[chatgpt]support llama (#3070)

applications/ChatGPT/chatgpt/models/llama/__init__.py

+from .llama_actor import LlamaActor
+from .llama_critic import LlamaCritic
+from .llama_rm import LlamaRM
+
+__all__ = ['LlamaActor', 'LlamaCritic', 'LlamaRM']

applications/ChatGPT/chatgpt/models/llama/llama_actor.py

+from typing import Optional
+
+import torch
+from transformers import AutoModelForCausalLM, LlamaConfig, LlamaForCausalLM
+
+from ..base import Actor
+
+
+class LlamaActor(Actor):
+    """
+    Llama Actor model.
+
+    Args:
+        pretrained (str): Pretrained model name or path.
+        config (LlamaConfig): Model config.
+        checkpoint (bool): Enable gradient checkpointing.
+        lora_rank (int): LoRA rank.
+        lora_train_bias (str): LoRA bias training mode.
+    """
+
+    def __init__(self,
+                 pretrained: Optional[str] = None,
+                 config: Optional[LlamaConfig] = None,
+                 checkpoint: bool = False,
+                 lora_rank: int = 0,
+                 lora_train_bias: str = 'none') -> None:
+
+        if pretrained is not None:
+            model = LlamaForCausalLM.from_pretrained(pretrained)
+        elif config is not None:
+            model = LlamaForCausalLM(config)
+        else:
+            model = LlamaForCausalLM(LlamaConfig())
+
+        if checkpoint:
+            model.gradient_checkpointing_enable()
+
+        super().__init__(model, lora_rank, lora_train_bias)

applications/ChatGPT/chatgpt/models/llama/llama_critic.py

+from typing import Optional
+
+import torch
+import torch.nn as nn
+from transformers import AutoModelForCausalLM, LlamaConfig, LlamaForCausalLM
+
+from ..base import Critic
+
+
+class LlamaCritic(Critic):
+    """
+    Llama Critic model.
+
+    Args:
+        pretrained (str): Pretrained model name or path.
+        config (LlamaConfig): Model config.
+        checkpoint (bool): Enable gradient checkpointing.
+        lora_rank (int): LoRA rank.
+        lora_train_bias (str): LoRA bias training mode.
+    """
+
+    def __init__(self,
+                 pretrained: Optional[str] = None,
+                 config: Optional[LlamaConfig] = None,
+                 checkpoint: bool = False,
+                 lora_rank: int = 0,
+                 lora_train_bias: str = 'none',
+                 **kwargs) -> None:
+
+        if pretrained is not None:
+            model = LlamaForCausalLM.from_pretrained(pretrained)
+        elif config is not None:
+            model = LlamaForCausalLM(config)
+        else:
+            model = LlamaForCausalLM(LlamaConfig())
+
+        if checkpoint:
+            model.gradient_checkpointing_enable()
+
+        value_head = nn.Linear(model.config.hidden_size, 1)
+
+        super().__init__(model, value_head, lora_rank, lora_train_bias, **kwargs)

applications/ChatGPT/chatgpt/models/llama/llama_rm.py

+from typing import Optional
+
+import torch.nn as nn
+from transformers import LlamaConfig, LlamaForCausalLM
+
+from ..base import RewardModel
+
+
+class LlamaRM(RewardModel):
+    """
+    Llama Reward model.
+
+    Args:
+        pretrained (str): Pretrained model name or path.
+        config (LlamaConfig): Model config.
+        checkpoint (bool): Enable gradient checkpointing.
+        lora_rank (int): LoRA rank.
+        lora_train_bias (str): LoRA bias training mode.
+    """
+
+    def __init__(self,
+                 pretrained: Optional[str] = None,
+                 config: Optional[LlamaConfig] = None,
+                 checkpoint: bool = False,
+                 lora_rank: int = 0,
+                 lora_train_bias: str = 'none') -> None:
+
+        if pretrained is not None:
+            model = LlamaForCausalLM.from_pretrained(pretrained)
+        elif config is not None:
+            model = LlamaForCausalLM(config)
+        else:
+            model = LlamaForCausalLM(LlamaConfig())
+
+        if checkpoint:
+            model.gradient_checkpointing_enable()
+
+        value_head = nn.Linear(model.config.hidden_size, 1)
+        value_head.weight.data.normal_(mean=0.0, std=1 / (model.config.hidden_size + 1))
+
+        super().__init__(model, lora_rank, lora_train_bias)