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author | Daniel Mueller <deso@posteo.net> | 2020-04-04 14:39:19 -0700 |
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committer | Daniel Mueller <deso@posteo.net> | 2020-04-04 14:39:19 -0700 |
commit | d0d9683df8398696147e7ee1fcffb2e4e957008c (patch) | |
tree | 4baa76712a76f4d072ee3936c07956580b230820 /rand/src/seq/index.rs | |
parent | 203e691f46d591a2cc8acdfd850fa9f5b0fb8a98 (diff) | |
download | nitrocli-d0d9683df8398696147e7ee1fcffb2e4e957008c.tar.gz nitrocli-d0d9683df8398696147e7ee1fcffb2e4e957008c.tar.bz2 |
Remove vendored dependencies
While it appears that by now we actually can get successful builds
without Cargo insisting on Internet access by virtue of using the
--frozen flag, maintaining vendored dependencies is somewhat of a pain
point. This state will also get worse with upcoming changes that replace
argparse in favor of structopt and pull in a slew of new dependencies by
doing so. Then there is also the repository structure aspect, which is
non-standard due to the way we vendor dependencies and a potential
source of confusion.
In order to fix these problems, this change removes all the vendored
dependencies we have.
Delete subrepo argparse/:argparse
Delete subrepo base32/:base32
Delete subrepo cc/:cc
Delete subrepo cfg-if/:cfg-if
Delete subrepo getrandom/:getrandom
Delete subrepo lazy-static/:lazy-static
Delete subrepo libc/:libc
Delete subrepo nitrokey-sys/:nitrokey-sys
Delete subrepo nitrokey/:nitrokey
Delete subrepo rand/:rand
Diffstat (limited to 'rand/src/seq/index.rs')
-rw-r--r-- | rand/src/seq/index.rs | 409 |
1 files changed, 0 insertions, 409 deletions
diff --git a/rand/src/seq/index.rs b/rand/src/seq/index.rs deleted file mode 100644 index 22a5733..0000000 --- a/rand/src/seq/index.rs +++ /dev/null @@ -1,409 +0,0 @@ -// Copyright 2018 Developers of the Rand project. -// -// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or -// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license -// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your -// option. This file may not be copied, modified, or distributed -// except according to those terms. - -//! Low-level API for sampling indices - -#[cfg(feature="alloc")] use core::slice; - -#[cfg(feature="std")] use std::vec; -#[cfg(all(feature="alloc", not(feature="std")))] use crate::alloc::vec::{self, Vec}; -// BTreeMap is not as fast in tests, but better than nothing. -#[cfg(feature="std")] use std::collections::{HashSet}; -#[cfg(all(feature="alloc", not(feature="std")))] use crate::alloc::collections::BTreeSet; - -#[cfg(feature="alloc")] use crate::distributions::{Distribution, Uniform, uniform::SampleUniform}; -use crate::Rng; - -/// A vector of indices. -/// -/// Multiple internal representations are possible. -#[derive(Clone, Debug)] -pub enum IndexVec { - #[doc(hidden)] U32(Vec<u32>), - #[doc(hidden)] USize(Vec<usize>), -} - -impl IndexVec { - /// Returns the number of indices - #[inline] - pub fn len(&self) -> usize { - match *self { - IndexVec::U32(ref v) => v.len(), - IndexVec::USize(ref v) => v.len(), - } - } - - /// Returns `true` if the length is 0. - #[inline] - pub fn is_empty(&self) -> bool { - match *self { - IndexVec::U32(ref v) => v.is_empty(), - IndexVec::USize(ref v) => v.is_empty(), - } - } - - /// Return the value at the given `index`. - /// - /// (Note: we cannot implement [`std::ops::Index`] because of lifetime - /// restrictions.) - #[inline] - pub fn index(&self, index: usize) -> usize { - match *self { - IndexVec::U32(ref v) => v[index] as usize, - IndexVec::USize(ref v) => v[index], - } - } - - /// Return result as a `Vec<usize>`. Conversion may or may not be trivial. - #[inline] - pub fn into_vec(self) -> Vec<usize> { - match self { - IndexVec::U32(v) => v.into_iter().map(|i| i as usize).collect(), - IndexVec::USize(v) => v, - } - } - - /// Iterate over the indices as a sequence of `usize` values - #[inline] - pub fn iter(&self) -> IndexVecIter<'_> { - match *self { - IndexVec::U32(ref v) => IndexVecIter::U32(v.iter()), - IndexVec::USize(ref v) => IndexVecIter::USize(v.iter()), - } - } - - /// Convert into an iterator over the indices as a sequence of `usize` values - #[inline] - pub fn into_iter(self) -> IndexVecIntoIter { - match self { - IndexVec::U32(v) => IndexVecIntoIter::U32(v.into_iter()), - IndexVec::USize(v) => IndexVecIntoIter::USize(v.into_iter()), - } - } -} - -impl PartialEq for IndexVec { - fn eq(&self, other: &IndexVec) -> bool { - use self::IndexVec::*; - match (self, other) { - (&U32(ref v1), &U32(ref v2)) => v1 == v2, - (&USize(ref v1), &USize(ref v2)) => v1 == v2, - (&U32(ref v1), &USize(ref v2)) => (v1.len() == v2.len()) - && (v1.iter().zip(v2.iter()).all(|(x, y)| *x as usize == *y)), - (&USize(ref v1), &U32(ref v2)) => (v1.len() == v2.len()) - && (v1.iter().zip(v2.iter()).all(|(x, y)| *x == *y as usize)), - } - } -} - -impl From<Vec<u32>> for IndexVec { - #[inline] - fn from(v: Vec<u32>) -> Self { - IndexVec::U32(v) - } -} - -impl From<Vec<usize>> for IndexVec { - #[inline] - fn from(v: Vec<usize>) -> Self { - IndexVec::USize(v) - } -} - -/// Return type of `IndexVec::iter`. -#[derive(Debug)] -pub enum IndexVecIter<'a> { - #[doc(hidden)] U32(slice::Iter<'a, u32>), - #[doc(hidden)] USize(slice::Iter<'a, usize>), -} - -impl<'a> Iterator for IndexVecIter<'a> { - type Item = usize; - #[inline] - fn next(&mut self) -> Option<usize> { - use self::IndexVecIter::*; - match *self { - U32(ref mut iter) => iter.next().map(|i| *i as usize), - USize(ref mut iter) => iter.next().cloned(), - } - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - match *self { - IndexVecIter::U32(ref v) => v.size_hint(), - IndexVecIter::USize(ref v) => v.size_hint(), - } - } -} - -impl<'a> ExactSizeIterator for IndexVecIter<'a> {} - -/// Return type of `IndexVec::into_iter`. -#[derive(Clone, Debug)] -pub enum IndexVecIntoIter { - #[doc(hidden)] U32(vec::IntoIter<u32>), - #[doc(hidden)] USize(vec::IntoIter<usize>), -} - -impl Iterator for IndexVecIntoIter { - type Item = usize; - - #[inline] - fn next(&mut self) -> Option<Self::Item> { - use self::IndexVecIntoIter::*; - match *self { - U32(ref mut v) => v.next().map(|i| i as usize), - USize(ref mut v) => v.next(), - } - } - - #[inline] - fn size_hint(&self) -> (usize, Option<usize>) { - use self::IndexVecIntoIter::*; - match *self { - U32(ref v) => v.size_hint(), - USize(ref v) => v.size_hint(), - } - } -} - -impl ExactSizeIterator for IndexVecIntoIter {} - - -/// Randomly sample exactly `amount` distinct indices from `0..length`, and -/// return them in random order (fully shuffled). -/// -/// This method is used internally by the slice sampling methods, but it can -/// sometimes be useful to have the indices themselves so this is provided as -/// an alternative. -/// -/// The implementation used is not specified; we automatically select the -/// fastest available algorithm for the `length` and `amount` parameters -/// (based on detailed profiling on an Intel Haswell CPU). Roughly speaking, -/// complexity is `O(amount)`, except that when `amount` is small, performance -/// is closer to `O(amount^2)`, and when `length` is close to `amount` then -/// `O(length)`. -/// -/// Note that performance is significantly better over `u32` indices than over -/// `u64` indices. Because of this we hide the underlying type behind an -/// abstraction, `IndexVec`. -/// -/// If an allocation-free `no_std` function is required, it is suggested -/// to adapt the internal `sample_floyd` implementation. -/// -/// Panics if `amount > length`. -pub fn sample<R>(rng: &mut R, length: usize, amount: usize) -> IndexVec -where R: Rng + ?Sized { - if amount > length { - panic!("`amount` of samples must be less than or equal to `length`"); - } - if length > (::core::u32::MAX as usize) { - // We never want to use inplace here, but could use floyd's alg - // Lazy version: always use the cache alg. - return sample_rejection(rng, length, amount); - } - let amount = amount as u32; - let length = length as u32; - - // Choice of algorithm here depends on both length and amount. See: - // https://github.com/rust-random/rand/pull/479 - // We do some calculations with f32. Accuracy is not very important. - - if amount < 163 { - const C: [[f32; 2]; 2] = [[1.6, 8.0/45.0], [10.0, 70.0/9.0]]; - let j = if length < 500_000 { 0 } else { 1 }; - let amount_fp = amount as f32; - let m4 = C[0][j] * amount_fp; - // Short-cut: when amount < 12, floyd's is always faster - if amount > 11 && (length as f32) < (C[1][j] + m4) * amount_fp { - sample_inplace(rng, length, amount) - } else { - sample_floyd(rng, length, amount) - } - } else { - const C: [f32; 2] = [270.0, 330.0/9.0]; - let j = if length < 500_000 { 0 } else { 1 }; - if (length as f32) < C[j] * (amount as f32) { - sample_inplace(rng, length, amount) - } else { - sample_rejection(rng, length, amount) - } - } -} - -/// Randomly sample exactly `amount` indices from `0..length`, using Floyd's -/// combination algorithm. -/// -/// The output values are fully shuffled. (Overhead is under 50%.) -/// -/// This implementation uses `O(amount)` memory and `O(amount^2)` time. -fn sample_floyd<R>(rng: &mut R, length: u32, amount: u32) -> IndexVec -where R: Rng + ?Sized { - // For small amount we use Floyd's fully-shuffled variant. For larger - // amounts this is slow due to Vec::insert performance, so we shuffle - // afterwards. Benchmarks show little overhead from extra logic. - let floyd_shuffle = amount < 50; - - debug_assert!(amount <= length); - let mut indices = Vec::with_capacity(amount as usize); - for j in length - amount .. length { - let t = rng.gen_range(0, j + 1); - if floyd_shuffle { - if let Some(pos) = indices.iter().position(|&x| x == t) { - indices.insert(pos, j); - continue; - } - } else if indices.contains(&t) { - indices.push(j); - continue; - } - indices.push(t); - } - if !floyd_shuffle { - // Reimplement SliceRandom::shuffle with smaller indices - for i in (1..amount).rev() { - // invariant: elements with index > i have been locked in place. - indices.swap(i as usize, rng.gen_range(0, i + 1) as usize); - } - } - IndexVec::from(indices) -} - -/// Randomly sample exactly `amount` indices from `0..length`, using an inplace -/// partial Fisher-Yates method. -/// Sample an amount of indices using an inplace partial fisher yates method. -/// -/// This allocates the entire `length` of indices and randomizes only the first `amount`. -/// It then truncates to `amount` and returns. -/// -/// This method is not appropriate for large `length` and potentially uses a lot -/// of memory; because of this we only implement for `u32` index (which improves -/// performance in all cases). -/// -/// Set-up is `O(length)` time and memory and shuffling is `O(amount)` time. -fn sample_inplace<R>(rng: &mut R, length: u32, amount: u32) -> IndexVec -where R: Rng + ?Sized { - debug_assert!(amount <= length); - let mut indices: Vec<u32> = Vec::with_capacity(length as usize); - indices.extend(0..length); - for i in 0..amount { - let j: u32 = rng.gen_range(i, length); - indices.swap(i as usize, j as usize); - } - indices.truncate(amount as usize); - debug_assert_eq!(indices.len(), amount as usize); - IndexVec::from(indices) -} - -trait UInt: Copy + PartialOrd + Ord + PartialEq + Eq + SampleUniform + core::hash::Hash { - fn zero() -> Self; - fn as_usize(self) -> usize; -} -impl UInt for u32 { - #[inline] fn zero() -> Self { 0 } - #[inline] fn as_usize(self) -> usize { self as usize } -} -impl UInt for usize { - #[inline] fn zero() -> Self { 0 } - #[inline] fn as_usize(self) -> usize { self } -} - -/// Randomly sample exactly `amount` indices from `0..length`, using rejection -/// sampling. -/// -/// Since `amount <<< length` there is a low chance of a random sample in -/// `0..length` being a duplicate. We test for duplicates and resample where -/// necessary. The algorithm is `O(amount)` time and memory. -/// -/// This function is generic over X primarily so that results are value-stable -/// over 32-bit and 64-bit platforms. -fn sample_rejection<X: UInt, R>(rng: &mut R, length: X, amount: X) -> IndexVec -where R: Rng + ?Sized, IndexVec: From<Vec<X>> { - debug_assert!(amount < length); - #[cfg(feature="std")] let mut cache = HashSet::with_capacity(amount.as_usize()); - #[cfg(not(feature="std"))] let mut cache = BTreeSet::new(); - let distr = Uniform::new(X::zero(), length); - let mut indices = Vec::with_capacity(amount.as_usize()); - for _ in 0..amount.as_usize() { - let mut pos = distr.sample(rng); - while !cache.insert(pos) { - pos = distr.sample(rng); - } - indices.push(pos); - } - - debug_assert_eq!(indices.len(), amount.as_usize()); - IndexVec::from(indices) -} - -#[cfg(test)] -mod test { - #[cfg(feature="std")] use std::vec; - #[cfg(all(feature="alloc", not(feature="std")))] use crate::alloc::vec; - use super::*; - - #[test] - fn test_sample_boundaries() { - let mut r = crate::test::rng(404); - - assert_eq!(sample_inplace(&mut r, 0, 0).len(), 0); - assert_eq!(sample_inplace(&mut r, 1, 0).len(), 0); - assert_eq!(sample_inplace(&mut r, 1, 1).into_vec(), vec![0]); - - assert_eq!(sample_rejection(&mut r, 1u32, 0).len(), 0); - - assert_eq!(sample_floyd(&mut r, 0, 0).len(), 0); - assert_eq!(sample_floyd(&mut r, 1, 0).len(), 0); - assert_eq!(sample_floyd(&mut r, 1, 1).into_vec(), vec![0]); - - // These algorithms should be fast with big numbers. Test average. - let sum: usize = sample_rejection(&mut r, 1 << 25, 10u32) - .into_iter().sum(); - assert!(1 << 25 < sum && sum < (1 << 25) * 25); - - let sum: usize = sample_floyd(&mut r, 1 << 25, 10) - .into_iter().sum(); - assert!(1 << 25 < sum && sum < (1 << 25) * 25); - } - - #[test] - #[cfg(not(miri))] // Miri is too slow - fn test_sample_alg() { - let seed_rng = crate::test::rng; - - // We can't test which algorithm is used directly, but Floyd's alg - // should produce different results from the others. (Also, `inplace` - // and `cached` currently use different sizes thus produce different results.) - - // A small length and relatively large amount should use inplace - let (length, amount): (usize, usize) = (100, 50); - let v1 = sample(&mut seed_rng(420), length, amount); - let v2 = sample_inplace(&mut seed_rng(420), length as u32, amount as u32); - assert!(v1.iter().all(|e| e < length)); - assert_eq!(v1, v2); - - // Test Floyd's alg does produce different results - let v3 = sample_floyd(&mut seed_rng(420), length as u32, amount as u32); - assert!(v1 != v3); - - // A large length and small amount should use Floyd - let (length, amount): (usize, usize) = (1<<20, 50); - let v1 = sample(&mut seed_rng(421), length, amount); - let v2 = sample_floyd(&mut seed_rng(421), length as u32, amount as u32); - assert!(v1.iter().all(|e| e < length)); - assert_eq!(v1, v2); - - // A large length and larger amount should use cache - let (length, amount): (usize, usize) = (1<<20, 600); - let v1 = sample(&mut seed_rng(422), length, amount); - let v2 = sample_rejection(&mut seed_rng(422), length as u32, amount as u32); - assert!(v1.iter().all(|e| e < length)); - assert_eq!(v1, v2); - } -} |