Class MTMDEmbeddingCache

examples/server/server.py:10394–10518

class MTMDEmbeddingCache:
    _metadata_version = "1"

    def __init__(
        self,
        *,
        path: str,
        max_bytes: int,
        model_fingerprint: str,
        mmproj_fingerprint: str,
    ) -> None:
        self.path = Path(path)
        self.max_bytes = max_bytes
        self.model_fingerprint = model_fingerprint
        self.mmproj_fingerprint = mmproj_fingerprint
        self.path.mkdir(parents=True, exist_ok=True)

    @staticmethod
    def _safe_open(path: Path) -> Any:
        try:
            from safetensors import safe_open
        except ImportError as exc:
            raise RuntimeError(
                "model.mtmd.embedding_cache requires safetensors. "
                "Install it with `pip install safetensors`."
            ) from exc
        return safe_open(str(path), framework="numpy")

    @staticmethod
    def _save_file(
        tensors: Dict[str, np.ndarray],
        path: Path,
        metadata: Dict[str, str],
    ) -> None:
        from safetensors.numpy import save_file

        save_file(tensors, str(path), metadata=metadata)

    @staticmethod
    def fingerprint_file(path: str) -> str:
        stat = os.stat(path)
        payload = f"{Path(path).resolve()}:{stat.st_size}:{stat.st_mtime_ns}"
        return hashlib.sha256(payload.encode("utf-8")).hexdigest()

    @staticmethod
    def _build_key(
        *,
        model_fingerprint: str,
        mmproj_fingerprint: str,
        kind: Literal["image", "audio", "video"],
        media_bytes: bytes,
    ) -> str:
        digest = hashlib.sha256(f"{kind}:".encode("utf-8") + media_bytes).hexdigest()
        payload = ":".join(
            [
                MTMDEmbeddingCache._metadata_version,
                model_fingerprint,
                mmproj_fingerprint,