Dynamic (#77)

tests/dynamic_python_build_pool.rs

@@ -0,0 +1,127 @@
+//! Phase 23 / Track O.1 micro-benchmark for the Python build pool.
+//!
+//! Asserts the warm-cache hot path (a `prepare_python` cache hit backed by the
+//! shared venv + `compileall` bytecode warm) stays ≤ 200ms, the interpreted
+//! budget.  Skips when `python3` is not runnable.
+
+#![cfg(feature = "dynamic")]
+
+use std::path::Path;
+use std::sync::{Mutex, MutexGuard};
+use std::time::{Duration, Instant};
+
+use nyx_scanner::dynamic::build_sandbox::prepare_python;
+use nyx_scanner::dynamic::spec::{
+    EntryKind, HarnessSpec, JavaToolchain, PayloadSlot, SpecDerivationStrategy,
+};
+use nyx_scanner::labels::Cap;
+use nyx_scanner::symbol::Lang;
+
+static ENV_LOCK: Mutex<()> = Mutex::new(());
+
+struct CacheGuard {
+    _lock: MutexGuard<'static, ()>,
+    prior_cache: Option<String>,
+    prior_pool: Option<String>,
+    _cache: tempfile::TempDir,
+    _pool: tempfile::TempDir,
+}
+
+impl CacheGuard {
+    fn isolated() -> Self {
+        let lock = ENV_LOCK.lock().unwrap_or_else(|p| p.into_inner());
+        let cache = tempfile::TempDir::new().unwrap();
+        let pool = tempfile::TempDir::new().unwrap();
+        let prior_cache = std::env::var("NYX_BUILD_CACHE").ok();
+        let prior_pool = std::env::var("NYX_BUILD_POOL_DIR").ok();
+        unsafe {
+            std::env::set_var("NYX_BUILD_CACHE", cache.path());
+            std::env::set_var("NYX_BUILD_POOL_DIR", pool.path());
+        }
+        Self {
+            _lock: lock,
+            prior_cache,
+            prior_pool,
+            _cache: cache,
+            _pool: pool,
+        }
+    }
+}
+
+impl Drop for CacheGuard {
+    fn drop(&mut self) {
+        restore("NYX_BUILD_CACHE", self.prior_cache.take());
+        restore("NYX_BUILD_POOL_DIR", self.prior_pool.take());
+    }
+}
+
+fn restore(key: &str, prior: Option<String>) {
+    match prior {
+        Some(v) => unsafe { std::env::set_var(key, v) },
+        None => unsafe { std::env::remove_var(key) },
+    }
+}
+
+fn median(mut ds: Vec<Duration>) -> Duration {
+    ds.sort();
+    ds[ds.len() / 2]
+}
+
+fn mk_spec() -> HarnessSpec {
+    HarnessSpec {
+        finding_id: "bench".to_owned(),
+        entry_file: "entry".to_owned(),
+        entry_name: "main".to_owned(),
+        entry_kind: EntryKind::Function,
+        lang: Lang::Python,
+        toolchain_id: "bench-python".to_owned(),
+        payload_slot: PayloadSlot::Param(0),
+        expected_cap: Cap::CODE_EXEC,
+        constraint_hints: vec![],
+        sink_file: "sink".to_owned(),
+        sink_line: 1,
+        spec_hash: "0000000000000000".to_owned(),
+        derivation: SpecDerivationStrategy::FromFlowSteps,
+        stubs_required: vec![],
+        framework: None,
+        java_toolchain: JavaToolchain::default(),
+    }
+}
+
+fn write_project(workdir: &Path) {
+    // Empty requirements: venv creation succeeds offline; the cached
+    // `.python_cache_done` marker turns every later call into a cache hit.
+    std::fs::write(workdir.join("requirements.txt"), "").unwrap();
+}
+
+#[test]
+#[ignore = "real-toolchain perf bench: spawns `python -m venv` + pip. Opt-in so the default suite stays hermetic + fast. Run: cargo nextest run --features dynamic --run-ignored ignored-only -E 'binary(~build_pool) | binary(~compile_pool)'"]
+fn warm_prepare_p50_under_200ms() {
+    let _guard = CacheGuard::isolated();
+    let spec = mk_spec();
+    let work = tempfile::TempDir::new().unwrap();
+    write_project(work.path());
+
+    match prepare_python(&spec, work.path()) {
+        Ok(_) => {}
+        Err(e) => {
+            eprintln!("skipping python build-pool bench: {e:?}");
+            return;
+        }
+    }
+
+    let mut hot = Vec::new();
+    for _ in 0..5 {
+        let start = Instant::now();
+        let r = prepare_python(&spec, work.path()).expect("warm prepare must succeed");
+        hot.push(start.elapsed());
+        assert!(r.cache_hit, "warm prepare_python must be a cache hit");
+    }
+
+    let p50 = median(hot);
+    eprintln!("python build-pool warm P50: {p50:?}");
+    assert!(
+        p50 <= Duration::from_millis(200),
+        "python warm-prepare P50 {p50:?} exceeds the 200ms interpreted budget",
+    );
+}