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Diffstat (limited to 'rand/rand_isaac/src/isaac_array.rs')
-rw-r--r-- | rand/rand_isaac/src/isaac_array.rs | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/rand/rand_isaac/src/isaac_array.rs b/rand/rand_isaac/src/isaac_array.rs new file mode 100644 index 0000000..0fa6147 --- /dev/null +++ b/rand/rand_isaac/src/isaac_array.rs @@ -0,0 +1,136 @@ +// Copyright 2018 Developers of the Rand project. +// Copyright 2017-2018 The Rust Project Developers. +// +// 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. + +//! ISAAC helper functions for 256-element arrays. + +// Terrible workaround because arrays with more than 32 elements do not +// implement `AsRef`, `Default`, `Serialize`, `Deserialize`, or any other +// traits for that matter. + +#[cfg(feature="serde1")] use serde::{Serialize, Deserialize}; + +const RAND_SIZE_LEN: usize = 8; +const RAND_SIZE: usize = 1 << RAND_SIZE_LEN; + + +#[derive(Copy, Clone)] +#[allow(missing_debug_implementations)] +#[cfg_attr(feature="serde1", derive(Serialize, Deserialize))] +pub struct IsaacArray<T> { + #[cfg_attr(feature="serde1",serde(with="isaac_array_serde"))] + #[cfg_attr(feature="serde1", serde(bound( + serialize = "T: Serialize", + deserialize = "T: Deserialize<'de> + Copy + Default")))] + inner: [T; RAND_SIZE] +} + +impl<T> ::core::convert::AsRef<[T]> for IsaacArray<T> { + #[inline(always)] + fn as_ref(&self) -> &[T] { + &self.inner[..] + } +} + +impl<T> ::core::convert::AsMut<[T]> for IsaacArray<T> { + #[inline(always)] + fn as_mut(&mut self) -> &mut [T] { + &mut self.inner[..] + } +} + +impl<T> ::core::ops::Deref for IsaacArray<T> { + type Target = [T; RAND_SIZE]; + #[inline(always)] + fn deref(&self) -> &Self::Target { + &self.inner + } +} + +impl<T> ::core::ops::DerefMut for IsaacArray<T> { + #[inline(always)] + fn deref_mut(&mut self) -> &mut [T; RAND_SIZE] { + &mut self.inner + } +} + +impl<T> ::core::default::Default for IsaacArray<T> where T: Copy + Default { + fn default() -> IsaacArray<T> { + IsaacArray { inner: [T::default(); RAND_SIZE] } + } +} + + +#[cfg(feature="serde1")] +pub(super) mod isaac_array_serde { + const RAND_SIZE_LEN: usize = 8; + const RAND_SIZE: usize = 1 << RAND_SIZE_LEN; + + use serde::{Deserialize, Deserializer, Serialize, Serializer}; + use serde::de::{Visitor,SeqAccess}; + use serde::de; + + use core::fmt; + + pub fn serialize<T, S>(arr: &[T;RAND_SIZE], ser: S) -> Result<S::Ok, S::Error> + where + T: Serialize, + S: Serializer + { + use serde::ser::SerializeTuple; + + let mut seq = ser.serialize_tuple(RAND_SIZE)?; + + for e in arr.iter() { + seq.serialize_element(&e)?; + } + + seq.end() + } + + #[inline] + pub fn deserialize<'de, T, D>(de: D) -> Result<[T;RAND_SIZE], D::Error> + where + T: Deserialize<'de>+Default+Copy, + D: Deserializer<'de>, + { + use core::marker::PhantomData; + struct ArrayVisitor<T> { + _pd: PhantomData<T>, + }; + impl<'de,T> Visitor<'de> for ArrayVisitor<T> + where + T: Deserialize<'de>+Default+Copy + { + type Value = [T; RAND_SIZE]; + + fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { + formatter.write_str("Isaac state array") + } + + #[inline] + fn visit_seq<A>(self, mut seq: A) -> Result<[T; RAND_SIZE], A::Error> + where + A: SeqAccess<'de>, + { + let mut out = [Default::default();RAND_SIZE]; + + for i in 0..RAND_SIZE { + match seq.next_element()? { + Some(val) => out[i] = val, + None => return Err(de::Error::invalid_length(i, &self)), + }; + } + + Ok(out) + } + } + + de.deserialize_tuple(RAND_SIZE, ArrayVisitor{_pd: PhantomData}) + } +} |