mirror of
https://github.com/langchain-ai/langgraph.git
synced 2026-08-17 21:25:46 +02:00
Nuno Campos
4e8fbe4525
- Instead store sends in a Topic channel, removing the need to fetch sends as writes against the parent checkpoint - Remove deprecated/unused functions in langgraph-checkpoint (will require bumping min range for langgraph-checkpoint in langgraph lib) - Implement migration of old pending sends in langgraph-checkpoint-postgres - Ensure parent config of `checkpoint_during=False` checkpoints always points to checkpoints that were also saved
52 lines
1.4 KiB
Python
52 lines
1.4 KiB
Python
from collections.abc import Mapping
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from datetime import datetime, timezone
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from typing import Any, Optional, Protocol
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from langgraph.checkpoint.base import Checkpoint, EmptyChannelError
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from langgraph.checkpoint.base.id import uuid6
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class ChannelProtocol(Protocol):
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def checkpoint(self) -> Optional[Any]: ...
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def empty_checkpoint() -> Checkpoint:
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return Checkpoint(
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v=1,
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id=str(uuid6(clock_seq=-2)),
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ts=datetime.now(timezone.utc).isoformat(),
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channel_values={},
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channel_versions={},
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versions_seen={},
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)
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def create_checkpoint(
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checkpoint: Checkpoint,
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channels: Optional[Mapping[str, ChannelProtocol]],
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step: int,
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*,
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id: Optional[str] = None,
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) -> Checkpoint:
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"""Create a checkpoint for the given channels."""
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ts = datetime.now(timezone.utc).isoformat()
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if channels is None:
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values = checkpoint["channel_values"]
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else:
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values = {}
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for k, v in channels.items():
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if k not in checkpoint["channel_versions"]:
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continue
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try:
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values[k] = v.checkpoint()
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except EmptyChannelError:
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pass
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return Checkpoint(
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v=1,
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ts=ts,
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id=id or str(uuid6(clock_seq=step)),
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channel_values=values,
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channel_versions=checkpoint["channel_versions"],
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versions_seen=checkpoint["versions_seen"],
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)
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