diff --git a/src/liballoc/Cargo.toml b/src/liballoc/Cargo.toml index ada21e04b30..1dad323769a 100644 --- a/src/liballoc/Cargo.toml +++ b/src/liballoc/Cargo.toml @@ -23,3 +23,8 @@ path = "../liballoc/tests/lib.rs" [[bench]] name = "collectionsbenches" path = "../liballoc/benches/lib.rs" + +[[bench]] +name = "vec_deque_append_bench" +path = "../liballoc/benches/vec_deque_append.rs" +harness = false diff --git a/src/liballoc/benches/vec_deque_append.rs b/src/liballoc/benches/vec_deque_append.rs new file mode 100644 index 00000000000..bd335651137 --- /dev/null +++ b/src/liballoc/benches/vec_deque_append.rs @@ -0,0 +1,48 @@ +// Copyright 2018 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#![feature(duration_as_u128)] +use std::{collections::VecDeque, time::Instant}; + +const VECDEQUE_LEN: i32 = 100000; +const WARMUP_N: usize = 100; +const BENCH_N: usize = 1000; + +fn main() { + let a: VecDeque = (0..VECDEQUE_LEN).collect(); + let b: VecDeque = (0..VECDEQUE_LEN).collect(); + + for _ in 0..WARMUP_N { + let mut c = a.clone(); + let mut d = b.clone(); + c.append(&mut d); + } + + let mut durations = Vec::with_capacity(BENCH_N); + + for _ in 0..BENCH_N { + let mut c = a.clone(); + let mut d = b.clone(); + let before = Instant::now(); + c.append(&mut d); + let after = Instant::now(); + durations.push(after.duration_since(before)); + } + + let l = durations.len(); + durations.sort(); + + assert!(BENCH_N % 2 == 0); + let median = (durations[(l / 2) - 1] + durations[l / 2]) / 2; + println!( + "\ncustom-bench vec_deque_append {:?} ns/iter\n", + median.as_nanos() + ); +}