Struct Pregel 

pub struct Pregel<S: State> { /* private fields */ }

The Pregel execution engine.

This implements the core superstep loop:

1. Load checkpoint (if resuming)
2. Write initial input to channels
3. Loop:
   • Find triggered nodes
   • Execute nodes in parallel
   • Apply writes to channels with reducers
   • Handle interrupts/commands
   • Save checkpoint
   • Yield stream events
4. Return final state

Implementations

impl<S: State> Pregel<S>

pub fn new( nodes: HashMap<String, PregelNode<S>>, channels: HashMap<String, Box<dyn BaseChannel>>, checkpointer: Option<Arc<dyn BaseCheckpointSaver>>, entry_point: String, finish_points: HashSet<String>, edges: HashMap<String, Vec<String>>, ) -> Self

Create a new Pregel executor

pub fn with_recursion_limit(self, limit: usize) -> Self

Set the recursion limit

pub async fn invoke(&mut self, input: S, config: Config) -> Result<S>

Execute the graph with the given input and configuration

pub async fn stream( &mut self, input: S, config: Config, mode: StreamMode, ) -> Result<Pin<Box<dyn Stream<Item = Result<StreamEvent>> + Send>>>

Stream execution events

pub async fn get_state( &self, config: &Config, ) -> Result<Option<StateSnapshot<S>>>

Get the current state snapshot

pub async fn get_state_history( &self, config: &Config, limit: Option<usize>, ) -> Result<Vec<StateSnapshot<S>>>

Get state history