From d4b6aaa0985d44b9fc12a12524aa3954a8ce1537 Mon Sep 17 00:00:00 2001
From: "Jorge C. Leitao" <jorgecarleitao@gmail.com>
Date: Thu, 26 Aug 2021 10:28:57 +0000
Subject: [PATCH] Refactored benches for null_count.

---
 Cargo.toml             |  2 +-
 benches/count_zeros.rs | 24 ++++++++++++++++++++++++
 benches/null_count.rs  | 42 ------------------------------------------
 benches/unset_count.rs | 24 ++++++++++++++++++++++++
 4 files changed, 49 insertions(+), 43 deletions(-)
 create mode 100644 benches/count_zeros.rs
 delete mode 100644 benches/null_count.rs
 create mode 100644 benches/unset_count.rs

diff --git a/Cargo.toml b/Cargo.toml
index e057c40de6e..ad96f42e54e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -141,7 +141,7 @@ name = "length_kernel"
 harness = false
 
 [[bench]]
-name = "null_count"
+name = "count_zeros"
 harness = false
 
 [[bench]]
diff --git a/benches/count_zeros.rs b/benches/count_zeros.rs
new file mode 100644
index 00000000000..f37d411bdf4
--- /dev/null
+++ b/benches/count_zeros.rs
@@ -0,0 +1,24 @@
+use arrow2::bitmap::utils::null_count;
+
+use criterion::{criterion_group, criterion_main, Criterion};
+
+fn add_benchmark(c: &mut Criterion) {
+    (10..=20).step_by(2).for_each(|log2_size| {
+        let size = 2usize.pow(log2_size);
+
+        let bytes = (0..size as u32)
+            .map(|x| 0b01011011u8.rotate_left(x))
+            .collect::<Vec<_>>();
+
+        c.bench_function(&format!("count_zeros 2^{}", log2_size), |b| {
+            b.iter(|| null_count(&bytes, 0, bytes.len() * 8))
+        });
+
+        c.bench_function(&format!("count_zeros offset 2^{}", log2_size), |b| {
+            b.iter(|| null_count(&bytes, 10, bytes.len() * 8 - 10))
+        });
+    })
+}
+
+criterion_group!(benches, add_benchmark);
+criterion_main!(benches);
diff --git a/benches/null_count.rs b/benches/null_count.rs
deleted file mode 100644
index 81eb4a8fbc9..00000000000
--- a/benches/null_count.rs
+++ /dev/null
@@ -1,42 +0,0 @@
-// Licensed to the Apache Software Foundation (ASF) under one
-// or more contributor license agreements.  See the NOTICE file
-// distributed with this work for additional information
-// regarding copyright ownership.  The ASF licenses this file
-// to you under the Apache License, Version 2.0 (the
-// "License"); you may not use this file except in compliance
-// with the License.  You may obtain a copy of the License at
-//
-//   http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing,
-// software distributed under the License is distributed on an
-// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-// KIND, either express or implied.  See the License for the
-// specific language governing permissions and limitations
-// under the License.
-extern crate arrow2;
-
-use arrow2::bitmap::utils::null_count;
-
-use criterion::{criterion_group, criterion_main, Criterion};
-
-fn add_benchmark(c: &mut Criterion) {
-    let bytes = (0..1026)
-        .map(|x| 0b01011011u8.rotate_left(x))
-        .collect::<Vec<_>>();
-
-    c.bench_function("null_count", |b| {
-        b.iter(|| null_count(&bytes, 0, bytes.len() * 8))
-    });
-
-    c.bench_function("null_count_offset", |b| {
-        b.iter(|| null_count(&bytes, 10, bytes.len() * 8 - 10))
-    });
-
-    c.bench_function("null_count_sliced", |b| {
-        b.iter(|| null_count(&bytes, 10, bytes.len() * 8 - 20))
-    });
-}
-
-criterion_group!(benches, add_benchmark);
-criterion_main!(benches);
diff --git a/benches/unset_count.rs b/benches/unset_count.rs
new file mode 100644
index 00000000000..6bc0e1907b4
--- /dev/null
+++ b/benches/unset_count.rs
@@ -0,0 +1,24 @@
+use arrow2::bitmap::utils::null_count;
+
+use criterion::{criterion_group, criterion_main, Criterion};
+
+fn add_benchmark(c: &mut Criterion) {
+    (10..=20).step_by(2).for_each(|log2_size| {
+        let size = 2usize.pow(log2_size);
+
+        let bytes = (0..size as u32)
+            .map(|x| 0b01011011u8.rotate_left(x))
+            .collect::<Vec<_>>();
+
+        c.bench_function(&format!("unset_count 2^{}", log2_size), |b| {
+            b.iter(|| null_count(&bytes, 0, bytes.len() * 8))
+        });
+
+        c.bench_function(&format!("unset_count offset 2^{}", log2_size), |b| {
+            b.iter(|| null_count(&bytes, 10, bytes.len() * 8 - 10))
+        });
+    })
+}
+
+criterion_group!(benches, add_benchmark);
+criterion_main!(benches);