Struct Checkpoint 

pub struct Checkpoint {
    pub id: String,
    pub channel_values: Value,
    pub channel_versions: HashMap<String, u64>,
    pub versions_seen: HashMap<String, HashMap<String, u64>>,
    pub pending_tasks: Vec<CheckpointPendingTask>,
    pub pending_sends: Vec<SerializedSend>,
    pub pending_interrupts: Vec<InterruptSignal>,
    pub schema_version: u32,
    pub created_at: String,
    pub v: u32,
    pub new_versions: HashMap<String, u64>,
    pub counters_since_delta_snapshot: HashMap<String, DeltaCounters>,
}

Complete checkpoint state

Captures the entire state of a graph execution at a specific point in time, including channel values, versions, pending tasks, and metadata.

Fields

id: String

Unique checkpoint identifier (UUID v6, time-ordered)

channel_values: Value

Serialized channel values (JSON or MessagePack)

channel_versions: HashMap<String, u64>

Version number for each channel

Keys are channel names, values are monotonically increasing version numbers.

versions_seen: HashMap<String, HashMap<String, u64>>

Versions of channels each node has consumed

Outer key is node name, inner key is channel name, value is version consumed.

pending_tasks: Vec<CheckpointPendingTask>

Tasks pending execution in the next superstep

pending_sends: Vec<SerializedSend>

Pending Send operations awaiting delivery

pending_interrupts: Vec<InterruptSignal>

Interrupt signals captured when execution was interrupted

Populated when checkpoint source is CheckpointSource::Interrupt. Used for ID-based resume to match incoming resume values.

schema_version: u32

State schema version for migration support

created_at: String

ISO 8601 timestamp of checkpoint creation

v: u32

Checkpoint format version

Used for forward compatibility when Checkpoint structure changes.

new_versions: HashMap<String, u64>

Channels updated in this checkpoint

Keys are channel names, values are the new version numbers.

counters_since_delta_snapshot: HashMap<String, DeltaCounters>

Delta counters since last full snapshot

Keys are channel names, values track changes since last complete snapshot.

Trait Implementations

impl Clone for Checkpoint

fn clone(&self) -> Checkpoint

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Checkpoint

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Checkpoint

fn deserialize<__D>( __deserializer: __D, ) -> Result<Checkpoint, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Checkpoint

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.