[topo] Switch Env from Arc to Rc, add benchmarks.

Author: anp

.cargo/config

@@ -45,4 +45,5 @@ watch --clear
     -x check-core
     -x test-core
     -x clippy-core
+    -x bench-core
 """

.gitignore

@@ -1,4 +1,4 @@
-/target
+target/
 **/*.rs.bk
 Cargo.lock
 *.log

CONTRIBUTING.md

@@ -6,10 +6,24 @@ This is a placeholder for if/when the project is ready to onboard more contribut
 
 ## Development environment
 
+### Requirements
+
 * [rustup](https://rustup.rs)
   * `rustup component add clippy rustfmt`
 * [cargo-watch](https://crates.io/crates/cargo-watch)
 
+### Workflows
+
+#### Core libraries
+
+From the project root, this command will run the default development loop:
+
+```shell
+$ cargo watch-core
+```
+
+See [its definition](./.cargo/config) for details.
+
 ### moxie-dom dev env
 
 * [node >= LTS](https://nodejs.org)

topo/Cargo.toml

@@ -9,3 +9,10 @@ im-rc = "13"
 owning_ref = "0.4"
 tokio-trace = { version = "0.1", features = ["log"] }
 topo-macro = { path = "macro" }
+
+[dev-dependencies]
+criterion = "0.2"
+
+[[bench]]
+name = "simple"
+harness = false

topo/benches/simple.rs

@@ -0,0 +1,106 @@
+#[macro_use]
+extern crate criterion;
+
+use criterion::{black_box, Criterion, ParameterizedBenchmark};
+
+fn empty_env(c: &mut Criterion) {
+    c.bench_function("call empty env", |b| {
+        b.iter(|| black_box(topo::call!(|| topo::Id::current())))
+    });
+}
+
+fn create_small_env(c: &mut Criterion) {
+    c.bench_function("call create small env", |b| {
+        b.iter(|| {
+            black_box(topo::call!(|| topo::Id::current(), Env {
+                u128 => 10
+            }))
+        });
+    });
+}
+
+#[allow(clippy::trivially_copy_pass_by_ref)]
+fn topo_bench(b: &mut criterion::Bencher, depth: &usize) {
+    macro_rules! mk {
+        (go $depth_spec:ident) => {
+            topo::call!(|| {
+                mk!(pass $depth_spec 0);
+            }, Env { u128 => 10 });
+        };
+        (pass $depth_spec:ident $call_depth:expr) => {
+            topo::call!(|| {
+                mk!(cur $depth_spec ($call_depth + 1));
+            });
+        };
+        (cur twelve $depth:expr) => {
+            mk!(pass eleven $depth);
+        };
+        (cur eleven $depth:expr) => {
+            mk!(pass ten $depth);
+        };
+        (cur ten $depth:expr) => {
+            mk!(pass nine $depth);
+        };
+        (cur nine $depth:expr) => {
+            mk!(pass eight $depth);
+        };
+        (cur eight $depth:expr) => {
+            mk!(pass seven $depth);
+        };
+        (cur seven $depth:expr) => {
+            mk!(pass six $depth);
+        };
+        (cur six $depth:expr) => {
+            mk!(pass five $depth);
+        };
+        (cur five $depth:expr) => {
+            mk!(pass four $depth);
+        };
+        (cur four $depth:expr) => {
+            mk!(pass three $depth);
+        };
+        (cur three $depth:expr) => {
+            mk!(pass two $depth);
+        };
+        (cur two $depth:expr) => {
+            mk!(pass one $depth);
+        };
+        (cur one $depth:expr) => {
+            mk!(pass zero ($depth + 1)); // lol what a cheater!
+        };
+        (cur zero $depth:expr) => {
+            b.iter(|| {
+                topo::call!(|| assert_eq!(10, *topo::from_env::<u128>().unwrap()))
+            });
+        };
+    }
+    match depth {
+        12 => mk!(go twelve),
+        11 => mk!(go eleven),
+        10 => mk!(go ten),
+        9 => mk!(go nine),
+        8 => mk!(go eight),
+        7 => mk!(go seven),
+        6 => mk!(go six),
+        5 => mk!(go five),
+        4 => mk!(go four),
+        3 => mk!(go three),
+        2 => mk!(go two),
+        1 => mk!(go one),
+        _ => unimplemented!(),
+    }
+}
+
+fn enter_small_env(c: &mut Criterion) {
+    c.bench(
+        "topo fns",
+        ParameterizedBenchmark::new(
+            "call from_env within small env at depth",
+            topo_bench,
+            vec![1, 3, 9, 12],
+        ),
+    );
+}
+
+criterion_group!(benches, empty_env, create_small_env, enter_small_env);
+criterion_main!(benches);

topo/src/lib.rs

@@ -56,7 +56,7 @@ use {
         collections::HashMap,
         hash::{Hash, Hasher},
         ops::Deref,
-        sync::Arc,
+        rc::Rc,
     },
 };
 
@@ -237,7 +237,7 @@ impl Callsite {
 #[doc(hidden)]
 #[derive(Clone, Debug, Default)]
 pub struct Env {
-    inner: HashMap<TypeId, Arc<dyn Any + Send + Sync>>,
+    inner: HashMap<TypeId, Rc<dyn Any + Send + Sync>>,
 }
 
 impl Env {
@@ -255,7 +255,7 @@ impl Env {
     where
         E: Any + Send + Sync + 'static,
     {
-        self.inner.insert(TypeId::of::<E>(), Arc::new(e));
+        self.inner.insert(TypeId::of::<E>(), Rc::new(e));
     }
 }