol=True)
+            shutil.rmtree(cachedir)
+        self._ydl.to_screen('.')