langchain/libs/partners/google-genai/langchain_google_genai/chat_models.py
2024-02-07 17:07:31 -08:00

694 lines
23 KiB
Python

from __future__ import annotations
import base64
import json
import logging
import os
from io import BytesIO
from typing import (
Any,
AsyncIterator,
Callable,
Dict,
Iterator,
List,
Mapping,
Optional,
Sequence,
Tuple,
Type,
Union,
cast,
)
from urllib.parse import urlparse
import google.api_core
# TODO: remove ignore once the google package is published with types
import google.generativeai as genai # type: ignore[import]
import requests
from google.ai.generativelanguage_v1beta import FunctionCall
from langchain_core.callbacks.manager import (
AsyncCallbackManagerForLLMRun,
CallbackManagerForLLMRun,
)
from langchain_core.language_models.chat_models import BaseChatModel
from langchain_core.messages import (
AIMessage,
AIMessageChunk,
BaseMessage,
ChatMessage,
ChatMessageChunk,
HumanMessage,
HumanMessageChunk,
SystemMessage,
)
from langchain_core.outputs import ChatGeneration, ChatGenerationChunk, ChatResult
from langchain_core.pydantic_v1 import SecretStr, root_validator
from langchain_core.utils import get_from_dict_or_env
from tenacity import (
before_sleep_log,
retry,
retry_if_exception_type,
stop_after_attempt,
wait_exponential,
)
from langchain_google_genai._common import GoogleGenerativeAIError
from langchain_google_genai._function_utils import (
convert_to_genai_function_declarations,
)
from langchain_google_genai.llms import GoogleModelFamily, _BaseGoogleGenerativeAI
IMAGE_TYPES: Tuple = ()
try:
import PIL
from PIL.Image import Image
IMAGE_TYPES = IMAGE_TYPES + (Image,)
except ImportError:
PIL = None # type: ignore
Image = None # type: ignore
logger = logging.getLogger(__name__)
class ChatGoogleGenerativeAIError(GoogleGenerativeAIError):
"""
Custom exception class for errors associated with the `Google GenAI` API.
This exception is raised when there are specific issues related to the
Google genai API usage in the ChatGoogleGenerativeAI class, such as unsupported
message types or roles.
"""
def _create_retry_decorator() -> Callable[[Any], Any]:
"""
Creates and returns a preconfigured tenacity retry decorator.
The retry decorator is configured to handle specific Google API exceptions
such as ResourceExhausted and ServiceUnavailable. It uses an exponential
backoff strategy for retries.
Returns:
Callable[[Any], Any]: A retry decorator configured for handling specific
Google API exceptions.
"""
multiplier = 2
min_seconds = 1
max_seconds = 60
max_retries = 10
return retry(
reraise=True,
stop=stop_after_attempt(max_retries),
wait=wait_exponential(multiplier=multiplier, min=min_seconds, max=max_seconds),
retry=(
retry_if_exception_type(google.api_core.exceptions.ResourceExhausted)
| retry_if_exception_type(google.api_core.exceptions.ServiceUnavailable)
| retry_if_exception_type(google.api_core.exceptions.GoogleAPIError)
),
before_sleep=before_sleep_log(logger, logging.WARNING),
)
def _chat_with_retry(generation_method: Callable, **kwargs: Any) -> Any:
"""
Executes a chat generation method with retry logic using tenacity.
This function is a wrapper that applies a retry mechanism to a provided
chat generation function. It is useful for handling intermittent issues
like network errors or temporary service unavailability.
Args:
generation_method (Callable): The chat generation method to be executed.
**kwargs (Any): Additional keyword arguments to pass to the generation method.
Returns:
Any: The result from the chat generation method.
"""
retry_decorator = _create_retry_decorator()
@retry_decorator
def _chat_with_retry(**kwargs: Any) -> Any:
try:
return generation_method(**kwargs)
# Do not retry for these errors.
except google.api_core.exceptions.FailedPrecondition as exc:
if "location is not supported" in exc.message:
error_msg = (
"Your location is not supported by google-generativeai "
"at the moment. Try to use ChatVertexAI LLM from "
"langchain_google_vertexai."
)
raise ValueError(error_msg)
except google.api_core.exceptions.InvalidArgument as e:
raise ChatGoogleGenerativeAIError(
f"Invalid argument provided to Gemini: {e}"
) from e
except Exception as e:
raise e
return _chat_with_retry(**kwargs)
async def _achat_with_retry(generation_method: Callable, **kwargs: Any) -> Any:
"""
Executes a chat generation method with retry logic using tenacity.
This function is a wrapper that applies a retry mechanism to a provided
chat generation function. It is useful for handling intermittent issues
like network errors or temporary service unavailability.
Args:
generation_method (Callable): The chat generation method to be executed.
**kwargs (Any): Additional keyword arguments to pass to the generation method.
Returns:
Any: The result from the chat generation method.
"""
retry_decorator = _create_retry_decorator()
from google.api_core.exceptions import InvalidArgument # type: ignore
@retry_decorator
async def _achat_with_retry(**kwargs: Any) -> Any:
try:
return await generation_method(**kwargs)
except InvalidArgument as e:
# Do not retry for these errors.
raise ChatGoogleGenerativeAIError(
f"Invalid argument provided to Gemini: {e}"
) from e
except Exception as e:
raise e
return await _achat_with_retry(**kwargs)
def _is_openai_parts_format(part: dict) -> bool:
return "type" in part
def _is_vision_model(model: str) -> bool:
return "vision" in model
def _is_url(s: str) -> bool:
try:
result = urlparse(s)
return all([result.scheme, result.netloc])
except Exception as e:
logger.debug(f"Unable to parse URL: {e}")
return False
def _is_b64(s: str) -> bool:
return s.startswith("data:image")
def _load_image_from_gcs(path: str, project: Optional[str] = None) -> Image:
try:
from google.cloud import storage # type: ignore[attr-defined]
except ImportError:
raise ImportError(
"google-cloud-storage is required to load images from GCS."
" Install it with `pip install google-cloud-storage`"
)
if PIL is None:
raise ImportError(
"PIL is required to load images. Please install it "
"with `pip install pillow`"
)
gcs_client = storage.Client(project=project)
pieces = path.split("/")
blobs = list(gcs_client.list_blobs(pieces[2], prefix="/".join(pieces[3:])))
if len(blobs) > 1:
raise ValueError(f"Found more than one candidate for {path}!")
img_bytes = blobs[0].download_as_bytes()
return PIL.Image.open(BytesIO(img_bytes))
def _url_to_pil(image_source: str) -> Image:
if PIL is None:
raise ImportError(
"PIL is required to load images. Please install it "
"with `pip install pillow`"
)
try:
if isinstance(image_source, IMAGE_TYPES):
return image_source # type: ignore[return-value]
elif _is_url(image_source):
if image_source.startswith("gs://"):
return _load_image_from_gcs(image_source)
response = requests.get(image_source)
response.raise_for_status()
return PIL.Image.open(BytesIO(response.content))
elif _is_b64(image_source):
_, encoded = image_source.split(",", 1)
data = base64.b64decode(encoded)
return PIL.Image.open(BytesIO(data))
elif os.path.exists(image_source):
return PIL.Image.open(image_source)
else:
raise ValueError(
"The provided string is not a valid URL, base64, or file path."
)
except Exception as e:
raise ValueError(f"Unable to process the provided image source: {e}")
def _convert_to_parts(
raw_content: Union[str, Sequence[Union[str, dict]]],
) -> List[genai.types.PartType]:
"""Converts a list of LangChain messages into a google parts."""
parts = []
content = [raw_content] if isinstance(raw_content, str) else raw_content
for part in content:
if isinstance(part, str):
parts.append(genai.types.PartDict(text=part))
elif isinstance(part, Mapping):
# OpenAI Format
if _is_openai_parts_format(part):
if part["type"] == "text":
parts.append({"text": part["text"]})
elif part["type"] == "image_url":
img_url = part["image_url"]
if isinstance(img_url, dict):
if "url" not in img_url:
raise ValueError(
f"Unrecognized message image format: {img_url}"
)
img_url = img_url["url"]
parts.append({"inline_data": _url_to_pil(img_url)})
else:
raise ValueError(f"Unrecognized message part type: {part['type']}")
else:
# Yolo
logger.warning(
"Unrecognized message part format. Assuming it's a text part."
)
parts.append(part)
else:
# TODO: Maybe some of Google's native stuff
# would hit this branch.
raise ChatGoogleGenerativeAIError(
"Gemini only supports text and inline_data parts."
)
return parts
def _parse_chat_history(
input_messages: Sequence[BaseMessage], convert_system_message_to_human: bool = False
) -> List[genai.types.ContentDict]:
messages: List[genai.types.MessageDict] = []
raw_system_message: Optional[SystemMessage] = None
for i, message in enumerate(input_messages):
if (
i == 0
and isinstance(message, SystemMessage)
and not convert_system_message_to_human
):
raise ValueError(
"""SystemMessages are not yet supported!
To automatically convert the leading SystemMessage to a HumanMessage,
set `convert_system_message_to_human` to True. Example:
llm = ChatGoogleGenerativeAI(model="gemini-pro", convert_system_message_to_human=True)
"""
)
elif i == 0 and isinstance(message, SystemMessage):
raw_system_message = message
continue
elif isinstance(message, AIMessage):
role = "model"
elif isinstance(message, HumanMessage):
role = "user"
else:
raise ValueError(
f"Unexpected message with type {type(message)} at the position {i}."
)
parts = _convert_to_parts(message.content)
if raw_system_message:
if role == "model":
raise ValueError(
"SystemMessage should be followed by a HumanMessage and "
"not by AIMessage."
)
parts = _convert_to_parts(raw_system_message.content) + parts
raw_system_message = None
messages.append({"role": role, "parts": parts})
return messages
def _retrieve_function_call_response(
parts: List[genai.types.PartType],
) -> Optional[Dict]:
for idx, part in enumerate(parts):
if part.function_call and part.function_call.name:
fc: FunctionCall = part.function_call
return {
"function_call": {
"name": fc.name,
"arguments": json.dumps(
dict(fc.args.items())
), # dump to match other function calling llms for now
}
}
return None
def _parts_to_content(
parts: List[genai.types.PartType],
) -> Tuple[Union[str, List[Union[Dict[Any, Any], str]]], Optional[Dict]]:
"""Converts a list of Gemini API Part objects into a list of LangChain messages."""
function_call_resp = _retrieve_function_call_response(parts)
if len(parts) == 1 and parts[0].text is not None and not parts[0].inline_data:
# Simple text response. The typical response
return parts[0].text, function_call_resp
elif not parts:
logger.warning("Gemini produced an empty response.")
return "", function_call_resp
messages: List[Union[Dict[Any, Any], str]] = []
for part in parts:
if part.text is not None:
messages.append(
{
"type": "text",
"text": part.text,
}
)
else:
# TODO: Handle inline_data if that's a thing?
raise ChatGoogleGenerativeAIError(f"Unexpected part type. {part}")
return messages, function_call_resp
def _response_to_result(
response: genai.types.GenerateContentResponse,
ai_msg_t: Type[BaseMessage] = AIMessage,
human_msg_t: Type[BaseMessage] = HumanMessage,
chat_msg_t: Type[BaseMessage] = ChatMessage,
generation_t: Type[ChatGeneration] = ChatGeneration,
) -> ChatResult:
"""Converts a PaLM API response into a LangChain ChatResult."""
llm_output = {}
if response.prompt_feedback:
try:
prompt_feedback = type(response.prompt_feedback).to_dict(
response.prompt_feedback, use_integers_for_enums=False
)
llm_output["prompt_feedback"] = prompt_feedback
except Exception as e:
logger.debug(f"Unable to convert prompt_feedback to dict: {e}")
generations: List[ChatGeneration] = []
role_map = {
"model": ai_msg_t,
"user": human_msg_t,
}
for candidate in response.candidates:
content = candidate.content
parts_content, additional_kwargs = _parts_to_content(content.parts)
if content.role not in role_map:
logger.warning(
f"Unrecognized role: {content.role}. Treating as a ChatMessage."
)
msg = chat_msg_t(
content=parts_content,
role=content.role,
additional_kwargs=additional_kwargs or {},
)
else:
msg = role_map[content.role](
content=parts_content,
additional_kwargs=additional_kwargs or {},
)
generation_info = {}
if candidate.finish_reason:
generation_info["finish_reason"] = candidate.finish_reason.name
if candidate.safety_ratings:
generation_info["safety_ratings"] = [
type(rating).to_dict(rating) for rating in candidate.safety_ratings
]
generations.append(generation_t(message=msg, generation_info=generation_info))
if not response.candidates:
# Likely a "prompt feedback" violation (e.g., toxic input)
# Raising an error would be different than how OpenAI handles it,
# so we'll just log a warning and continue with an empty message.
logger.warning(
"Gemini produced an empty response. Continuing with empty message\n"
f"Feedback: {response.prompt_feedback}"
)
generations = [generation_t(message=ai_msg_t(content=""), generation_info={})]
return ChatResult(generations=generations, llm_output=llm_output)
class ChatGoogleGenerativeAI(_BaseGoogleGenerativeAI, BaseChatModel):
"""`Google Generative AI` Chat models API.
To use, you must have either:
1. The ``GOOGLE_API_KEY``` environment variable set with your API key, or
2. Pass your API key using the google_api_key kwarg to the ChatGoogle
constructor.
Example:
.. code-block:: python
from langchain_google_genai import ChatGoogleGenerativeAI
chat = ChatGoogleGenerativeAI(model="gemini-pro")
chat.invoke("Write me a ballad about LangChain")
"""
client: Any #: :meta private:
convert_system_message_to_human: bool = False
"""Whether to merge any leading SystemMessage into the following HumanMessage.
Gemini does not support system messages; any unsupported messages will
raise an error."""
class Config:
allow_population_by_field_name = True
@property
def lc_secrets(self) -> Dict[str, str]:
return {"google_api_key": "GOOGLE_API_KEY"}
@property
def _llm_type(self) -> str:
return "chat-google-generative-ai"
@classmethod
def is_lc_serializable(self) -> bool:
return True
@root_validator()
def validate_environment(cls, values: Dict) -> Dict:
"""Validates params and passes them to google-generativeai package."""
google_api_key = get_from_dict_or_env(
values, "google_api_key", "GOOGLE_API_KEY"
)
if isinstance(google_api_key, SecretStr):
google_api_key = google_api_key.get_secret_value()
genai.configure(
api_key=google_api_key,
transport=values.get("transport"),
client_options=values.get("client_options"),
)
if (
values.get("temperature") is not None
and not 0 <= values["temperature"] <= 1
):
raise ValueError("temperature must be in the range [0.0, 1.0]")
if values.get("top_p") is not None and not 0 <= values["top_p"] <= 1:
raise ValueError("top_p must be in the range [0.0, 1.0]")
if values.get("top_k") is not None and values["top_k"] <= 0:
raise ValueError("top_k must be positive")
model = values["model"]
values["client"] = genai.GenerativeModel(model_name=model)
return values
@property
def _identifying_params(self) -> Dict[str, Any]:
"""Get the identifying parameters."""
return {
"model": self.model,
"temperature": self.temperature,
"top_k": self.top_k,
"n": self.n,
}
def _prepare_params(
self, stop: Optional[List[str]], **kwargs: Any
) -> Dict[str, Any]:
gen_config = {
k: v
for k, v in {
"candidate_count": self.n,
"temperature": self.temperature,
"stop_sequences": stop,
"max_output_tokens": self.max_output_tokens,
"top_k": self.top_k,
"top_p": self.top_p,
}.items()
if v is not None
}
if "generation_config" in kwargs:
gen_config = {**gen_config, **kwargs.pop("generation_config")}
params = {"generation_config": gen_config, **kwargs}
return params
def _generate(
self,
messages: List[BaseMessage],
stop: Optional[List[str]] = None,
run_manager: Optional[CallbackManagerForLLMRun] = None,
**kwargs: Any,
) -> ChatResult:
params, chat, message = self._prepare_chat(
messages,
stop=stop,
functions=kwargs.get("functions"),
)
response: genai.types.GenerateContentResponse = _chat_with_retry(
content=message,
**params,
generation_method=chat.send_message,
)
return _response_to_result(response)
async def _agenerate(
self,
messages: List[BaseMessage],
stop: Optional[List[str]] = None,
run_manager: Optional[AsyncCallbackManagerForLLMRun] = None,
**kwargs: Any,
) -> ChatResult:
params, chat, message = self._prepare_chat(
messages,
stop=stop,
functions=kwargs.get("functions"),
)
response: genai.types.GenerateContentResponse = await _achat_with_retry(
content=message,
**params,
generation_method=chat.send_message_async,
)
return _response_to_result(response)
def _stream(
self,
messages: List[BaseMessage],
stop: Optional[List[str]] = None,
run_manager: Optional[CallbackManagerForLLMRun] = None,
**kwargs: Any,
) -> Iterator[ChatGenerationChunk]:
params, chat, message = self._prepare_chat(
messages,
stop=stop,
functions=kwargs.get("functions"),
)
response: genai.types.GenerateContentResponse = _chat_with_retry(
content=message,
**params,
generation_method=chat.send_message,
stream=True,
)
for chunk in response:
_chat_result = _response_to_result(
chunk,
ai_msg_t=AIMessageChunk,
human_msg_t=HumanMessageChunk,
chat_msg_t=ChatMessageChunk,
generation_t=ChatGenerationChunk,
)
gen = cast(ChatGenerationChunk, _chat_result.generations[0])
yield gen
if run_manager:
run_manager.on_llm_new_token(gen.text)
async def _astream(
self,
messages: List[BaseMessage],
stop: Optional[List[str]] = None,
run_manager: Optional[AsyncCallbackManagerForLLMRun] = None,
**kwargs: Any,
) -> AsyncIterator[ChatGenerationChunk]:
params, chat, message = self._prepare_chat(
messages,
stop=stop,
functions=kwargs.get("functions"),
)
async for chunk in await _achat_with_retry(
content=message,
**params,
generation_method=chat.send_message_async,
stream=True,
):
_chat_result = _response_to_result(
chunk,
ai_msg_t=AIMessageChunk,
human_msg_t=HumanMessageChunk,
chat_msg_t=ChatMessageChunk,
generation_t=ChatGenerationChunk,
)
gen = cast(ChatGenerationChunk, _chat_result.generations[0])
yield gen
if run_manager:
await run_manager.on_llm_new_token(gen.text)
def _prepare_chat(
self,
messages: List[BaseMessage],
stop: Optional[List[str]] = None,
**kwargs: Any,
) -> Tuple[Dict[str, Any], genai.ChatSession, genai.types.ContentDict]:
client = self.client
functions = kwargs.pop("functions", None)
if functions:
tools = convert_to_genai_function_declarations(functions)
client = genai.GenerativeModel(model_name=self.model, tools=tools)
params = self._prepare_params(stop, **kwargs)
history = _parse_chat_history(
messages,
convert_system_message_to_human=self.convert_system_message_to_human,
)
message = history.pop()
chat = client.start_chat(history=history)
return params, chat, message
def get_num_tokens(self, text: str) -> int:
"""Get the number of tokens present in the text.
Useful for checking if an input will fit in a model's context window.
Args:
text: The string input to tokenize.
Returns:
The integer number of tokens in the text.
"""
if self._model_family == GoogleModelFamily.GEMINI:
result = self.client.count_tokens(text)
token_count = result.total_tokens
else:
result = self.client.count_text_tokens(model=self.model, prompt=text)
token_count = result["token_count"]
return token_count