From acf854f558e97481d840460539e5d573999fc25a Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Sun, 5 May 2019 15:32:09 +1000
Subject: [PATCH] Add profiling tools, examples

---
 Cargo.toml                            |  3 +++
 eth2/utils/ssz/Cargo.toml             |  5 ++++
 eth2/utils/ssz/benches/benches.rs     | 38 +++++++++++++++++++++++++++
 eth2/utils/ssz/examples/large_list.rs | 16 +++++++++++
 eth2/utils/ssz/src/decode/impls.rs    | 38 +++++++++++++--------------
 5 files changed, 81 insertions(+), 19 deletions(-)
 create mode 100644 eth2/utils/ssz/benches/benches.rs
 create mode 100644 eth2/utils/ssz/examples/large_list.rs

diff --git a/Cargo.toml b/Cargo.toml
index c05e22286..20c4cd0a8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -36,3 +36,6 @@ members = [
 	"validator_client",
 	"account_manager",
 ]
+
+[profile.release]
+debug = true
diff --git a/eth2/utils/ssz/Cargo.toml b/eth2/utils/ssz/Cargo.toml
index dda169006..0423b1a8b 100644
--- a/eth2/utils/ssz/Cargo.toml
+++ b/eth2/utils/ssz/Cargo.toml
@@ -4,7 +4,12 @@ version = "0.1.0"
 authors = ["Paul Hauner <paul@paulhauner.com>"]
 edition = "2018"
 
+[[bench]]
+name = "benches"
+harness = false
+
 [dev-dependencies]
+criterion = "0.2"
 ssz_derive = { path = "../ssz_derive" }
 
 [dependencies]
diff --git a/eth2/utils/ssz/benches/benches.rs b/eth2/utils/ssz/benches/benches.rs
new file mode 100644
index 000000000..45a57adef
--- /dev/null
+++ b/eth2/utils/ssz/benches/benches.rs
@@ -0,0 +1,38 @@
+#[macro_use]
+extern crate criterion;
+
+use criterion::black_box;
+use criterion::{Benchmark, Criterion};
+use ssz::{Decodable, Encodable};
+
+fn criterion_benchmark(c: &mut Criterion) {
+    let n = 8196;
+
+    let vec: Vec<u64> = vec![4242; 8196];
+    c.bench(
+        &format!("vec_of_{}_u64", n),
+        Benchmark::new("as_ssz_bytes", move |b| {
+            b.iter_with_setup(|| vec.clone(), |vec| black_box(vec.as_ssz_bytes()))
+        })
+        .sample_size(100),
+    );
+
+    let vec: Vec<u64> = vec![4242; 8196];
+    let bytes = vec.as_ssz_bytes();
+    c.bench(
+        &format!("vec_of_{}_u64", n),
+        Benchmark::new("from_ssz_bytes", move |b| {
+            b.iter_with_setup(
+                || bytes.clone(),
+                |bytes| {
+                    let vec: Vec<u64> = Vec::from_ssz_bytes(&bytes).unwrap();
+                    black_box(vec)
+                },
+            )
+        })
+        .sample_size(100),
+    );
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);
diff --git a/eth2/utils/ssz/examples/large_list.rs b/eth2/utils/ssz/examples/large_list.rs
new file mode 100644
index 000000000..b235771fc
--- /dev/null
+++ b/eth2/utils/ssz/examples/large_list.rs
@@ -0,0 +1,16 @@
+//! Encode and decode a list 10,000 times.
+//!
+//! Useful for `cargo flamegraph`.
+
+use ssz::{Decodable, Encodable};
+
+fn main() {
+    let vec: Vec<u64> = vec![4242; 8196];
+
+    let output: Vec<Vec<u64>> = (0..10_000)
+        .into_iter()
+        .map(|_| Vec::from_ssz_bytes(&vec.as_ssz_bytes()).unwrap())
+        .collect();
+
+    println!("{}", output.len());
+}
diff --git a/eth2/utils/ssz/src/decode/impls.rs b/eth2/utils/ssz/src/decode/impls.rs
index 366d9d6b6..2741a0800 100644
--- a/eth2/utils/ssz/src/decode/impls.rs
+++ b/eth2/utils/ssz/src/decode/impls.rs
@@ -211,28 +211,28 @@ mod tests {
         /*
          * Input is exact length
          */
-        let input = vec![42_u8; 32];
-        let (decoded, i) = H256::from_ssz_bytes(&input).unwrap();
-        assert_eq!(decoded.as_bytes(), &input[..]);
-        assert_eq!(i, 32);
+    let input = vec![42_u8; 32];
+    let (decoded, i) = H256::from_ssz_bytes(&input).unwrap();
+    assert_eq!(decoded.as_bytes(), &input[..]);
+    assert_eq!(i, 32);
 
-        /*
-         * Input is too long
-         */
-        let mut input = vec![42_u8; 32];
-        input.push(12);
-        let (decoded, i) = H256::from_ssz_bytes(&input, 0).unwrap();
-        assert_eq!(decoded.as_bytes(), &input[0..32]);
-        assert_eq!(i, 32);
+    /*
+     * Input is too long
+     */
+    let mut input = vec![42_u8; 32];
+    input.push(12);
+    let (decoded, i) = H256::from_ssz_bytes(&input, 0).unwrap();
+    assert_eq!(decoded.as_bytes(), &input[0..32]);
+    assert_eq!(i, 32);
 
-        /*
-         * Input is too short
-         */
-        let input = vec![42_u8; 31];
-        let res = H256::from_ssz_bytes(&input, 0);
-        assert_eq!(res, Err(DecodeError::TooShort));
+    /*
+     * Input is too short
+     */
+    let input = vec![42_u8; 31];
+    let res = H256::from_ssz_bytes(&input, 0);
+    assert_eq!(res, Err(DecodeError::TooShort));
     }
-    */
+     */
 
     #[test]
     fn first_length_points_backwards() {