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""" |
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GPT-OSS モデル実装 |
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OpenAIの完全オープンソースモデル（Apache 2.0） |
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MoEアーキテクチャで21Bパラメータ、active 3.6B |
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""" |
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from typing import List, Tuple |
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import torch |
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from transformers import AutoModelForCausalLM, AutoTokenizer |
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from .base import BaseLanguageModel, ModelConfig |
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GPT_OSS_20B_CONFIG = ModelConfig( |
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name="GPT-OSS 20B (MoE)", |
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model_id="openai/gpt-oss-20b", |
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embedding_dim=4096, |
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vocab_size=128000, |
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) |
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class GPTOSSModel(BaseLanguageModel): |
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""" |
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GPT-OSS MoEモデルの実装 |
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OpenAIがApache 2.0でリリースした完全オープンソースモデル。 |
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21Bパラメータ（active 3.6B）のMoEアーキテクチャ。 |
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""" |
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LOGITS_NOISE_SCALE = 10.0 |
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def load(self) -> None: |
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"""モデルとトークナイザーをロード""" |
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if self._is_loaded: |
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return |
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try: |
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self._model = AutoModelForCausalLM.from_pretrained( |
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self._config.model_id, |
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torch_dtype="auto", |
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device_map="auto", |
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) |
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self._tokenizer = AutoTokenizer.from_pretrained(self._config.model_id) |
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self._model.eval() |
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self._is_loaded = True |
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except Exception as e: |
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raise RuntimeError(f"Failed to load model {self._config.model_id}: {e}") |
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def forward_with_noise( |
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self, noise: torch.Tensor |
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) -> Tuple[torch.Tensor, torch.Tensor]: |
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""" |
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ノイズを入力として順伝播を実行し、出力にもノイズを加算 |
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Args: |
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noise: 入力ノイズテンソル [batch, seq_len, embedding_dim] |
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Returns: |
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Tuple[logits, corrupted_logits] |
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""" |
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if not self._is_loaded: |
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raise RuntimeError("Model not loaded. Call load() first.") |
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with torch.no_grad(): |
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outputs = self._model(inputs_embeds=noise) |
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logits = outputs.logits |
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logits_noise = ( |
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torch.randn_like(logits) * logits.std() * self.LOGITS_NOISE_SCALE |
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) |
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corrupted_logits = logits + logits_noise |
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return logits, corrupted_logits |
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def decode_indices(self, indices: List[int]) -> List[str]: |
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"""トークンインデックスをデコード""" |
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if not self._is_loaded: |
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raise RuntimeError("Model not loaded. Call load() first.") |
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return [self._tokenizer.decode([i]) for i in indices] |
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