Files
2026-07-13 13:22:34 +08:00

126 lines
5.0 KiB
Python

import inspect
import logging
from typing import Any, Generator
from mlflow.exceptions import MlflowException
from mlflow.models.utils import _convert_llm_ndarray_to_list
from mlflow.protos.databricks_pb2 import INTERNAL_ERROR
from mlflow.pyfunc.model import (
_load_context_model_and_signature,
)
from mlflow.types.llm import ChatCompletionChunk, ChatCompletionResponse, ChatMessage, ChatParams
_logger = logging.getLogger(__name__)
def _load_pyfunc(model_path: str, model_config: dict[str, Any] | None = None):
context, chat_model, signature = _load_context_model_and_signature(model_path, model_config)
return _ChatModelPyfuncWrapper(chat_model=chat_model, context=context, signature=signature)
class _ChatModelPyfuncWrapper:
"""
Wrapper class that converts dict inputs to pydantic objects accepted by :class:`~ChatModel`.
"""
def __init__(self, chat_model, context, signature):
"""
Args:
chat_model: An instance of a subclass of :class:`~ChatModel`.
context: A :class:`~PythonModelContext` instance containing artifacts that
``chat_model`` may use when performing inference.
signature: :class:`~ModelSignature` instance describing model input and output.
"""
self.chat_model = chat_model
self.context = context
self.signature = signature
def get_raw_model(self):
"""
Returns the underlying model.
"""
return self.chat_model
def _convert_input(self, model_input):
import pandas
if isinstance(model_input, dict):
dict_input = model_input
elif isinstance(model_input, pandas.DataFrame):
dict_input = {
k: _convert_llm_ndarray_to_list(v[0])
for k, v in model_input.to_dict(orient="list").items()
}
else:
raise MlflowException(
"Unsupported model input type. Expected a dict or pandas.DataFrame, "
f"but got {type(model_input)} instead.",
error_code=INTERNAL_ERROR,
)
messages = [ChatMessage.from_dict(message) for message in dict_input.pop("messages", [])]
params = ChatParams.from_dict(dict_input)
return messages, params
def predict(
self, model_input: dict[str, Any], params: dict[str, Any] | None = None
) -> dict[str, Any]:
"""
Args:
model_input: Model input data in the form of a chat request.
params: Additional parameters to pass to the model for inference.
Unused in this implementation, as the params are handled
via ``self._convert_input()``.
Returns:
Model predictions in :py:class:`~ChatCompletionResponse` format.
"""
messages, params = self._convert_input(model_input)
parameters = inspect.signature(self.chat_model.predict).parameters
if "context" in parameters or len(parameters) == 3:
response = self.chat_model.predict(self.context, messages, params)
else:
response = self.chat_model.predict(messages, params)
return self._response_to_dict(response)
def _response_to_dict(self, response: ChatCompletionResponse) -> dict[str, Any]:
if not isinstance(response, ChatCompletionResponse):
raise MlflowException(
"Model returned an invalid response. Expected a ChatCompletionResponse, but "
f"got {type(response)} instead.",
error_code=INTERNAL_ERROR,
)
return response.to_dict()
def _streaming_response_to_dict(self, response: ChatCompletionChunk) -> dict[str, Any]:
if not isinstance(response, ChatCompletionChunk):
raise MlflowException(
"Model returned an invalid response. Expected a ChatCompletionChunk, but "
f"got {type(response)} instead.",
error_code=INTERNAL_ERROR,
)
return response.to_dict()
def predict_stream(
self, model_input: dict[str, Any], params: dict[str, Any] | None = None
) -> Generator[dict[str, Any], None, None]:
"""
Args:
model_input: Model input data in the form of a chat request.
params: Additional parameters to pass to the model for inference.
Unused in this implementation, as the params are handled
via ``self._convert_input()``.
Returns:
Generator over model predictions in :py:class:`~ChatCompletionChunk` format.
"""
messages, params = self._convert_input(model_input)
parameters = inspect.signature(self.chat_model.predict_stream).parameters
if "context" in parameters or len(parameters) == 3:
stream = self.chat_model.predict_stream(self.context, messages, params)
else:
stream = self.chat_model.predict_stream(messages, params)
for response in stream:
yield self._streaming_response_to_dict(response)