Stop-gap to improve web app perf: skip low-count edges. #14

aggregate_routes/src/main.rs

@@ -33,6 +33,9 @@ struct Args {
     /// Don't output OSM tags in the GeoJSON output, to reduce file size.
     #[clap(long)]
     no_output_osm_tags: bool,
+    /// Don't output edges with total counts below this threshold.
+    #[clap(long)]
+    skip_edges_with_low_count: Option<usize>,
 
     /// Instead of doing what this tool normally does, instead calculate this many routes and write
     /// a separate GeoJSON file for each of them, with full segment-level detail. This will be slow
@@ -160,6 +163,7 @@ fn main() -> Result<()> {
         counts,
         !args.no_output_od_points,
         !args.no_output_osm_tags,
+        args.skip_edges_with_low_count,
         config.lts,
     )?;
     timer.stop();

aggregate_routes/src/osm2network.rs

@@ -342,6 +342,7 @@ impl Network {
         counts: Counts,
         output_od_points: bool,
         output_osm_tags: bool,
+        skip_edges_with_low_count: Option<usize>,
         lts: LtsMapping,
     ) -> Result<()> {
         // Write one feature at a time to avoid memory problems
@@ -350,6 +351,13 @@ impl Network {
         let mut skipped = 0;
         let mut id_counter = 0;
         for ((node1, node2), count) in counts.count_per_edge {
+            if let Some(min) = skip_edges_with_low_count {
+                if (count as usize) < min {
+                    skipped += 1;
+                    continue;
+                }
+            }
+
             // TODO Track forwards and backwards counts separately, and optionally merge later?
             if let Some(edge) = self
                 .edges
@@ -367,7 +375,7 @@ impl Network {
             }
         }
         println!(
-            "Skipped {} edges (started/ended mid-edge)",
+            "Skipped {} edges (started/ended mid-edge, or count too low)",
             HumanCount(skipped)
         );