How can I cumulatively sum a vector in parallel using Rayon?
来源： https://stackoverflow.com/questions/64784587/how-can-i-cumulatively-sum-a-vector-in-parallel-using-rayon
rayon
Is there a way to directly consume a Rayon chain without collecting it first?
问题 I am using Rayon to produce reasonably large return values. This uses a lot of memory when collecting all returned values into a Vec . Is there a way to avoid creating a Vec and directly consuming as an iterable? Here is an example which doesn't work: fn main() { let numbers: Vec<_> = "12.03 0.3 44.2 45 zzz".split_whitespace().collect(); let x = numbers .par_iter() .map(|n| n.parse::<f32>()) .filter_map(|n| n.ok()); for n in x { println!("{:?}", n); } } error[E0277]: the trait bound `rayon:
Implement rayon `as_parallel_slice` using iterators
问题 I have a small problem of my own: extern crate rayon; use rayon::prelude::*; #[derive(Debug)] struct Pixel { r: Vec<i8>, g: Vec<i8>, b: Vec<i8>, } #[derive(Debug)] struct Node{ r: i8, g: i8, b: i8, } struct PixelIterator<'a> { pixel: &'a Pixel, index: usize, } impl<'a> IntoIterator for &'a Pixel { type Item = Node; type IntoIter = PixelIterator<'a>; fn into_iter(self) -> Self::IntoIter { println!("Into &"); PixelIterator { pixel: self, index: 0 } } } impl<'a> Iterator for PixelIterator<'a> {
How to satisfy the Iterator trait bound in order to use Rayon here?
问题 I'm attempting to parallelise the Ramer–Douglas-Peucker line simplification algorithm by using Rayon's par_iter instead of iter : extern crate num_traits; use num_traits::{Float, ToPrimitive}; extern crate rayon; use self::rayon::prelude::*; #[derive(PartialEq, Clone, Copy, Debug)] pub struct Coordinate<T> where T: Float { pub x: T, pub y: T, } #[derive(PartialEq, Clone, Copy, Debug)] pub struct Point<T>(pub Coordinate<T>) where T: Float; impl<T> Point<T> where T: Float + ToPrimitive { pub fn
How do I use Rayon with an existing iterator?
问题 I turn a regex into a HashSet after doing some filtering. I am trying to use it with Rayon, but I can't figure out how to make Rayon work with an existing iterator without converting it to a vector first. Is this possible? let re = Regex::new("url=\"(?P<url>.+?)\"").unwrap(); let urls: HashSet<String> = re.captures_iter(&contents) .map(|m| Url::parse(m.name("url").unwrap().as_str())) .filter(|parsed_url| parsed_url.is_ok()) .map(|parsed_url| parsed_url.unwrap()) .filter(|parsed_url| parsed
How to satisfy the Iterator trait bound in order to use Rayon here?
I'm attempting to parallelise the Ramer–Douglas-Peucker line simplification algorithm by using Rayon's par_iter instead of iter : extern crate num_traits; use num_traits::{Float, ToPrimitive}; extern crate rayon; use self::rayon::prelude::*; #[derive(PartialEq, Clone, Copy, Debug)] pub struct Coordinate<T> where T: Float { pub x: T, pub y: T, } #[derive(PartialEq, Clone, Copy, Debug)] pub struct Point<T>(pub Coordinate<T>) where T: Float; impl<T> Point<T> where T: Float + ToPrimitive { pub fn new(x: T, y: T) -> Point<T> { Point(Coordinate { x: x, y: y }) } pub fn x(&self) -> T { self.0.x } pub
Simultaneous mutable access to arbitrary indices of a large vector that are guaranteed to be disjoint
问题 Context I have a case where multiple threads must update objects stored in a shared vector. However, the vector is very large, and the number of elements to update is relatively small. Problem In a minimal example, the set of elements to update can be identified by a (hash-)set containing the indices of elements to update. The code could hence look as follows: let mut big_vector_of_elements = generate_data_vector(); while has_things_to_do() { let indices_to_update = compute_indices(); indices
How do I use Rayon with an existing iterator?
I turn a regex into a HashSet after doing some filtering. I am trying to use it with Rayon, but I can't figure out how to make Rayon work with an existing iterator without converting it to a vector first. Is this possible? let re = Regex::new("url=\"(?P<url>.+?)\"").unwrap(); let urls: HashSet<String> = re.captures_iter(&contents) .map(|m| Url::parse(m.name("url").unwrap().as_str())) .filter(|parsed_url| parsed_url.is_ok()) .map(|parsed_url| parsed_url.unwrap()) .filter(|parsed_url| parsed_url.has_host()) .map(|parsed_url| parsed_url.into_string()) .collect(); This answer is outdated for the