vllm.multimodal.hasher ¶

class MultiModalHasher:
    @classmethod
    def serialize_item(cls, obj: object) -> Iterable[bytes | memoryview]:
        # Simple cases
        if isinstance(obj, (bytes, memoryview)):
            return (obj,)
        if isinstance(obj, str):
            return (obj.encode("utf-8"),)
        if isinstance(obj, (int, float)):
            return (np.array(obj).tobytes(),)

        if isinstance(obj, Image.Image):
            exif = obj.getexif()
            if Image.ExifTags.Base.ImageID in exif and isinstance(
                exif[Image.ExifTags.Base.ImageID], uuid.UUID
            ):
                # If the image has exif ImageID tag, use that
                return (exif[Image.ExifTags.Base.ImageID].bytes,)
            data = {"mode": obj.mode, "data": np.asarray(obj)}
            if obj.palette is not None:
                data["palette"] = obj.palette.palette
                if obj.palette.rawmode is not None:
                    data["palette_rawmode"] = obj.palette.rawmode
            return cls.iter_item_to_bytes("image", data)
        if isinstance(obj, torch.Tensor):
            tensor_obj: torch.Tensor = obj.cpu()
            tensor_dtype = tensor_obj.dtype
            tensor_shape = tensor_obj.shape

            # NumPy does not support bfloat16.
            # Workaround: View the tensor as a contiguous 1D array of bytes
            if tensor_dtype == torch.bfloat16:
                tensor_obj = tensor_obj.contiguous()
                tensor_obj = tensor_obj.view((tensor_obj.numel(),)).view(torch.uint8)

                return cls.iter_item_to_bytes(
                    "tensor",
                    {
                        "original_dtype": str(tensor_dtype),
                        "original_shape": tuple(tensor_shape),
                        "data": tensor_obj.numpy(),
                    },
                )
            return cls.iter_item_to_bytes("tensor", tensor_obj.numpy())
        if isinstance(obj, np.ndarray):
            # If the array is non-contiguous, we need to copy it first
            arr_data = (
                obj.view(np.uint8).data if obj.flags.c_contiguous else obj.tobytes()
            )
            return cls.iter_item_to_bytes(
                "ndarray",
                {
                    "dtype": obj.dtype.str,
                    "shape": obj.shape,
                    "data": arr_data,
                },
            )
        logger.warning(
            "No serialization method found for %s. Falling back to pickle.", type(obj)
        )

        return (pickle.dumps(obj),)

    @classmethod
    def iter_item_to_bytes(
        cls,
        key: str,
        obj: object,
    ) -> Iterable[bytes | memoryview]:
        # Recursive cases
        if isinstance(obj, (list, tuple)):
            for i, elem in enumerate(obj):
                yield from cls.iter_item_to_bytes(f"{key}.{i}", elem)
        elif isinstance(obj, dict):
            for k, v in obj.items():
                yield from cls.iter_item_to_bytes(f"{key}.{k}", v)
        else:
            yield key.encode("utf-8")
            yield from cls.serialize_item(obj)

    @classmethod
    def hash_kwargs(cls, **kwargs: object) -> str:
        hasher = blake3()

        for k, v in kwargs.items():
            for bytes_ in cls.iter_item_to_bytes(k, v):
                hasher.update(bytes_)

        return hasher.hexdigest()