Struct CheckpointBatcher 

pub struct CheckpointBatcher { /* private fields */ }

The checkpoint batcher collects checkpoint requests and sends them in batches.

This improves efficiency by reducing the number of API calls to the Lambda service. The batcher sends a batch when any of these conditions are met:

• The batch reaches the maximum size in bytes
• The batch reaches the maximum number of operations
• The maximum batch time has elapsed

Implementations

impl CheckpointBatcher

pub fn new( config: CheckpointBatcherConfig, queue_rx: Receiver<CheckpointRequest>, service_client: SharedDurableServiceClient, durable_execution_arn: String, checkpoint_token: Arc<RwLock<String>>, ) -> Self

Creates a new CheckpointBatcher.

Arguments

• config - Configuration for batching behavior
• queue_rx - Receiver for checkpoint requests
• service_client - Service client for sending checkpoints
• durable_execution_arn - The ARN of the durable execution
• checkpoint_token - The initial checkpoint token from Lambda invocation input

Requirements

• 2.9: THE Checkpointing_System SHALL use the CheckpointToken from invocation input for the first checkpoint

pub async fn run(&mut self)

Runs the batcher loop, processing checkpoint requests.

This method runs until the queue is closed (sender dropped).

pub fn sort_checkpoint_batch( batch: Vec<CheckpointRequest>, ) -> Vec<CheckpointRequest>

Sorts checkpoint requests according to the ordering rules.

The ordering rules are:

1. Operations are checkpointed in execution order (preserving original order)
2. EXECUTION completion (SUCCEED/FAIL on EXECUTION type) must be last in the batch
3. Child operations must come after their parent CONTEXT starts
4. START and completion (SUCCEED/FAIL) for the same operation can be in the same batch

Requirements

• 2.12: WHEN batching operations, THE Checkpointing_System SHALL checkpoint in execution order with EXECUTION completion last
• 2.13: THE Checkpointing_System SHALL support including both START and completion actions for STEP/CONTEXT in the same batch