Files
lang-agent/lang_agent/base.py
2026-01-26 17:39:54 +08:00

200 lines
7.2 KiB
Python

from __future__ import annotations
from typing import List, Callable, Tuple, Dict, AsyncIterator, TYPE_CHECKING
from abc import ABC, abstractmethod
from PIL import Image
from io import BytesIO
import matplotlib.pyplot as plt
from loguru import logger
from lang_agent.utils import tree_leaves
from langgraph.graph.state import CompiledStateGraph
from langchain_core.messages import BaseMessage, HumanMessage, SystemMessage
from langchain_core.messages.base import BaseMessageChunk
from lang_agent.components.text_releaser import TextReleaser, AsyncTextReleaser
if TYPE_CHECKING:
from lang_agent.graphs.graph_states import State
class LangToolBase(ABC):
"""
class to inherit if to create a new local tool
"""
@abstractmethod
def get_tool_fnc(self)->List[Callable]:
pass
class GraphBase(ABC):
workflow: CompiledStateGraph # the main workflow
streamable_tags: List[List[str]] # which llm to stream outputs; see routing.py for complex usage
textreleaser_delay_keys: List[str] = (None, None) # use to control when to start streaming; see routing.py for complex usage
def _stream_result(self, *nargs, **kwargs):
def text_iterator():
for chunk, metadata in self.workflow.stream({"inp": nargs},
stream_mode="messages",
subgraphs=True,
**kwargs):
if isinstance(metadata, tuple):
chunk, metadata = metadata
tags = metadata.get("tags")
if not (tags in self.streamable_tags):
continue
if isinstance(chunk, (BaseMessageChunk, BaseMessage)) and getattr(chunk, "content", None):
yield chunk.content
text_releaser = TextReleaser(*self.textreleaser_delay_keys)
logger.info("streaming output")
for chunk in text_releaser.release(text_iterator()):
print(f"\033[92m{chunk}\033[0m", end="", flush=True)
yield chunk
# NOTE: DEFAULT IMPLEMENTATION; Overide to support your class
def invoke(self, *nargs, as_stream:bool=False, as_raw:bool=False, **kwargs):
self._validate_input(*nargs, **kwargs)
if as_stream:
# Stream messages from the workflow
print("\033[93m====================STREAM OUTPUT=============================\033[0m")
return self._stream_result(*nargs, **kwargs)
else:
state = self.workflow.invoke({"inp": nargs})
msg_list = tree_leaves(state)
for e in msg_list:
if isinstance(e, BaseMessage):
e.pretty_print()
if as_raw:
return msg_list
return msg_list[-1].content
# NOTE: DEFAULT IMPLEMENTATION; Overide to support your class
async def ainvoke(self, *nargs, as_stream:bool=False, as_raw:bool=False, **kwargs):
"""Async version of invoke using LangGraph's native async support."""
self._validate_input(*nargs, **kwargs)
if as_stream:
# Stream messages from the workflow asynchronously
print("\033[93m====================ASYNC STREAM OUTPUT=============================\033[0m")
return self._astream_result(*nargs, **kwargs)
else:
state = await self.workflow.ainvoke({"inp": nargs})
msg_list = tree_leaves(state)
for e in msg_list:
if isinstance(e, BaseMessage):
e.pretty_print()
if as_raw:
return msg_list
return msg_list[-1].content
async def _astream_result(self, *nargs, **kwargs) -> AsyncIterator[str]:
"""Async streaming using LangGraph's astream method."""
async def text_iterator():
async for chunk, metadata in self.workflow.astream(
{"inp": nargs},
stream_mode="messages",
subgraphs=True,
**kwargs
):
if isinstance(metadata, tuple):
chunk, metadata = metadata
tags = metadata.get("tags")
if not (tags in self.streamable_tags):
continue
if isinstance(chunk, (BaseMessageChunk, BaseMessage)) and getattr(chunk, "content", None):
yield chunk.content
text_releaser = AsyncTextReleaser(*self.textreleaser_delay_keys)
async for chunk in text_releaser.release(text_iterator()):
print(f"\033[92m{chunk}\033[0m", end="", flush=True)
yield chunk
def _validate_input(self, *nargs, **kwargs):
print("\033[93m====================INPUT HUMAN MESSAGES=============================\033[0m")
for e in nargs[0]["messages"]:
if isinstance(e, HumanMessage):
e.pretty_print()
print("\033[93m====================END INPUT HUMAN MESSAGES=============================\033[0m")
print(f"\033[93m model used: {self.config.llm_name}\033[0m")
assert len(kwargs) == 0, "due to inp assumptions"
def _agent_call_template(self, system_prompt:str,
model:CompiledStateGraph,
state:State,
human_msg:str = None):
if state.get("messages") is not None:
inp = state["messages"], state["inp"][1]
else:
inp = state["inp"]
messages = [
SystemMessage(system_prompt),
*state["inp"][0]["messages"][1:]
]
if human_msg is not None:
messages.append(HumanMessage(human_msg))
inp = ({"messages": messages}, state["inp"][1])
out = model.invoke(*inp)
return {"messages": out}
def show_graph(self, ret_img:bool=False):
#NOTE: just a useful tool for debugging; has zero useful functionality
err_str = f"{type(self)} does not have workflow, this is unsupported"
assert hasattr(self, "workflow"), err_str
logger.info("creating image")
img = Image.open(BytesIO(self.workflow.get_graph().draw_mermaid_png()))
if not ret_img:
plt.imshow(img)
plt.show()
else:
return img
class ToolNodeBase(GraphBase):
@abstractmethod
def get_streamable_tags(self)->List[List[str]]:
"""
returns names of llm model to listen to when streaming
NOTE: must be [['A1'], ['A2'] ...]
"""
return [["tool_llm"]]
def get_delay_keys(self)->Tuple[str, str]:
"""
returns 2 words, one for starting delayed yeilding, the other for ending delayed yielding,
they should be of format ('[key1]', '[key2]'); key1 is starting, key2 is ending
"""
return None, None
@abstractmethod
def invoke(self, inp)->Dict[str, List[BaseMessage]]:
pass
async def ainvoke(self, inp)->Dict[str, List[BaseMessage]]:
"""Async version of invoke. Subclasses should override for true async support."""
raise NotImplementedError("Subclass should implement ainvoke for async support")