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Pythonlanggraphpregel_algoprepare_next_tasks
Functionā—Since v0.6

prepare_next_tasks

Prepare the set of tasks that will make up the next Pregel step.

Copy
prepare_next_tasks(
  checkpoint: Checkpoint,
  pending_writes: list[PendingWrite],
  processes: Mapping[str, PregelNode],
  channels: Mapping[str, BaseChannel],
  managed: ManagedValueMapping,
  config: RunnableConfig,
  step: int,
  stop: int,
  *,
  for_execution: bool,
  store: BaseStore | None = None,
  checkpointer: BaseCheckpointSaver | None = None,
  manager: None | ParentRunManager | AsyncParentRunManager = None,
  trigger_to_nodes: Mapping[str, Sequence[str]] | None = None,
  updated_channels: set[str] | None = None,
  retry_policy: Sequence[RetryPolicy] = (),
  cache_policy: CachePolicy | None = None
) -> dict[str, PregelTask] | dict[str, PregelExecutableTask]

Parameters

NameTypeDescription
checkpoint*Checkpoint

The current checkpoint.

pending_writes*list[PendingWrite]

The list of pending writes.

processes*Mapping[str, PregelNode]

The mapping of process names to PregelNode instances.

channels*Mapping[str, BaseChannel]

The mapping of channel names to BaseChannel instances.

managed*ManagedValueMapping

The mapping of managed value names to functions.

config*RunnableConfig

The Runnable configuration.

step*int

The current step.

for_execution*bool

Whether the tasks are being prepared for execution.

storeBaseStore | None
Default:None

An instance of BaseStore to make it available for usage within tasks.

checkpointerBaseCheckpointSaver | None
Default:None

Checkpointer instance used for saving checkpoints.

managerNone | ParentRunManager | AsyncParentRunManager
Default:None

The parent run manager to use for the tasks.

trigger_to_nodesMapping[str, Sequence[str]] | None
Default:None

Optional: Mapping of channel names to the set of nodes that are can be triggered by that channel.

updated_channelsset[str] | None
Default:None

Optional. Set of channel names that have been updated during the previous step. Using in conjunction with trigger_to_nodes to speed up the process of determining which nodes should be triggered in the next step.

View source on GitHub