1 files changed, 165 insertions, 0 deletions
diff --git a/vendor/zerovec/benches/zerovec.rs b/vendor/zerovec/benches/zerovec.rs
new file mode 100644
index 000000000..5ed942160
--- /dev/null
+++ b/vendor/zerovec/benches/zerovec.rs
@@ -0,0 +1,165 @@
+// This file is part of ICU4X. For terms of use, please see the file
+// called LICENSE at the top level of the ICU4X source tree
+// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
+
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+use rand::SeedableRng;
+use rand_distr::{Distribution, LogNormal};
+use rand_pcg::Lcg64Xsh32;
+use std::fmt;
+
+#[path = "../src/samples.rs"]
+mod samples;
+use samples::*;
+
+use zerovec::ule::*;
+use zerovec::ZeroVec;
+
+#[repr(align(8))]
+#[derive(Default)]
+struct AlignedBuffer(Vec<u8>);
+
+/// Generate a large list of u32s for stress testing.
+#[allow(dead_code)]
+fn get_needles_and_haystack() -> (Vec<u32>, Vec<u32>) {
+    // Lcg64Xsh32 is a small, fast PRNG for reproducible benchmarks.
+    // LogNormal(10, 1) generates numbers with mean 36315 and mode 8103, a distribution that, in
+    // spirit, correlates with Unicode properties (many low values and a long tail of high values)
+    let mut rng = Lcg64Xsh32::seed_from_u64(2021);
+    let dist = LogNormal::new(10.0, 1.0).unwrap();
+    let haystack = {
+        let mut unsorted: Vec<u32> = (&dist)
+            .sample_iter(&mut rng)
+            .take(1000)
+            .map(|f| f as u32)
+            .collect();
+        unsorted.sort_unstable();
+        unsorted
+    };
+    let needles: Vec<u32> = (&dist)
+        .sample_iter(&mut rng)
+        .take(100)
+        .map(|f| f as u32)
+        .collect();
+    (needles, haystack)
+}
+
+#[allow(dead_code, clippy::ptr_arg)]
+fn vec_to_unaligned_uvec<'a, T>(vec: &Vec<T>, buffer: &'a mut AlignedBuffer) -> ZeroVec<'a, T>
+where
+    T: EqULE + Copy + PartialEq + fmt::Debug,
+{
+    // Pad with zero to ensure it is not aligned
+    buffer.0.push(0);
+    buffer
+        .0
+        .extend(ZeroVec::from_slice_or_alloc(vec.as_slice()).as_bytes());
+    ZeroVec::<T>::parse_byte_slice(&buffer.0[1..]).unwrap()
+}
+
+fn overview_bench(c: &mut Criterion) {
+    c.bench_function("zerovec/overview", |b| {
+        b.iter(|| {
+            ZeroVec::<u32>::parse_byte_slice(black_box(TEST_BUFFER_LE))
+                .unwrap()
+                .iter()
+                .sum::<u32>()
+        });
+    });
+
+    #[cfg(feature = "bench")]
+    {
+        sum_benches(c);
+        binary_search_benches(c);
+    }
+}
+
+#[cfg(feature = "bench")]
+fn sum_benches(c: &mut Criterion) {
+    let normal_slice = &TEST_SLICE[0..19];
+    let aligned_ule_slice = <u32 as AsULE>::ULE::parse_byte_slice(&TEST_BUFFER_LE[0..76]).unwrap();
+    let unalign_ule_slice = <u32 as AsULE>::ULE::parse_byte_slice(&TEST_BUFFER_LE[1..77]).unwrap();
+
+    assert_eq!(normal_slice.len(), aligned_ule_slice.len());
+    assert_eq!(normal_slice.len(), unalign_ule_slice.len());
+
+    c.bench_function("zerovec/sum/sample/slice", |b| {
+        b.iter(|| {
+            black_box(normal_slice)
+                .iter()
+                .copied()
+                .fold(0u32, |sum, val| sum.wrapping_add(val))
+        })
+    });
+
+    c.bench_function("zerovec/sum/sample/zerovec_aligned", |b| {
+        b.iter(|| {
+            ZeroVec::<u32>::new_borrowed(black_box(aligned_ule_slice))
+                .iter()
+                .fold(0u32, |sum, val| sum.wrapping_add(val))
+        });
+    });
+
+    c.bench_function("zerovec/sum/sample/zerovec_unaligned", |b| {
+        b.iter(|| {
+            ZeroVec::<u32>::new_borrowed(black_box(unalign_ule_slice))
+                .iter()
+                .fold(0u32, |sum, val| sum.wrapping_add(val))
+        });
+    });
+}
+
+#[cfg(feature = "bench")]
+fn binary_search_benches(c: &mut Criterion) {
+    c.bench_function("zerovec/binary_search/sample/slice", |b| {
+        b.iter(|| black_box(&TEST_SLICE).binary_search(&0x0c0d0c));
+    });
+
+    c.bench_function("zerovec/binary_search/sample/zerovec", |b| {
+        let zerovec = ZeroVec::<u32>::parse_byte_slice(black_box(TEST_BUFFER_LE)).unwrap();
+        b.iter(|| zerovec.binary_search(&0x0c0d0c));
+    });
+
+    let (needles_100, haystack) = get_needles_and_haystack();
+    // Only search for 50 needles to put all figures in nanoseconds
+    let needles_50 = &needles_100[0..50];
+
+    // *** Binary search vec of 1000 `u32` 50 times ***
+    c.bench_function("zerovec/binary_search/log_normal/slice", |b| {
+        b.iter(|| {
+            black_box(&needles_50)
+                .iter()
+                .map(|needle| black_box(&haystack).binary_search(needle))
+                .filter(|r| r.is_ok())
+                .count()
+        });
+    });
+
+    let mut buffer = AlignedBuffer::default();
+    let zerovec = vec_to_unaligned_uvec(black_box(&haystack), &mut buffer);
+    assert_eq!(zerovec, haystack.as_slice());
+
+    // *** Binary search vec of 1000 `u32` 50 times ***
+    c.bench_function("zerovec/binary_search/log_normal/zerovec", |b| {
+        b.iter(|| {
+            black_box(&needles_50)
+                .iter()
+                .map(|needle| black_box(&zerovec).binary_search(needle))
+                .filter(|r| r.is_ok())
+                .count()
+        });
+    });
+
+    let single_needle = 36315;
+
+    c.bench_function("zerovec/binary_search/log_normal/single/slice", |b| {
+        b.iter(|| black_box(&haystack).binary_search(&single_needle));
+    });
+
+    c.bench_function("zerovec/binary_search/log_normal/single/zerovec", |b| {
+        b.iter(|| black_box(&zerovec).binary_search(&single_needle));
+    });
+}
+
+criterion_group!(benches, overview_bench,);
+criterion_main!(benches);