mirror of
https://github.com/langchain-ai/langgraph.git
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Sydney RunkleandGitHub
2d3121a17c
* `strict=False` is the default, pyupgrade to min version 3.10 adds this to be explicit w/ behavior
59 lines
1.8 KiB
Python
59 lines
1.8 KiB
Python
import os
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import tempfile
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from collections import defaultdict
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from functools import partial
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from langgraph.checkpoint.base import (
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ChannelVersions,
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Checkpoint,
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CheckpointMetadata,
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SerializerProtocol,
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)
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from langgraph.checkpoint.memory import InMemorySaver, PersistentDict
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from langgraph.pregel._checkpoint import copy_checkpoint
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class MemorySaverAssertImmutable(InMemorySaver):
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storage_for_copies: defaultdict[str, dict[str, dict[str, Checkpoint]]]
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def __init__(
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self,
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*,
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serde: SerializerProtocol | None = None,
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put_sleep: float | None = None,
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) -> None:
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_, filename = tempfile.mkstemp()
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super().__init__(
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serde=serde, factory=partial(PersistentDict, filename=filename)
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)
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self.storage_for_copies = defaultdict(lambda: defaultdict(dict))
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self.put_sleep = put_sleep
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self.stack.callback(os.remove, filename)
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def put(
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self,
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config: dict,
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checkpoint: Checkpoint,
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metadata: CheckpointMetadata,
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new_versions: ChannelVersions,
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) -> None:
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if self.put_sleep:
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import time
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time.sleep(self.put_sleep)
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# assert checkpoint hasn't been modified since last written
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thread_id = config["configurable"]["thread_id"]
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checkpoint_ns = config["configurable"]["checkpoint_ns"]
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if saved := super().get(config):
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assert (
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self.serde.loads_typed(
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self.storage_for_copies[thread_id][checkpoint_ns][saved["id"]]
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)
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== saved
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)
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self.storage_for_copies[thread_id][checkpoint_ns][checkpoint["id"]] = (
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self.serde.dumps_typed(copy_checkpoint(checkpoint))
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)
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# call super to write checkpoint
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return super().put(config, checkpoint, metadata, new_versions)
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