parse: handle many curvepoints efficiently

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Upcoming
 
+- parse:
+  - Efficiently handle huge amounts of curvepoints
+
 - osu:
   - Fixed panic on unwrapping unavailable hit results
   - Fixed occasional underflow when calculating pp with passed_objects

src/osu/versions/no_leniency/mod.rs

@@ -280,7 +280,7 @@ mod tests {
     #[test]
     #[ignore]
     fn no_leniency_single() {
-        let file = match File::open("./maps/1791963.osu") {
+        let file = match File::open("./maps/2573164.osu") {
             Ok(file) => file,
             Err(why) => panic!("Could not open file: {}", why),
         };
@@ -291,11 +291,11 @@ mod tests {
         };
 
         let result = OsuPP::new(&map)
-            .n300(1206)
+            .mods(0)
-            .n100(15)
+            // .n300(1206)
-            .n50(0)
+            // .n100(15)
-            .combo(1643)
+            // .n50(0)
-            .mods(24)
+            // .combo(1643)
             .calculate();
 
         println!("Stars: {}", result.stars());

src/parse/mod.rs

@@ -115,6 +115,12 @@ pub struct Beatmap {
 
 pub(crate) const OSU_FILE_HEADER: &str = "osu file format v";
 
+#[cfg(any(
+    feature = "fruits",
+    all(feature = "osu", not(feature = "no_sliders_no_leniency"))
+))]
+const CURVE_POINT_THRESHOLD: usize = 256;
+
 impl Beatmap {
     const CIRCLE_FLAG: u8 = 1 << 0;
     const SLIDER_FLAG: u8 = 1 << 1;
@@ -476,6 +482,23 @@ impl Beatmap {
                         }
                     }
 
+                    // Reduce amount of curvepoints but keep the elements evenly spaced.
+                    // Necessary to handle maps like XNOR (2573164) that have
+                    // tens of thousands of curvepoints more efficiently.
+                    if curve_points.len() > CURVE_POINT_THRESHOLD {
+                        while curve_points.len() > CURVE_POINT_THRESHOLD {
+                            let last = curve_points[curve_points.len() - 1];
+                            let last_idx = (curve_points.len() - 1) / 2;
+
+                            for i in 1..=last_idx {
+                                curve_points.swap(i, 2 * i);
+                            }
+
+                            curve_points[last_idx] = last;
+                            curve_points.truncate(last_idx + 1);
+                        }
+                    }
+
                     if curve_points.is_empty() {
                         HitObjectKind::Circle
                     } else {