From ae9513f00a8f5e905fa1f7b8f42b709ff24369ba Mon Sep 17 00:00:00 2001
From: HaoranYi <haoran.yi@gmail.com>
Date: Thu, 26 May 2022 09:06:53 -0500
Subject: [PATCH] Opt: optimize dedup hash filter reset (#25555)

* refactor compute_hash

* optimize dedup filter reset

* clippy

* clippy2

* Revert "refactor compute_hash"

This reverts commit 4d09ad07f71c8cd634d405876ae8139a5e7a121a.
---
 perf/benches/reset.rs | 46 +++++++++++++++++++++++++++++++++++++++++++
 perf/src/sigverify.rs |  6 +++---
 2 files changed, 49 insertions(+), 3 deletions(-)
 create mode 100644 perf/benches/reset.rs

diff --git a/perf/benches/reset.rs b/perf/benches/reset.rs
new file mode 100644
index 000000000..caa2f143b
--- /dev/null
+++ b/perf/benches/reset.rs
@@ -0,0 +1,46 @@
+#![feature(test)]
+
+extern crate test;
+
+use {
+    std::sync::atomic::{AtomicU64, Ordering},
+    test::Bencher,
+};
+
+const N: usize = 1_000_000;
+
+// test bench_reset1 ... bench:     436,240 ns/iter (+/- 176,714)
+// test bench_reset2 ... bench:     274,007 ns/iter (+/- 129,552)
+
+#[bench]
+fn bench_reset1(bencher: &mut Bencher) {
+    solana_logger::setup();
+
+    let mut v = Vec::with_capacity(N);
+    v.resize_with(N, AtomicU64::default);
+
+    bencher.iter(|| {
+        test::black_box({
+            for i in &v {
+                i.store(0, Ordering::Relaxed);
+            }
+            0
+        });
+    });
+}
+
+#[bench]
+fn bench_reset2(bencher: &mut Bencher) {
+    solana_logger::setup();
+
+    let mut v = Vec::with_capacity(N);
+    v.resize_with(N, AtomicU64::default);
+
+    bencher.iter(|| {
+        test::black_box({
+            v.clear();
+            v.resize_with(N, AtomicU64::default);
+            0
+        });
+    });
+}
diff --git a/perf/src/sigverify.rs b/perf/src/sigverify.rs
index 592ce310c..104932a6f 100644
--- a/perf/src/sigverify.rs
+++ b/perf/src/sigverify.rs
@@ -476,9 +476,9 @@ impl Deduper {
         //false positive rate is 1/1000 at that point
         let saturated = self.saturated.load(Ordering::Relaxed);
         if saturated || now.duration_since(self.age) > self.max_age {
-            for i in &self.filter {
-                i.store(0, Ordering::Relaxed);
-            }
+            let len = self.filter.len();
+            self.filter.clear();
+            self.filter.resize_with(len, AtomicU64::default);
             self.seed = thread_rng().gen();
             self.age = now;
             self.saturated.store(false, Ordering::Relaxed);