Files
2025-08-05 19:02:46 +08:00

412 lines
16 KiB
Python

from functools import cached_property
from typing import (Iterable, List, Literal, Mapping, Optional, Tuple,
TypedDict, Union)
import torch
import torch.nn as nn
from PIL import Image
from transformers import CLIPVisionConfig, LlavaConfig, SiglipVisionConfig
from vllm.attention import AttentionMetadata
from vllm.config import CacheConfig, MultiModalConfig
from vllm.inputs import INPUT_REGISTRY, InputContext, LLMInputs
from vllm.model_executor.layers.activation import get_act_fn
from vllm.model_executor.layers.quantization import QuantizationConfig
from vllm.model_executor.layers.sampler import Sampler, SamplerOutput
from vllm.model_executor.sampling_metadata import SamplingMetadata
from vllm.multimodal import MULTIMODAL_REGISTRY
from vllm.sequence import IntermediateTensors
from vllm.utils import is_list_of
from .clip import (CLIPVisionModel, dummy_image_for_clip,
dummy_seq_data_for_clip, get_max_clip_image_tokens,
input_processor_for_clip)
from .interfaces import SupportsMultiModal, SupportsPP
from .siglip import (SiglipVisionModel, dummy_image_for_siglip,
dummy_seq_data_for_siglip, get_max_siglip_image_tokens,
input_processor_for_siglip)
from .utils import (AutoWeightsLoader, flatten_bn, init_vllm_registered_model,
merge_multimodal_embeddings)
class LlavaImagePixelInputs(TypedDict):
type: Literal["pixel_values"]
data: torch.Tensor
"""Shape: `(batch_size * num_images, num_channels, height, width)`"""
class LlavaImageEmbeddingInputs(TypedDict):
type: Literal["image_embeds"]
data: torch.Tensor
"""Shape: `(batch_size * num_images, image_feature_size, hidden_size)`
`hidden_size` must match the hidden size of language model backbone.
"""
LlavaImageInputs = Union[LlavaImagePixelInputs, LlavaImageEmbeddingInputs]
# TODO(xwjiang): Run benchmark and decide if TP.
class LlavaMultiModalProjector(nn.Module):
def __init__(self, vision_hidden_size: int, text_hidden_size: int,
projector_hidden_act: str):
super().__init__()
self.linear_1 = nn.Linear(vision_hidden_size,
text_hidden_size,
bias=True)
self.act = get_act_fn(projector_hidden_act)
self.linear_2 = nn.Linear(text_hidden_size,
text_hidden_size,
bias=True)
def forward(self, image_features: torch.Tensor) -> torch.Tensor:
hidden_states = self.linear_1(image_features)
hidden_states = self.act(hidden_states)
hidden_states = self.linear_2(hidden_states)
return hidden_states
def get_max_llava_image_tokens(ctx: InputContext):
hf_config = ctx.get_hf_config(LlavaConfig)
vision_config = hf_config.vision_config
if isinstance(vision_config, CLIPVisionConfig):
num_image_tokens = get_max_clip_image_tokens(vision_config)
elif isinstance(vision_config, SiglipVisionConfig):
num_image_tokens = get_max_siglip_image_tokens(vision_config)
else:
msg = f"Unsupported vision config: {type(vision_config)}"
raise NotImplementedError(msg)
strategy = hf_config.vision_feature_select_strategy
if strategy == "default":
return num_image_tokens - 1
elif strategy == "full":
return num_image_tokens
else:
raise ValueError(f"Unexpected select feature strategy: {strategy}")
def dummy_data_for_llava(ctx: InputContext, seq_len: int,
mm_counts: Mapping[str, int]):
hf_config = ctx.get_hf_config(LlavaConfig)
vision_config = hf_config.vision_config
num_images = mm_counts["image"]
image_feature_size = get_max_llava_image_tokens(ctx)
if isinstance(vision_config, CLIPVisionConfig):
seq_data = dummy_seq_data_for_clip(
vision_config,
seq_len,
num_images,
image_token_id=hf_config.image_token_index,
image_feature_size_override=image_feature_size,
)
mm_data = dummy_image_for_clip(vision_config, num_images)
return seq_data, mm_data
elif isinstance(vision_config, SiglipVisionConfig):
seq_data = dummy_seq_data_for_siglip(
vision_config,
seq_len,
num_images,
image_token_id=hf_config.image_token_index,
image_feature_size_override=image_feature_size,
)
mm_data = dummy_image_for_siglip(vision_config, num_images)
return seq_data, mm_data
msg = f"Unsupported vision config: {type(vision_config)}"
raise NotImplementedError(msg)
def input_processor_for_llava(ctx: InputContext, llm_inputs: LLMInputs):
multi_modal_data = llm_inputs.get("multi_modal_data")
if multi_modal_data is None or "image" not in multi_modal_data:
return llm_inputs
model_config = ctx.model_config
hf_config = ctx.get_hf_config(LlavaConfig)
vision_config = hf_config.vision_config
image_data = multi_modal_data["image"]
if isinstance(image_data, Image.Image):
image_feature_size = get_max_llava_image_tokens(ctx)
elif is_list_of(image_data, Image.Image):
image_feature_size = [get_max_llava_image_tokens(ctx)
] * len(image_data)
elif isinstance(image_data, torch.Tensor):
num_images, image_feature_size, hidden_size = image_data.shape
elif is_list_of(image_data, torch.Tensor):
image_feature_size = [item.shape[1] for item in image_data]
else:
raise TypeError(f"Invalid image type: {type(image_data)}")
if isinstance(vision_config, CLIPVisionConfig):
return input_processor_for_clip(
model_config,
vision_config,
llm_inputs,
image_token_id=hf_config.image_token_index,
image_feature_size_override=image_feature_size,
)
elif isinstance(vision_config, SiglipVisionConfig):
return input_processor_for_siglip(
model_config,
vision_config,
llm_inputs,
image_token_id=hf_config.image_token_index,
image_feature_size_override=image_feature_size,
)
msg = f"Unsupported vision config: {type(vision_config)}"
raise NotImplementedError(msg)
def _init_vision_tower(hf_config: LlavaConfig):
vision_config = hf_config.vision_config
# Initialize the vision tower only up to the required feature layer
vision_feature_layer = hf_config.vision_feature_layer
if vision_feature_layer < 0:
num_hidden_layers = hf_config.vision_config.num_hidden_layers \
+ vision_feature_layer + 1
else:
num_hidden_layers = vision_feature_layer + 1
if isinstance(vision_config, CLIPVisionConfig):
return CLIPVisionModel(
vision_config,
num_hidden_layers_override=num_hidden_layers,
)
elif isinstance(vision_config, SiglipVisionConfig):
return SiglipVisionModel(
vision_config,
num_hidden_layers_override=num_hidden_layers,
)
msg = f"Unsupported vision config: {type(vision_config)}"
raise NotImplementedError(msg)
@MULTIMODAL_REGISTRY.register_image_input_mapper()
@MULTIMODAL_REGISTRY.register_max_image_tokens(get_max_llava_image_tokens)
@INPUT_REGISTRY.register_dummy_data(dummy_data_for_llava)
@INPUT_REGISTRY.register_input_processor(input_processor_for_llava)
class LlavaForConditionalGeneration(nn.Module, SupportsMultiModal, SupportsPP):
def __init__(self,
config: LlavaConfig,
multimodal_config: MultiModalConfig,
cache_config: Optional[CacheConfig] = None,
quant_config: Optional[QuantizationConfig] = None) -> None:
super().__init__()
self.config = config
self.multimodal_config = multimodal_config
# TODO: Optionally initializes this for supporting embeddings.
self.vision_tower = _init_vision_tower(config)
self.multi_modal_projector = LlavaMultiModalProjector(
vision_hidden_size=config.vision_config.hidden_size,
text_hidden_size=config.text_config.hidden_size,
projector_hidden_act=config.projector_hidden_act)
self.language_model = init_vllm_registered_model(
config.text_config, cache_config, quant_config)
self.make_empty_intermediate_tensors = (
self.language_model.make_empty_intermediate_tensors)
@cached_property
def sampler(self):
if hasattr(self.language_model, "sampler"):
return self.language_model.sampler
return Sampler()
def _validate_pixel_values(self, data: torch.Tensor) -> torch.Tensor:
h = w = self.config.vision_config.image_size
expected_dims = (3, h, w)
actual_dims = tuple(data.shape[1:])
if actual_dims != expected_dims:
expected_expr = ("batch_size", *map(str, expected_dims))
raise ValueError(
f"The expected shape of pixel values is {expected_expr}. "
f"You supplied {tuple(data.shape)}.")
return data
def _parse_and_validate_image_input(
self, **kwargs: object) -> Optional[LlavaImageInputs]:
pixel_values = kwargs.pop("pixel_values", None)
image_embeds = kwargs.pop("image_embeds", None)
if pixel_values is None and image_embeds is None:
return None
if pixel_values is not None:
if not isinstance(pixel_values, (torch.Tensor, list)):
raise ValueError("Incorrect type of pixel values. "
f"Got type: {type(pixel_values)}")
return LlavaImagePixelInputs(
type="pixel_values",
data=self._validate_pixel_values(
flatten_bn(pixel_values, concat=True)),
)
if image_embeds is not None:
if not isinstance(image_embeds, (torch.Tensor, list)):
raise ValueError("Incorrect type of image embeddings. "
f"Got type: {type(image_embeds)}")
return LlavaImageEmbeddingInputs(
type="image_embeds",
data=flatten_bn(image_embeds, concat=True),
)
raise AssertionError("This line should be unreachable.")
def _select_image_features(self, image_features: torch.Tensor, *,
strategy: str) -> torch.Tensor:
# Copied from https://github.com/huggingface/transformers/blob/39c3c0a72af6fbda5614dde02ff236069bb79827/src/transformers/models/llava/modeling_llava.py#L421 # noqa
if strategy == "default":
return image_features[:, 1:]
elif strategy == "full":
return image_features
raise ValueError(f"Unexpected select feature strategy: {strategy}")
def _image_pixels_to_features(
self,
vision_tower: Union[CLIPVisionModel, SiglipVisionModel],
pixel_values: torch.Tensor,
) -> torch.Tensor:
# NOTE: we skip the step to select the vision feature layer since
# this is already done inside the vision tower
image_features = vision_tower(pixel_values)
return self._select_image_features(
image_features,
strategy=self.config.vision_feature_select_strategy,
)
def _process_image_pixels(self,
inputs: LlavaImagePixelInputs) -> torch.Tensor:
assert self.vision_tower is not None
pixel_values = inputs["data"]
return self._image_pixels_to_features(self.vision_tower, pixel_values)
def _process_image_input(self,
image_input: LlavaImageInputs) -> torch.Tensor:
if image_input["type"] == "image_embeds":
return image_input["data"]
assert self.vision_tower is not None
image_features = self._process_image_pixels(image_input)
return self.multi_modal_projector(image_features)
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
kv_caches: List[torch.Tensor],
attn_metadata: AttentionMetadata,
intermediate_tensors: Optional[IntermediateTensors] = None,
**kwargs: object,
) -> Union[torch.Tensor, IntermediateTensors]:
"""Run forward pass for LLaVA-1.5.
One key thing to understand is the `input_ids` already accounts for the
positions of the to-be-inserted image embeddings.
Concretely, consider a text prompt:
`"USER: <image>\\nWhat's the content of the image?\\nASSISTANT:"`.
Tokenizer outputs:
`[1, 3148, 1001, 29901, 29871, 32000, 29871, 13, 5618, 29915, 29879,
278, 2793, 310, 278, 1967, 29973, 13, 22933, 9047, 13566, 29901]`.
To reserve space in KV cache, we have to insert placeholder tokens
before they are inputted to the model, so the input processor prepends
additional image tokens (denoted as `32000`), resulting in:
`[1, 3148, 1001, 29901, 29871, 32000, ..., 32000, 29871, 13, 5618,
29915, 29879, 278, 2793, 310, 278, 1967, 29973, 13, 22933, 9047, 13566,
29901]`.
We insert 575 tokens so that including the original image token in the
input, there are a total of 576 (24 * 24) image tokens, which
corresponds to the number of image tokens inputted to the language
model, i.e. the number of image tokens outputted by the visual encoder.
This way, the `positions` and `attn_metadata` are consistent
with the `input_ids`.
Args:
input_ids: Flattened (concatenated) input_ids corresponding to a
batch.
pixel_values: The pixels in each input image.
See also:
:class:`LlavaImageInputs`
"""
if intermediate_tensors is not None:
input_ids = None
inputs_embeds = None
else:
# always pass the input via `inputs_embeds`
# to make sure the computation graph is consistent
image_input = self._parse_and_validate_image_input(**kwargs)
if image_input is not None:
vision_embeddings = self._process_image_input(image_input)
inputs_embeds = self.language_model.model.get_input_embeddings(
input_ids)
inputs_embeds = merge_multimodal_embeddings(
input_ids, inputs_embeds, vision_embeddings,
self.config.image_token_index)
else:
inputs_embeds = self.language_model.model.get_input_embeddings(
input_ids)
input_ids = None
hidden_states = self.language_model.model(input_ids,
positions,
kv_caches,
attn_metadata,
intermediate_tensors,
inputs_embeds=inputs_embeds)
return hidden_states
def compute_logits(
self,
hidden_states: torch.Tensor,
sampling_metadata: SamplingMetadata,
) -> Optional[torch.Tensor]:
return self.language_model.compute_logits(hidden_states,
sampling_metadata)
def sample(
self,
logits: torch.Tensor,
sampling_metadata: SamplingMetadata,
) -> Optional[SamplerOutput]:
return self.language_model.sample(logits, sampling_metadata)
def load_weights(self, weights: Iterable[Tuple[str, torch.Tensor]]):
loader = AutoWeightsLoader(self)
loader.load_weights(weights)