perf(bitmap): change the buffer unit from u8 to usize (#7030)

* bitmap: use pointer-sized element for underlying buffer

Signed-off-by: Runji Wang <wangrunji0408@163.com>

* use `Box<[usize]>` to save 8 bytes

Signed-off-by: Runji Wang <wangrunji0408@163.com>

* rename functions and add docs

Signed-off-by: Runji Wang <wangrunji0408@163.com>

* add bench for bitmap

Signed-off-by: Runji Wang <wangrunji0408@163.com>

Signed-off-by: Runji Wang <wangrunji0408@163.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

src/common/Cargo.toml

@@ -82,3 +82,7 @@ tempfile = "3"
 [[bench]]
 name = "bench_encoding"
 harness = false
+
+[[bench]]
+name = "bitmap"
+harness = false

src/common/benches/bitmap.rs

@@ -0,0 +1,32 @@
+// Copyright 2022 Singularity Data
+//
+// Licensed 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.
+
+use criterion::{criterion_group, criterion_main, Criterion};
+use risingwave_common::buffer::Bitmap;
+
+fn bench_bitmap(c: &mut Criterion) {
+    const CHUNK_SIZE: usize = 1024;
+    let x = Bitmap::zeros(CHUNK_SIZE);
+    let y = Bitmap::ones(CHUNK_SIZE);
+    let i = 0x123;
+    c.bench_function("zeros", |b| b.iter(|| Bitmap::zeros(CHUNK_SIZE)));
+    c.bench_function("ones", |b| b.iter(|| Bitmap::ones(CHUNK_SIZE)));
+    c.bench_function("get", |b| b.iter(|| x.is_set(i)));
+    c.bench_function("and", |b| b.iter(|| &x & &y));
+    c.bench_function("or", |b| b.iter(|| &x | &y));
+    c.bench_function("not", |b| b.iter(|| !&x));
+}
+
+criterion_group!(benches, bench_bitmap);
+criterion_main!(benches);

src/common/src/array/bool_array.rs

@@ -56,7 +56,7 @@ impl FromIterator<bool> for BoolArray {
     fn from_iter<I: IntoIterator<Item = bool>>(iter: I) -> Self {
         let data: Bitmap = iter.into_iter().collect();
         BoolArray {
-            bitmap: Bitmap::all_high_bits(data.len()),
+            bitmap: Bitmap::ones(data.len()),
             data,
         }
     }

src/common/src/array/data_chunk.rs

@@ -109,7 +109,7 @@ impl DataChunk {
     /// `cardinality` returns the number of visible tuples
     pub fn cardinality(&self) -> usize {
         match &self.vis2 {
-            Vis::Bitmap(b) => b.num_high_bits(),
+            Vis::Bitmap(b) => b.count_ones(),
             Vis::Compact(len) => *len,
         }
     }

src/common/src/array/primitive_array.rs

@@ -153,7 +153,7 @@ impl<T: PrimitiveArrayItemType> FromIterator<T> for PrimitiveArray<T> {
     fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
         let data: Vec<T> = iter.into_iter().collect();
         PrimitiveArray {
-            bitmap: Bitmap::all_high_bits(data.len()),
+            bitmap: Bitmap::ones(data.len()),
             data,
         }
     }

src/common/src/array/vis.rs

@@ -57,8 +57,8 @@ impl Vis {
         self.as_ref().iter()
     }
 
-    pub fn ones(&self) -> impl Iterator<Item = usize> + '_ {
-        self.as_ref().ones()
+    pub fn iter_ones(&self) -> impl Iterator<Item = usize> + '_ {
+        self.as_ref().iter_ones()
     }
 
     #[inline(always)]
@@ -145,9 +145,9 @@ impl<'a> VisRef<'a> {
     }
 
     #[auto_enum(Iterator)]
-    pub fn ones(self) -> impl Iterator<Item = usize> + 'a {
+    pub fn iter_ones(self) -> impl Iterator<Item = usize> + 'a {
         match self {
-            VisRef::Bitmap(b) => b.ones(),
+            VisRef::Bitmap(b) => b.iter_ones(),
             VisRef::Compact(c) => 0..c,
         }
     }