#![cfg(test)]
#![feature(test)]
#![feature(slice_fill)]

extern crate num;
extern crate test;

use rust_samples::swapper::{CAllocaSwapper, CLoopSwapper, LoopSwapper, PtrSwapper, Swapper};

use heapless::consts::{U10, U100, U1000, U10000, U100000, U1000000};
use num::{one, zero, Num};
use test::{black_box, Bencher};

fn bench_swap<S, T, N>(b: &mut Bencher)
where
    S: Swapper,
    N: heapless::ArrayLength<T>,
    T: Num + Copy,
{
    let (mut arr1, mut arr2) = bench_swap_setup::<T, N>();

    b.iter(|| {
        S::swap(&mut arr1, &mut arr2);
        black_box(&arr1);
        black_box(&arr2);
    });
}

/// Allocates two vectors of fixed length on the heap.
fn bench_swap_setup<T, N>() -> (Vec<T>, Vec<T>)
where
    N: heapless::ArrayLength<T>,
    T: Num + Clone,
{
    let mut arr1: Vec<T> = Vec::new();
    let mut arr2 = arr1.clone();

    arr1.resize(N::to_usize(), black_box(zero()));
    arr2.resize(N::to_usize(), black_box(one()));

    (arr1, arr2)
}

/// A heapless version of `bench_swap_setup`.
fn _bench_swap_setup_heapless<T, N>() -> (heapless::Vec<T, N>, heapless::Vec<T, N>)
where
    N: heapless::ArrayLength<T>,
    T: Num + Clone,
{
    let mut arr1: heapless::Vec<T, N> = heapless::Vec::new();
    let mut arr2 = arr1.clone();

    arr1.resize(N::to_usize(), black_box(zero()))
        .expect("insufficient stack space");
    arr2.resize(N::to_usize(), black_box(one()))
        .expect("insufficient stack space");

    (arr1, arr2)
}

type BenchInt = u8;

#[bench]
fn bench_swap_loop_len_10(b: &mut Bencher) {
    bench_swap::<LoopSwapper, BenchInt, U10>(b);
}

#[bench]
fn bench_swap_loop_len_100(b: &mut Bencher) {
    bench_swap::<LoopSwapper, BenchInt, U100>(b);
}

#[bench]
fn bench_swap_loop_len_1000(b: &mut Bencher) {
    bench_swap::<LoopSwapper, BenchInt, U1000>(b);
}

#[bench]
fn bench_swap_loop_len_10000(b: &mut Bencher) {
    bench_swap::<LoopSwapper, BenchInt, U10000>(b);
}

#[bench]
fn bench_swap_loop_len_100000(b: &mut Bencher) {
    bench_swap::<LoopSwapper, BenchInt, U100000>(b);
}

#[bench]
fn bench_swap_loop_len_1000000(b: &mut Bencher) {
    bench_swap::<LoopSwapper, BenchInt, U1000000>(b);
}

#[bench]
fn bench_swap_ptrswap_len_10(b: &mut Bencher) {
    bench_swap::<PtrSwapper, BenchInt, U10>(b);
}

#[bench]
fn bench_swap_ptrswap_len_100(b: &mut Bencher) {
    bench_swap::<PtrSwapper, BenchInt, U100>(b);
}

#[bench]
fn bench_swap_ptrswap_len_1000(b: &mut Bencher) {
    bench_swap::<PtrSwapper, BenchInt, U1000>(b);
}

#[bench]
fn bench_swap_ptrswap_len_10000(b: &mut Bencher) {
    bench_swap::<PtrSwapper, BenchInt, U10000>(b);
}

#[bench]
fn bench_swap_ptrswap_len_100000(b: &mut Bencher) {
    bench_swap::<PtrSwapper, BenchInt, U100000>(b);
}

#[bench]
fn bench_swap_ptrswap_len_1000000(b: &mut Bencher) {
    bench_swap::<PtrSwapper, BenchInt, U1000000>(b);
}

#[bench]
fn bench_cswap_loop_len_10(b: &mut Bencher) {
    bench_swap::<CLoopSwapper, BenchInt, U10>(b);
}

#[bench]
fn bench_cswap_loop_len_100(b: &mut Bencher) {
    bench_swap::<CLoopSwapper, BenchInt, U100>(b);
}

#[bench]
fn bench_cswap_loop_len_1000(b: &mut Bencher) {
    bench_swap::<CLoopSwapper, BenchInt, U1000>(b);
}

#[bench]
fn bench_cswap_loop_len_10000(b: &mut Bencher) {
    bench_swap::<CLoopSwapper, BenchInt, U10000>(b);
}

#[bench]
fn bench_cswap_loop_len_100000(b: &mut Bencher) {
    bench_swap::<CLoopSwapper, BenchInt, U100000>(b);
}

#[bench]
fn bench_cswap_loop_len_1000000(b: &mut Bencher) {
    bench_swap::<CLoopSwapper, BenchInt, U1000000>(b);
}

#[bench]
fn bench_cswap_alloca_len_10(b: &mut Bencher) {
    bench_swap::<CAllocaSwapper, BenchInt, U10>(b);
}

#[bench]
fn bench_cswap_alloca_len_100(b: &mut Bencher) {
    bench_swap::<CAllocaSwapper, BenchInt, U100>(b);
}

#[bench]
fn bench_cswap_alloca_len_1000(b: &mut Bencher) {
    bench_swap::<CAllocaSwapper, BenchInt, U1000>(b);
}

#[bench]
fn bench_cswap_alloca_len_10000(b: &mut Bencher) {
    bench_swap::<CAllocaSwapper, BenchInt, U10000>(b);
}

#[bench]
fn bench_cswap_alloca_len_100000(b: &mut Bencher) {
    bench_swap::<CAllocaSwapper, BenchInt, U100000>(b);
}

#[bench]
fn bench_cswap_alloca_len_1000000(b: &mut Bencher) {
    bench_swap::<CAllocaSwapper, BenchInt, U1000000>(b);
}