osm_to_railjson: minor upgrades

editoast/osm_to_railjson/README.md

@@ -6,6 +6,12 @@ Example for Germany:
 
 1. Download OSM's German data (~4Gb `germany-latest.osm.pbf`) from
     https://download.geofabrik.de/europe/germany.html
+
+    This is not mandatory, but we strongly recommend using [osmium](https://osmcode.org/osmium-tool/) to filter the osm.pbf file with only the data needed by osm_to_railjson.
+    ```sh
+    osmium tags-filter <path/to/germany-latest.osm.pbf> nwr/railway nwr/train -o <path/to/germany-latest.osm.pbf>
+    ```
+    It can divide by 3 the time taken by osm_to_railjson.
 2. Launch conversion (release build of editoast and conversion can be long):
     ```sh
     cd ../../editoast

editoast/osm_to_railjson/src/osm_to_railjson.rs

@@ -47,6 +47,8 @@ pub fn parse_osm(
         .reject("gauge", "600")
         .reject("roller_coaster", "*")
         .reject("construction", "*")
+        .reject("usage", "science")
+        .reject("usage", "tourism")
         .read_tag("maxspeed")
         .read_tag("maxspeed:forward")
         .read_tag("maxspeed:backward")
@@ -69,7 +71,11 @@ pub fn parse_osm(
     }
 
     let nodes_tracks = NodeToTrack::from_edges(&edges);
-    let signals = signals(&osm_pbf_in, &nodes_tracks, &adjacencies);
+    let signals = if generate_signals {
+        vec![]
+    } else {
+        signals(&osm_pbf_in, &nodes_tracks, &adjacencies)
+    };
     let mut railjson = RailJson {
         extended_switch_types: vec![],
         detectors: signals.iter().map(detector).collect(),

editoast/osm_to_railjson/src/utils.rs

@@ -449,13 +449,17 @@ pub fn electrifications(edge: &Edge) -> Option<Electrification> {
     })
 }
 
-fn map_node_id_to_node(
+fn map_node_id_to_trigram(
     pbf: &mut OsmPbfReader<std::fs::File>,
-) -> HashMap<osm4routing::osmpbfreader::NodeId, osm4routing::osmpbfreader::Node> {
+) -> HashMap<osm4routing::osmpbfreader::NodeId, String> {
     pbf.iter()
         .flatten()
         .filter_map(|obj| match obj {
-            osm4routing::osmpbfreader::OsmObj::Node(node) => Some((node.id, node)),
+            osm4routing::osmpbfreader::OsmObj::Node(node) => node
+                .tags
+                .get("railway:ref")
+                .filter(|trigram| trigram.len() <= 3)
+                .map(|tag| (node.id, tag.to_string())),
             _ => None,
         })
         .collect()
@@ -467,7 +471,7 @@ pub fn operational_points(
 ) -> Vec<OperationalPoint> {
     let file = std::fs::File::open(osm_pbf_in).unwrap();
     let mut pbf: OsmPbfReader<std::fs::File> = osm4routing::osmpbfreader::OsmPbfReader::new(file);
-    let node_id_to_node = map_node_id_to_node(&mut pbf);
+    let node_id_to_trigram = map_node_id_to_trigram(&mut pbf);
     pbf.rewind().expect("Could not rewind file.");
     pbf.iter()
         .flatten()
@@ -504,11 +508,8 @@ pub fn operational_points(
                     _ => None,
                 })
                 .find_map(|node_id| {
-                    node_id_to_node.get(&node_id).and_then(|node| {
-                        node.tags
-                            .get("railway:ref")
-                            .map(ToString::to_string)
-                    })
+                    node_id_to_trigram.get(&node_id)
+                        .cloned()
                 })
                 .unwrap_or_default();
             // Parts can be empty when the stop_area references stops that are not railway (e.g. bus station)