Spaces:
Runtime error
Runtime error
# Copyright 2024 Salesforce.com, inc. | |
# Copyright 2024 The HuggingFace Team. All rights reserved. | |
# | |
# Licensed under the Apache License, Version 2.0 (the "License"); | |
# you may not use this file except in compliance with the License. | |
# You may obtain a copy of the License at | |
# | |
# http://www.apache.org/licenses/LICENSE-2.0 | |
# | |
# Unless required by applicable law or agreed to in writing, software | |
# distributed under the License is distributed on an "AS IS" BASIS, | |
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
# See the License for the specific language governing permissions and | |
# limitations under the License. | |
from typing import Optional, Tuple, Union | |
import torch | |
from torch import nn | |
from transformers import CLIPPreTrainedModel | |
from transformers.modeling_outputs import BaseModelOutputWithPooling | |
from transformers.models.clip.configuration_clip import CLIPTextConfig | |
from transformers.models.clip.modeling_clip import CLIPEncoder | |
def _expand_mask(mask: torch.Tensor, dtype: torch.dtype, tgt_len: Optional[int] = None): | |
""" | |
Expands attention_mask from `[bsz, seq_len]` to `[bsz, 1, tgt_seq_len, src_seq_len]`. | |
""" | |
bsz, src_len = mask.size() | |
tgt_len = tgt_len if tgt_len is not None else src_len | |
expanded_mask = mask[:, None, None, :].expand(bsz, 1, tgt_len, src_len).to(dtype) | |
inverted_mask = 1.0 - expanded_mask | |
return inverted_mask.masked_fill(inverted_mask.to(torch.bool), torch.finfo(dtype).min) | |
# This is a modified version of the CLIPTextModel from transformers.models.clip.modeling_clip | |
# Which allows for an extra input of "context embeddings", which are the query embeddings used in Qformer | |
# They pass through the clip model, along with the text embeddings, and interact with them using self attention | |
class ContextCLIPTextModel(CLIPPreTrainedModel): | |
config_class = CLIPTextConfig | |
_no_split_modules = ["CLIPEncoderLayer"] | |
def __init__(self, config: CLIPTextConfig): | |
super().__init__(config) | |
self.text_model = ContextCLIPTextTransformer(config) | |
# Initialize weights and apply final processing | |
self.post_init() | |
def forward( | |
self, | |
ctx_embeddings: torch.Tensor = None, | |
ctx_begin_pos: list = None, | |
input_ids: Optional[torch.Tensor] = None, | |
attention_mask: Optional[torch.Tensor] = None, | |
position_ids: Optional[torch.Tensor] = None, | |
output_attentions: Optional[bool] = None, | |
output_hidden_states: Optional[bool] = None, | |
return_dict: Optional[bool] = None, | |
) -> Union[Tuple, BaseModelOutputWithPooling]: | |
return self.text_model( | |
ctx_embeddings=ctx_embeddings, | |
ctx_begin_pos=ctx_begin_pos, | |
input_ids=input_ids, | |
attention_mask=attention_mask, | |
position_ids=position_ids, | |
output_attentions=output_attentions, | |
output_hidden_states=output_hidden_states, | |
return_dict=return_dict, | |
) | |
class ContextCLIPTextTransformer(nn.Module): | |
def __init__(self, config: CLIPTextConfig): | |
super().__init__() | |
self.config = config | |
embed_dim = config.hidden_size | |
self.embeddings = ContextCLIPTextEmbeddings(config) | |
self.encoder = CLIPEncoder(config) | |
self.final_layer_norm = nn.LayerNorm(embed_dim) | |
def forward( | |
self, | |
ctx_embeddings: torch.Tensor, | |
ctx_begin_pos: list, | |
input_ids: Optional[torch.Tensor] = None, | |
attention_mask: Optional[torch.Tensor] = None, | |
position_ids: Optional[torch.Tensor] = None, | |
output_attentions: Optional[bool] = None, | |
output_hidden_states: Optional[bool] = None, | |
return_dict: Optional[bool] = None, | |
) -> Union[Tuple, BaseModelOutputWithPooling]: | |
r""" | |
Returns: | |
""" | |
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions | |
output_hidden_states = ( | |
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states | |
) | |
return_dict = return_dict if return_dict is not None else self.config.use_return_dict | |
if input_ids is None: | |
raise ValueError("You have to specify either input_ids") | |
input_shape = input_ids.size() | |
input_ids = input_ids.view(-1, input_shape[-1]) | |
hidden_states = self.embeddings( | |
input_ids=input_ids, | |
position_ids=position_ids, | |
ctx_embeddings=ctx_embeddings, | |
ctx_begin_pos=ctx_begin_pos, | |
) | |
bsz, seq_len = input_shape | |
if ctx_embeddings is not None: | |
seq_len += ctx_embeddings.size(1) | |
# CLIP's text model uses causal mask, prepare it here. | |
# https://github.com/openai/CLIP/blob/cfcffb90e69f37bf2ff1e988237a0fbe41f33c04/clip/model.py#L324 | |
causal_attention_mask = self._build_causal_attention_mask(bsz, seq_len, hidden_states.dtype).to( | |
hidden_states.device | |
) | |
# expand attention_mask | |
if attention_mask is not None: | |
# [bsz, seq_len] -> [bsz, 1, tgt_seq_len, src_seq_len] | |
attention_mask = _expand_mask(attention_mask, hidden_states.dtype) | |
encoder_outputs = self.encoder( | |
inputs_embeds=hidden_states, | |
attention_mask=attention_mask, | |
causal_attention_mask=causal_attention_mask, | |
output_attentions=output_attentions, | |
output_hidden_states=output_hidden_states, | |
return_dict=return_dict, | |
) | |
last_hidden_state = encoder_outputs[0] | |
last_hidden_state = self.final_layer_norm(last_hidden_state) | |
# text_embeds.shape = [batch_size, sequence_length, transformer.width] | |
# take features from the eot embedding (eot_token is the highest number in each sequence) | |
# casting to torch.int for onnx compatibility: argmax doesn't support int64 inputs with opset 14 | |
pooled_output = last_hidden_state[ | |
torch.arange(last_hidden_state.shape[0], device=input_ids.device), | |
input_ids.to(torch.int).argmax(dim=-1), | |
] | |
if not return_dict: | |
return (last_hidden_state, pooled_output) + encoder_outputs[1:] | |
return BaseModelOutputWithPooling( | |
last_hidden_state=last_hidden_state, | |
pooler_output=pooled_output, | |
hidden_states=encoder_outputs.hidden_states, | |
attentions=encoder_outputs.attentions, | |
) | |
def _build_causal_attention_mask(self, bsz, seq_len, dtype): | |
# lazily create causal attention mask, with full attention between the vision tokens | |
# pytorch uses additive attention mask; fill with -inf | |
mask = torch.empty(bsz, seq_len, seq_len, dtype=dtype) | |
mask.fill_(torch.tensor(torch.finfo(dtype).min)) | |
mask.triu_(1) # zero out the lower diagonal | |
mask = mask.unsqueeze(1) # expand mask | |
return mask | |
class ContextCLIPTextEmbeddings(nn.Module): | |
def __init__(self, config: CLIPTextConfig): | |
super().__init__() | |
embed_dim = config.hidden_size | |
self.token_embedding = nn.Embedding(config.vocab_size, embed_dim) | |
self.position_embedding = nn.Embedding(config.max_position_embeddings, embed_dim) | |
# position_ids (1, len position emb) is contiguous in memory and exported when serialized | |
self.register_buffer("position_ids", torch.arange(config.max_position_embeddings).expand((1, -1))) | |
def forward( | |
self, | |
ctx_embeddings: torch.Tensor, | |
ctx_begin_pos: list, | |
input_ids: Optional[torch.LongTensor] = None, | |
position_ids: Optional[torch.LongTensor] = None, | |
inputs_embeds: Optional[torch.FloatTensor] = None, | |
) -> torch.Tensor: | |
if ctx_embeddings is None: | |
ctx_len = 0 | |
else: | |
ctx_len = ctx_embeddings.shape[1] | |
seq_length = (input_ids.shape[-1] if input_ids is not None else inputs_embeds.shape[-2]) + ctx_len | |
if position_ids is None: | |
position_ids = self.position_ids[:, :seq_length] | |
if inputs_embeds is None: | |
inputs_embeds = self.token_embedding(input_ids) | |
# for each input embeddings, add the ctx embeddings at the correct position | |
input_embeds_ctx = [] | |
bsz = inputs_embeds.shape[0] | |
if ctx_embeddings is not None: | |
for i in range(bsz): | |
cbp = ctx_begin_pos[i] | |
prefix = inputs_embeds[i, :cbp] | |
# remove the special token embedding | |
suffix = inputs_embeds[i, cbp:] | |
input_embeds_ctx.append(torch.cat([prefix, ctx_embeddings[i], suffix], dim=0)) | |
inputs_embeds = torch.stack(input_embeds_ctx, dim=0) | |
position_embeddings = self.position_embedding(position_ids) | |
embeddings = inputs_embeds + position_embeddings | |
return embeddings | |