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src/llmfactory/model/utils/valuehead.py

+from typing import TYPE_CHECKING, Dict
+
+import torch
+from transformers.utils import cached_file
+
+from ...extras.constants import V_HEAD_SAFE_WEIGHTS_NAME, V_HEAD_WEIGHTS_NAME
+from ...extras.logging import get_logger
+
+
+if TYPE_CHECKING:
+    from transformers import PreTrainedModel
+
+    from ...hparams import ModelArguments
+
+
+logger = get_logger(__name__)
+
+
+def load_valuehead_params(path_or_repo_id: str, model_args: "ModelArguments") -> Dict[str, torch.Tensor]:
+    r"""
+    Loads value head parameters from Hugging Face Hub or local disk.
+
+    Returns: dict with keys `v_head.summary.weight` and `v_head.summary.bias`.
+    """
+    kwargs = {"path_or_repo_id": path_or_repo_id, "cache_dir": model_args.cache_dir, "token": model_args.hf_hub_token}
+
+    try:
+        from safetensors import safe_open
+
+        vhead_file = cached_file(filename=V_HEAD_SAFE_WEIGHTS_NAME, **kwargs)
+        with safe_open(vhead_file, framework="pt", device="cpu") as f:
+            return {key: f.get_tensor(key) for key in f.keys()}
+    except Exception as err:
+        logger.info("Failed to load {}: {}".format(V_HEAD_SAFE_WEIGHTS_NAME, str(err)))
+
+    try:
+        vhead_file = cached_file(filename=V_HEAD_WEIGHTS_NAME, **kwargs)
+        return torch.load(vhead_file, map_location="cpu")
+    except Exception as err:
+        logger.info("Failed to load {}: {}".format(V_HEAD_WEIGHTS_NAME, str(err)))
+
+    logger.info("Provided path ({}) does not contain value head weights.".format(path_or_repo_id))
+    logger.info("Ignore these messages if you are not resuming the training of a value head model.")
+    return None
+
+
+def prepare_valuehead_model(model: "PreTrainedModel") -> None:
+    if getattr(model.config, "model_type", None) == "llava":
+        setattr(model, "lm_head", model.language_model.get_output_embeddings())
+        setattr(model, "_keys_to_ignore_on_save", ["lm_head.weight"])
+
+    if getattr(model.config, "model_type", None) == "chatglm":
+        setattr(model, "lm_head", model.transformer.output_layer)
+        setattr(model, "_keys_to_ignore_on_save", ["lm_head.weight"])
+
+    if getattr(model.config, "model_type", None) == "internlm2":
+        setattr(model, "lm_head", model.output)
+        setattr(model, "_keys_to_ignore_on_save", ["lm_head.weight"])