Add skeleton

src/alignment/model_utils.py

@@ -0,0 +1,79 @@
+from typing import Dict, Union
+
+import torch
+from transformers import AutoTokenizer, BitsAndBytesConfig, PreTrainedTokenizer
+
+from accelerate import Accelerator
+from peft import LoraConfig, PeftConfig
+
+from .configs import DataArguments, ModelArguments
+from .data import DEFAULT_CHAT_TEMPLATE
+
+
+def get_current_device() -> int:
+    """Get the current device. For GPU we return the local process index to enable multiple GPU training."""
+    return Accelerator().local_process_index if torch.cuda.is_available() else "cpu"
+
+
+def get_kbit_device_map() -> Dict[str, int] | None:
+    """Useful for running inference with quantized models by setting `device_map=get_peft_device_map()`"""
+    return {"": get_current_device()} if torch.cuda.is_available() else None
+
+
+def get_quantization_config(model_args) -> BitsAndBytesConfig | None:
+    if model_args.load_in_4bit:
+        quantization_config = BitsAndBytesConfig(
+            load_in_4bit=True,
+            bnb_4bit_compute_dtype=torch.float16,  # For consistency with model weights, we use the same value as `torch_dtype` which is float16 for PEFT models
+            bnb_4bit_quant_type=model_args.bnb_4bit_quant_type,
+            bnb_4bit_use_double_quant=model_args.use_bnb_nested_quant,
+        )
+    elif model_args.load_in_8bit:
+        quantization_config = BitsAndBytesConfig(
+            load_in_8bit=True,
+        )
+    else:
+        quantization_config = None
+
+    return quantization_config
+
+
+def get_tokenizer(model_args: ModelArguments, data_args: DataArguments) -> PreTrainedTokenizer:
+    """Get the tokenizer for the model."""
+    tokenizer = AutoTokenizer.from_pretrained(
+        model_args.model_name_or_path,
+        revision=model_args.model_revision,
+    )
+    if tokenizer.pad_token_id is None:
+        tokenizer.pad_token_id = tokenizer.eos_token_id
+
+    if data_args.truncation_side is not None:
+        tokenizer.truncation_side = data_args.truncation_side
+
+    # Set reasonable default for models without max length
+    if tokenizer.model_max_length > 100_000:
+        tokenizer.model_max_length = 2048
+
+    if data_args.chat_template is not None:
+        tokenizer.chat_template = data_args.chat_template
+    elif tokenizer.chat_template is None:
+        tokenizer.chat_template = DEFAULT_CHAT_TEMPLATE
+
+    return tokenizer
+
+
+def get_peft_config(model_args: ModelArguments) -> Union[PeftConfig, None]:
+    if model_args.use_peft is False:
+        return None
+
+    peft_config = LoraConfig(
+        r=model_args.lora_r,
+        lora_alpha=model_args.lora_alpha,
+        lora_dropout=model_args.lora_dropout,
+        bias="none",
+        task_type="CAUSAL_LM",
+        target_modules=model_args.lora_target_modules,
+        modules_to_save=model_args.lora_modules_to_save,
+    )
+
+    return peft_config