57 lines
2.1 KiB
Python
57 lines
2.1 KiB
Python
import torch
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import torch.nn as nn
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import torch.nn.functional as F
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from transformers import AutoModel
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class TransClassifier(nn.Module):
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def __init__(self, model_dir: str, output_classes: int, device: str="cuda"):
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super().__init__()
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self.backbone = AutoModel.from_pretrained(
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model_dir,
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dtype = "bfloat16",
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attn_implementation="flash_attention_2"
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).to(device).eval()
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self.device = device
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self.torch_dtype = torch.bfloat16
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self.hidden_size = self.backbone.config.hidden_size
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self.token_proj = nn.Linear(self.hidden_size, self.hidden_size).to(device=device, dtype=self.torch_dtype)
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self.classifier = nn.Sequential(
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nn.LayerNorm(self.hidden_size),
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nn.Linear(self.hidden_size, self.hidden_size//2),
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nn.GELU(),
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nn.Dropout(0.3),
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nn.Linear(self.hidden_size//2, self.hidden_size//4),
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nn.GELU(),
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nn.Dropout(0.2),
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nn.Linear(self.hidden_size//4, output_classes)
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).to(device=device, dtype=self.torch_dtype)
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for param in self.backbone.parameters():
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param.requires_grad = False
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def forward(self, model_inputs: dict):
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outputs = self.backbone(**model_inputs)
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proj_states = self.token_proj(outputs.last_hidden_state)
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attention_mask = model_inputs['attention_mask']
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mask_expanded = attention_mask.unsqueeze(-1).expand_as(proj_states).to(proj_states.dtype)
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sum_states = (proj_states * mask_expanded).sum(dim=1)
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valid_tokens = mask_expanded.sum(dim=1)
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pooled = sum_states / valid_tokens.clamp(min=1e-9)
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logits = self.classifier(pooled)
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return logits
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if __name__ == "__main__":
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model_dir = r"C:\Users\GA\Desktop\models\Qwen3-1.7B"
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device = "cuda"
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model = TransClassifier(model_dir, device)
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print(model.hidden_size)
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print(model)
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total_params = sum(p.numel() for p in model.parameters())
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trainable_params = sum(p.numel() for p in model.parameters() if p.requires_grad)
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print(f"总参数量: {total_params:,}")
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print(f"可训练参数量: {trainable_params:,}") |