Struct CchEngine 

pub struct CchEngine<P: ProfileId> {
    pub data: Arc<ArcSwap<EngineData<P>>>,
}

The thread-safe, high-performance CCH routing engine.

This is the primary entry point for issuing queries and updating graph state. By utilizing ArcSwap, topology updates are atomically swapped in. Metric updates mutate the affected profile in place behind a read-write lock, so queries to that profile may wait briefly.

Fields

data: Arc<ArcSwap<EngineData<P>>>

Lock-free pointer to the current active routing state.

Implementations

impl<P: ProfileId> CchEngine<P>

pub fn new<'a, G: CchGraph + Sync>( graph: &G, profile_weights: impl IntoIterator<Item = (&'a P, &'a Vec<f32>)>, ) -> Self

Bootstraps a new routing engine from a base graph and a set of initial profiles.

This performs the initial Nested Dissection ordering, topology contraction, and heavily parallelized metric customization for all provided profiles.

pub fn update_weights(&self, profile_id: P, new_weights: &[f32])

Performs a zero-downtime update of the edge weights for a specific profile (e.g., live traffic).

This triggers the parallel Customization phase for the new weights and updates the profile in place. Queries to the same profile will wait on the profile lock.

pub fn update_weights_partial(&self, profile_id: P, updates: &[(usize, f32)])

Performs an incremental metric update for an existing profile.

updates contains (original_edge_index, new_weight) pairs in the base graph’s CSR edge order. The engine only recomputes the affected hierarchy arcs and their dependents.

pub fn update_topology<G: CchGraph + Sync>( &self, graph: &G, modified_old_nodes: &[u32], new_nodes: &[u32], profile_weights: &FxHashMap<P, Vec<f32>>, )

Performs a partial structural update to the elimination tree (e.g., minor road closures).

Instead of rebuilding the entire graph from scratch, this identifies the affected branches of the elimination tree and only recontracts the modified segments. It then re-customizes the metrics and hot-swaps the active state.

pub fn rebuild_topology<G: CchGraph + Sync>( &self, graph: &G, profile_weights: &FxHashMap<P, Vec<f32>>, )

Triggers a complete rebuild of the underlying topology and metric data.

This behaves exactly like new(), but atomically swaps the newly built engine state into the current instance.

pub fn query_path(&self, profile: P, from: u32, to: u32) -> Option<PathResult>

Executes a shortest-path query between a source and target node for the given profile.

This method leverages thread-local storage to ensure zero dynamic memory allocation during the query. It evaluates a bidirectional Dijkstra search over the shortcut hierarchy.

Returns None if the profile doesn’t exist or if no path can be found.

Trait Implementations

impl<P: Clone + ProfileId> Clone for CchEngine<P>

fn clone(&self) -> CchEngine<P>

Returns a duplicate of the value.

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

Performs copy-assignment from source.