51 lines
2.0 KiB
Python
51 lines
2.0 KiB
Python
# Copyright (c) ModelScope Contributors. All rights reserved.
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import torch
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from swift.utils import get_last_valid_indices, get_logger
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from .trainer import Trainer
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from .utils import gather_for_unpadded_tensors
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logger = get_logger()
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class RerankerTrainer(Trainer):
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def __init__(self, *args, **kwargs):
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super().__init__(*args, **kwargs)
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self.gather_function = gather_for_unpadded_tensors
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def compute_loss(self, model, inputs, return_outputs=False, num_items_in_batch=None):
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# Check if we have a custom loss function
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if self.compute_loss_func is not None:
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# Get labels and compute outputs
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labels = inputs.pop('labels', None)
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outputs = model(**inputs)
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if self.task_type == 'generative_reranker':
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logits = outputs.logits
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attention_mask = inputs.get('attention_mask')
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last_valid_indices = -1 if attention_mask is None else get_last_valid_indices(attention_mask)
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batch_indices = torch.arange(logits.shape[0], device=logits.device)
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outputs.logits = logits[batch_indices, last_valid_indices]
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if labels is not None:
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# Call custom loss function
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loss = self.compute_loss_func(outputs, labels, num_items_in_batch=num_items_in_batch)
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else:
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# Fallback to model's loss
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loss = outputs.loss
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if num_items_in_batch is not None and self.model_accepts_loss_kwargs:
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loss = loss / self.args.gradient_accumulation_steps
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if labels is not None:
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self._compute_acc(outputs, labels)
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return (loss, outputs) if return_outputs else loss
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else:
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return super().compute_loss(model, inputs, return_outputs, num_items_in_batch)
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def evaluation_loop(self, *args, **kwargs):
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output = super().evaluation_loop(*args, **kwargs)
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self.gather_function = gather_for_unpadded_tensors
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return output
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