Module checkpoint 

Streaming checkpoint support.

Provides optional, zero-overhead checkpointing for the streaming API. When disabled (the default), no runtime cost is incurred. When enabled, captures source sequences, watermarks, and persists checkpoint snapshots.

Architecture

Ring 0 (Hot Path): Source.push() -> increment sequence (AtomicU64 Relaxed ~1ns)
Ring 1 (Background): StreamCheckpointManager.trigger() -> capture atomics -> store
Ring 2 (Control):    LaminarDB.checkpoint() -> manual trigger

Structs

StreamChangelogBuffer

A pre-allocated ring buffer for changelog entries.

StreamChangelogEntry

A single changelog entry — fixed 24 bytes, no heap allocation.

StreamCheckpoint

A point-in-time snapshot of streaming pipeline state.

StreamCheckpointConfig

Configuration for streaming checkpoints.

StreamCheckpointManager

Coordinates checkpoint lifecycle for streaming sources and sinks.

Enums

CheckpointError

Errors from checkpoint operations.

OverflowPolicy

Policy when the changelog buffer is full.

StreamChangeOp

Type of changelog operation.

WalMode

WAL mode for checkpoint durability.