mirror of
https://github.com/langchain-ai/langgraph.git
synced 2026-08-30 03:39:38 +02:00
Nuno Campos
5c2afc9418
- checkpoints are now copied before being mutated - compiled graph and compiled state graph no longer need to override get_state/update_state - pregel class now natively supports interrupt before/after
78 lines
2.8 KiB
Python
78 lines
2.8 KiB
Python
from typing import Any, Mapping, Sequence, Union
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from langgraph.channels.base import BaseChannel
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from langgraph.channels.last_value import LastValue
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from langgraph.constants import INTERRUPT
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from langgraph.pregel.read import ChannelBatch, ChannelInvoke
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from langgraph.pregel.reserved import ReservedChannels
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def validate_graph(
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nodes: Mapping[str, Union[ChannelInvoke, ChannelBatch]],
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channels: dict[str, BaseChannel],
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input: Union[str, Sequence[str]],
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output: Union[str, Sequence[str]],
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hidden: Sequence[str],
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interrupt_after: Sequence[str],
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interrupt_before: Sequence[str],
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) -> None:
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subscribed_channels = set[str]()
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for name, node in nodes.items():
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if name == INTERRUPT:
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raise ValueError(f"Node name {INTERRUPT} is reserved")
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if isinstance(node, ChannelInvoke):
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subscribed_channels.update(node.channels.values())
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elif isinstance(node, ChannelBatch):
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subscribed_channels.add(node.channel)
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else:
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raise TypeError(
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f"Invalid node type {type(node)}, expected Channel.subscribe_to() or Channel.subscribe_to_each()"
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)
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for chan in subscribed_channels:
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if chan not in channels:
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channels[chan] = LastValue(Any) # type: ignore[arg-type]
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if isinstance(input, str):
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if input not in channels:
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channels[input] = LastValue(Any) # type: ignore[arg-type]
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if input not in subscribed_channels:
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raise ValueError(f"Input channel {input} is not subscribed to by any node")
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else:
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for chan in input:
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if chan not in channels:
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channels[chan] = LastValue(Any) # type: ignore[arg-type]
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if all(chan not in subscribed_channels for chan in input):
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raise ValueError(
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f"None of the input channels {input} are subscribed to by any node"
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)
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if isinstance(output, str):
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if output not in channels:
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channels[output] = LastValue(Any) # type: ignore[arg-type]
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else:
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for chan in output:
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if chan not in channels:
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channels[chan] = LastValue(Any) # type: ignore[arg-type]
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for chan in ReservedChannels:
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if chan not in channels:
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channels[chan] = LastValue(Any) # type: ignore[arg-type]
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validate_keys(hidden, channels)
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validate_keys(interrupt_after, channels)
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validate_keys(interrupt_before, channels)
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def validate_keys(
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keys: Union[str, Sequence[str]],
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channels: Mapping[str, BaseChannel],
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) -> None:
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if isinstance(keys, str):
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if keys not in channels:
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raise ValueError(f"Key {keys} not in channels")
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else:
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for chan in keys:
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if chan not in channels:
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raise ValueError(f"Key {chan} not in channels")
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