mirror of
https://github.com/hwchase17/langchain
synced 2024-11-02 09:40:22 +00:00
31891092d8
- Description: Add missing chunk parameter for _stream/_astream for some chat models, make all chat models in a consistent behaviour. - Issue: N/A - Dependencies: N/A
304 lines
10 KiB
Python
304 lines
10 KiB
Python
import json
|
|
import logging
|
|
from typing import Any, AsyncIterator, Dict, List, Optional, cast
|
|
|
|
import requests
|
|
from langchain_core.callbacks import (
|
|
AsyncCallbackManagerForLLMRun,
|
|
CallbackManagerForLLMRun,
|
|
)
|
|
from langchain_core.language_models.chat_models import BaseChatModel
|
|
from langchain_core.messages import (
|
|
AIMessage,
|
|
AIMessageChunk,
|
|
BaseMessage,
|
|
ChatMessage,
|
|
HumanMessage,
|
|
SystemMessage,
|
|
)
|
|
from langchain_core.outputs import ChatGeneration, ChatGenerationChunk, ChatResult
|
|
from langchain_core.pydantic_v1 import root_validator
|
|
from langchain_core.utils import get_from_dict_or_env
|
|
|
|
from langchain_community.llms.utils import enforce_stop_tokens
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
class PaiEasChatEndpoint(BaseChatModel):
|
|
"""Eas LLM Service chat model API.
|
|
|
|
To use, must have a deployed eas chat llm service on AliCloud. One can set the
|
|
environment variable ``eas_service_url`` and ``eas_service_token`` set with your eas
|
|
service url and service token.
|
|
|
|
Example:
|
|
.. code-block:: python
|
|
|
|
from langchain_community.chat_models import PaiEasChatEndpoint
|
|
eas_chat_endpoint = PaiEasChatEndpoint(
|
|
eas_service_url="your_service_url",
|
|
eas_service_token="your_service_token"
|
|
)
|
|
"""
|
|
|
|
"""PAI-EAS Service URL"""
|
|
eas_service_url: str
|
|
|
|
"""PAI-EAS Service TOKEN"""
|
|
eas_service_token: str
|
|
|
|
"""PAI-EAS Service Infer Params"""
|
|
max_new_tokens: Optional[int] = 512
|
|
temperature: Optional[float] = 0.8
|
|
top_p: Optional[float] = 0.1
|
|
top_k: Optional[int] = 10
|
|
do_sample: Optional[bool] = False
|
|
use_cache: Optional[bool] = True
|
|
stop_sequences: Optional[List[str]] = None
|
|
|
|
"""Enable stream chat mode."""
|
|
streaming: bool = False
|
|
|
|
"""Key/value arguments to pass to the model. Reserved for future use"""
|
|
model_kwargs: Optional[dict] = None
|
|
|
|
version: Optional[str] = "2.0"
|
|
|
|
timeout: Optional[int] = 5000
|
|
|
|
@root_validator()
|
|
def validate_environment(cls, values: Dict) -> Dict:
|
|
"""Validate that api key and python package exists in environment."""
|
|
values["eas_service_url"] = get_from_dict_or_env(
|
|
values, "eas_service_url", "EAS_SERVICE_URL"
|
|
)
|
|
values["eas_service_token"] = get_from_dict_or_env(
|
|
values, "eas_service_token", "EAS_SERVICE_TOKEN"
|
|
)
|
|
|
|
return values
|
|
|
|
@property
|
|
def _identifying_params(self) -> Dict[str, Any]:
|
|
"""Get the identifying parameters."""
|
|
_model_kwargs = self.model_kwargs or {}
|
|
return {
|
|
"eas_service_url": self.eas_service_url,
|
|
"eas_service_token": self.eas_service_token,
|
|
**{"model_kwargs": _model_kwargs},
|
|
}
|
|
|
|
@property
|
|
def _llm_type(self) -> str:
|
|
"""Return type of llm."""
|
|
return "pai_eas_chat_endpoint"
|
|
|
|
@property
|
|
def _default_params(self) -> Dict[str, Any]:
|
|
"""Get the default parameters for calling Cohere API."""
|
|
return {
|
|
"max_new_tokens": self.max_new_tokens,
|
|
"temperature": self.temperature,
|
|
"top_k": self.top_k,
|
|
"top_p": self.top_p,
|
|
"stop_sequences": [],
|
|
"do_sample": self.do_sample,
|
|
"use_cache": self.use_cache,
|
|
}
|
|
|
|
def _invocation_params(
|
|
self, stop_sequences: Optional[List[str]], **kwargs: Any
|
|
) -> dict:
|
|
params = self._default_params
|
|
if self.model_kwargs:
|
|
params.update(self.model_kwargs)
|
|
if self.stop_sequences is not None and stop_sequences is not None:
|
|
raise ValueError("`stop` found in both the input and default params.")
|
|
elif self.stop_sequences is not None:
|
|
params["stop"] = self.stop_sequences
|
|
else:
|
|
params["stop"] = stop_sequences
|
|
return {**params, **kwargs}
|
|
|
|
def format_request_payload(
|
|
self, messages: List[BaseMessage], **model_kwargs: Any
|
|
) -> dict:
|
|
prompt: Dict[str, Any] = {}
|
|
user_content: List[str] = []
|
|
assistant_content: List[str] = []
|
|
|
|
for message in messages:
|
|
"""Converts message to a dict according to role"""
|
|
content = cast(str, message.content)
|
|
if isinstance(message, HumanMessage):
|
|
user_content = user_content + [content]
|
|
elif isinstance(message, AIMessage):
|
|
assistant_content = assistant_content + [content]
|
|
elif isinstance(message, SystemMessage):
|
|
prompt["system_prompt"] = content
|
|
elif isinstance(message, ChatMessage) and message.role in [
|
|
"user",
|
|
"assistant",
|
|
"system",
|
|
]:
|
|
if message.role == "system":
|
|
prompt["system_prompt"] = content
|
|
elif message.role == "user":
|
|
user_content = user_content + [content]
|
|
elif message.role == "assistant":
|
|
assistant_content = assistant_content + [content]
|
|
else:
|
|
supported = ",".join([role for role in ["user", "assistant", "system"]])
|
|
raise ValueError(
|
|
f"""Received unsupported role.
|
|
Supported roles for the LLaMa Foundation Model: {supported}"""
|
|
)
|
|
prompt["prompt"] = user_content[len(user_content) - 1]
|
|
history = [
|
|
history_item
|
|
for _, history_item in enumerate(zip(user_content[:-1], assistant_content))
|
|
]
|
|
|
|
prompt["history"] = history
|
|
|
|
return {**prompt, **model_kwargs}
|
|
|
|
def _format_response_payload(
|
|
self, output: bytes, stop_sequences: Optional[List[str]]
|
|
) -> str:
|
|
"""Formats response"""
|
|
try:
|
|
text = json.loads(output)["response"]
|
|
if stop_sequences:
|
|
text = enforce_stop_tokens(text, stop_sequences)
|
|
return text
|
|
except Exception as e:
|
|
if isinstance(e, json.decoder.JSONDecodeError):
|
|
return output.decode("utf-8")
|
|
raise e
|
|
|
|
def _generate(
|
|
self,
|
|
messages: List[BaseMessage],
|
|
stop: Optional[List[str]] = None,
|
|
run_manager: Optional[CallbackManagerForLLMRun] = None,
|
|
**kwargs: Any,
|
|
) -> ChatResult:
|
|
output_str = self._call(messages, stop=stop, run_manager=run_manager, **kwargs)
|
|
message = AIMessage(content=output_str)
|
|
generation = ChatGeneration(message=message)
|
|
return ChatResult(generations=[generation])
|
|
|
|
def _call(
|
|
self,
|
|
messages: List[BaseMessage],
|
|
stop: Optional[List[str]] = None,
|
|
run_manager: Optional[CallbackManagerForLLMRun] = None,
|
|
**kwargs: Any,
|
|
) -> str:
|
|
params = self._invocation_params(stop, **kwargs)
|
|
|
|
request_payload = self.format_request_payload(messages, **params)
|
|
response_payload = self._call_eas(request_payload)
|
|
generated_text = self._format_response_payload(response_payload, params["stop"])
|
|
|
|
if run_manager:
|
|
run_manager.on_llm_new_token(generated_text)
|
|
|
|
return generated_text
|
|
|
|
def _call_eas(self, query_body: dict) -> Any:
|
|
"""Generate text from the eas service."""
|
|
headers = {
|
|
"Content-Type": "application/json",
|
|
"Accept": "application/json",
|
|
"Authorization": f"{self.eas_service_token}",
|
|
}
|
|
|
|
# make request
|
|
response = requests.post(
|
|
self.eas_service_url, headers=headers, json=query_body, timeout=self.timeout
|
|
)
|
|
|
|
if response.status_code != 200:
|
|
raise Exception(
|
|
f"Request failed with status code {response.status_code}"
|
|
f" and message {response.text}"
|
|
)
|
|
|
|
return response.text
|
|
|
|
def _call_eas_stream(self, query_body: dict) -> Any:
|
|
"""Generate text from the eas service."""
|
|
headers = {
|
|
"Content-Type": "application/json",
|
|
"Accept": "application/json",
|
|
"Authorization": f"{self.eas_service_token}",
|
|
}
|
|
|
|
# make request
|
|
response = requests.post(
|
|
self.eas_service_url, headers=headers, json=query_body, timeout=self.timeout
|
|
)
|
|
|
|
if response.status_code != 200:
|
|
raise Exception(
|
|
f"Request failed with status code {response.status_code}"
|
|
f" and message {response.text}"
|
|
)
|
|
|
|
return response
|
|
|
|
def _convert_chunk_to_message_message(
|
|
self,
|
|
chunk: str,
|
|
) -> AIMessageChunk:
|
|
data = json.loads(chunk.encode("utf-8"))
|
|
return AIMessageChunk(content=data.get("response", ""))
|
|
|
|
async def _astream(
|
|
self,
|
|
messages: List[BaseMessage],
|
|
stop: Optional[List[str]] = None,
|
|
run_manager: Optional[AsyncCallbackManagerForLLMRun] = None,
|
|
**kwargs: Any,
|
|
) -> AsyncIterator[ChatGenerationChunk]:
|
|
params = self._invocation_params(stop, **kwargs)
|
|
|
|
request_payload = self.format_request_payload(messages, **params)
|
|
request_payload["use_stream_chat"] = True
|
|
|
|
response = self._call_eas_stream(request_payload)
|
|
for chunk in response.iter_lines(
|
|
chunk_size=8192, decode_unicode=False, delimiter=b"\0"
|
|
):
|
|
if chunk:
|
|
content = self._convert_chunk_to_message_message(chunk)
|
|
|
|
# identify stop sequence in generated text, if any
|
|
stop_seq_found: Optional[str] = None
|
|
for stop_seq in params["stop"]:
|
|
if stop_seq in content.content:
|
|
stop_seq_found = stop_seq
|
|
|
|
# identify text to yield
|
|
text: Optional[str] = None
|
|
if stop_seq_found:
|
|
content.content = content.content[
|
|
: content.content.index(stop_seq_found)
|
|
]
|
|
|
|
# yield text, if any
|
|
if text:
|
|
cg_chunk = ChatGenerationChunk(message=content)
|
|
if run_manager:
|
|
await run_manager.on_llm_new_token(
|
|
cast(str, content.content), chunk=cg_chunk
|
|
)
|
|
yield cg_chunk
|
|
|
|
# break if stop sequence found
|
|
if stop_seq_found:
|
|
break
|