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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
use crate::digit;
use crate::doc;
// use core::mem::MaybeUninit;
macro_rules! endian {
($BUint: ident, $BInt: ident, $Digit: ident) => {
#[doc = doc::endian::impl_desc!($BUint)]
impl<const N: usize> $BUint<N> {
#[doc = doc::endian::from_be!(U 256)]
#[must_use]
#[inline]
pub const fn from_be(x: Self) -> Self {
#[cfg(target_endian = "big")]
return x;
#[cfg(not(target_endian = "big"))]
x.swap_bytes()
}
#[doc = doc::endian::from_le!(U 256)]
#[must_use]
#[inline]
pub const fn from_le(x: Self) -> Self {
#[cfg(target_endian = "little")]
return x;
#[cfg(not(target_endian = "little"))]
x.swap_bytes()
}
#[doc = doc::endian::to_be!(U 256)]
#[must_use = doc::must_use_op!()]
#[inline]
pub const fn to_be(self) -> Self {
Self::from_be(self)
}
#[doc = doc::endian::to_le!(U 256)]
#[must_use = doc::must_use_op!()]
#[inline]
pub const fn to_le(self) -> Self {
Self::from_le(self)
}
/// Create an integer value from a slice of bytes in big endian. The value is wrapped in an `Option` as the integer represented by the slice of bytes may represent an integer too large to be represented by the type.
///
/// If the length of the slice is shorter than `Self::BYTES`, the slice is padded with zeros at the start so that it's length equals `Self::BYTES`.
///
/// If the length of the slice is longer than `Self::BYTES`, `None` will be returned, unless leading zeros from the slice can be removed until the length of the slice equals `Self::BYTES`.
///
/// # Examples
///
/// ```
/// use bnum::types::U128;
///
/// let value_from_array = U128::from(u128::from_be_bytes([0, 0, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]));
/// // using the `from_be_bytes` method on the primitve `u128` here instead of on `U128` as `from_be_bytes` is currently only available in bnum on nightly
/// let value_from_slice = U128::from_be_slice(&[0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]).unwrap();
/// let value_from_long_slice = U128::from_be_slice(&[0, 0, 0, 0, 0, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]).unwrap();
///
/// assert_eq!(value_from_array, value_from_slice);
/// assert_eq!(value_from_array, value_from_long_slice);
///
/// let invalid_slice = &[0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90];
/// assert_eq!(U128::from_be_slice(invalid_slice), None);
/// ```
#[must_use]
pub const fn from_be_slice(slice: &[u8]) -> Option<Self> {
let len = slice.len();
let mut out = Self::ZERO;
// let slice_ptr = slice.as_ptr();
let mut i = 0;
let exact = len >> digit::$Digit::BYTE_SHIFT;
while i < exact {
let mut digit_bytes = [0u8; digit::$Digit::BYTES as usize];
let init_index = len - digit::$Digit::BYTES as usize;
let mut j = init_index;
while j < slice.len() {
digit_bytes[j - init_index] = slice[j - (i << digit::$Digit::BYTE_SHIFT)];
j += 1;
}
let digit = $Digit::from_be_bytes(digit_bytes);
if i < N {
out.digits[i] = digit;
} else if digit != 0 {
return None;
};
i += 1;
}
let rem = len & (digit::$Digit::BYTES as usize - 1);
if rem == 0 {
Some(out)
} else {
let mut last_digit_bytes = [0; digit::$Digit::BYTES as usize];
let mut j = 0;
while j < rem {
last_digit_bytes[digit::$Digit::BYTES as usize - rem + j] = slice[j];
j += 1;
}
let digit = $Digit::from_be_bytes(last_digit_bytes);
if i < N {
out.digits[i] = digit;
} else if digit != 0 {
return None;
};
Some(out)
}
}
/// Creates an integer value from a slice of bytes in little endian. The value is wrapped in an `Option` as the bytes may represent an integer too large to be represented by the type.
///
/// If the length of the slice is shorter than `Self::BYTES`, the slice is padded with zeros at the end so that it's length equals `Self::BYTES`.
///
/// If the length of the slice is longer than `Self::BYTES`, `None` will be returned, unless trailing zeros from the slice can be removed until the length of the slice equals `Self::BYTES`.
///
/// # Examples
///
/// ```
/// use bnum::types::U128;
///
/// let value_from_array = U128::from(u128::from_le_bytes([0x12, 0x90, 0x78, 0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0, 0]));
/// // using the `from_le_bytes` method on the primitve `u128` here instead of on `U128` as `from_le_bytes` is currently only available in bnum on nightly
/// let value_from_slice = U128::from_le_slice(&[0x12, 0x90, 0x78, 0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12, 0x90, 0x78, 0x56]).unwrap();
/// let value_from_long_slice = U128::from_le_slice(&[0x12, 0x90, 0x78, 0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0, 0, 0, 0, 0, 0]).unwrap();
///
/// assert_eq!(value_from_array, value_from_slice);
/// assert_eq!(value_from_array, value_from_long_slice);
///
/// let invalid_slice = &[0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90];
/// assert_eq!(U128::from_le_slice(invalid_slice), None);
/// ```
#[must_use]
pub const fn from_le_slice(slice: &[u8]) -> Option<Self> {
let len = slice.len();
let mut out = Self::ZERO;
// let slice_ptr = slice.as_ptr();
let mut i = 0;
let exact = len >> digit::$Digit::BYTE_SHIFT;
while i < exact {
let mut digit_bytes = [0u8; digit::$Digit::BYTES as usize];
let init_index = i << digit::$Digit::BYTE_SHIFT;
let mut j = init_index;
while j < init_index + digit::$Digit::BYTES as usize {
digit_bytes[j - init_index] = slice[j];
j += 1;
}
let digit = $Digit::from_le_bytes(digit_bytes);
if i < N {
out.digits[i] = digit;
} else if digit != 0 {
return None;
};
i += 1;
}
if len & (digit::$Digit::BYTES as usize - 1) == 0 {
Some(out)
} else {
let mut last_digit_bytes = [0; digit::$Digit::BYTES as usize];
let addition = exact << digit::$Digit::BYTE_SHIFT;
let mut j = 0;
while j + addition < len {
last_digit_bytes[j] = slice[j + addition];
j += 1;
}
let digit = $Digit::from_le_bytes(last_digit_bytes);
if i < N {
out.digits[i] = digit;
} else if digit != 0 {
return None;
};
Some(out)
}
}
#[cfg(feature = "nightly")]
#[doc = doc::endian::to_be_bytes!(U)]
#[doc = doc::requires_feature!("nightly")]
#[must_use = doc::must_use_op!()]
#[inline]
pub const fn to_be_bytes(self) -> [u8; N * digit::$Digit::BYTES as usize] {
let mut bytes = [0; N * digit::$Digit::BYTES as usize];
let mut i = N;
while i > 0 {
let digit_bytes = self.digits[N - i].to_be_bytes();
i -= 1;
let mut j = 0;
while j < digit::$Digit::BYTES as usize {
bytes[(i << digit::$Digit::BYTE_SHIFT) + j] = digit_bytes[j];
j += 1;
}
}
bytes
}
#[cfg(feature = "nightly")]
#[doc = doc::endian::to_le_bytes!(U)]
#[doc = doc::requires_feature!("nightly")]
#[must_use = doc::must_use_op!()]
#[inline]
pub const fn to_le_bytes(self) -> [u8; N * digit::$Digit::BYTES as usize] {
// Strangely, this is slightly faster than direct transmutation by either `mem::transmute_copy` or `ptr::read`.
// Also, initialising the bytes with zeros is faster than using MaybeUninit.
// The Rust compiler is probably being very smart and optimizing this code.
// The same goes for `to_be_bytes`.
let mut bytes = [0; N * digit::$Digit::BYTES as usize];
let mut i = 0;
while i < N {
let digit_bytes = self.digits[i].to_le_bytes();
let mut j = 0;
while j < digit::$Digit::BYTES as usize {
bytes[(i << digit::$Digit::BYTE_SHIFT) + j] = digit_bytes[j];
j += 1;
}
i += 1;
}
bytes
}
#[cfg(feature = "nightly")]
#[doc = doc::endian::to_ne_bytes!(U)]
#[doc = doc::requires_feature!("nightly")]
#[must_use = doc::must_use_op!()]
#[inline]
pub const fn to_ne_bytes(self) -> [u8; N * digit::$Digit::BYTES as usize] {
#[cfg(target_endian = "big")]
return self.to_be_bytes();
#[cfg(not(target_endian = "big"))]
self.to_le_bytes()
}
#[cfg(feature = "nightly")]
#[doc = doc::endian::from_be_bytes!(U)]
#[doc = doc::requires_feature!("nightly")]
#[must_use]
#[inline]
pub const fn from_be_bytes(bytes: [u8; N * digit::$Digit::BYTES as usize]) -> Self {
let mut out = Self::ZERO;
let arr_ptr = bytes.as_ptr();
let mut i = 0;
while i < N {
let mut digit_bytes = [0u8; digit::$Digit::BYTES as usize];
let init_index = N * digit::$Digit::BYTES as usize - digit::$Digit::BYTES as usize;
let mut j = init_index;
while j < N * digit::$Digit::BYTES as usize {
digit_bytes[j - init_index] = bytes[j - (i << digit::$Digit::BYTE_SHIFT)];
j += 1;
}
out.digits[i] = $Digit::from_be_bytes(digit_bytes);
i += 1;
}
out
}
#[cfg(feature = "nightly")]
#[doc = doc::endian::from_le_bytes!(U)]
#[doc = doc::requires_feature!("nightly")]
#[must_use]
#[inline]
pub const fn from_le_bytes(bytes: [u8; N * digit::$Digit::BYTES as usize]) -> Self {
let mut out = Self::ZERO;
let arr_ptr = bytes.as_ptr();
let mut i = 0;
while i < N {
let mut digit_bytes = [0u8; digit::$Digit::BYTES as usize];
let init_index = i << digit::$Digit::BYTE_SHIFT;
let mut j = init_index;
while j < init_index + digit::$Digit::BYTES as usize {
digit_bytes[j - init_index] = bytes[j];
j += 1;
}
out.digits[i] = $Digit::from_le_bytes(digit_bytes);
i += 1;
}
out
}
#[cfg(feature = "nightly")]
#[doc = doc::endian::from_ne_bytes!(U)]
#[doc = doc::requires_feature!("nightly")]
#[must_use]
#[inline]
pub const fn from_ne_bytes(bytes: [u8; N * digit::$Digit::BYTES as usize]) -> Self {
#[cfg(target_endian = "big")]
return Self::from_be_bytes(bytes);
#[cfg(not(target_endian = "big"))]
Self::from_le_bytes(bytes)
}
}
#[cfg(test)]
paste::paste! {
mod [<$Digit _digit_tests>] {
use crate::test::types::big_types::$Digit::*;
use crate::test::{test_bignum, types::utest};
crate::int::endian::tests!($Digit; utest);
}
}
};
}
crate::macro_impl!(endian);