mirror of https://github.com/hpcaitech/ColossalAI
76 lines
2.3 KiB
Python
76 lines
2.3 KiB
Python
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from dataclasses import dataclass
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from typing import List, Optional
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import torch
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import torch.nn.functional as F
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from coati.experience_maker.base import Experience
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@dataclass
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class BufferItem:
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"""BufferItem is an item of experience data.
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Shapes of each tensor:
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sequences: (S)
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action_log_probs: (A)
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values: (1)
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reward: (1)
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advantages: (1)
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attention_mask: (S)
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action_mask: (A)
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"A" is the number of actions.
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"""
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sequences: torch.Tensor
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action_log_probs: torch.Tensor
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values: torch.Tensor
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reward: torch.Tensor
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advantages: torch.Tensor
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attention_mask: Optional[torch.LongTensor]
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action_mask: Optional[torch.BoolTensor]
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def split_experience_batch(experience: Experience) -> List[BufferItem]:
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batch_size = experience.sequences.size(0)
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batch_kwargs = [{} for _ in range(batch_size)]
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keys = ('sequences', 'action_log_probs', 'values',
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'reward', 'advantages', 'attention_mask', 'action_mask')
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for key in keys:
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value = getattr(experience, key)
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if isinstance(value, torch.Tensor):
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vals = torch.unbind(value)
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else:
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# None
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vals = [value for _ in range(batch_size)]
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assert batch_size == len(vals)
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for i, v in enumerate(vals):
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batch_kwargs[i][key] = v
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items = [BufferItem(**kwargs) for kwargs in batch_kwargs]
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return items
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def _zero_pad_sequences(sequences: List[torch.Tensor], side: str = 'left') -> torch.Tensor:
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assert side in ('left', 'right')
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max_len = max(seq.size(0) for seq in sequences)
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padded_sequences = []
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for seq in sequences:
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pad_len = max_len - seq.size(0)
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padding = (pad_len, 0) if side == 'left' else (0, pad_len)
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padded_sequences.append(F.pad(seq, padding))
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return torch.stack(padded_sequences, dim=0)
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def make_experience_batch(items: List[BufferItem]) -> Experience:
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kwargs = {}
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to_pad_keys = set(('action_log_probs', 'action_mask'))
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keys = ('sequences', 'action_log_probs', 'values',
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'reward', 'advantages', 'attention_mask', 'action_mask')
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for key in keys:
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vals = [getattr(item, key) for item in items]
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if key in to_pad_keys:
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batch_data = _zero_pad_sequences(vals)
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else:
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batch_data = torch.stack(vals, dim=0)
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kwargs[key] = batch_data
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return Experience(**kwargs)
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