Files
langgraph/permchain/channels/topic.py
T

80 lines
2.5 KiB
Python

from contextlib import contextmanager
from typing import Any, Generator, Generic, Iterator, Optional, Sequence, Type, Union
from typing_extensions import Self
from permchain.channels.base import BaseChannel, Value
def flatten(values: Sequence[Value | list[Value]]) -> Iterator[Value]:
for value in values:
if isinstance(value, list):
yield from value
else:
yield value
class Topic(
Generic[Value],
BaseChannel[Sequence[Value], Value | list[Value], tuple[set[Value], list[Value]]],
):
"""A configurable PubSub Topic.
Args:
typ: The type of the value stored in the channel.
unique: Whether to discard duplicate values.
accumulate: Whether to accummulate values across steps. If False, the channel will be emptied after each step.
"""
def __init__(
self, typ: Type[Value], unique: bool = False, accumulate: bool = False
) -> None:
# attrs
self.typ = typ
self.unique = unique
self.accumulate = accumulate
# state
self.seen = set[Value]()
self.values = list[Value]()
@property
def ValueType(self) -> Any:
"""The type of the value stored in the channel."""
return Sequence[self.typ] # type: ignore[name-defined]
@property
def UpdateType(self) -> Type[Value]:
"""The type of the update received by the channel."""
return Union[self.typ, list[self.typ]] # type: ignore[name-defined]
@contextmanager
def empty(
self, checkpoint: Optional[tuple[set[Value], list[Value]]] = None
) -> Generator[Self, None, None]:
empty = self.__class__(self.typ, self.unique, self.accumulate)
if checkpoint is not None:
empty.seen = checkpoint[0]
empty.values = checkpoint[1]
try:
yield empty
finally:
pass
def update(self, values: Sequence[Value | list[Value]]) -> None:
if not self.accumulate:
self.values = list[Value]()
if flat_values := flatten(values):
if self.unique:
for value in flat_values:
if value not in self.seen:
self.seen.add(value)
self.values.append(value)
else:
self.values.extend(flat_values)
def get(self) -> Sequence[Value]:
return list(self.values)
def checkpoint(self) -> tuple[set[Value], list[Value]]:
return (self.seen, self.values)