File size: 5,980 Bytes
eec676d
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
import os
from pathlib import Path
from typing import Any, Dict, Optional, Union

import torch
from torch.nn import CrossEntropyLoss
from transformers import GenerationConfig, PretrainedConfig, PreTrainedModel
from transformers.modeling_outputs import CausalLMOutputWithPast

from modules import RoPE, shared
from modules.logging_colors import logger

try:
    from exllama.model import ExLlama, ExLlamaCache, ExLlamaConfig
except:
    logger.warning('Exllama module failed to load. Will attempt to load from repositories.')
    try:
        from modules.relative_imports import RelativeImport

        with RelativeImport("repositories/exllama"):
            from model import ExLlama, ExLlamaCache, ExLlamaConfig
    except:
        logger.error("Could not find repositories/exllama/. Make sure that exllama is cloned inside repositories/ and is up to date.")
        raise


class ExllamaHF(PreTrainedModel):
    def __init__(self, config: ExLlamaConfig):
        super().__init__(PretrainedConfig())
        self.ex_config = config
        self.ex_model = ExLlama(self.ex_config)
        self.generation_config = GenerationConfig()
        self.lora = None

        self.ex_cache = ExLlamaCache(self.ex_model)
        self.past_seq = None

        if shared.args.cfg_cache:
            self.ex_cache_negative = ExLlamaCache(self.ex_model)
            self.past_seq_negative = None

    def _validate_model_class(self):
        pass

    def _validate_model_kwargs(self, model_kwargs: Dict[str, Any]):
        pass

    def prepare_inputs_for_generation(self, input_ids, **kwargs):
        return {'input_ids': input_ids, **kwargs}

    @property
    def device(self) -> torch.device:
        return torch.device(0)

    def __call__(self, *args, **kwargs):
        use_cache = kwargs.get('use_cache', True)
        labels = kwargs.get('labels', None)
        past_key_values = kwargs.get('past_key_values', None)

        if len(args) > 0:
            if not shared.args.cfg_cache:
                logger.error("Please enable the cfg-cache option to use CFG with ExLlama_HF.")
                return

            input_ids = args[0]
            is_negative = True
            past_seq = self.past_seq_negative
            ex_cache = self.ex_cache_negative
        else:
            input_ids = kwargs['input_ids']
            is_negative = False
            past_seq = self.past_seq
            ex_cache = self.ex_cache

        seq = input_ids[0].tolist()
        if is_negative and past_key_values is not None:
            seq = past_key_values + seq

        seq_tensor = torch.tensor(seq)

        # Make the forward call
        if labels is None:
            if past_seq is None or not torch.equal(past_seq, seq_tensor[:-1]):
                ex_cache.current_seq_len = 0
                self.ex_model.forward(torch.tensor([seq[:-1]], dtype=torch.long), ex_cache, preprocess_only=True, lora=self.lora)

            logits = self.ex_model.forward(torch.tensor([seq[-1:]], dtype=torch.long), ex_cache, lora=self.lora).to(input_ids.device)
        else:
            ex_cache.current_seq_len = 0
            logits = self.ex_model.forward(torch.tensor([seq], dtype=torch.long), ex_cache, last_id_only=False, lora=self.lora)

        if is_negative:
            self.past_seq_negative = seq_tensor
        else:
            self.past_seq = seq_tensor

        loss = None
        if labels is not None:
            # Shift so that tokens < n predict n
            shift_logits = logits[..., :-1, :].contiguous()
            shift_labels = labels[..., 1:].contiguous()
            # Flatten the tokens
            loss_fct = CrossEntropyLoss()
            shift_logits = shift_logits.view(-1, logits.shape[-1])
            shift_labels = shift_labels.view(-1)
            # Enable model parallelism
            shift_labels = shift_labels.to(shift_logits.device)
            loss = loss_fct(shift_logits, shift_labels)

        return CausalLMOutputWithPast(logits=logits, past_key_values=seq if use_cache else None, loss=loss)

    @classmethod
    def from_pretrained(cls, pretrained_model_name_or_path: Optional[Union[str, os.PathLike]], *model_args, **kwargs):
        assert len(model_args) == 0 and len(kwargs) == 0, "extra args is currently not supported"
        if isinstance(pretrained_model_name_or_path, str):
            pretrained_model_name_or_path = Path(pretrained_model_name_or_path)

        pretrained_model_name_or_path = Path(f'{shared.args.model_dir}') / Path(pretrained_model_name_or_path)
        config = ExLlamaConfig(pretrained_model_name_or_path / 'config.json')

        # from 'oobabooga/text-generation-webui/modules/exllama.py'
        weight_path = None
        for ext in ['.safetensors', '.pt', '.bin']:
            found = list(pretrained_model_name_or_path.glob(f"*{ext}"))
            if len(found) > 0:
                weight_path = found[-1]
                break
        assert weight_path is not None, f'could not find weight in "{pretrained_model_name_or_path}"'

        config.model_path = str(weight_path)
        config.max_seq_len = shared.args.max_seq_len
        config.compress_pos_emb = shared.args.compress_pos_emb
        if shared.args.gpu_split:
            config.set_auto_map(shared.args.gpu_split)
            config.gpu_peer_fix = True

        if shared.args.alpha_value > 1 or shared.args.rope_freq_base > 0:
            config.alpha_value = RoPE.get_alpha_value(shared.args.alpha_value, shared.args.rope_freq_base)
            config.calculate_rotary_embedding_base()

        if torch.version.hip:
            config.rmsnorm_no_half2 = True
            config.rope_no_half2 = True
            config.matmul_no_half2 = True
            config.silu_no_half2 = True

        # This slowes down a bit but align better with autogptq generation.
        # TODO: Should give user choice to tune the exllama config
        # config.fused_attn = False
        # config.fused_mlp_thd = 0

        return ExllamaHF(config)