Struct DrainageGraph 

pub struct DrainageGraph { /* private fields */ }

The complete upstream adjacency graph over drainage units.

This is the canonical in-memory representation of graph.parquet for validation and construction purposes. The HashMap-based index provides O(1) lookup by unit ID.

Note for engine implementors: this representation is optimized for validation and random access, not traversal. A delineation engine will typically convert to CSR (compressed sparse row) or another traversal-optimized layout at load time, as permitted by the HFX spec.

Implementations

impl DrainageGraph

pub fn new(rows: Vec<AdjacencyRow>) -> Result<Self, GraphError>

Construct a DrainageGraph from a vector of AdjacencyRows.

Builds the internal O(1) lookup index as part of construction.

Errors

Condition	Error variant
rows is empty	GraphError::EmptyGraph
The same UnitId appears in two or more rows	GraphError::DuplicateUnitId

pub fn rows(&self) -> &[AdjacencyRow]

Return all rows in the graph.

pub fn len(&self) -> usize

Return the number of rows in the graph.

pub fn is_empty(&self) -> bool

Return true if the graph contains no rows.

pub fn get(&self, id: UnitId) -> Option<&AdjacencyRow>

Look up a row by UnitId in O(1) time.

Returns None if no row with the given ID exists in the graph.

Trait Implementations

impl Clone for DrainageGraph

fn clone(&self) -> DrainageGraph

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DrainageGraph

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

Formats the value using the given formatter.

impl PartialEq for DrainageGraph

fn eq(&self, other: &DrainageGraph) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for DrainageGraph