Lint & small changes

server-rs/src/aggregation.rs

@@ -1,6 +1,13 @@
 use crate::consts::NAN_U16;
 use crate::data::QuantRef;
 
+/// Optional per-enum-value distribution tracking for a single feature.
+/// Counts how many rows have each enum value (by raw u16 index).
+pub struct EnumDist {
+    pub feat_idx: usize,
+    pub counts: Box<[u32]>,
+}
+
 /// Per-cell accumulator for aggregating features (min/max/sum/count).
 /// Uses Box<[T]> instead of Vec<T> to avoid storing capacity (saves 8 bytes per field per cell).
 /// Shared by hexagon and postcode aggregation routes.
@@ -10,16 +17,26 @@ pub struct Aggregator {
     pub maxs: Box<[f32]>,
     pub sums: Box<[f64]>,
     pub feat_counts: Box<[u32]>,
+    /// Optional: per-value counts for a single enum feature (for pie chart visualization).
+    pub enum_dist: Option<EnumDist>,
 }
 
+/// Configuration for enum distribution tracking, passed to Aggregator::new.
+/// (feature_index, number_of_enum_values)
+pub type EnumDistConfig = Option<(usize, usize)>;
+
 impl Aggregator {
-    pub fn new(num_features: usize) -> Self {
+    pub fn new(num_features: usize, enum_dist_config: EnumDistConfig) -> Self {
         Aggregator {
             count: 0,
             mins: vec![f32::INFINITY; num_features].into_boxed_slice(),
             maxs: vec![f32::NEG_INFINITY; num_features].into_boxed_slice(),
             sums: vec![0.0f64; num_features].into_boxed_slice(),
             feat_counts: vec![0u32; num_features].into_boxed_slice(),
+            enum_dist: enum_dist_config.map(|(feat_idx, num_values)| EnumDist {
+                feat_idx,
+                counts: vec![0u32; num_values].into_boxed_slice(),
+            }),
         }
     }
 
@@ -50,6 +67,17 @@ impl Aggregator {
                 self.feat_counts[feat_index] += 1;
             }
         }
+        // Enum distribution: single branch per row (not per feature).
+        // Uses raw u16 directly — enum features are stored as u16 indices.
+        if let Some(ref mut ed) = self.enum_dist {
+            let raw = row_slice[ed.feat_idx];
+            if raw != NAN_U16 {
+                let idx = raw as usize;
+                if idx < ed.counts.len() {
+                    ed.counts[idx] += 1;
+                }
+            }
+        }
     }
 
     /// Merge another aggregator's results into this one.
@@ -67,6 +95,12 @@ impl Aggregator {
                 self.feat_counts[i] += other.feat_counts[i];
             }
         }
+        // Merge enum distribution counts
+        if let (Some(ref mut mine), Some(ref theirs)) = (&mut self.enum_dist, &other.enum_dist) {
+            for (m, t) in mine.counts.iter_mut().zip(theirs.counts.iter()) {
+                *m += t;
+            }
+        }
     }
 
     /// Add a row, only aggregating the features at the given indices.
@@ -95,5 +129,15 @@ impl Aggregator {
                 self.feat_counts[feat_index] += 1;
             }
         }
+        // Enum distribution (same raw u16 approach)
+        if let Some(ref mut ed) = self.enum_dist {
+            let raw = feature_data[base + ed.feat_idx];
+            if raw != NAN_U16 {
+                let idx = raw as usize;
+                if idx < ed.counts.len() {
+                    ed.counts[idx] += 1;
+                }
+            }
+        }
     }
 }