A generated many-part assembly: test and open-phase benchmark (#927)

Generates N parts of four primitive bodies, each moved into a placed component. The test (12 parts) checks the open, the world placement and the saved round trip; the ignored bench_generated_assembly prints parse, evaluation inside and outside the features, mesh warm-up and Measure.

crates/engine/src/large_assembly_tests.rs

@@ -0,0 +1,124 @@
+//! A generated many-part assembly, shaped like a large design built through the MCP tools: each
+//! part is a few primitives, and every body is then moved into its own
+//! placed component. Opening one runs a long timeline over many bodies, which is where costs
+//! that grow with the number of bodies after every feature show up (#255, #662).
+//!
+//! The test keeps it small. The benchmark times the open phases at any size:
+//! `SOLIDCRAFT_BENCH_PARTS=400 cargo test --release -p solidcraft-engine bench_generated_assembly -- --ignored --nocapture`
+
+use serde_json::json;
+use solidcraft_doc::{Document, FeatureKind, Operation, mat_inverse, point_expr, rigid};
+use solidcraft_geom::Vec3;
+
+use crate::Session;
+
+/// `parts` parts, four bodies each, in `parts / 4` (at least one) placed components.
+fn generated_assembly(parts: usize) -> Document {
+    let mut doc = Document::new("generated assembly");
+    let groups = parts.div_ceil(4).max(1);
+    let comps: Vec<(u64, solidcraft_doc::Mat)> = (0..groups)
+        .map(|g| {
+            let id = doc.add_component(Some(&format!("Module {g}")), 0).unwrap();
+            let m = rigid(Vec3::new(5.0 * g as f64, -3.0, 2.0), Vec3::ZERO, Vec3::Z, 0.1 * g as f64);
+            doc.occurrences.iter_mut().find(|o| o.component == id).unwrap().transform = m;
+            (id, m)
+        })
+        .collect();
+    let mm = |v: f64| format!("{v} mm");
+    let mut made = Vec::new();
+    for i in 0..parts {
+        let o = Vec3::new(30.0 * (i % 20) as f64, 30.0 * (i / 20) as f64, 0.0);
+        let block = FeatureKind::Box { corner: point_expr(o), length: mm(20.0), width: mm(12.0), height: mm(6.0), operation: Operation::NewBody };
+        made.push((i, doc.add_feature(block, Some(&format!("Plate {i}"))).unwrap()));
+        for (k, x) in [2.0, 9.0, 16.0].into_iter().enumerate() {
+            let pin = FeatureKind::Cylinder {
+                base: point_expr(o + Vec3::new(x, 20.0, 0.0)),
+                axis: Vec3::Z,
+                radius: mm(1.5),
+                height: mm(4.0 + k as f64),
+                operation: Operation::NewBody,
+            };
+            made.push((i, doc.add_feature(pin, Some(&format!("Pin {i}.{k}"))).unwrap()));
+        }
+    }
+    // Every body moves into its part's component, keeping its place in the world.
+    let s = Session::new(doc.clone());
+    let state = s.model.state();
+    for (part, feature) in made {
+        let (to, m) = comps[part / 4 % groups];
+        for b in state.bodies.iter().filter(|b| b.feature == feature) {
+            let kind = FeatureKind::BodyTransfer { bodies: vec![b.name.clone()], from: 0, to, transform: mat_inverse(&m).unwrap() };
+            doc.add_feature(kind, None).unwrap();
+        }
+    }
+    doc
+}
+
+fn measured(s: &mut Session) -> serde_json::Value {
+    let mut m = s.execute("inspect.measure", &json!({})).unwrap();
+    for b in m["bodies"].as_array_mut().unwrap() {
+        b.as_object_mut().unwrap().remove("name");
+    }
+    m
+}
+
+#[test]
+fn generated_assembly_opens_with_every_body_in_place() {
+    let parts = 12;
+    let doc = generated_assembly(parts);
+    let mut s = Session::new(doc.clone());
+    assert!(s.model.results.iter().all(|r| r.error.is_none()), "{:?}", s.model.results.iter().find(|r| r.error.is_some()));
+    let world = s.world_state();
+    assert_eq!(world.bodies.len(), parts * 4);
+    assert!(world.bodies.iter().all(|b| b.component != 0 && b.transferred));
+    world.warm_meshes(|| true);
+    assert!(world.bodies.iter().all(|b| !b.mesh().triangles.is_empty()));
+    // Moving bodies into components keeps them where they were.
+    let before = measured(&mut Session::new({
+        let mut d = doc.clone();
+        d.features.retain(|f| !matches!(f.kind, FeatureKind::BodyTransfer { .. }));
+        d
+    }));
+    let after = measured(&mut s);
+    for (a, b) in before["bodies"].as_array().unwrap().iter().zip(after["bodies"].as_array().unwrap()) {
+        for k in ["volume_mm3", "area_mm2"] {
+            assert!((a[k].as_f64().unwrap() - b[k].as_f64().unwrap()).abs() < 1e-6, "{k}: {a} vs {b}");
+        }
+        for (p, q) in a["bbox"]["min"].as_array().unwrap().iter().zip(b["bbox"]["min"].as_array().unwrap()) {
+            assert!((p.as_f64().unwrap() - q.as_f64().unwrap()).abs() < 1e-6);
+        }
+    }
+    // A saved copy opens to the same model.
+    let reopened = solidcraft_io::read_design(&solidcraft_io::write_design(&doc)).unwrap();
+    assert_eq!(measured(&mut Session::new(reopened)), after);
+}
+
+/// Open-phase timings of a generated assembly (`SOLIDCRAFT_BENCH_PARTS` parts, default 200).
+#[test]
+#[ignore = "benchmark: run with --release --ignored --nocapture"]
+fn bench_generated_assembly() {
+    let parts = std::env::var("SOLIDCRAFT_BENCH_PARTS").ok().and_then(|v| v.parse().ok()).unwrap_or(200);
+    let bytes = solidcraft_io::write_design(&generated_assembly(parts));
+    let ms = |t: std::time::Instant| t.elapsed().as_secs_f64() * 1000.0;
+    let t = std::time::Instant::now();
+    let doc = solidcraft_io::read_design(&bytes).unwrap();
+    let parse = ms(t);
+    let t = std::time::Instant::now();
+    let s = Session::new(doc);
+    let evaluate = ms(t);
+    let features: f64 = s.model.results.iter().map(|r| r.ms).sum();
+    let t = std::time::Instant::now();
+    let world = s.world_state();
+    world.warm_meshes(|| true);
+    let mesh = ms(t);
+    let t = std::time::Instant::now();
+    let mut s = s;
+    let m = measured(&mut s);
+    let measure = ms(t);
+    println!(
+        "{}",
+        json!({"parts": parts, "features": s.doc.features.len(), "bodies": world.bodies.len(), "parse_ms": parse, "evaluate_ms": evaluate,
+               "in_features_ms": features, "outside_features_ms": evaluate - features, "mesh_ms": mesh, "measure_ms": measure,
+               "volume_mm3": m["total"]["volume_mm3"]})
+    );
+}

crates/engine/src/lib.rs

@@ -812,6 +812,8 @@ mod extent_tests;
 #[cfg(test)]
 mod hole_face_tests;
 #[cfg(test)]
+mod large_assembly_tests;
+#[cfg(test)]
 mod naming_history_tests;
 #[cfg(test)]
 mod pattern_suppress_tests;