dify/api/core/completion.py

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Python
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2023-05-15 08:51:32 +08:00
from typing import Optional, List, Union
from langchain.callbacks import CallbackManager
from langchain.chat_models.base import BaseChatModel
from langchain.llms import BaseLLM
from langchain.schema import BaseMessage, BaseLanguageModel, HumanMessage
from core.constant import llm_constant
from core.callback_handler.llm_callback_handler import LLMCallbackHandler
from core.callback_handler.std_out_callback_handler import DifyStreamingStdOutCallbackHandler, \
DifyStdOutCallbackHandler
from core.conversation_message_task import ConversationMessageTask, ConversationTaskStoppedException
from core.llm.error import LLMBadRequestError
from core.llm.llm_builder import LLMBuilder
from core.chain.main_chain_builder import MainChainBuilder
from core.llm.streamable_chat_open_ai import StreamableChatOpenAI
from core.llm.streamable_open_ai import StreamableOpenAI
from core.memory.read_only_conversation_token_db_buffer_shared_memory import \
ReadOnlyConversationTokenDBBufferSharedMemory
from core.memory.read_only_conversation_token_db_string_buffer_shared_memory import \
ReadOnlyConversationTokenDBStringBufferSharedMemory
from core.prompt.prompt_builder import PromptBuilder
from core.prompt.prompt_template import OutLinePromptTemplate
from core.prompt.prompts import MORE_LIKE_THIS_GENERATE_PROMPT
from models.model import App, AppModelConfig, Account, Conversation, Message
class Completion:
@classmethod
def generate(cls, task_id: str, app: App, app_model_config: AppModelConfig, query: str, inputs: dict,
user: Account, conversation: Optional[Conversation], streaming: bool, is_override: bool = False):
"""
errors: ProviderTokenNotInitError
"""
cls.validate_query_tokens(app.tenant_id, app_model_config, query)
memory = None
if conversation:
# get memory of conversation (read-only)
memory = cls.get_memory_from_conversation(
tenant_id=app.tenant_id,
app_model_config=app_model_config,
conversation=conversation
)
inputs = conversation.inputs
conversation_message_task = ConversationMessageTask(
task_id=task_id,
app=app,
app_model_config=app_model_config,
user=user,
conversation=conversation,
is_override=is_override,
inputs=inputs,
query=query,
streaming=streaming
)
# build main chain include agent
main_chain = MainChainBuilder.to_langchain_components(
tenant_id=app.tenant_id,
agent_mode=app_model_config.agent_mode_dict,
memory=ReadOnlyConversationTokenDBStringBufferSharedMemory(memory=memory) if memory else None,
conversation_message_task=conversation_message_task
)
chain_output = ''
if main_chain:
chain_output = main_chain.run(query)
# run the final llm
try:
cls.run_final_llm(
tenant_id=app.tenant_id,
mode=app.mode,
app_model_config=app_model_config,
query=query,
inputs=inputs,
chain_output=chain_output,
conversation_message_task=conversation_message_task,
memory=memory,
streaming=streaming
)
except ConversationTaskStoppedException:
return
@classmethod
def run_final_llm(cls, tenant_id: str, mode: str, app_model_config: AppModelConfig, query: str, inputs: dict,
chain_output: str,
conversation_message_task: ConversationMessageTask,
memory: Optional[ReadOnlyConversationTokenDBBufferSharedMemory], streaming: bool):
final_llm = LLMBuilder.to_llm_from_model(
tenant_id=tenant_id,
model=app_model_config.model_dict,
streaming=streaming
)
# get llm prompt
prompt = cls.get_main_llm_prompt(
mode=mode,
llm=final_llm,
pre_prompt=app_model_config.pre_prompt,
query=query,
inputs=inputs,
chain_output=chain_output,
memory=memory
)
final_llm.callback_manager = cls.get_llm_callback_manager(final_llm, streaming, conversation_message_task)
cls.recale_llm_max_tokens(
final_llm=final_llm,
prompt=prompt,
mode=mode
)
response = final_llm.generate([prompt])
return response
@classmethod
def get_main_llm_prompt(cls, mode: str, llm: BaseLanguageModel, pre_prompt: str, query: str, inputs: dict, chain_output: Optional[str],
memory: Optional[ReadOnlyConversationTokenDBBufferSharedMemory]) -> \
Union[str | List[BaseMessage]]:
pre_prompt = PromptBuilder.process_template(pre_prompt) if pre_prompt else pre_prompt
if mode == 'completion':
prompt_template = OutLinePromptTemplate.from_template(
template=("Use the following pieces of [CONTEXT] to answer the question at the end. "
"If you don't know the answer, "
"just say that you don't know, don't try to make up an answer. \n"
"```\n"
"[CONTEXT]\n"
"{context}\n"
"```\n" if chain_output else "")
+ (pre_prompt + "\n" if pre_prompt else "")
+ "{query}\n"
)
if chain_output:
inputs['context'] = chain_output
prompt_inputs = {k: inputs[k] for k in prompt_template.input_variables if k in inputs}
prompt_content = prompt_template.format(
query=query,
**prompt_inputs
)
if isinstance(llm, BaseChatModel):
# use chat llm as completion model
return [HumanMessage(content=prompt_content)]
else:
return prompt_content
else:
messages: List[BaseMessage] = []
system_message = None
if pre_prompt:
# append pre prompt as system message
system_message = PromptBuilder.to_system_message(pre_prompt, inputs)
if chain_output:
# append context as system message, currently only use simple stuff prompt
context_message = PromptBuilder.to_system_message(
"""Use the following pieces of [CONTEXT] to answer the users question.
If you don't know the answer, just say that you don't know, don't try to make up an answer.
```
[CONTEXT]
{context}
```""",
{'context': chain_output}
)
if not system_message:
system_message = context_message
else:
system_message.content = context_message.content + "\n\n" + system_message.content
if system_message:
messages.append(system_message)
human_inputs = {
"query": query
}
# construct main prompt
human_message = PromptBuilder.to_human_message(
prompt_content="{query}",
inputs=human_inputs
)
if memory:
# append chat histories
tmp_messages = messages.copy() + [human_message]
curr_message_tokens = memory.llm.get_messages_tokens(tmp_messages)
rest_tokens = llm_constant.max_context_token_length[
memory.llm.model_name] - memory.llm.max_tokens - curr_message_tokens
rest_tokens = max(rest_tokens, 0)
history_messages = cls.get_history_messages_from_memory(memory, rest_tokens)
messages += history_messages
messages.append(human_message)
return messages
@classmethod
def get_llm_callback_manager(cls, llm: Union[StreamableOpenAI, StreamableChatOpenAI],
streaming: bool, conversation_message_task: ConversationMessageTask) -> CallbackManager:
llm_callback_handler = LLMCallbackHandler(llm, conversation_message_task)
if streaming:
callback_handlers = [llm_callback_handler, DifyStreamingStdOutCallbackHandler()]
else:
callback_handlers = [llm_callback_handler, DifyStdOutCallbackHandler()]
return CallbackManager(callback_handlers)
@classmethod
def get_history_messages_from_memory(cls, memory: ReadOnlyConversationTokenDBBufferSharedMemory,
max_token_limit: int) -> \
List[BaseMessage]:
"""Get memory messages."""
memory.max_token_limit = max_token_limit
memory_key = memory.memory_variables[0]
external_context = memory.load_memory_variables({})
return external_context[memory_key]
@classmethod
def get_memory_from_conversation(cls, tenant_id: str, app_model_config: AppModelConfig,
conversation: Conversation,
**kwargs) -> ReadOnlyConversationTokenDBBufferSharedMemory:
# only for calc token in memory
memory_llm = LLMBuilder.to_llm_from_model(
tenant_id=tenant_id,
model=app_model_config.model_dict
)
# use llm config from conversation
memory = ReadOnlyConversationTokenDBBufferSharedMemory(
conversation=conversation,
llm=memory_llm,
max_token_limit=kwargs.get("max_token_limit", 2048),
memory_key=kwargs.get("memory_key", "chat_history"),
return_messages=kwargs.get("return_messages", True),
input_key=kwargs.get("input_key", "input"),
output_key=kwargs.get("output_key", "output"),
message_limit=kwargs.get("message_limit", 10),
)
return memory
@classmethod
def validate_query_tokens(cls, tenant_id: str, app_model_config: AppModelConfig, query: str):
llm = LLMBuilder.to_llm_from_model(
tenant_id=tenant_id,
model=app_model_config.model_dict
)
model_limited_tokens = llm_constant.max_context_token_length[llm.model_name]
max_tokens = llm.max_tokens
if model_limited_tokens - max_tokens - llm.get_num_tokens(query) < 0:
raise LLMBadRequestError("Query is too long")
@classmethod
def recale_llm_max_tokens(cls, final_llm: Union[StreamableOpenAI, StreamableChatOpenAI],
prompt: Union[str, List[BaseMessage]], mode: str):
# recalc max_tokens if sum(prompt_token + max_tokens) over model token limit
model_limited_tokens = llm_constant.max_context_token_length[final_llm.model_name]
max_tokens = final_llm.max_tokens
if mode == 'completion' and isinstance(final_llm, BaseLLM):
prompt_tokens = final_llm.get_num_tokens(prompt)
else:
prompt_tokens = final_llm.get_messages_tokens(prompt)
if prompt_tokens + max_tokens > model_limited_tokens:
max_tokens = max(model_limited_tokens - prompt_tokens, 16)
final_llm.max_tokens = max_tokens
@classmethod
def generate_more_like_this(cls, task_id: str, app: App, message: Message, pre_prompt: str,
app_model_config: AppModelConfig, user: Account, streaming: bool):
llm: StreamableOpenAI = LLMBuilder.to_llm(
tenant_id=app.tenant_id,
model_name='gpt-3.5-turbo',
streaming=streaming
)
# get llm prompt
original_prompt = cls.get_main_llm_prompt(
mode="completion",
llm=llm,
pre_prompt=pre_prompt,
query=message.query,
inputs=message.inputs,
chain_output=None,
memory=None
)
original_completion = message.answer.strip()
prompt = MORE_LIKE_THIS_GENERATE_PROMPT
prompt = prompt.format(prompt=original_prompt, original_completion=original_completion)
if isinstance(llm, BaseChatModel):
prompt = [HumanMessage(content=prompt)]
conversation_message_task = ConversationMessageTask(
task_id=task_id,
app=app,
app_model_config=app_model_config,
user=user,
inputs=message.inputs,
query=message.query,
is_override=True if message.override_model_configs else False,
streaming=streaming
)
llm.callback_manager = cls.get_llm_callback_manager(llm, streaming, conversation_message_task)
cls.recale_llm_max_tokens(
final_llm=llm,
prompt=prompt,
mode='completion'
)
llm.generate([prompt])