[ie/youtube] Add a PO Token Provider Framework (#12840)

https://github.com/yt-dlp/yt-dlp/tree/master/yt_dlp/extractor/youtube/pot/README.md

Authored by: coletdjnz

yt_dlp/extractor/youtube/pot/cache.py

@@ -0,0 +1,97 @@
+"""PUBLIC API"""
+
+from __future__ import annotations
+
+import abc
+import dataclasses
+import enum
+import typing
+
+from yt_dlp.extractor.youtube.pot._provider import (
+    IEContentProvider,
+    IEContentProviderError,
+    register_preference_generic,
+    register_provider_generic,
+)
+from yt_dlp.extractor.youtube.pot._registry import (
+    _pot_cache_provider_preferences,
+    _pot_cache_providers,
+    _pot_pcs_providers,
+)
+from yt_dlp.extractor.youtube.pot.provider import PoTokenRequest
+
+
+class PoTokenCacheProviderError(IEContentProviderError):
+    """An error occurred while fetching a PO Token"""
+
+
+class PoTokenCacheProvider(IEContentProvider, abc.ABC, suffix='PCP'):
+    @abc.abstractmethod
+    def get(self, key: str) -> str | None:
+        pass
+
+    @abc.abstractmethod
+    def store(self, key: str, value: str, expires_at: int):
+        pass
+
+    @abc.abstractmethod
+    def delete(self, key: str):
+        pass
+
+
+class CacheProviderWritePolicy(enum.Enum):
+    WRITE_ALL = enum.auto()    # Write to all cache providers
+    WRITE_FIRST = enum.auto()  # Write to only the first cache provider
+
+
+@dataclasses.dataclass
+class PoTokenCacheSpec:
+    key_bindings: dict[str, str | None]
+    default_ttl: int
+    write_policy: CacheProviderWritePolicy = CacheProviderWritePolicy.WRITE_ALL
+
+    # Internal
+    _provider: PoTokenCacheSpecProvider | None = None
+
+
+class PoTokenCacheSpecProvider(IEContentProvider, abc.ABC, suffix='PCSP'):
+
+    def is_available(self) -> bool:
+        return True
+
+    @abc.abstractmethod
+    def generate_cache_spec(self, request: PoTokenRequest) -> PoTokenCacheSpec | None:
+        """Generate a cache spec for the given request"""
+        pass
+
+
+def register_provider(provider: type[PoTokenCacheProvider]):
+    """Register a PoTokenCacheProvider class"""
+    return register_provider_generic(
+        provider=provider,
+        base_class=PoTokenCacheProvider,
+        registry=_pot_cache_providers.value,
+    )
+
+
+def register_spec(provider: type[PoTokenCacheSpecProvider]):
+    """Register a PoTokenCacheSpecProvider class"""
+    return register_provider_generic(
+        provider=provider,
+        base_class=PoTokenCacheSpecProvider,
+        registry=_pot_pcs_providers.value,
+    )
+
+
+def register_preference(
+        *providers: type[PoTokenCacheProvider]) -> typing.Callable[[CacheProviderPreference], CacheProviderPreference]:
+    """Register a preference for a PoTokenCacheProvider"""
+    return register_preference_generic(
+        PoTokenCacheProvider,
+        _pot_cache_provider_preferences.value,
+        *providers,
+    )
+
+
+if typing.TYPE_CHECKING:
+    CacheProviderPreference = typing.Callable[[PoTokenCacheProvider, PoTokenRequest], int]