rdst is a flexible native Rust implementation of multi-threaded unstable radix sort.
```rust let mut my_vec = vec![4, 7, 1, 6, 5, 3, 2, 8, 9];
myvec.radixsort_unstable(); ```
In the simplest case, you can use this sort by simply calling my_vec.radix_sort_unstable(). If you have a custom type to sort, you may need to implement RadixKey for that type.
RadixKey is implemented for Vec and [T] of the following types out-of-the-box:
u8, u16, u32, u64, u128, usizei8, i16, i32, i64, i128, isizef32, f64[u8; N]RadixKeyTo be able to sort custom types, implement RadixKey as below.
LEVELS should be set to the total number of bytes you will consider for each item being sortedget_level should return the corresponding bytes from the least significant byte to the most significant byteNotes: * This allows you to implement radix keys that span multiple values, or to implement radix keys that only look at part of a value. * You should try to make this as fast as possible, so consider using branchless implementations wherever possible
```rust use rdst::RadixKey;
struct MyType(u32);
impl RadixKey for MyType { const LEVELS: usize = 4;
#[inline]
fn get_level(&self, level: usize) -> u8 {
(self.0 >> (level * 8)) as u8
}
} ```
RadixKeyIf you know your type has bytes that will always be zero, you can skip those bytes to speed up the sorting process. For instance, if you have a u32 where values never exceed 10000, you only need to consider two of the bytes. You could implement this as such:
```rust use rdst::RadixKey; struct U32Wrapper(u32);
impl RadixKey for U32Wrapper { const LEVELS: usize = 2;
#[inline]
fn get_level(&self, level: usize) -> u8 {
(self.0 >> (level * 8)) as u8
}
} ```
RadixKeyIf your type has multiple values you need to search by, simply create a RadixKey that spans both values.
```rust use rdst::RadixKey; struct MyStruct { key1: u8, key2: u8, key_3: u8, } impl RadixKey for MyStruct { const LEVELS: usize = 3;
#[inline]
fn get_level(&self, level: usize) -> u8 {
match level {
0 => self.key_1[0],
1 => self.key_2[1],
_ => self.key_3[0],
}
}
} ```
rust
use rdst::RadixSort;
let mut my_vec: Vec<usize> = vec![10, 15, 0, 22, 9];
my_vec
.radix_sort_builder()
.with_low_mem_tuner()
.sort();
This library also includes a mostly in-place variant of radix sort. This is useful in cases where memory or memory bandwidth are more limited. Generally, this algorithm is slightly slower than the standard algorithm, however in specific circumstances this algorithm may even provide a speed boost. It is worth benchmarking against your use-case if you need the ultimate level of performance.
To make this library use an entirely single-threaded set of algorithms and processes, you can use the following snippet.
```rust
use rdst::RadixSort;
let mut my_vec: Vec
myvec .radixsortbuilder() // Use a tuner that only includes single-threaded algorithms .withsinglethreadedtuner() // Don't run multiple algorithms (even single-threaded ones) in parallel .with_parallel(false) .sort(); ```
Tuners are things which you can implement to control which sorting algorithms are used. There are many radix sorting algorithms implemented as part of this crate, and they all have their pros and cons. If you have a very specific use-case it may be worth your time to tune the sort yourself.
```rust use rdst::RadixSort; use rdst::tuner::{Algorithm, Tuner, TuningParams};
struct MyTuner;
impl Tuner for MyTuner { fn pickalgorithm(&self, p: &TuningParams, _counts: &[usize]) -> Algorithm { if p.inputlen >= 500_000 { Algorithm::Ska } else { Algorithm::Lsb } } }
let mut myvec: Vec
Licensed under either of
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.