Add benchmark for from_bitmap_bytes

benchmarks/benches/lib.rs

@@ -149,6 +149,27 @@ fn creation(c: &mut Criterion) {
 
  group.throughput(Throughput::Elements(dataset.bitmaps.iter().map(|rb| rb.len()).sum()));
 
+ group.bench_function(BenchmarkId::new("from_bitmap_bytes", &dataset.name), |b| {
+ let bitmap_bytes = dataset_numbers
+ .iter()
+ .map(|bitmap_numbers| {
+ let max_number = *bitmap_numbers.iter().max().unwrap() as usize;
+ let mut buf = vec![0u8; max_number.next_multiple_of(8) / 8 + 1];
+ for n in bitmap_numbers {
+ let byte = (n / 8) as usize;
+ let bit = n % 8;
+ buf[byte] |= 1 << bit;
+ }
+ buf
+ })
+ .collect::<Vec<_>>();
+ b.iter(|| {
+ for bitmap_bytes in &bitmap_bytes {
+ black_box(RoaringBitmap::from_bitmap_bytes(0, bitmap_bytes));
+ }
+ })
+ });
+
  group.bench_function(BenchmarkId::new("from_sorted_iter", &dataset.name), |b| {
  b.iter(|| {
  for bitmap_numbers in &dataset_numbers {

roaring/src/bitmap/inherent.rs

@@ -45,7 +45,7 @@ impl RoaringBitmap {
  /// assert!(rb.contains(31));
  /// ```
  pub fn from_bitmap_bytes(offset: u32, bytes: &[u8]) -> RoaringBitmap {
- const BITS_IN_ONE_CONTAINER: usize = 8 * size_of::<u64>() * BITMAP_LENGTH;
+ const BITS_IN_ONE_CONTAINER: usize = u64::BITS as usize * BITMAP_LENGTH;
  const BYTE_IN_ONE_CONTAINER: usize = BITS_IN_ONE_CONTAINER / 8;
  assert_eq!(offset % BITS_IN_ONE_CONTAINER as u32, 0);
  let mut containers = Vec::with_capacity(bytes.len() / BYTE_IN_ONE_CONTAINER);