kamera geht

tools/install_detection_model.py

@@ -0,0 +1,47 @@
+"""Expliziter, SHA-256-geprüfter Download des lokalen Erkennungsmodells."""
+
+import argparse
+import hashlib
+import json
+import os
+from pathlib import Path
+import tempfile
+import urllib.request
+
+
+def main():
+    root = Path(__file__).resolve().parent.parent
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--state-dir", type=Path, default=Path(os.environ.get("HALLOWEEN_STATE_DIR", root / "data")))
+    args = parser.parse_args()
+    manifest = json.loads((root / "halloween/nanodet-model.json").read_text())
+    target = args.state_dir / "models" / manifest["file"]
+    if target.exists() and hashlib.sha256(target.read_bytes()).hexdigest() == manifest["sha256"]:
+        print(f"Modell bereits geprüft: {target}")
+        return
+    target.parent.mkdir(parents=True, exist_ok=True)
+    temp = None
+    try:
+        with tempfile.NamedTemporaryFile(dir=target.parent, delete=False) as output:
+            temp = Path(output.name)
+            digest, size = hashlib.sha256(), 0
+            with urllib.request.urlopen(manifest["url"], timeout=30) as response:
+                while block := response.read(65536):
+                    size += len(block)
+                    if size > manifest["size"]:
+                        raise ValueError("Modell größer als erwartet")
+                    digest.update(block)
+                    output.write(block)
+            if size != manifest["size"] or digest.hexdigest() != manifest["sha256"]:
+                raise ValueError("Modell-Prüfsumme oder Größe stimmt nicht")
+            output.flush()
+            os.fsync(output.fileno())
+        os.replace(temp, target)
+        print(f"Modell installiert und SHA-256 geprüft: {target}")
+    finally:
+        if temp is not None:
+            temp.unlink(missing_ok=True)
+
+
+if __name__ == "__main__":
+    main()