feat: 增加桌面端登录、视频清单和封面缓存

server/services/covers.py

@@ -0,0 +1,51 @@
+import hashlib
+import re
+import threading
+from pathlib import Path
+
+from server.services.http import http
+
+CACHE_DIR = Path(__file__).resolve().parents[2] / "cache" / "covers"
+_lock = threading.Lock()
+
+
+class CoverCache:
+    def local_url(self, remote: str) -> str:
+        remote = (remote or "").strip()
+        if not remote.startswith(("http://", "https://")):
+            return remote
+        digest = hashlib.sha256(remote.encode("utf-8")).hexdigest()
+        CACHE_DIR.mkdir(parents=True, exist_ok=True)
+        meta = CACHE_DIR / f"{digest}.url"
+        if not meta.is_file():
+            meta.write_text(remote, encoding="utf-8")
+        return f"/api/covers/{digest}"
+
+    def read(self, digest: str) -> tuple[bytes, str]:
+        if not re.fullmatch(r"[0-9a-f]{64}", digest):
+            raise RuntimeError("封面不存在")
+        meta = CACHE_DIR / f"{digest}.url"
+        body = CACHE_DIR / digest
+        if not meta.is_file():
+            raise RuntimeError("封面不存在")
+        if body.is_file() and body.stat().st_size > 0:
+            return body.read_bytes(), _media_type(body)
+        remote = meta.read_text(encoding="utf-8").strip()
+        data, media = http.get_bytes(remote)
+        with _lock:
+            CACHE_DIR.mkdir(parents=True, exist_ok=True)
+            body.write_bytes(data)
+            (CACHE_DIR / f"{digest}.type").write_text(media, encoding="utf-8")
+        return data, media
+
+
+def _media_type(path: Path) -> str:
+    sidecar = Path(f"{path}.type")
+    if sidecar.is_file():
+        media = sidecar.read_text(encoding="utf-8").strip()
+        if media.startswith("image/"):
+            return media
+    return "image/jpeg"
+
+
+covers = CoverCache()