41 lines
1.4 KiB
Python
41 lines
1.4 KiB
Python
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import torch
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classs BaseReranker:
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def process_input(self, pairs):
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inputs = self.tokenizer(
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pairs, padding=False, truncation='longest_first',
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return_attention_mask=False, max_length=self.max_length
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)
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inputs = self.tokenizer.pad(inputs, padding=True, return_tensors="pt", max_length=self.max_length)
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for key in inputs:
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inputs[key] = inputs[key].to(self.model.device)
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return inputs
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def build_sys_prompt(self, sys_prompt):
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return f"<|im_start|>system\n{sys_prompt}\n<|im_end|>"
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def build_user_prompt(self, query, docs, instruct=''):
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return f'<|im_start|>user\n<Instruct>: {instruct}\n<Query>:{query}\n<Document>:\n{doc}<|im_end|>'
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def build_assistant_prompt(self):
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return "<|im_start|>assistant\n<think>\n\n</think>\n\n"
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def compute_logits(self, inputs, **kwargs):
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batch_scores = self.model(**inputs).logits[:, -1, :]
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# true_vector = batch_scores[:, token_true_id]
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# false_vector = batch_scores[:, token_false_id]
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# batch_scores = torch.stack([false_vector, true_vector], dim=1)
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batch_scores = torch.nn.functional.log_softmax(batch_scores, dim=1)
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scores = batch_scores[:, 1].exp().tolist()
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return scores
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def rerank(self, query, docs, sys_prompt="", task=""):
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sys_str = self.build_sys_prompt(sys_prompt)
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ass_str = self.build_assistant_prompt()
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pairs = [ sys_str + '\n' + self.build_user_prompt(task, query, doc) + '\n' + ass_str for doc in docs ]
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inputs = self.process_inputs(pairs)
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scores = self.compute_logits(inputs)
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