omni / src /dataset /sft.py
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Flatten src layout: drop omni namespace, modules live directly under src/
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import json
import torch
from torch.utils.data import Dataset
from datasets import load_dataset, Features, Value
from dataset.common import pre_processing_chat, post_processing_chat
class SFTDataset(Dataset):
def __init__(self, jsonl_path, tokenizer, max_length=1024):
super().__init__()
self.tokenizer = tokenizer
self.max_length = max_length
features = Features({'conversations': [{'role': Value('string'), 'content': Value('string'), 'reasoning_content': Value('string'), 'tools': Value('string'), 'tool_calls': Value('string')}]})
self.samples = load_dataset('json', data_files=jsonl_path, split='train', features=features)
self.bos_id = tokenizer(f'{tokenizer.bos_token}assistant\n', add_special_tokens=False).input_ids
self.eos_id = tokenizer(f'{tokenizer.eos_token}\n', add_special_tokens=False).input_ids
def __len__(self):
return len(self.samples)
def create_chat_prompt(self, conversations):
messages = []
tools = None
for message in conversations:
message = dict(message)
if message.get("role") == "system" and message.get("tools"):
tools = json.loads(message["tools"]) if isinstance(message["tools"], str) else message["tools"]
if message.get("tool_calls") and isinstance(message["tool_calls"], str):
message["tool_calls"] = json.loads(message["tool_calls"])
messages.append(message)
return self.tokenizer.apply_chat_template(
messages,
tokenize=False,
add_generation_prompt=False,
tools=tools
)
def generate_labels(self, input_ids):
labels = [-100] * len(input_ids)
i = 0
while i < len(input_ids):
if input_ids[i:i + len(self.bos_id)] == self.bos_id:
start = i + len(self.bos_id)
end = start
while end < len(input_ids):
if input_ids[end:end + len(self.eos_id)] == self.eos_id:
break
end += 1
for j in range(start, min(end + len(self.eos_id), self.max_length)):
labels[j] = input_ids[j]
i = end + len(self.eos_id) if end < len(input_ids) else len(input_ids)
else:
i += 1
return labels
def __getitem__(self, index):
sample = self.samples[index]
conversations = pre_processing_chat(sample['conversations'])
prompt = self.create_chat_prompt(conversations)
prompt = post_processing_chat(prompt)
input_ids = self.tokenizer(prompt).input_ids[:self.max_length]
input_ids += [self.tokenizer.pad_token_id] * (self.max_length - len(input_ids))
labels = self.generate_labels(input_ids)
return torch.tensor(input_ids, dtype=torch.long), torch.tensor(labels, dtype=torch.long)