diff options
-rw-r--r-- | .cargo_vcs_info.json | 6 | ||||
-rw-r--r-- | Android.bp | 7 | ||||
-rw-r--r-- | CHANGELOG.md | 9 | ||||
-rw-r--r-- | Cargo.toml | 32 | ||||
-rw-r--r-- | Cargo.toml.orig | 23 | ||||
-rw-r--r-- | METADATA | 13 | ||||
-rw-r--r-- | README.md | 13 | ||||
-rw-r--r-- | benches/bench.rs | 10 | ||||
-rw-r--r-- | src/global_rng.rs | 218 | ||||
-rw-r--r-- | src/lib.rs | 367 | ||||
-rw-r--r-- | tests/smoke.rs | 35 |
11 files changed, 230 insertions, 503 deletions
diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json deleted file mode 100644 index 4cb67dc..0000000 --- a/.cargo_vcs_info.json +++ /dev/null @@ -1,6 +0,0 @@ -{ - "git": { - "sha1": "6315dd1907b735a0b7585dd1d84d0f50b21f40b5" - }, - "path_in_vcs": "" -}
\ No newline at end of file @@ -42,14 +42,9 @@ rust_library { host_supported: true, crate_name: "fastrand", cargo_env_compat: true, - cargo_pkg_version: "2.0.0", + cargo_pkg_version: "1.9.0", srcs: ["src/lib.rs"], edition: "2018", - features: [ - "alloc", - "default", - "std", - ], apex_available: [ "//apex_available:platform", "com.android.virt", diff --git a/CHANGELOG.md b/CHANGELOG.md index be0bf5c..869f314 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -1,12 +1,3 @@ -# Version 2.0.0 - -- **Breaking:** Remove interior mutability from `Rng`. (#47) -- Add a `fork()` method. (#49) -- Add a `no_std` mode. (#50) -- Add an iterator selection function. (#51) -- Add a `choose_multiple()` function for sampling several elements from an iterator. (#55) -- Use the `getrandom` crate for seeding on WebAssembly targets if the `js` feature is enabled. (#60) - # Version 1.9.0 - Add `Rng::fill()` (#35, #43) @@ -11,9 +11,9 @@ [package] edition = "2018" -rust-version = "1.36" +rust-version = "1.34" name = "fastrand" -version = "2.0.0" +version = "1.9.0" authors = ["Stjepan Glavina <stjepang@gmail.com>"] exclude = ["/.*"] description = "A simple and fast random number generator" @@ -29,13 +29,6 @@ categories = ["algorithms"] license = "Apache-2.0 OR MIT" repository = "https://github.com/smol-rs/fastrand" -[package.metadata.docs.rs] -all-features = true -rustdoc-args = [ - "--cfg", - "docsrs", -] - [dev-dependencies.getrandom] version = "0.2" @@ -45,23 +38,16 @@ version = "0.8" [dev-dependencies.wyhash] version = "0.5" -[features] -alloc = [] -default = ["std"] -js = [ - "std", - "getrandom", -] -std = ["alloc"] +[target."cfg(all(target_arch = \"wasm32\", not(target_os = \"wasi\")))".dependencies.instant] +version = "0.1" -[target."cfg(all(any(target_arch = \"wasm32\", target_arch = \"wasm64\"), target_os = \"unknown\"))".dependencies.getrandom] +[target."cfg(all(target_arch = \"wasm32\", not(target_os = \"wasi\")))".dev-dependencies.getrandom] version = "0.2" features = ["js"] -optional = true -[target."cfg(all(any(target_arch = \"wasm32\", target_arch = \"wasm64\"), target_os = \"unknown\"))".dev-dependencies.getrandom] -version = "0.2" -features = ["js"] +[target."cfg(all(target_arch = \"wasm32\", not(target_os = \"wasi\")))".dev-dependencies.instant] +version = "0.1" +features = ["wasm-bindgen"] -[target."cfg(all(any(target_arch = \"wasm32\", target_arch = \"wasm64\"), target_os = \"unknown\"))".dev-dependencies.wasm-bindgen-test] +[target."cfg(all(target_arch = \"wasm32\", not(target_os = \"wasi\")))".dev-dependencies.wasm-bindgen-test] version = "0.3" diff --git a/Cargo.toml.orig b/Cargo.toml.orig index d79b133..8c80502 100644 --- a/Cargo.toml.orig +++ b/Cargo.toml.orig @@ -2,11 +2,11 @@ name = "fastrand" # When publishing a new version: # - Update CHANGELOG.md -# - Create "v2.x.y" git tag -version = "2.0.0" +# - Create "v1.x.y" git tag +version = "1.9.0" authors = ["Stjepan Glavina <stjepang@gmail.com>"] edition = "2018" -rust-version = "1.36" +rust-version = "1.34" description = "A simple and fast random number generator" license = "Apache-2.0 OR MIT" repository = "https://github.com/smol-rs/fastrand" @@ -14,16 +14,11 @@ keywords = ["simple", "fast", "rand", "random", "wyrand"] categories = ["algorithms"] exclude = ["/.*"] -[features] -default = ["std"] -alloc = [] -std = ["alloc"] -js = ["std", "getrandom"] +[target.'cfg(all(target_arch = "wasm32", not(target_os = "wasi")))'.dependencies] +instant = "0.1" -[target.'cfg(all(any(target_arch = "wasm32", target_arch = "wasm64"), target_os = "unknown"))'.dependencies] -getrandom = { version = "0.2", features = ["js"], optional = true } - -[target.'cfg(all(any(target_arch = "wasm32", target_arch = "wasm64"), target_os = "unknown"))'.dev-dependencies] +[target.'cfg(all(target_arch = "wasm32", not(target_os = "wasi")))'.dev-dependencies] +instant = { version = "0.1", features = ["wasm-bindgen"] } wasm-bindgen-test = "0.3" getrandom = { version = "0.2", features = ["js"] } @@ -31,7 +26,3 @@ getrandom = { version = "0.2", features = ["js"] } rand = "0.8" wyhash = "0.5" getrandom = "0.2" - -[package.metadata.docs.rs] -all-features = true -rustdoc-args = ["--cfg", "docsrs"] @@ -1,7 +1,3 @@ -# This project was upgraded with external_updater. -# Usage: tools/external_updater/updater.sh update rust/crates/fastrand -# For more info, check https://cs.android.com/android/platform/superproject/+/main:tools/external_updater/README.md - name: "fastrand" description: "A simple and fast random number generator" third_party { @@ -11,13 +7,14 @@ third_party { } url { type: ARCHIVE - value: "https://static.crates.io/crates/fastrand/fastrand-2.0.0.crate" + value: "https://static.crates.io/crates/fastrand/fastrand-1.9.0.crate" } - version: "2.0.0" + version: "1.9.0" + # Dual-licensed, using the least restrictive per go/thirdpartylicenses#same. license_type: NOTICE last_upgrade_date { year: 2023 - month: 9 - day: 5 + month: 2 + day: 17 } } @@ -40,13 +40,6 @@ let i = fastrand::usize(..v.len()); let elem = v[i]; ``` -Sample values from an array with `O(n)` complexity (`n` is the length of array): - -```rust -fastrand::choose_multiple(vec![1, 4, 5].iter(), 2); -fastrand::choose_multiple(0..20, 12); -``` - Shuffle an array: ```rust @@ -83,12 +76,6 @@ let rng = fastrand::Rng::new(); let mut bytes: Vec<u8> = repeat_with(|| rng.u8(..)).take(10_000).collect(); ``` -# Features - -- `std` (enabled by default): Enables the `std` library. This is required for the global - generator and global entropy. Without this feature, [`Rng`] can only be instantiated using - the [`with_seed`](Rng::with_seed) method. - ## License Licensed under either of diff --git a/benches/bench.rs b/benches/bench.rs index a940aac..4b882b7 100644 --- a/benches/bench.rs +++ b/benches/bench.rs @@ -18,7 +18,7 @@ fn shuffle_wyhash(b: &mut Bencher) { #[bench] fn shuffle_fastrand(b: &mut Bencher) { - let mut rng = fastrand::Rng::new(); + let rng = fastrand::Rng::new(); let mut x = (0..100).collect::<Vec<usize>>(); b.iter(|| { rng.shuffle(&mut x); @@ -40,7 +40,7 @@ fn u8_wyhash(b: &mut Bencher) { #[bench] fn u8_fastrand(b: &mut Bencher) { - let mut rng = fastrand::Rng::new(); + let rng = fastrand::Rng::new(); b.iter(|| { let mut sum = 0u8; for _ in 0..10_000 { @@ -64,7 +64,7 @@ fn u32_wyhash(b: &mut Bencher) { #[bench] fn u32_fastrand(b: &mut Bencher) { - let mut rng = fastrand::Rng::new(); + let rng = fastrand::Rng::new(); b.iter(|| { let mut sum = 0u32; for _ in 0..10_000 { @@ -76,7 +76,7 @@ fn u32_fastrand(b: &mut Bencher) { #[bench] fn fill(b: &mut Bencher) { - let mut rng = fastrand::Rng::new(); + let rng = fastrand::Rng::new(); b.iter(|| { // Pick a size that isn't divisble by 8. let mut bytes = [0u8; 367]; @@ -87,7 +87,7 @@ fn fill(b: &mut Bencher) { #[bench] fn fill_naive(b: &mut Bencher) { - let mut rng = fastrand::Rng::new(); + let rng = fastrand::Rng::new(); b.iter(|| { let mut bytes = [0u8; 367]; for item in &mut bytes { diff --git a/src/global_rng.rs b/src/global_rng.rs deleted file mode 100644 index f994902..0000000 --- a/src/global_rng.rs +++ /dev/null @@ -1,218 +0,0 @@ -//! A global, thread-local random number generator. - -use crate::Rng; - -use std::cell::Cell; -use std::ops::RangeBounds; - -// Chosen by fair roll of the dice. -const DEFAULT_RNG_SEED: u64 = 0xef6f79ed30ba75a; - -impl Default for Rng { - /// Initialize the `Rng` from the system's random number generator. - /// - /// This is equivalent to [`Rng::new()`]. - #[inline] - fn default() -> Rng { - Rng::new() - } -} - -impl Rng { - /// Creates a new random number generator. - #[inline] - pub fn new() -> Rng { - try_with_rng(Rng::fork).unwrap_or_else(|_| Rng::with_seed(0x4d595df4d0f33173)) - } -} - -thread_local! { - static RNG: Cell<Rng> = Cell::new(Rng(random_seed().unwrap_or(DEFAULT_RNG_SEED))); -} - -/// Run an operation with the current thread-local generator. -#[inline] -fn with_rng<R>(f: impl FnOnce(&mut Rng) -> R) -> R { - RNG.with(|rng| { - let current = rng.replace(Rng(0)); - - let mut restore = RestoreOnDrop { rng, current }; - - f(&mut restore.current) - }) -} - -/// Try to run an operation with the current thread-local generator. -#[inline] -fn try_with_rng<R>(f: impl FnOnce(&mut Rng) -> R) -> Result<R, std::thread::AccessError> { - RNG.try_with(|rng| { - let current = rng.replace(Rng(0)); - - let mut restore = RestoreOnDrop { rng, current }; - - f(&mut restore.current) - }) -} - -/// Make sure the original RNG is restored even on panic. -struct RestoreOnDrop<'a> { - rng: &'a Cell<Rng>, - current: Rng, -} - -impl Drop for RestoreOnDrop<'_> { - fn drop(&mut self) { - self.rng.set(Rng(self.current.0)); - } -} - -/// Initializes the thread-local generator with the given seed. -#[inline] -pub fn seed(seed: u64) { - with_rng(|r| r.seed(seed)); -} - -/// Gives back **current** seed that is being held by the thread-local generator. -#[inline] -pub fn get_seed() -> u64 { - with_rng(|r| r.get_seed()) -} - -/// Generates a random `bool`. -#[inline] -pub fn bool() -> bool { - with_rng(|r| r.bool()) -} - -/// Generates a random `char` in ranges a-z and A-Z. -#[inline] -pub fn alphabetic() -> char { - with_rng(|r| r.alphabetic()) -} - -/// Generates a random `char` in ranges a-z, A-Z and 0-9. -#[inline] -pub fn alphanumeric() -> char { - with_rng(|r| r.alphanumeric()) -} - -/// Generates a random `char` in range a-z. -#[inline] -pub fn lowercase() -> char { - with_rng(|r| r.lowercase()) -} - -/// Generates a random `char` in range A-Z. -#[inline] -pub fn uppercase() -> char { - with_rng(|r| r.uppercase()) -} - -/// Choose an item from an iterator at random. -/// -/// This function may have an unexpected result if the `len()` property of the -/// iterator does not match the actual number of items in the iterator. If -/// the iterator is empty, this returns `None`. -#[inline] -pub fn choice<I>(iter: I) -> Option<I::Item> -where - I: IntoIterator, - I::IntoIter: ExactSizeIterator, -{ - with_rng(|r| r.choice(iter)) -} - -/// Generates a random digit in the given `base`. -/// -/// Digits are represented by `char`s in ranges 0-9 and a-z. -/// -/// Panics if the base is zero or greater than 36. -#[inline] -pub fn digit(base: u32) -> char { - with_rng(|r| r.digit(base)) -} - -/// Shuffles a slice randomly. -#[inline] -pub fn shuffle<T>(slice: &mut [T]) { - with_rng(|r| r.shuffle(slice)) -} - -macro_rules! integer { - ($t:tt, $doc:tt) => { - #[doc = $doc] - /// - /// Panics if the range is empty. - #[inline] - pub fn $t(range: impl RangeBounds<$t>) -> $t { - with_rng(|r| r.$t(range)) - } - }; -} - -integer!(u8, "Generates a random `u8` in the given range."); -integer!(i8, "Generates a random `i8` in the given range."); -integer!(u16, "Generates a random `u16` in the given range."); -integer!(i16, "Generates a random `i16` in the given range."); -integer!(u32, "Generates a random `u32` in the given range."); -integer!(i32, "Generates a random `i32` in the given range."); -integer!(u64, "Generates a random `u64` in the given range."); -integer!(i64, "Generates a random `i64` in the given range."); -integer!(u128, "Generates a random `u128` in the given range."); -integer!(i128, "Generates a random `i128` in the given range."); -integer!(usize, "Generates a random `usize` in the given range."); -integer!(isize, "Generates a random `isize` in the given range."); -integer!(char, "Generates a random `char` in the given range."); - -/// Generates a random `f32` in range `0..1`. -pub fn f32() -> f32 { - with_rng(|r| r.f32()) -} - -/// Generates a random `f64` in range `0..1`. -pub fn f64() -> f64 { - with_rng(|r| r.f64()) -} - -/// Collects `amount` values at random from the iterator into a vector. -pub fn choose_multiple<T: Iterator>(source: T, amount: usize) -> Vec<T::Item> { - with_rng(|rng| rng.choose_multiple(source, amount)) -} - -#[cfg(not(all( - any(target_arch = "wasm32", target_arch = "wasm64"), - target_os = "unknown" -)))] -fn random_seed() -> Option<u64> { - use std::collections::hash_map::DefaultHasher; - use std::hash::{Hash, Hasher}; - use std::thread; - use std::time::Instant; - - let mut hasher = DefaultHasher::new(); - Instant::now().hash(&mut hasher); - thread::current().id().hash(&mut hasher); - let hash = hasher.finish(); - Some((hash << 1) | 1) -} - -#[cfg(all( - any(target_arch = "wasm32", target_arch = "wasm64"), - target_os = "unknown", - feature = "js" -))] -fn random_seed() -> Option<u64> { - // TODO(notgull): Failures should be logged somewhere. - let mut seed = [0u8; 8]; - getrandom::getrandom(&mut seed).ok()?; - Some(u64::from_ne_bytes(seed)) -} - -#[cfg(all( - any(target_arch = "wasm32", target_arch = "wasm64"), - target_os = "unknown", - not(feature = "js") -))] -fn random_seed() -> Option<u64> { - None -} @@ -29,14 +29,6 @@ //! let elem = v[i]; //! ``` //! -//! Sample values from an array with `O(n)` complexity (`n` is the length of array): -//! -//! ``` -//! fastrand::choose_multiple(vec![1, 4, 5].iter(), 2); -//! fastrand::choose_multiple(0..20, 12); -//! ``` -//! -//! //! Shuffle an array: //! //! ``` @@ -69,88 +61,87 @@ //! ``` //! use std::iter::repeat_with; //! -//! let mut rng = fastrand::Rng::new(); +//! let rng = fastrand::Rng::new(); //! let mut bytes: Vec<u8> = repeat_with(|| rng.u8(..)).take(10_000).collect(); //! ``` -//! -//! # Features -//! -//! - `std` (enabled by default): Enables the `std` library. This is required for the global -//! generator and global entropy. Without this feature, [`Rng`] can only be instantiated using -//! the [`with_seed`](Rng::with_seed) method. -//! - `js`: Assumes that WebAssembly targets are being run in a JavaScript environment. See the -//! [WebAssembly Notes](#webassembly-notes) section for more information. -//! -//! # WebAssembly Notes -//! -//! For non-WASI WASM targets, there is additional sublety to consider when utilizing the global RNG. -//! By default, `std` targets will use entropy sources in the standard library to seed the global RNG. -//! However, these sources are not available by default on WASM targets outside of WASI. -//! -//! If the `js` feature is enabled, this crate will assume that it is running in a JavaScript -//! environment. At this point, the [`getrandom`] crate will be used in order to access the available -//! entropy sources and seed the global RNG. If the `js` feature is not enabled, the global RNG will -//! use a predefined seed. -//! -//! [`getrandom`]: https://crates.io/crates/getrandom -#![cfg_attr(not(feature = "std"), no_std)] -#![cfg_attr(docsrs, feature(doc_cfg))] #![forbid(unsafe_code)] #![warn(missing_docs, missing_debug_implementations, rust_2018_idioms)] -#[cfg(feature = "alloc")] -extern crate alloc; - -use core::convert::{TryFrom, TryInto}; -use core::ops::{Bound, RangeBounds}; +use std::cell::Cell; +use std::collections::hash_map::DefaultHasher; +use std::convert::TryInto; +use std::hash::{Hash, Hasher}; +use std::ops::{Bound, RangeBounds}; +use std::thread; -#[cfg(feature = "alloc")] -use alloc::vec::Vec; - -#[cfg(feature = "std")] -#[cfg_attr(docsrs, doc(cfg(feature = "std")))] -mod global_rng; - -#[cfg(feature = "std")] -pub use global_rng::*; +#[cfg(all(target_arch = "wasm32", not(target_os = "wasi")))] +use instant::Instant; +#[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"))))] +use std::time::Instant; /// A random number generator. #[derive(Debug, PartialEq, Eq)] -pub struct Rng(u64); +pub struct Rng(Cell<u64>); + +impl Default for Rng { + #[inline] + fn default() -> Rng { + Rng::new() + } +} impl Clone for Rng { - /// Clones the generator by creating a new generator with the same seed. + /// Clones the generator by deterministically deriving a new generator based on the initial + /// seed. + /// + /// # Example + /// + /// ``` + /// // Seed two generators equally, and clone both of them. + /// let base1 = fastrand::Rng::new(); + /// base1.seed(0x4d595df4d0f33173); + /// base1.bool(); // Use the generator once. + /// + /// let base2 = fastrand::Rng::new(); + /// base2.seed(0x4d595df4d0f33173); + /// base2.bool(); // Use the generator once. + /// + /// let rng1 = base1.clone(); + /// let rng2 = base2.clone(); + /// + /// assert_eq!(rng1.u64(..), rng2.u64(..), "the cloned generators are identical"); + /// ``` fn clone(&self) -> Rng { - Rng::with_seed(self.0) + Rng::with_seed(self.gen_u64()) } } impl Rng { /// Generates a random `u32`. #[inline] - fn gen_u32(&mut self) -> u32 { + fn gen_u32(&self) -> u32 { self.gen_u64() as u32 } /// Generates a random `u64`. #[inline] - fn gen_u64(&mut self) -> u64 { - let s = self.0.wrapping_add(0xA0761D6478BD642F); - self.0 = s; + fn gen_u64(&self) -> u64 { + let s = self.0.get().wrapping_add(0xA0761D6478BD642F); + self.0.set(s); let t = u128::from(s) * u128::from(s ^ 0xE7037ED1A0B428DB); (t as u64) ^ (t >> 64) as u64 } /// Generates a random `u128`. #[inline] - fn gen_u128(&mut self) -> u128 { + fn gen_u128(&self) -> u128 { (u128::from(self.gen_u64()) << 64) | u128::from(self.gen_u64()) } /// Generates a random `u32` in `0..n`. #[inline] - fn gen_mod_u32(&mut self, n: u32) -> u32 { + fn gen_mod_u32(&self, n: u32) -> u32 { // Adapted from: https://lemire.me/blog/2016/06/30/fast-random-shuffling/ let mut r = self.gen_u32(); let mut hi = mul_high_u32(r, n); @@ -168,7 +159,7 @@ impl Rng { /// Generates a random `u64` in `0..n`. #[inline] - fn gen_mod_u64(&mut self, n: u64) -> u64 { + fn gen_mod_u64(&self, n: u64) -> u64 { // Adapted from: https://lemire.me/blog/2016/06/30/fast-random-shuffling/ let mut r = self.gen_u64(); let mut hi = mul_high_u64(r, n); @@ -186,7 +177,7 @@ impl Rng { /// Generates a random `u128` in `0..n`. #[inline] - fn gen_mod_u128(&mut self, n: u128) -> u128 { + fn gen_mod_u128(&self, n: u128) -> u128 { // Adapted from: https://lemire.me/blog/2016/06/30/fast-random-shuffling/ let mut r = self.gen_u128(); let mut hi = mul_high_u128(r, n); @@ -203,6 +194,16 @@ impl Rng { } } +thread_local! { + static RNG: Rng = Rng(Cell::new({ + let mut hasher = DefaultHasher::new(); + Instant::now().hash(&mut hasher); + thread::current().id().hash(&mut hasher); + let hash = hasher.finish(); + (hash << 1) | 1 + })); +} + /// Computes `(a * b) >> 32`. #[inline] fn mul_high_u32(a: u32, b: u32) -> u32 { @@ -234,7 +235,7 @@ macro_rules! rng_integer { /// /// Panics if the range is empty. #[inline] - pub fn $t(&mut self, range: impl RangeBounds<$t>) -> $t { + pub fn $t(&self, range: impl RangeBounds<$t>) -> $t { let panic_empty_range = || { panic!( "empty range: {:?}..{:?}", @@ -244,13 +245,13 @@ macro_rules! rng_integer { }; let low = match range.start_bound() { - Bound::Unbounded => core::$t::MIN, + Bound::Unbounded => std::$t::MIN, Bound::Included(&x) => x, Bound::Excluded(&x) => x.checked_add(1).unwrap_or_else(panic_empty_range), }; let high = match range.end_bound() { - Bound::Unbounded => core::$t::MAX, + Bound::Unbounded => std::$t::MAX, Bound::Included(&x) => x, Bound::Excluded(&x) => x.checked_sub(1).unwrap_or_else(panic_empty_range), }; @@ -259,7 +260,7 @@ macro_rules! rng_integer { panic_empty_range(); } - if low == core::$t::MIN && high == core::$t::MAX { + if low == std::$t::MIN && high == std::$t::MAX { self.$gen() as $t } else { let len = high.wrapping_sub(low).wrapping_add(1); @@ -270,59 +271,46 @@ macro_rules! rng_integer { } impl Rng { + /// Creates a new random number generator. + #[inline] + pub fn new() -> Rng { + Rng::with_seed( + RNG.try_with(|rng| rng.u64(..)) + .unwrap_or(0x4d595df4d0f33173), + ) + } + /// Creates a new random number generator with the initial seed. #[inline] #[must_use = "this creates a new instance of `Rng`; if you want to initialize the thread-local generator, use `fastrand::seed()` instead"] pub fn with_seed(seed: u64) -> Self { - let mut rng = Rng(0); + let rng = Rng(Cell::new(0)); rng.seed(seed); rng } - /// Clones the generator by deterministically deriving a new generator based on the initial - /// seed. - /// - /// # Example - /// - /// ``` - /// // Seed two generators equally, and clone both of them. - /// let mut base1 = fastrand::Rng::new(); - /// base1.seed(0x4d595df4d0f33173); - /// base1.bool(); // Use the generator once. - /// - /// let mut base2 = fastrand::Rng::new(); - /// base2.seed(0x4d595df4d0f33173); - /// base2.bool(); // Use the generator once. - /// - /// let mut rng1 = base1.clone(); - /// let mut rng2 = base2.clone(); - /// - /// assert_eq!(rng1.u64(..), rng2.u64(..), "the cloned generators are identical"); - /// ``` - #[inline] - #[must_use = "this creates a new instance of `Rng`"] - pub fn fork(&mut self) -> Self { - Rng::with_seed(self.gen_u64()) - } - /// Generates a random `char` in ranges a-z and A-Z. #[inline] - pub fn alphabetic(&mut self) -> char { + pub fn alphabetic(&self) -> char { const CHARS: &[u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; - *self.choice(CHARS).unwrap() as char + let len = CHARS.len() as u8; + let i = self.u8(..len); + CHARS[i as usize] as char } /// Generates a random `char` in ranges a-z, A-Z and 0-9. #[inline] - pub fn alphanumeric(&mut self) -> char { + pub fn alphanumeric(&self) -> char { const CHARS: &[u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; - *self.choice(CHARS).unwrap() as char + let len = CHARS.len() as u8; + let i = self.u8(..len); + CHARS[i as usize] as char } /// Generates a random `bool`. #[inline] - pub fn bool(&mut self) -> bool { + pub fn bool(&self) -> bool { self.u8(..) % 2 == 0 } @@ -332,7 +320,7 @@ impl Rng { /// /// Panics if the base is zero or greater than 36. #[inline] - pub fn digit(&mut self, base: u32) -> char { + pub fn digit(&self, base: u32) -> char { if base == 0 { panic!("base cannot be zero"); } @@ -348,57 +336,19 @@ impl Rng { } /// Generates a random `f32` in range `0..1`. - pub fn f32(&mut self) -> f32 { + pub fn f32(&self) -> f32 { let b = 32; - let f = core::f32::MANTISSA_DIGITS - 1; + let f = std::f32::MANTISSA_DIGITS - 1; f32::from_bits((1 << (b - 2)) - (1 << f) + (self.u32(..) >> (b - f))) - 1.0 } /// Generates a random `f64` in range `0..1`. - pub fn f64(&mut self) -> f64 { + pub fn f64(&self) -> f64 { let b = 64; - let f = core::f64::MANTISSA_DIGITS - 1; + let f = std::f64::MANTISSA_DIGITS - 1; f64::from_bits((1 << (b - 2)) - (1 << f) + (self.u64(..) >> (b - f))) - 1.0 } - /// Collects `amount` values at random from the iterator into a vector. - /// - /// The length of the returned vector equals `amount` unless the iterator - /// contains insufficient elements, in which case it equals the number of - /// elements available. - /// - /// Complexity is `O(n)` where `n` is the length of the iterator. - #[cfg(feature = "alloc")] - #[cfg_attr(docsrs, doc(cfg(feature = "alloc")))] - pub fn choose_multiple<T: Iterator>(&mut self, mut source: T, amount: usize) -> Vec<T::Item> { - // Adapted from: https://docs.rs/rand/latest/rand/seq/trait.IteratorRandom.html#method.choose_multiple - let mut reservoir = Vec::with_capacity(amount); - - reservoir.extend(source.by_ref().take(amount)); - - // Continue unless the iterator was exhausted - // - // note: this prevents iterators that "restart" from causing problems. - // If the iterator stops once, then so do we. - if reservoir.len() == amount { - for (i, elem) in source.enumerate() { - let end = i + 1 + amount; - let k = self.usize(0..end); - if let Some(slot) = reservoir.get_mut(k) { - *slot = elem; - } - } - } else { - // If less than one third of the `Vec` was used, reallocate - // so that the unused space is not wasted. There is a corner - // case where `amount` was much less than `self.len()`. - if reservoir.capacity() > 3 * reservoir.len() { - reservoir.shrink_to_fit(); - } - } - reservoir - } - rng_integer!( i8, u8, @@ -466,49 +416,28 @@ impl Rng { /// Generates a random `char` in range a-z. #[inline] - pub fn lowercase(&mut self) -> char { + pub fn lowercase(&self) -> char { const CHARS: &[u8] = b"abcdefghijklmnopqrstuvwxyz"; - *self.choice(CHARS).unwrap() as char + let len = CHARS.len() as u8; + let i = self.u8(..len); + CHARS[i as usize] as char } /// Initializes this generator with the given seed. #[inline] - pub fn seed(&mut self, seed: u64) { - self.0 = seed; + pub fn seed(&self, seed: u64) { + self.0.set(seed); } /// Gives back **current** seed that is being held by this generator. #[inline] pub fn get_seed(&self) -> u64 { - self.0 - } - - /// Choose an item from an iterator at random. - /// - /// This function may have an unexpected result if the `len()` property of the - /// iterator does not match the actual number of items in the iterator. If - /// the iterator is empty, this returns `None`. - #[inline] - pub fn choice<I>(&mut self, iter: I) -> Option<I::Item> - where - I: IntoIterator, - I::IntoIter: ExactSizeIterator, - { - let mut iter = iter.into_iter(); - - // Get the item at a random index. - let len = iter.len(); - if len == 0 { - return None; - } - let index = self.usize(0..len); - - iter.nth(index) + self.0.get() } /// Shuffles a slice randomly. #[inline] - pub fn shuffle<T>(&mut self, slice: &mut [T]) { + pub fn shuffle<T>(&self, slice: &mut [T]) { for i in 1..slice.len() { slice.swap(i, self.usize(..=i)); } @@ -516,7 +445,7 @@ impl Rng { /// Fill a byte slice with random data. #[inline] - pub fn fill(&mut self, slice: &mut [u8]) { + pub fn fill(&self, slice: &mut [u8]) { // We fill the slice by chunks of 8 bytes, or one block of // WyRand output per new state. let mut chunks = slice.chunks_exact_mut(core::mem::size_of::<u64>()); @@ -613,16 +542,20 @@ impl Rng { /// Generates a random `char` in range A-Z. #[inline] - pub fn uppercase(&mut self) -> char { + pub fn uppercase(&self) -> char { const CHARS: &[u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZ"; - *self.choice(CHARS).unwrap() as char + let len = CHARS.len() as u8; + let i = self.u8(..len); + CHARS[i as usize] as char } /// Generates a random `char` in the given range. /// /// Panics if the range is empty. #[inline] - pub fn char(&mut self, range: impl RangeBounds<char>) -> char { + pub fn char(&self, range: impl RangeBounds<char>) -> char { + use std::convert::TryFrom; + let panic_empty_range = || { panic!( "empty range: {:?}..{:?}", @@ -648,7 +581,7 @@ impl Rng { }; let high = match range.end_bound() { - Bound::Unbounded => core::char::MAX, + Bound::Unbounded => std::char::MAX, Bound::Included(&x) => x, Bound::Excluded(&x) => { let scalar = if x as u32 == surrogate_start + surrogate_len { @@ -677,3 +610,97 @@ impl Rng { val.try_into().unwrap() } } + +/// Initializes the thread-local generator with the given seed. +#[inline] +pub fn seed(seed: u64) { + RNG.with(|rng| rng.seed(seed)) +} + +/// Gives back **current** seed that is being held by the thread-local generator. +#[inline] +pub fn get_seed() -> u64 { + RNG.with(|rng| rng.get_seed()) +} + +/// Generates a random `bool`. +#[inline] +pub fn bool() -> bool { + RNG.with(|rng| rng.bool()) +} + +/// Generates a random `char` in ranges a-z and A-Z. +#[inline] +pub fn alphabetic() -> char { + RNG.with(|rng| rng.alphabetic()) +} + +/// Generates a random `char` in ranges a-z, A-Z and 0-9. +#[inline] +pub fn alphanumeric() -> char { + RNG.with(|rng| rng.alphanumeric()) +} + +/// Generates a random `char` in range a-z. +#[inline] +pub fn lowercase() -> char { + RNG.with(|rng| rng.lowercase()) +} + +/// Generates a random `char` in range A-Z. +#[inline] +pub fn uppercase() -> char { + RNG.with(|rng| rng.uppercase()) +} + +/// Generates a random digit in the given `base`. +/// +/// Digits are represented by `char`s in ranges 0-9 and a-z. +/// +/// Panics if the base is zero or greater than 36. +#[inline] +pub fn digit(base: u32) -> char { + RNG.with(|rng| rng.digit(base)) +} + +/// Shuffles a slice randomly. +#[inline] +pub fn shuffle<T>(slice: &mut [T]) { + RNG.with(|rng| rng.shuffle(slice)) +} + +macro_rules! integer { + ($t:tt, $doc:tt) => { + #[doc = $doc] + /// + /// Panics if the range is empty. + #[inline] + pub fn $t(range: impl RangeBounds<$t>) -> $t { + RNG.with(|rng| rng.$t(range)) + } + }; +} + +integer!(u8, "Generates a random `u8` in the given range."); +integer!(i8, "Generates a random `i8` in the given range."); +integer!(u16, "Generates a random `u16` in the given range."); +integer!(i16, "Generates a random `i16` in the given range."); +integer!(u32, "Generates a random `u32` in the given range."); +integer!(i32, "Generates a random `i32` in the given range."); +integer!(u64, "Generates a random `u64` in the given range."); +integer!(i64, "Generates a random `i64` in the given range."); +integer!(u128, "Generates a random `u128` in the given range."); +integer!(i128, "Generates a random `i128` in the given range."); +integer!(usize, "Generates a random `usize` in the given range."); +integer!(isize, "Generates a random `isize` in the given range."); +integer!(char, "Generates a random `char` in the given range."); + +/// Generates a random `f32` in range `0..1`. +pub fn f32() -> f32 { + RNG.with(|rng| rng.f32()) +} + +/// Generates a random `f64` in range `0..1`. +pub fn f64() -> f64 { + RNG.with(|rng| rng.f64()) +} diff --git a/tests/smoke.rs b/tests/smoke.rs index 7c92ee5..ff3cea6 100644 --- a/tests/smoke.rs +++ b/tests/smoke.rs @@ -77,7 +77,7 @@ fn u128() { #[test] fn fill() { - let mut r = fastrand::Rng::new(); + let r = fastrand::Rng::new(); let mut a = [0u8; 64]; let mut b = [0u8; 64]; @@ -89,7 +89,7 @@ fn fill() { #[test] fn rng() { - let mut r = fastrand::Rng::new(); + let r = fastrand::Rng::new(); assert_ne!(r.u64(..), r.u64(..)); @@ -102,8 +102,8 @@ fn rng() { #[test] fn rng_init() { - let mut a = fastrand::Rng::new(); - let mut b = fastrand::Rng::new(); + let a = fastrand::Rng::new(); + let b = fastrand::Rng::new(); assert_ne!(a.u64(..), b.u64(..)); a.seed(7); @@ -113,31 +113,8 @@ fn rng_init() { #[test] fn with_seed() { - let mut a = fastrand::Rng::with_seed(7); - let mut b = fastrand::Rng::new(); + let a = fastrand::Rng::with_seed(7); + let b = fastrand::Rng::new(); b.seed(7); assert_eq!(a.u64(..), b.u64(..)); } - -#[test] -fn choose_multiple() { - let mut a = fastrand::Rng::new(); - let mut elements = (0..20).collect::<Vec<_>>(); - - while !elements.is_empty() { - let chosen = a.choose_multiple(0..20, 5); - for &x in &chosen { - elements.retain(|&y| y != x); - } - } -} - -#[test] -fn choice() { - let items = [1, 4, 9, 5, 2, 3, 6, 7, 8, 0]; - let mut r = fastrand::Rng::new(); - - for item in &items { - while r.choice(&items).unwrap() != item {} - } -} |