Struct DagChangelogPropagator 

pub struct DagChangelogPropagator { /* private fields */ }

Per-node changelog buffer management for DAG pipelines.

Wraps a ChangelogBuffer per node, with global and per-node enable flags for zero-overhead disabled mode.

Implementations

impl DagChangelogPropagator

pub fn from_dag(dag: &StreamingDag, capacity: usize) -> Self

Creates a propagator from a finalized DAG with the given buffer capacity.

All nodes start enabled. Use set_node_enabled to selectively disable.

pub fn disabled(slot_count: usize) -> Self

Creates a disabled propagator (zero overhead).

No buffers are allocated. All record calls return false immediately.

pub fn record(&mut self, node: NodeId, changelog_ref: ChangelogRef) -> bool

Records a changelog reference at a node.

Returns true if the reference was recorded, false if the propagator is disabled, the node is disabled, or the buffer is full (backpressure).

pub fn record_retraction( &mut self, node: NodeId, batch_offset: u32, old_row_index: u32, new_row_index: u32, ) -> bool

Records a retraction pair (update-before + update-after) at a node.

Returns true if both references were recorded.

pub fn drain_node(&mut self, node: NodeId) -> Vec<ChangelogRef>

Drains all changelog references from a node’s buffer.

Returns the drained references. The buffer is cleared but retains capacity.

pub fn drain_all(&mut self)

Drains all changelog references from all node buffers.

pub fn has_pending(&self) -> bool

Returns true if any node has pending changelog references.

pub fn pending_count(&self, node: NodeId) -> usize

Returns the number of pending changelog references at a node.

pub fn set_node_enabled(&mut self, node: NodeId, enabled: bool)

Enables or disables changelog recording for a specific node.

pub fn set_globally_enabled(&mut self, enabled: bool)

Enables or disables changelog recording globally.

pub fn is_globally_enabled(&self) -> bool

Returns whether changelog recording is globally enabled.

pub fn slot_count(&self) -> usize

Returns the number of node slots.

Trait Implementations

impl Debug for DagChangelogPropagator

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

Formats the value using the given formatter.