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
use crate::{BitBuf, Error, Result, StorageMut};
impl<S: StorageMut> BitBuf<S> {
/// Write a [`u8`] in BE-bit-order at `byte_offset` without performing bound checks
///
/// # Safety
///
/// * This is UB if [`byte_offset >= self.bytes().len()`][Self::bytes]
///
/// # Panics
///
/// * Panics in debug mode if [`byte_offset >= self.bytes().len()`][Self::bytes]
#[inline(always)]
pub unsafe fn write_u8_be_aligned_full_at_unchecked(
&mut self,
byte_offset: usize,
v: u8,
) -> &mut Self {
let bytes = self.bytes_mut();
debug_assert!(
byte_offset < bytes.len(),
"BitBuf::write_u8_be_aligned_full_at_unchecked: index out of bounds! len is {}, offset is {}",
bytes.len(),
byte_offset,
);
unsafe { *bytes.get_unchecked_mut(byte_offset) = v };
self
}
/// Write a [`u8`] in BE-bit-order without performing bound checks, advancing the internal cursor
///
/// # Safety
///
/// * The internal cursor must be byte-aligned ([`self.is_aligned()`][Self::is_aligned])
/// * This is UB if the internal cursor points past the end of storage (<code>[self.byte_pos()][Self::byte_pos] >= [self.bytes().len()][Self::bytes]</code>)
///
/// # Panics
///
/// * Panics in debug mode if the internal cursor is not byte-aligned ([`!self.is_aligned()`][Self::is_aligned])
/// * Panics in debug mode if the internal cursor points past the end of storage (<code>[self.byte_pos()][Self::byte_pos] >= [self.bytes().len()][Self::bytes]</code>)
#[inline(always)]
pub unsafe fn write_u8_be_aligned_full_unchecked(&mut self, v: u8) -> &mut Self {
debug_assert!(
self.is_aligned(),
"BitBuf::write_u8_be_aligned_full_unchecked called at unaligned bit position: {}",
self.pos(),
);
unsafe { self.write_u8_be_aligned_full_at_unchecked(self.byte_pos(), v) };
self.advance_bytes(1);
self
}
/// Write a [`u8`] in BE-bit-order at `offset` without performing bound checks
///
/// # Safety
///
/// * This is UB if <code>(offset / 8) >= [`self.bytes().len()`][Self::bytes]</code>
/// * This is UB if <code>(offset % 8 != 0) && (offset / 8) + 1 >= [`self.bytes().len()`][Self::bytes]</code>
///
/// # Panics
///
/// * Panics in debug mode if <code>(offset / 8) >= [`self.bytes().len()`][Self::bytes]</code>
/// * Panics in debug mode if <code>(offset % 8 != 0) && (offset / 8) + 1 >= [`self.bytes().len()`][Self::bytes]</code>
#[inline(always)]
pub unsafe fn write_u8_be_full_at_unchecked(&mut self, offset: usize, v: u8) -> &mut Self {
let byte_idx = offset / 8;
let shift = offset % 8;
let bytes = self.bytes_mut();
debug_assert!(
byte_idx < bytes.len(),
"BitBuf::write_u8_be_full_at_unchecked: index out of bounds! len is {}, byte_idx is {}",
bytes.len(),
byte_idx,
);
if shift == 0 {
unsafe { self.write_u8_be_aligned_full_at_unchecked(byte_idx, v) };
} else {
let next_idx = byte_idx + 1;
debug_assert!(
next_idx < bytes.len(),
"BitBuf::write_u8_be_full_at_unchecked: lookahead index out of bounds! len is {}, lookahead byte_idx is {}",
bytes.len(),
next_idx,
);
// first byte, higher part of value
unsafe {
// mask to keep high bits of the current byte
let mask = !0 << (8 - shift);
let b = bytes.get_unchecked(byte_idx) & mask;
// high bits of the value, shifted down
let new = v >> shift;
*bytes.get_unchecked_mut(byte_idx) = b | new;
}
// second byte, lower part of value
unsafe {
// mask to keep low bits of the current byte
let mask = !0 >> shift;
let b = bytes.get_unchecked(next_idx) & mask;
// low bits of the value, shifted up
let new = v << (8 - shift);
*bytes.get_unchecked_mut(next_idx) = b | new;
}
}
self
}
/// Write a BE-bit-order [`u8`] at `offset` while performing bound checks
///
/// # Errors
///
/// * Returns [`Error::OutOfBounds`]
/// * if <code>(offset / 8) >= [`self.bytes().len()`][Self::bytes]</code>
/// * if <code>(offset % 8 != 0) && (offset / 8) + 1 >= [`self.bytes().len()`][Self::bytes]</code>
#[inline(always)]
pub fn try_write_u8_be_full_at(&mut self, offset: usize, v: u8) -> Result<&mut Self> {
let byte_idx = offset / 8;
let shift = offset % 8;
let len = self.bytes().len();
if byte_idx >= len {
return Err(Error::OutOfBounds);
}
if shift != 0 && byte_idx + 1 >= len {
return Err(Error::OutOfBounds);
}
Ok(unsafe { self.write_u8_be_full_at_unchecked(offset, v) })
}
/// Write a BE-bit-order [`u8`] at `offset`, panicking on out of bounds
///
/// # Panics
///
/// * Panics if <code>(offset / 8) >= [`self.bytes().len()`][Self::bytes]</code>
/// * Panics if <code>(offset % 8 != 0) && (offset / 8) + 1 >= [`self.bytes().len()`][Self::bytes]</code>
#[inline(always)]
pub fn write_u8_be_full_at(&mut self, offset: usize, v: u8) -> &mut Self {
self
.try_write_u8_be_full_at(offset, v)
.expect("BitBuf::write_u8_be_full_at out of bounds")
}
/// Write a [`u16`] in [BE-bit, BE-byte] order at `byte_offset` without performing bound checks
///
/// # Safety
///
/// * This is UB if [`byte_offset + 1 >= self.bytes().len()`][Self::bytes]
///
/// # Panics
///
/// * Panics in debug mode if [`byte_offset + 1 >= self.bytes().len()`][Self::bytes]
#[inline(always)]
pub unsafe fn write_u16_be_aligned_full_at_unchecked(
&mut self,
byte_offset: usize,
v: u16,
) -> &mut Self {
let bytes = self.bytes_mut();
debug_assert!(
byte_offset + 1 < bytes.len(),
"BitBuf::write_u16_be_aligned_full_at_unchecked: index out of bounds! len is {}, offset is {}",
bytes.len(),
byte_offset + 1,
);
let [high, low] = v.to_be_bytes();
unsafe {
*bytes.get_unchecked_mut(byte_offset) = high;
*bytes.get_unchecked_mut(byte_offset + 1) = low;
}
self
}
/// Write a [`u16`] in [BE-bit, BE-byte] order without performing bound checks, advancing the internal cursor
///
/// # Safety
///
/// * The internal cursor must be byte-aligned ([`self.is_aligned()`][Self::is_aligned])
/// * This is UB if the internal cursor points past the end of storage (<code>[self.byte_pos()][Self::byte_pos] + 1 >= [self.bytes().len()][Self::bytes]</code>)
///
/// # Panics
///
/// * Panics in debug mode if the internal cursor is not byte-aligned ([`!self.is_aligned()`][Self::is_aligned])
/// * Panics in debug mode if the internal cursor points past the end of storage (<code>[self.byte_pos()][Self::byte_pos] + 1 >= [self.bytes().len()][Self::bytes]</code>)
#[inline(always)]
pub unsafe fn write_u16_be_aligned_full_unchecked(&mut self, v: u16) -> &mut Self {
debug_assert!(
self.is_aligned(),
"BitBuf::write_u16_be_aligned_full_unchecked called at unaligned bit position: {}",
self.pos(),
);
unsafe { self.write_u16_be_aligned_full_at_unchecked(self.byte_pos(), v) };
self.advance_bytes(2);
self
}
}