upload modeling_llava_phi.py

modeling_llava_phi.py

@@ -0,0 +1,252 @@
+from typing import List, Optional, Tuple, Union
+
+import torch
+import torch.nn as nn
+import math 
+import pdb
+from typing import Dict, Any
+from PIL import Image
+
+from transformers import AutoConfig, AutoModelForCausalLM, PretrainedConfig, PreTrainedModel
+                         
+
+from transformers.modeling_outputs import CausalLMOutputWithPast
+
+from .llava_arch import LlavaMetaModel, LlavaMetaForCausalLM
+
+from transformers.cache_utils import Cache, DynamicCache
+
+from transformers.generation.utils import GenerationConfig
+
+import sys
+from .modeling_phi import PhiForCausalLM, PhiModel, PhiConfig
+from .generation_utils import build_allava_input
+
+
+
+
+################ Phi ###############################
+
+class LlavaPhiConfig(PhiConfig):
+    model_type = "llava_phi"
+
+class LlavaPhiModel(LlavaMetaModel, PhiModel):
+    config_class = LlavaPhiConfig
+
+    def __init__(self, config: PhiConfig):
+        super(LlavaPhiModel, self).__init__(config)
+
+
+
+class LlavaPhiForCausalLM(PhiForCausalLM, LlavaMetaForCausalLM):
+    config_class = LlavaPhiConfig
+
+    def __init__(self, config, init_vision_encoder_from_ckpt=True): 
+        # note that the default value is set to True for this inference version. In training `init_vision_encoder_from_ckpt` is default to be True. 
+        config._attn_implementation = "flash_attention_2"
+
+        super(PhiForCausalLM, self).__init__(config)
+        # self.model is used in LlavaMetaForCausalLM.get_model(); self.transformer is used in PhiForCausalLM.forward()
+        self.model = LlavaPhiModel(config)
+        if hasattr(self.model, '_use_flash_attention_2'):
+            assert self.model._use_flash_attention_2, 'flash attn is not enabled. check it out!'
+        self.vocab_size = config.vocab_size
+        self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)
+        
+        if init_vision_encoder_from_ckpt:
+            vision_tower = self.get_vision_tower()
+            print(f'loading from CLIP first. This should only be used at inference!!!')
+            vision_tower.load_model() # 
+            
+        # Initialize weights and apply final processing
+        self.post_init()
+
+    def get_model(self):
+        return self.model
+    
+    def get_tokenizer(self):
+        return self.tokenizer
+    
+    def get_processor(self):
+        return self.model.vision_tower.image_processor
+    
+
+    def forward(
+        self,
+        input_ids: torch.LongTensor = None,
+        attention_mask: Optional[torch.Tensor] = None,
+        position_ids: Optional[torch.LongTensor] = None,
+        past_key_values: Optional[List[torch.FloatTensor]] = None,
+        inputs_embeds: Optional[torch.FloatTensor] = None,
+        labels: Optional[torch.LongTensor] = None,
+        use_cache: Optional[bool] = None,
+        output_attentions: Optional[bool] = None,
+        output_hidden_states: Optional[bool] = None,
+        images: Optional[torch.FloatTensor] = None,
+        return_dict: Optional[bool] = None,
+    ) -> Union[Tuple, CausalLMOutputWithPast]:
+        
+
+        if inputs_embeds is None:
+            (
+                input_ids,
+                position_ids,
+                attention_mask,
+                past_key_values,
+                inputs_embeds,
+                labels
+            # ) = self.prepare_inputs_labels_for_multimodal(
+            ) = self.prepare_inputs_labels_for_multimodal_new(
+                input_ids,
+                position_ids,
+                attention_mask,
+                past_key_values,
+                labels,
+                images
+            )
+
+        # pdb.set_trace()
+        return super().forward(
+            input_ids=input_ids,
+            attention_mask=attention_mask,
+            position_ids=position_ids,
+            past_key_values=past_key_values,
+            inputs_embeds=inputs_embeds,
+            labels=labels,
+            use_cache=use_cache,
+            output_attentions=output_attentions,
+            output_hidden_states=output_hidden_states,
+            return_dict=return_dict
+        )
+
+    def prepare_inputs_for_generation(self, input_ids, past_key_values=None, attention_mask=None, inputs_embeds=None, **kwargs):
+        '''
+        This function is called for each token at inference
+        '''
+        # pdb.set_trace()
+        images = kwargs.pop("images", None)
+
+        ####################################################
+        # lines from modeling_phi.py
+        ####################################################
+
+        if past_key_values is not None:
+            if isinstance(past_key_values, Cache):
+                cache_length = past_key_values.get_seq_length()
+                past_length = past_key_values.seen_tokens
+                max_cache_length = past_key_values.get_max_length()
+            else:
+                cache_length = past_length = past_key_values[0][0].shape[2]
+                max_cache_length = None
+
+            # Keep only the unprocessed tokens:
+            # 1 - If the length of the attention_mask exceeds the length of input_ids, then we are in a setting where
+            # some of the inputs are exclusively passed as part of the cache (e.g. when passing input_embeds as
+            # input)
+            if attention_mask is not None and attention_mask.shape[1] > input_ids.shape[1]:
+                input_ids = input_ids[:, -(attention_mask.shape[1] - past_length) :]
+            # 2 - If the past_length is smaller than input_ids', then input_ids holds all input tokens. We can discard
+            # input_ids based on the past_length.
+            elif past_length < input_ids.shape[1]:
+                input_ids = input_ids[:, past_length:]
+            # 3 - Otherwise (past_length >= input_ids.shape[1]), let's assume input_ids only has unprocessed tokens.
+            elif past_length >= input_ids.shape[1]:
+                input_ids = input_ids[:, [-1]] # only keep the last one!
+
+            # If we are about to go beyond the maximum cache length, we need to crop the input attention mask.
+            if (
+                max_cache_length is not None
+                and attention_mask is not None
+                and cache_length + input_ids.shape[1] > max_cache_length
+            ):
+                attention_mask = attention_mask[:, -max_cache_length:]
+
+        position_ids = kwargs.get("position_ids", None)
+        if attention_mask is not None and position_ids is None:
+            # create position_ids on the fly for batch generation
+            position_ids = attention_mask.long().cumsum(-1) - 1
+            position_ids.masked_fill_(attention_mask == 0, 1)
+            if past_key_values:
+                position_ids = position_ids[:, -input_ids.shape[1] :]
+
+        # if `inputs_embeds` are passed, we only want to use them in the 1st generation step
+        if inputs_embeds is not None and past_key_values is None:
+            model_inputs = {"inputs_embeds": inputs_embeds}
+        else:
+            model_inputs = {"input_ids": input_ids}
+        
+        model_inputs.update(
+            {
+                "position_ids": position_ids,
+                "past_key_values": past_key_values,
+                "use_cache": kwargs.get("use_cache"),
+                "attention_mask": attention_mask,
+            }
+        )
+        ####################################################
+        # end of lines from modeling_phi.py
+        ####################################################
+
+
+        if images is not None:
+            model_inputs['images'] = images
+        return model_inputs
+
+
+
+
+    def chat(
+        self, 
+        texts: Optional[str | list[list[str, str]]], 
+        images: Optional[str | list[str]] = None, 
+        history: Optional[list[str]] = None, 
+        stream = False, 
+        return_history = False, 
+        **kwargs
+    ):
+        '''
+        texts: if `str`, then generate for a single round; if list[dict], 
+        images: str (optional), local path to an image.
+        '''
+        use_cache = kwargs.pop('use_cache', True)
+
+
+        ############################
+        # merge history
+        ############################            
+        input_ids, image_tensors, history = build_allava_input(
+            tokenizer = self.get_tokenizer(), 
+            processor = self.get_processor(), 
+            texts = texts, 
+            images = images, 
+            history=history,
+            return_history=return_history,
+            device = self.device
+        )
+
+        ############################
+        # generate response
+        ############################
+        # with torch.autocast(device_type='cuda'):
+        if 'cuda' in str(self.device):
+            device_type = 'cuda'
+        else:
+            device_type = 'cpu'
+
+        with torch.autocast(device_type=device_type, dtype=self.dtype):
+            output_ids = self.generate(
+                inputs=input_ids,
+                images=image_tensors,
+                use_cache=use_cache,
+                **kwargs)
+
+        answer = self.get_tokenizer().decode(output_ids[0, input_ids.shape[1]:], skip_special_tokens=True).strip()
+
+        if return_history:
+            history[-1][-1] = answer
+            return answer, history
+        return answer
+
+
+AutoConfig.register("llava_phi", LlavaPhiConfig)
+AutoModelForCausalLM.register(LlavaPhiConfig, LlavaPhiForCausalLM)