Maximilien de Bayser 515b413ebf
Prevent the cross-encoder logic from being applied to classification tasks (#18838)
Signed-off-by: Max de Bayser <mbayser@br.ibm.com>
Co-authored-by: Cyrus Leung <cyrus.tl.leung@gmail.com>
2025-05-28 19:16:17 -07:00

843 lines
31 KiB
Python

# SPDX-License-Identifier: Apache-2.0
import enum
import json
import os
import time
from functools import cache
from pathlib import Path
from typing import Any, Callable, Literal, Optional, Union
import huggingface_hub
from huggingface_hub import hf_hub_download
from huggingface_hub import list_repo_files as hf_list_repo_files
from huggingface_hub import try_to_load_from_cache
from huggingface_hub.utils import (EntryNotFoundError, HfHubHTTPError,
HFValidationError, LocalEntryNotFoundError,
RepositoryNotFoundError,
RevisionNotFoundError)
from torch import nn
from transformers import GenerationConfig, PretrainedConfig
from transformers.models.auto.image_processing_auto import (
get_image_processor_config)
from transformers.models.auto.modeling_auto import (
MODEL_FOR_CAUSAL_LM_MAPPING_NAMES)
from transformers.utils import CONFIG_NAME as HF_CONFIG_NAME
from vllm import envs
from vllm.logger import init_logger
# yapf conflicts with isort for this block
# yapf: disable
from vllm.transformers_utils.configs import (ChatGLMConfig, Cohere2Config,
DbrxConfig, DeepseekVLV2Config,
EAGLEConfig, ExaoneConfig,
H2OVLChatConfig,
InternVLChatConfig, JAISConfig,
KimiVLConfig, MedusaConfig,
MiniMaxText01Config,
MiniMaxVL01Config, MllamaConfig,
MLPSpeculatorConfig, MPTConfig,
NemotronConfig, NVLM_D_Config,
OvisConfig, RWConfig,
SkyworkR1VChatConfig, SolarConfig,
Telechat2Config, UltravoxConfig)
# yapf: enable
from vllm.transformers_utils.utils import check_gguf_file
from vllm.utils import resolve_obj_by_qualname
if envs.VLLM_USE_MODELSCOPE:
from modelscope import AutoConfig
else:
from transformers import AutoConfig
MISTRAL_CONFIG_NAME = "params.json"
logger = init_logger(__name__)
_CONFIG_REGISTRY_OVERRIDE_HF: dict[str, type[PretrainedConfig]] = {
"mllama": MllamaConfig
}
_CONFIG_REGISTRY: dict[str, type[PretrainedConfig]] = {
"chatglm": ChatGLMConfig,
"cohere2": Cohere2Config,
"dbrx": DbrxConfig,
"deepseek_vl_v2": DeepseekVLV2Config,
"kimi_vl": KimiVLConfig,
"mpt": MPTConfig,
"RefinedWeb": RWConfig, # For tiiuae/falcon-40b(-instruct)
"RefinedWebModel": RWConfig, # For tiiuae/falcon-7b(-instruct)
"jais": JAISConfig,
"mlp_speculator": MLPSpeculatorConfig,
"medusa": MedusaConfig,
"eagle": EAGLEConfig,
"exaone": ExaoneConfig,
"h2ovl_chat": H2OVLChatConfig,
"internvl_chat": InternVLChatConfig,
"minimax_text_01": MiniMaxText01Config,
"minimax_vl_01": MiniMaxVL01Config,
"nemotron": NemotronConfig,
"NVLM_D": NVLM_D_Config,
"ovis": OvisConfig,
"solar": SolarConfig,
"skywork_chat": SkyworkR1VChatConfig,
"telechat": Telechat2Config,
"ultravox": UltravoxConfig,
**_CONFIG_REGISTRY_OVERRIDE_HF
}
class ConfigFormat(str, enum.Enum):
AUTO = "auto"
HF = "hf"
MISTRAL = "mistral"
def with_retry(func: Callable[[], Any],
log_msg: str,
max_retries: int = 2,
retry_delay: int = 2):
for attempt in range(max_retries):
try:
return func()
except Exception as e:
if attempt == max_retries - 1:
logger.error("%s: %s", log_msg, e)
raise
logger.error("%s: %s, retrying %d of %d", log_msg, e, attempt + 1,
max_retries)
time.sleep(retry_delay)
retry_delay *= 2
# @cache doesn't cache exceptions
@cache
def list_repo_files(
repo_id: str,
*,
revision: Optional[str] = None,
repo_type: Optional[str] = None,
token: Union[str, bool, None] = None,
) -> list[str]:
def lookup_files() -> list[str]:
# directly list files if model is local
if (local_path := Path(repo_id)).exists():
return [
str(file.relative_to(local_path))
for file in local_path.rglob('*') if file.is_file()
]
# if model is remote, use hf_hub api to list files
try:
if envs.VLLM_USE_MODELSCOPE:
from vllm.transformers_utils.utils import (
modelscope_list_repo_files)
return modelscope_list_repo_files(repo_id,
revision=revision,
token=token)
return hf_list_repo_files(repo_id,
revision=revision,
repo_type=repo_type,
token=token)
except huggingface_hub.errors.OfflineModeIsEnabled:
# Don't raise in offline mode,
# all we know is that we don't have this
# file cached.
return []
return with_retry(lookup_files, "Error retrieving file list")
def file_exists(
repo_id: str,
file_name: str,
*,
repo_type: Optional[str] = None,
revision: Optional[str] = None,
token: Union[str, bool, None] = None,
) -> bool:
file_list = list_repo_files(repo_id,
repo_type=repo_type,
revision=revision,
token=token)
return file_name in file_list
# In offline mode the result can be a false negative
def file_or_path_exists(model: Union[str, Path], config_name: str,
revision: Optional[str]) -> bool:
if (local_path := Path(model)).exists():
return (local_path / config_name).is_file()
# Offline mode support: Check if config file is cached already
cached_filepath = try_to_load_from_cache(repo_id=model,
filename=config_name,
revision=revision)
if isinstance(cached_filepath, str):
# The config file exists in cache- we can continue trying to load
return True
# NB: file_exists will only check for the existence of the config file on
# hf_hub. This will fail in offline mode.
# Call HF to check if the file exists
return file_exists(str(model),
config_name,
revision=revision,
token=os.getenv('HF_TOKEN', None))
def patch_rope_scaling(config: PretrainedConfig) -> None:
"""Provide backwards compatibility for RoPE."""
text_config = getattr(config, "text_config", None)
if text_config is not None:
patch_rope_scaling(text_config)
rope_scaling = getattr(config, "rope_scaling", None)
if rope_scaling is not None:
patch_rope_scaling_dict(rope_scaling)
def patch_rope_scaling_dict(rope_scaling: dict[str, Any]) -> None:
if "rope_type" in rope_scaling and "type" in rope_scaling:
rope_type = rope_scaling["rope_type"]
rope_type_legacy = rope_scaling["type"]
if rope_type != rope_type_legacy:
raise ValueError(
f"Found conflicts between 'rope_type={rope_type}' (modern "
f"field) and 'type={rope_type_legacy}' (legacy field). "
"You should only specify one of them.")
if "rope_type" not in rope_scaling and "type" in rope_scaling:
rope_scaling["rope_type"] = rope_scaling["type"]
logger.info("Replacing legacy 'type' key with 'rope_type'")
if "rope_type" not in rope_scaling:
raise ValueError("rope_scaling should have a 'rope_type' key")
if rope_scaling["rope_type"] == "su":
rope_scaling["rope_type"] = "longrope"
logger.warning("Replacing legacy rope_type 'su' with 'longrope'")
elif rope_scaling["rope_type"] == "mrope":
assert "mrope_section" in rope_scaling
rope_scaling["rope_type"] = "default"
logger.warning("Replacing legacy rope_type 'mrope' with 'default'")
def _uses_mrope(config: PretrainedConfig) -> bool:
rope_scaling = getattr(config, "rope_scaling", None)
if rope_scaling is None:
return False
return "mrope_section" in rope_scaling
def uses_mrope(config: PretrainedConfig) -> bool:
"""Detect if the model with this config uses M-ROPE."""
return _uses_mrope(config) or thinker_uses_mrope(config)
def thinker_uses_mrope(config: PretrainedConfig) -> bool:
"""Detect if the model contains a thinker config and it uses M-ROPE."""
thinker_config = getattr(config, "thinker_config", None)
if thinker_config is None:
return False
thinker_text_config = getattr(thinker_config, "text_config", None)
if thinker_text_config is None:
return False
return uses_mrope(thinker_text_config)
def is_encoder_decoder(config: PretrainedConfig) -> bool:
"""Detect if the model with this config is used as an encoder/decoder."""
text_config = getattr(config, "text_config", None)
if text_config is not None:
return is_encoder_decoder(text_config)
return getattr(config, "is_encoder_decoder", False)
def get_config(
model: Union[str, Path],
trust_remote_code: bool,
revision: Optional[str] = None,
code_revision: Optional[str] = None,
config_format: ConfigFormat = ConfigFormat.AUTO,
**kwargs,
) -> PretrainedConfig:
# Separate model folder from file path for GGUF models
is_gguf = check_gguf_file(model)
if is_gguf:
kwargs["gguf_file"] = Path(model).name
model = Path(model).parent
if config_format == ConfigFormat.AUTO:
try:
if is_gguf or file_or_path_exists(
model, HF_CONFIG_NAME, revision=revision):
config_format = ConfigFormat.HF
elif file_or_path_exists(model,
MISTRAL_CONFIG_NAME,
revision=revision):
config_format = ConfigFormat.MISTRAL
else:
raise ValueError(
"Could not detect config format for no config file found. "
"Ensure your model has either config.json (HF format) "
"or params.json (Mistral format).")
except Exception as e:
error_message = (
"Invalid repository ID or local directory specified:"
" '{model}'.\nPlease verify the following requirements:\n"
"1. Provide a valid Hugging Face repository ID.\n"
"2. Specify a local directory that contains a recognized "
"configuration file.\n"
" - For Hugging Face models: ensure the presence of a "
"'config.json'.\n"
" - For Mistral models: ensure the presence of a "
"'params.json'.\n"
"3. For GGUF: pass the local path of the GGUF checkpoint.\n"
" Loading GGUF from a remote repo directly is not yet "
"supported.\n").format(model=model)
raise ValueError(error_message) from e
if config_format == ConfigFormat.HF:
config_dict, _ = PretrainedConfig.get_config_dict(
model,
revision=revision,
code_revision=code_revision,
token=os.getenv('HF_TOKEN', None),
**kwargs,
)
# Use custom model class if it's in our registry
model_type = config_dict.get("model_type")
if model_type in _CONFIG_REGISTRY:
config_class = _CONFIG_REGISTRY[model_type]
config = config_class.from_pretrained(
model,
revision=revision,
code_revision=code_revision,
token=os.getenv('HF_TOKEN', None),
**kwargs,
)
else:
try:
config = AutoConfig.from_pretrained(
model,
trust_remote_code=trust_remote_code,
revision=revision,
code_revision=code_revision,
token=os.getenv('HF_TOKEN', None),
**kwargs,
)
except ValueError as e:
if (not trust_remote_code
and "requires you to execute the configuration file"
in str(e)):
err_msg = (
"Failed to load the model config. If the model "
"is a custom model not yet available in the "
"HuggingFace transformers library, consider setting "
"`trust_remote_code=True` in LLM or using the "
"`--trust-remote-code` flag in the CLI.")
raise RuntimeError(err_msg) from e
else:
raise e
elif config_format == ConfigFormat.MISTRAL:
config = load_params_config(model, revision, **kwargs)
else:
supported_formats = [
fmt.value for fmt in ConfigFormat if fmt != ConfigFormat.AUTO
]
raise ValueError(
f"Unsupported config format: {config_format}. "
f"Supported formats are: {', '.join(supported_formats)}. "
f"Ensure your model uses one of these configuration formats "
f"or specify the correct format explicitly.")
# Special architecture mapping check for GGUF models
if is_gguf:
if config.model_type not in MODEL_FOR_CAUSAL_LM_MAPPING_NAMES:
raise RuntimeError(
f"Can't get gguf config for {config.model_type}.")
model_type = MODEL_FOR_CAUSAL_LM_MAPPING_NAMES[config.model_type]
config.update({"architectures": [model_type]})
patch_rope_scaling(config)
if trust_remote_code:
maybe_register_config_serialize_by_value()
return config
def try_get_local_file(model: Union[str, Path],
file_name: str,
revision: Optional[str] = 'main') -> Optional[Path]:
file_path = Path(model) / file_name
if file_path.is_file():
return file_path
else:
try:
cached_filepath = try_to_load_from_cache(repo_id=model,
filename=file_name,
revision=revision)
if isinstance(cached_filepath, str):
return Path(cached_filepath)
except HFValidationError:
...
return None
def get_hf_file_to_dict(file_name: str,
model: Union[str, Path],
revision: Optional[str] = 'main'):
"""
Downloads a file from the Hugging Face Hub and returns
its contents as a dictionary.
Parameters:
- file_name (str): The name of the file to download.
- model (str): The name of the model on the Hugging Face Hub.
- revision (str): The specific version of the model.
Returns:
- config_dict (dict): A dictionary containing
the contents of the downloaded file.
"""
file_path = try_get_local_file(model=model,
file_name=file_name,
revision=revision)
if file_path is None:
try:
hf_hub_file = hf_hub_download(model, file_name, revision=revision)
except huggingface_hub.errors.OfflineModeIsEnabled:
return None
except (RepositoryNotFoundError, RevisionNotFoundError,
EntryNotFoundError, LocalEntryNotFoundError) as e:
logger.debug("File or repository not found in hf_hub_download", e)
return None
except HfHubHTTPError as e:
logger.warning(
"Cannot connect to Hugging Face Hub. Skipping file "
"download for '%s':",
file_name,
exc_info=e)
return None
file_path = Path(hf_hub_file)
if file_path is not None and file_path.is_file():
with open(file_path) as file:
return json.load(file)
return None
@cache
def get_pooling_config(model: str, revision: Optional[str] = 'main'):
"""
This function gets the pooling and normalize
config from the model - only applies to
sentence-transformers models.
Args:
model (str): The name of the Hugging Face model.
revision (str, optional): The specific version
of the model to use. Defaults to 'main'.
Returns:
dict: A dictionary containing the pooling
type and whether normalization is used.
"""
modules_file_name = "modules.json"
modules_dict = None
if file_or_path_exists(model=model,
config_name=modules_file_name,
revision=revision):
modules_dict = get_hf_file_to_dict(modules_file_name, model, revision)
if modules_dict is None:
return None
logger.info("Found sentence-transformers modules configuration.")
pooling = next((item for item in modules_dict
if item["type"] == "sentence_transformers.models.Pooling"),
None)
normalize = bool(
next((item for item in modules_dict
if item["type"] == "sentence_transformers.models.Normalize"),
False))
if pooling:
pooling_file_name = "{}/config.json".format(pooling["path"])
pooling_dict = get_hf_file_to_dict(pooling_file_name, model, revision)
pooling_type_name = next(
(item for item, val in pooling_dict.items() if val is True), None)
if pooling_type_name is not None:
pooling_type_name = get_pooling_config_name(pooling_type_name)
logger.info("Found pooling configuration.")
return {"pooling_type": pooling_type_name, "normalize": normalize}
return None
def get_pooling_config_name(pooling_name: str) -> Union[str, None]:
if "pooling_mode_" in pooling_name:
pooling_name = pooling_name.replace("pooling_mode_", "")
if "_" in pooling_name:
pooling_name = pooling_name.split("_")[0]
if "lasttoken" in pooling_name:
pooling_name = "last"
supported_pooling_types = ['LAST', 'ALL', 'CLS', 'STEP', 'MEAN']
pooling_type_name = pooling_name.upper()
try:
if pooling_type_name in supported_pooling_types:
return pooling_type_name
except NotImplementedError as e:
logger.debug("Pooling type not supported", e)
return None
return None
@cache
def get_sentence_transformer_tokenizer_config(model: str,
revision: Optional[str] = 'main'
):
"""
Returns the tokenization configuration dictionary for a
given Sentence Transformer BERT model.
Parameters:
- model (str): The name of the Sentence Transformer
BERT model.
- revision (str, optional): The revision of the m
odel to use. Defaults to 'main'.
Returns:
- dict: A dictionary containing the configuration parameters
for the Sentence Transformer BERT model.
"""
sentence_transformer_config_files = [
"sentence_bert_config.json",
"sentence_roberta_config.json",
"sentence_distilbert_config.json",
"sentence_camembert_config.json",
"sentence_albert_config.json",
"sentence_xlm-roberta_config.json",
"sentence_xlnet_config.json",
]
encoder_dict = None
for config_file in sentence_transformer_config_files:
if try_get_local_file(model=model,
file_name=config_file,
revision=revision) is not None:
encoder_dict = get_hf_file_to_dict(config_file, model, revision)
if encoder_dict:
break
if not encoder_dict and not model.startswith("/"):
try:
# If model is on HuggingfaceHub, get the repo files
repo_files = list_repo_files(model,
revision=revision,
token=os.getenv('HF_TOKEN', None))
except Exception:
repo_files = []
for config_name in sentence_transformer_config_files:
if config_name in repo_files:
encoder_dict = get_hf_file_to_dict(config_name, model,
revision)
if encoder_dict:
break
if not encoder_dict:
return None
logger.info("Found sentence-transformers tokenize configuration.")
if all(k in encoder_dict for k in ("max_seq_length", "do_lower_case")):
return encoder_dict
return None
def maybe_register_config_serialize_by_value() -> None:
"""Try to register HF model configuration class to serialize by value
If trust_remote_code is set, and the model's config file specifies an
`AutoConfig` class, then the config class is typically an instance of
a custom class imported from the HF modules cache.
Examples:
>>> from transformers import AutoConfig
>>> klass = AutoConfig.from_pretrained('meta-llama/Meta-Llama-3-8B', trust_remote_code=True)
>>> klass.__class__ # transformers.models.llama.configuration_llama.LlamaConfig
>>> import transformers_modules # error, not initialized
>>> klass = AutoConfig.from_pretrained('deepseek-ai/DeepSeek-V2.5', trust_remote_code=True)
>>> import transformers_modules # success, initialized
>>> klass.__class__ # transformers_modules.deepseek-ai.DeepSeek-V2.5.98b11844770b2c3ffc18b175c758a803640f4e77.configuration_deepseek.DeepseekV2Config
In the DeepSeek example, the config class is an instance of a custom
class that is not serializable by default. This class will not be
importable in spawned workers, and won't exist at all on
other nodes, which breaks serialization of the config.
In this function we tell the cloudpickle serialization library to pass
instances of these generated classes by value instead of by reference,
i.e. the class definition is serialized along with its data so that the
class module does not need to be importable on the receiving end.
See: https://github.com/cloudpipe/cloudpickle?tab=readme-ov-file#overriding-pickles-serialization-mechanism-for-importable-constructs
""" # noqa
try:
import transformers_modules
except ImportError:
# the config does not need trust_remote_code
return
try:
import cloudpickle
cloudpickle.register_pickle_by_value(transformers_modules)
# ray vendors its own version of cloudpickle
from vllm.executor.ray_utils import ray
if ray:
ray.cloudpickle.register_pickle_by_value(transformers_modules)
# multiprocessing uses pickle to serialize arguments when using spawn
# Here we get pickle to use cloudpickle to serialize config objects
# that contain instances of the custom config class to avoid
# serialization problems if the generated module (and model) has a `.`
# in its name
import multiprocessing
import pickle
from vllm.config import VllmConfig
def _reduce_config(config: VllmConfig):
return (pickle.loads, (cloudpickle.dumps(config), ))
multiprocessing.reducer.register(VllmConfig, _reduce_config)
except Exception as e:
logger.warning(
"Unable to register remote classes used by"
" trust_remote_code with by-value serialization. This may"
" lead to a later error. If remote code is not needed"
" remove `--trust-remote-code`",
exc_info=e)
def load_params_config(model: Union[str, Path], revision: Optional[str],
**kwargs) -> PretrainedConfig:
# This function loads a params.json config which
# should be used when loading models in mistral format
config_file_name = "params.json"
config_dict = get_hf_file_to_dict(config_file_name, model, revision)
if config_dict is None:
raise ValueError(
f"Failed to load mistral '{config_file_name}' config for model "
f"{model}. Please check if the model is a mistral-format model "
f"and if the config file exists.")
assert isinstance(config_dict, dict)
config_mapping = {
"dim": "hidden_size",
"norm_eps": "rms_norm_eps",
"n_kv_heads": "num_key_value_heads",
"n_layers": "num_hidden_layers",
"n_heads": "num_attention_heads",
"hidden_dim": "intermediate_size",
}
def recurse_elems(elem: Any):
if isinstance(elem, dict):
config_dict = {}
for key, value in elem.items():
key = config_mapping.get(key, key)
config_dict[key] = recurse_elems(value)
return config_dict
else:
return elem
config_dict["model_type"] = config_dict.get("model_type", "transformer")
config_dict["hidden_act"] = config_dict.get("activation", "silu")
config_dict["tie_word_embeddings"] = config_dict.get(
"tie_embeddings", False)
if config_dict.get("max_position_embeddings") is None:
max_position_embeddings = 128_000
try:
trust_remote_code_val = kwargs.get("trust_remote_code", False)
hf_config = get_config(model=model,
trust_remote_code=trust_remote_code_val,
revision=revision,
config_format=ConfigFormat.HF)
if hf_value := hf_config.get_text_config().max_position_embeddings:
max_position_embeddings = hf_value
except Exception as e:
logger.warning(
"The params.json file is missing 'max_position_embeddings'"
" and could not get a value from the HF config."
" Defaulting to 128000",
exc_info=e)
config_dict["max_position_embeddings"] = max_position_embeddings
if config_dict.get("quantization") is not None:
quantization = config_dict.get("quantization", {})
if quantization.get("qformat_weight") == "fp8_e4m3":
# This maps to the FP8 static per-tensor quantization scheme
quantization_config = {
"quant_method": "fp8",
"activation_scheme": "static"
}
elif quantization.get("quant_method") == "compressed-tensors":
# Pass through the quantization config to compressed-tensors
quantization_config = quantization
else:
raise ValueError(
f"Found unknown quantization='{quantization}' in config")
config_dict["quantization_config"] = quantization_config
config_type: Literal["text",
"multimodal"] = "multimodal" if config_dict.get(
"vision_encoder") is not None else "text"
if config_dict.get("moe") is not None:
config_dict["architectures"] = ["MixtralForCausalLM"]
else:
config_dict["architectures"] = ["MistralForCausalLM"]
if config_type == "multimodal":
multimodal_config = config_dict.pop("vision_encoder")
quantization_config = config_dict.get("quantization_config", {})
config_dict = {
"text_config": config_dict,
"vision_config": multimodal_config
}
config_dict["architectures"] = ["PixtralForConditionalGeneration"]
config_dict["model_type"] = "pixtral"
if quantization_config:
config_dict["quantization_config"] = quantization_config
config_dict.update(kwargs)
config_dict = recurse_elems(config_dict)
# transform to HF config format
if config_type == "multimodal":
config_dict["text_config"] = PretrainedConfig(
**config_dict["text_config"])
config_dict["vision_config"] = PretrainedConfig(
**config_dict["vision_config"])
return PretrainedConfig(**config_dict)
def get_hf_image_processor_config(
model: Union[str, Path],
hf_token: Optional[Union[bool, str]] = None,
revision: Optional[str] = None,
**kwargs,
) -> dict[str, Any]:
# ModelScope does not provide an interface for image_processor
if envs.VLLM_USE_MODELSCOPE:
return dict()
# Separate model folder from file path for GGUF models
if check_gguf_file(model):
model = Path(model).parent
return get_image_processor_config(model,
token=hf_token,
revision=revision,
**kwargs)
def get_hf_text_config(config: PretrainedConfig):
"""Get the "sub" config relevant to llm for multi modal models.
No op for pure text models.
"""
# This block should be unnecessary after https://github.com/huggingface/transformers/pull/37517
if hasattr(config, "thinker_config"):
# TODO(suyang.fy): Refactor code.
# For Qwen2.5-Omni, change hf_text_config to
# thinker_config.text_config.
return config.thinker_config.text_config
text_config = config.get_text_config()
if text_config is not config:
# The code operates under the assumption that text_config should have
# `num_attention_heads` (among others). Assert here to fail early
# if transformers config doesn't align with this assumption.
assert hasattr(text_config, "num_attention_heads")
return text_config
def try_get_generation_config(
model: str,
trust_remote_code: bool,
revision: Optional[str] = None,
) -> Optional[GenerationConfig]:
try:
return GenerationConfig.from_pretrained(
model,
revision=revision,
)
except OSError: # Not found
try:
config = get_config(
model,
trust_remote_code=trust_remote_code,
revision=revision,
)
return GenerationConfig.from_model_config(config)
except OSError: # Not found
return None
def get_cross_encoder_activation_function(config: PretrainedConfig):
function_name: Optional[str] = None
if hasattr(config, "sentence_transformers") and "activation_fn" in \
config.sentence_transformers:
function_name = config.sentence_transformers["activation_fn"]
elif (hasattr(config, "sbert_ce_default_activation_function")
and config.sbert_ce_default_activation_function is not None):
function_name = config.sbert_ce_default_activation_function
if function_name is not None:
assert function_name.startswith("torch.nn.modules."), \
"Loading of activation functions is restricted to " \
"torch.nn.modules for security reasons"
return resolve_obj_by_qualname(function_name)()
else:
return nn.Sigmoid() if config.num_labels == 1 else nn.Identity()