snark-verifier 0.2.2

//! Utilities.

pub mod arithmetic;
pub mod hash;
pub mod msm;
pub mod poly;
pub mod transcript;

pub(crate) use itertools::Itertools;

#[cfg(feature = "parallel")]
pub(crate) use rayon::current_num_threads;

/// Parallelly executing the function on the items of the given iterator.
pub fn parallelize_iter<I, T, F>(iter: I, f: F)
where
    I: Send + Iterator<Item = T>,
    T: Send,
    F: Fn(T) + Send + Sync + Clone,
{
    #[cfg(feature = "parallel")]
    rayon::scope(|scope| {
        for item in iter {
            let f = f.clone();
            scope.spawn(move |_| f(item));
        }
    });
    #[cfg(not(feature = "parallel"))]
    iter.for_each(f);
}

/// Parallelly executing the function on the given mutable slice.
pub fn parallelize<T, F>(v: &mut [T], f: F)
where
    T: Send,
    F: Fn((&mut [T], usize)) + Send + Sync + Clone,
{
    #[cfg(feature = "parallel")]
    {
        let num_threads = current_num_threads();
        let chunk_size = v.len() / num_threads;
        if chunk_size < num_threads {
            f((v, 0));
        } else {
            parallelize_iter(v.chunks_mut(chunk_size).zip((0..).step_by(chunk_size)), f);
        }
    }
    #[cfg(not(feature = "parallel"))]
    f((v, 0));
}