Files
vllm-dev/vllm/multimodal/hasher.py
2025-08-30 18:01:22 -07:00

111 lines
3.6 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
import pickle
import uuid
from collections.abc import Iterable
from typing import Union
import numpy as np
import torch
from blake3 import blake3
from PIL import Image
from vllm.logger import init_logger
from vllm.multimodal.image import convert_image_mode
logger = init_logger(__name__)
class MultiModalHasher:
@classmethod
def serialize_item(cls, obj: object) -> Union[bytes, memoryview]:
# Simple cases
if isinstance(obj, str):
return obj.encode("utf-8")
if isinstance(obj, (bytes, memoryview)):
return obj
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
return cls.item_to_bytes(
"image", np.asarray(convert_image_mode(obj, "RGBA")))
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.item_to_bytes(
"tensor", {
"original_dtype": str(tensor_dtype),
"original_shape": tuple(tensor_shape),
"data": tensor_obj.numpy(),
})
return cls.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.data if obj.flags.c_contiguous else obj.tobytes()
return cls.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 item_to_bytes(
cls,
key: str,
obj: object,
) -> bytes:
return b''.join(kb + vb for kb, vb in cls.iter_item_to_bytes(key, obj))
@classmethod
def iter_item_to_bytes(
cls,
key: str,
obj: object,
) -> Iterable[tuple[bytes, Union[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:
key_bytes = key.encode("utf-8")
value_bytes = cls.serialize_item(obj)
yield key_bytes, value_bytes
@classmethod
def hash_kwargs(cls, **kwargs: object) -> str:
hasher = blake3()
for k, v in kwargs.items():
for k_bytes, v_bytes in cls.iter_item_to_bytes(k, v):
hasher.update(k_bytes)
hasher.update(v_bytes)
return hasher.hexdigest()