refactored data loading code

src/utils.rs

@@ -1,9 +1,49 @@
+use crate::alt::LandmarkSet;
+use crate::gridgraph::GridGraph;
 use serde::{Deserialize, Serialize};
+use std::fs::File;
+use std::io::BufReader;
+use std::process::exit;
 
 pub const EARTH_RADIUS: f64 = 6_371_000.0; // meters
 
 #[derive(Serialize, Deserialize, Debug, Copy, Clone)]
-pub struct RoutingQuery{
+pub struct RoutingQuery {
     pub source: usize,
     pub destination: usize,
 }
+
+pub fn load_graph(path: &str) -> Box<GridGraph> {
+    println!("Loading file from {}", path);
+    let file = match File::open(path) {
+        Ok(f) => f,
+        Err(e) => {
+            println!("Error while opening the file {}: {}", path, e);
+            exit(1)
+        }
+    };
+
+    let graph = match GridGraph::from_fmi_file(file) {
+        Ok(g) => g,
+        Err(e) => {
+            println!("Error while reading the graph: {:?}", e);
+            exit(1);
+        }
+    };
+
+    println!("Loaded graph file");
+
+    graph
+}
+
+pub fn load_landmarks(path: &str) -> LandmarkSet {
+    let landmarks = match File::open(path) {
+        Ok(f) => f,
+        Err(e) => {
+            println!("Error while opening landmark file {}: {:?}", path, e);
+            exit(1);
+        }
+    };
+
+    bincode::deserialize_from(BufReader::new(landmarks)).unwrap()
+}