Refactor and improve

server-rs/src/routes/pois.rs

@@ -2,15 +2,31 @@ use std::sync::Arc;
 
 use axum::extract::Query;
 use axum::http::StatusCode;
-use axum::response::{IntoResponse, Json};
+use axum::response::Json;
 use serde::{Deserialize, Serialize};
 use tracing::info;
 
 use crate::consts::MAX_POIS_PER_REQUEST;
-use crate::state::{AppState, POICategoryGroup};
+use crate::data::POICategoryGroup;
+use crate::parsing::parse_bounds;
+use crate::state::AppState;
 
-use super::hexagons::write_json_escaped;
-use super::parse::parse_bounds;
+#[derive(Serialize)]
+#[allow(clippy::upper_case_acronyms)]
+pub struct POI {
+    id: String,
+    name: String,
+    category: String,
+    group: String,
+    lat: f32,
+    lng: f32,
+    emoji: String,
+}
+
+#[derive(Serialize)]
+pub struct POIsResponse {
+    pois: Vec<POI>,
+}
 
 #[derive(Deserialize)]
 pub struct POIParams {
@@ -22,7 +38,7 @@ pub struct POIParams {
 pub async fn get_pois(
     state: Arc<AppState>,
     Query(params): Query<POIParams>,
-) -> Result<impl IntoResponse, (StatusCode, String)> {
+) -> Result<Json<POIsResponse>, (StatusCode, String)> {
     let bounds_str = params.bounds.ok_or((
         StatusCode::BAD_REQUEST,
         "bounds parameter is required".into(),
@@ -43,12 +59,10 @@ pub async fn get_pois(
 
     let num_categories = category_filter.as_ref().map(|cats| cats.len()).unwrap_or(0);
 
-    let json_body = tokio::task::spawn_blocking(move || {
+    let pois = tokio::task::spawn_blocking(move || {
         let t0 = std::time::Instant::now();
         let row_indices = state.poi_grid.query(south, west, north, east);
 
-        // Collect matching row indices first, then sample randomly so the
-        // subset covers the viewport uniformly instead of clustering in one area.
         let mut matching_rows: Vec<usize> = row_indices
             .iter()
             .filter_map(|&row_idx| {
@@ -73,36 +87,22 @@ pub async fn get_pois(
             }
         }
 
-        // Write JSON directly to string buffer, avoiding intermediate POI allocations
-        let mut buf = String::with_capacity(matching_rows.len() * 128);
-        buf.push_str("{\"pois\":[");
-
-        for (i, &row) in matching_rows.iter().enumerate() {
-            if i > 0 {
-                buf.push(',');
-            }
-            buf.push_str("{\"id\":\"");
-            write_json_escaped(&mut buf, &state.poi_data.id[row]);
-            buf.push_str("\",\"name\":\"");
-            write_json_escaped(&mut buf, &state.poi_data.name[row]);
-            buf.push_str("\",\"category\":\"");
-            write_json_escaped(&mut buf, state.poi_data.category.get(row));
-            buf.push_str("\",\"group\":\"");
-            write_json_escaped(&mut buf, state.poi_data.group.get(row));
-            buf.push_str("\",\"lat\":");
-            buf.push_str(&state.poi_data.lat[row].to_string());
-            buf.push_str(",\"lng\":");
-            buf.push_str(&state.poi_data.lng[row].to_string());
-            buf.push_str(",\"emoji\":\"");
-            write_json_escaped(&mut buf, state.poi_data.emoji.get(row));
-            buf.push_str("\"}");
-        }
-
-        buf.push_str("]}");
+        let pois: Vec<POI> = matching_rows
+            .iter()
+            .map(|&row| POI {
+                id: state.poi_data.id[row].clone(),
+                name: state.poi_data.name[row].clone(),
+                category: state.poi_data.category.get(row).to_string(),
+                group: state.poi_data.group.get(row).to_string(),
+                lat: state.poi_data.lat[row],
+                lng: state.poi_data.lng[row],
+                emoji: state.poi_data.emoji.get(row).to_string(),
+            })
+            .collect();
 
         let elapsed = t0.elapsed();
         info!(
-            results = matching_rows.len(),
+            results = pois.len(),
             candidates = row_indices.len(),
             categories = num_categories,
             categories_raw = categories_str.as_deref().unwrap_or("-"),
@@ -110,12 +110,12 @@ pub async fn get_pois(
             "GET /api/pois"
         );
 
-        buf
+        pois
     })
     .await
     .map_err(|error| (StatusCode::INTERNAL_SERVER_ERROR, error.to_string()))?;
 
-    Ok(([("content-type", "application/json")], json_body))
+    Ok(Json(POIsResponse { pois }))
 }
 
 #[derive(Serialize)]