Function aesgcm_decrypt_generator

Scripts/ButSystem.py:570–602

aesgcm_decrypt_generator. Cryptography helper for encrypting/decrypting application data. This docstring was expanded to make future maintenance easier. Args: src_path: Parameter. Returns: Varies.

(src_path: str)

        return None

def _save_plain_upload(file_storage, tmp_path: str) -> int:
    """Save uploaded file to disk quickly (plain) and return size.

    Speed notes:
      - Prefer Werkzeug's built-in `save()` which streams efficiently to disk.
      - Fallback to a large-buffer copy for environments where `save()` misbehaves.
    """
    os.makedirs(os.path.dirname(tmp_path), exist_ok=True)

    # Fast path: Werkzeug's streaming save (usually the quickest).
    try:
        file_storage.save(tmp_path)
        return int(os.path.getsize(tmp_path))
    except Exception:
        pass

    # Fallback: manual copy with a large buffer (minimize Python overhead).
    size = 0
    try:
        try:
            file_storage.stream.seek(0)
        except Exception:
            pass
        with open(tmp_path, "wb") as out:
            shutil.copyfileobj(file_storage.stream, out, length=8 * 1024 * 1024)  # 8 MiB buffer
        size = int(os.path.getsize(tmp_path))
    except Exception:
        # Last resort: try save again (some backends reset stream after failure)
        file_storage.save(tmp_path)
        size = int(os.path.getsize(tmp_path))
    return int(size)

def _bg_encrypt_file(tmp_plain: str, out_enc: str, finalize_fn):
    """Encrypt tmp_plain -> out_enc in a background thread, then call finalize_fn(success:bool, err:str|None)."""
    def worker():
        """worker.