Struct Walk 

struct Walk<'a> {

    room_id: &'a RoomId,
    room_version: &'a RoomVersionId,
    room_rules: RoomVersionRules,
    create_event_id: &'a EventId,
    mode: WalkMode,
    max_nodes: usize,
    top_prevs: PrevEvents,
    class: HashMap<OwnedEventId, Class>,
    nodes: Vec<Node>,
    order: Vec<usize>,
    frontier: HashMap<OwnedEventId, usize>,
    resolved: HashMap<OwnedEventId, Arc<HashMap<ShortStateKey, OwnedEventId>>>,
    live_entries: usize,
    peak_entries: usize,
    forks: usize,
    gate_drops: usize,
    memo_hits: usize,
    fallback: Option<Fallback>,
}

State threaded through one walk’s discovery and build phases.

Fields

room_id: &'a RoomId

room_version: &'a RoomVersionId

room_rules: RoomVersionRules

create_event_id: &'a EventId

mode: WalkMode

max_nodes: usize

top_prevs: PrevEvents

class: HashMap<OwnedEventId, Class>

nodes: Vec<Node>

order: Vec<usize>

frontier: HashMap<OwnedEventId, usize>

resolved: HashMap<OwnedEventId, Arc<HashMap<ShortStateKey, OwnedEventId>>>

live_entries: usize

peak_entries: usize

forks: usize

gate_drops: usize

memo_hits: usize

fallback: Option<Fallback>

Implementations

impl<'a> Walk<'a>

fn new( room_id: &'a RoomId, room_version: &'a RoomVersionId, create_event_id: &'a EventId, mode: WalkMode, max_nodes: usize, top_prevs: PrevEvents, ) -> Result<Self>

fn count_consumers(&mut self)

Consumer counts drive state-map reaping: each held node’s prevs and the incoming event’s own prevs each count one consumption.

fn retain( &mut self, event_id: OwnedEventId, state: Arc<HashMap<ShortStateKey, OwnedEventId>>, ) -> bool

Retain a computed state map until its last consumer releases it; the running live-entry total is the walk’s memory ceiling. Arc-shared maps count once per holder, deliberately over-counting toward the ceiling.

fn release(&mut self, prevs: &[OwnedEventId])

Release one consumption of each prev, dropping maps no consumer awaits.