Function swh_graph::utils::sort::par_sort_arcs

pub fn par_sort_arcs<Item, Iter, F>(
    temp_dir: &Path,
    batch_size: usize,
    iter: Iter,
    num_partitions: usize,
    f: F
) -> Result<Vec<Map<KMergeIters<impl Iterator<Item = (usize, usize, ())> + Clone + Send + Sync>, impl FnMut((usize, usize, ())) -> (usize, usize) + Clone + Send + Sync>>>where
    F: Fn(&mut PartitionedBuffer, Item) -> Result<()> + Send + Sync,
    Iter: ParallelIterator<Item = Item>,

Given an iterator and a function to insert its items to [BatchIterator]s, returns an iterator of pairs.

f gets as parameters num_partitions BatchIterators; and should place its pair in such a way that all (src, dst, ()) in partition n should be lexicographically lower than those in partition n+1.

In orther words, f writes in arbitrary order in each partition, but partitions should be sorted with respect to each other. This allows merging partitions in parallel after they are sorted.