1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148

use std::{marker::PhantomData, ops::Deref};

use wuffs_sys::wuffs_base__slice_u8;

#[derive(Clone)]
pub enum WuffsSlice<'a, T: WuffsSliceImpl> {
  Owned(WuffsSliceOwned<T>),
  Borrowed(WuffsSliceBorrowed<'a, T>),
}

impl<T: WuffsSliceImpl> WuffsSlice<'_, T> {
  pub fn from_inner(inner: T::Native) -> Self {
    Self::Borrowed(WuffsSliceBorrowed::from(inner))
  }

  pub fn into_inner(self) -> T::Native {
    match self {
      Self::Owned(owned) => owned.into_inner(),
      Self::Borrowed(borrowed) => borrowed.into_inner(),
    }
  }

  /// Convert read-only slice reference into a `T::Native`
  ///
  /// # Safety
  /// Potential cast to `*mut` ptr underlying with the hope the underlying data isn't
  /// modified.
  pub unsafe fn from_readonly(slice: &[T]) -> T::Native {
    T::from_ptr(slice.as_ptr() as *mut _, slice.len())
  }
}

impl<T: WuffsSliceImpl> AsRef<[T]> for WuffsSlice<'_, T> {
  fn as_ref(&self) -> &[T] {
    self.data()
  }
}

impl<'a, T: WuffsSliceImpl> From<&'a mut [T]> for WuffsSlice<'a, T> {
  fn from(slice: &'a mut [T]) -> Self {
    Self::Borrowed(WuffsSliceBorrowed::new(slice))
  }
}

impl<'a, T: WuffsSliceImpl> From<Vec<T>> for WuffsSlice<'a, T> {
  fn from(vec: Vec<T>) -> Self {
    Self::Owned(WuffsSliceOwned::new(vec))
  }
}

impl<T: WuffsSliceImpl> Deref for WuffsSlice<'_, T> {
  type Target = T::Native;

  fn deref(&self) -> &Self::Target {
    match self {
      Self::Owned(owned) => owned,
      Self::Borrowed(borrowed) => borrowed,
    }
  }
}

#[derive(Clone)]
pub struct WuffsSliceOwned<T: WuffsSliceImpl> {
  data: Vec<T>,
  inner: T::Native,
}

impl<T: WuffsSliceImpl> WuffsSliceOwned<T> {
  pub fn new(mut data: Vec<T>) -> Self {
    let inner = T::from_ptr(data.as_mut_ptr(), data.len());

    Self { data, inner }
  }

  pub fn into_data(self) -> Vec<T> {
    self.data
  }

  pub fn into_inner(self) -> T::Native {
    self.inner
  }
}

impl<T: WuffsSliceImpl> Deref for WuffsSliceOwned<T> {
  type Target = T::Native;

  fn deref(&self) -> &Self::Target {
    &self.inner
  }
}

#[derive(Clone)]
pub struct WuffsSliceBorrowed<'a, T: WuffsSliceImpl> {
  inner: T::Native,
  phantom: PhantomData<&'a u8>,
}

impl<'a, T: WuffsSliceImpl> WuffsSliceBorrowed<'a, T> {
  pub fn new(slice: &'a mut [T]) -> Self {
    Self {
      inner: T::from_ptr(slice.as_mut_ptr(), slice.len()),
      phantom: Default::default(),
    }
  }

  pub fn from(inner: T::Native) -> Self {
    Self {
      inner,
      phantom: Default::default(),
    }
  }

  pub fn into_inner(self) -> T::Native {
    self.inner
  }
}

impl<T: WuffsSliceImpl> Deref for WuffsSliceBorrowed<'_, T> {
  type Target = T::Native;

  fn deref(&self) -> &Self::Target {
    &self.inner
  }
}

pub trait WuffsSliceImpl: Sized + Clone {
  type Native: WuffsSliceNative<Self> + Clone;

  fn from_ptr(ptr: *mut Self, len: usize) -> Self::Native;
}

pub trait WuffsSliceNative<T> {
  fn data(&self) -> &[T];
}

impl WuffsSliceImpl for u8 {
  type Native = wuffs_base__slice_u8;

  fn from_ptr(ptr: *mut Self, len: usize) -> Self::Native {
    wuffs_base__slice_u8 { ptr, len: len as _ }
  }
}

impl WuffsSliceNative<u8> for wuffs_base__slice_u8 {
  fn data(&self) -> &[u8] {
    unsafe { std::slice::from_raw_parts(self.ptr, self.len as _) }
  }
}