1//! The underlying OsString/OsStr implementation on Unix and many other
2//! systems: just a `Vec<u8>`/`[u8]`.
3
4use core::clone::CloneToUninit;
5
6use crate::borrow::Cow;
7use crate::collections::TryReserveError;
8use crate::fmt::Write;
9use crate::rc::Rc;
10use crate::sync::Arc;
11use crate::sys_common::{AsInner, FromInner, IntoInner};
12use crate::{fmt, mem, str};
13
14#[cfg(test)]
15mod tests;
16
17#[derive(Hash)]
18#[repr(transparent)]
19pub struct Buf {
20 pub inner: Vec<u8>,
21}
22
23#[repr(transparent)]
24pub struct Slice {
25 pub inner: [u8],
26}
27
28impl IntoInner<Vec<u8>> for Buf {
29 fn into_inner(self) -> Vec<u8> {
30 self.inner
31 }
32}
33
34impl FromInner<Vec<u8>> for Buf {
35 fn from_inner(inner: Vec<u8>) -> Self {
36 Buf { inner }
37 }
38}
39
40impl AsInner<[u8]> for Buf {
41 #[inline]
42 fn as_inner(&self) -> &[u8] {
43 &self.inner
44 }
45}
46
47impl fmt::Debug for Buf {
48 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
49 fmt::Debug::fmt(self.as_slice(), f)
50 }
51}
52
53impl fmt::Display for Buf {
54 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
55 fmt::Display::fmt(self.as_slice(), f)
56 }
57}
58
59impl fmt::Debug for Slice {
60 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
61 fmt::Debug::fmt(&self.inner.utf8_chunks().debug(), f)
62 }
63}
64
65impl fmt::Display for Slice {
66 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
67 // If we're the empty string then our iterator won't actually yield
68 // anything, so perform the formatting manually
69 if self.inner.is_empty() {
70 return "".fmt(f);
71 }
72
73 for chunk: Utf8Chunk<'_> in self.inner.utf8_chunks() {
74 let valid: &str = chunk.valid();
75 // If we successfully decoded the whole chunk as a valid string then
76 // we can return a direct formatting of the string which will also
77 // respect various formatting flags if possible.
78 if chunk.invalid().is_empty() {
79 return valid.fmt(f);
80 }
81
82 f.write_str(data:valid)?;
83 f.write_char(char::REPLACEMENT_CHARACTER)?;
84 }
85 Ok(())
86 }
87}
88
89impl Clone for Buf {
90 #[inline]
91 fn clone(&self) -> Self {
92 Buf { inner: self.inner.clone() }
93 }
94
95 #[inline]
96 fn clone_from(&mut self, source: &Self) {
97 self.inner.clone_from(&source.inner)
98 }
99}
100
101impl Buf {
102 #[inline]
103 pub fn into_encoded_bytes(self) -> Vec<u8> {
104 self.inner
105 }
106
107 #[inline]
108 pub unsafe fn from_encoded_bytes_unchecked(s: Vec<u8>) -> Self {
109 Self { inner: s }
110 }
111
112 #[inline]
113 pub fn into_string(self) -> Result<String, Buf> {
114 String::from_utf8(self.inner).map_err(|p| Buf { inner: p.into_bytes() })
115 }
116
117 #[inline]
118 pub fn from_string(s: String) -> Buf {
119 Buf { inner: s.into_bytes() }
120 }
121
122 #[inline]
123 pub fn with_capacity(capacity: usize) -> Buf {
124 Buf { inner: Vec::with_capacity(capacity) }
125 }
126
127 #[inline]
128 pub fn clear(&mut self) {
129 self.inner.clear()
130 }
131
132 #[inline]
133 pub fn capacity(&self) -> usize {
134 self.inner.capacity()
135 }
136
137 #[inline]
138 pub fn push_slice(&mut self, s: &Slice) {
139 self.inner.extend_from_slice(&s.inner)
140 }
141
142 #[inline]
143 pub fn push_str(&mut self, s: &str) {
144 self.inner.extend_from_slice(s.as_bytes());
145 }
146
147 #[inline]
148 pub fn reserve(&mut self, additional: usize) {
149 self.inner.reserve(additional)
150 }
151
152 #[inline]
153 pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
154 self.inner.try_reserve(additional)
155 }
156
157 #[inline]
158 pub fn reserve_exact(&mut self, additional: usize) {
159 self.inner.reserve_exact(additional)
160 }
161
162 #[inline]
163 pub fn try_reserve_exact(&mut self, additional: usize) -> Result<(), TryReserveError> {
164 self.inner.try_reserve_exact(additional)
165 }
166
167 #[inline]
168 pub fn shrink_to_fit(&mut self) {
169 self.inner.shrink_to_fit()
170 }
171
172 #[inline]
173 pub fn shrink_to(&mut self, min_capacity: usize) {
174 self.inner.shrink_to(min_capacity)
175 }
176
177 #[inline]
178 pub fn as_slice(&self) -> &Slice {
179 // SAFETY: Slice just wraps [u8],
180 // and &*self.inner is &[u8], therefore
181 // transmuting &[u8] to &Slice is safe.
182 unsafe { mem::transmute(self.inner.as_slice()) }
183 }
184
185 #[inline]
186 pub fn as_mut_slice(&mut self) -> &mut Slice {
187 // SAFETY: Slice just wraps [u8],
188 // and &mut *self.inner is &mut [u8], therefore
189 // transmuting &mut [u8] to &mut Slice is safe.
190 unsafe { mem::transmute(self.inner.as_mut_slice()) }
191 }
192
193 #[inline]
194 pub fn leak<'a>(self) -> &'a mut Slice {
195 unsafe { mem::transmute(self.inner.leak()) }
196 }
197
198 #[inline]
199 pub fn into_box(self) -> Box<Slice> {
200 unsafe { mem::transmute(self.inner.into_boxed_slice()) }
201 }
202
203 #[inline]
204 pub fn from_box(boxed: Box<Slice>) -> Buf {
205 let inner: Box<[u8]> = unsafe { mem::transmute(boxed) };
206 Buf { inner: inner.into_vec() }
207 }
208
209 #[inline]
210 pub fn into_arc(&self) -> Arc<Slice> {
211 self.as_slice().into_arc()
212 }
213
214 #[inline]
215 pub fn into_rc(&self) -> Rc<Slice> {
216 self.as_slice().into_rc()
217 }
218
219 /// Provides plumbing to core `Vec::truncate`.
220 /// More well behaving alternative to allowing outer types
221 /// full mutable access to the core `Vec`.
222 #[inline]
223 pub(crate) fn truncate(&mut self, len: usize) {
224 self.inner.truncate(len);
225 }
226
227 /// Provides plumbing to core `Vec::extend_from_slice`.
228 /// More well behaving alternative to allowing outer types
229 /// full mutable access to the core `Vec`.
230 #[inline]
231 pub(crate) fn extend_from_slice(&mut self, other: &[u8]) {
232 self.inner.extend_from_slice(other);
233 }
234}
235
236impl Slice {
237 #[inline]
238 pub fn as_encoded_bytes(&self) -> &[u8] {
239 &self.inner
240 }
241
242 #[inline]
243 pub unsafe fn from_encoded_bytes_unchecked(s: &[u8]) -> &Slice {
244 unsafe { mem::transmute(s) }
245 }
246
247 #[track_caller]
248 #[inline]
249 pub fn check_public_boundary(&self, index: usize) {
250 if index == 0 || index == self.inner.len() {
251 return;
252 }
253 if index < self.inner.len()
254 && (self.inner[index - 1].is_ascii() || self.inner[index].is_ascii())
255 {
256 return;
257 }
258
259 slow_path(&self.inner, index);
260
261 /// We're betting that typical splits will involve an ASCII character.
262 ///
263 /// Putting the expensive checks in a separate function generates notably
264 /// better assembly.
265 #[track_caller]
266 #[inline(never)]
267 fn slow_path(bytes: &[u8], index: usize) {
268 let (before, after) = bytes.split_at(index);
269
270 // UTF-8 takes at most 4 bytes per codepoint, so we don't
271 // need to check more than that.
272 let after = after.get(..4).unwrap_or(after);
273 match str::from_utf8(after) {
274 Ok(_) => return,
275 Err(err) if err.valid_up_to() != 0 => return,
276 Err(_) => (),
277 }
278
279 for len in 2..=4.min(index) {
280 let before = &before[index - len..];
281 if str::from_utf8(before).is_ok() {
282 return;
283 }
284 }
285
286 panic!("byte index {index} is not an OsStr boundary");
287 }
288 }
289
290 #[inline]
291 pub fn from_str(s: &str) -> &Slice {
292 unsafe { Slice::from_encoded_bytes_unchecked(s.as_bytes()) }
293 }
294
295 #[inline]
296 pub fn to_str(&self) -> Result<&str, crate::str::Utf8Error> {
297 str::from_utf8(&self.inner)
298 }
299
300 #[inline]
301 pub fn to_string_lossy(&self) -> Cow<'_, str> {
302 String::from_utf8_lossy(&self.inner)
303 }
304
305 #[inline]
306 pub fn to_owned(&self) -> Buf {
307 Buf { inner: self.inner.to_vec() }
308 }
309
310 #[inline]
311 pub fn clone_into(&self, buf: &mut Buf) {
312 self.inner.clone_into(&mut buf.inner)
313 }
314
315 #[inline]
316 pub fn into_box(&self) -> Box<Slice> {
317 let boxed: Box<[u8]> = self.inner.into();
318 unsafe { mem::transmute(boxed) }
319 }
320
321 #[inline]
322 pub fn empty_box() -> Box<Slice> {
323 let boxed: Box<[u8]> = Default::default();
324 unsafe { mem::transmute(boxed) }
325 }
326
327 #[inline]
328 pub fn into_arc(&self) -> Arc<Slice> {
329 let arc: Arc<[u8]> = Arc::from(&self.inner);
330 unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Slice) }
331 }
332
333 #[inline]
334 pub fn into_rc(&self) -> Rc<Slice> {
335 let rc: Rc<[u8]> = Rc::from(&self.inner);
336 unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Slice) }
337 }
338
339 #[inline]
340 pub fn make_ascii_lowercase(&mut self) {
341 self.inner.make_ascii_lowercase()
342 }
343
344 #[inline]
345 pub fn make_ascii_uppercase(&mut self) {
346 self.inner.make_ascii_uppercase()
347 }
348
349 #[inline]
350 pub fn to_ascii_lowercase(&self) -> Buf {
351 Buf { inner: self.inner.to_ascii_lowercase() }
352 }
353
354 #[inline]
355 pub fn to_ascii_uppercase(&self) -> Buf {
356 Buf { inner: self.inner.to_ascii_uppercase() }
357 }
358
359 #[inline]
360 pub fn is_ascii(&self) -> bool {
361 self.inner.is_ascii()
362 }
363
364 #[inline]
365 pub fn eq_ignore_ascii_case(&self, other: &Self) -> bool {
366 self.inner.eq_ignore_ascii_case(&other.inner)
367 }
368}
369
370#[unstable(feature = "clone_to_uninit", issue = "126799")]
371unsafe impl CloneToUninit for Slice {
372 #[inline]
373 #[cfg_attr(debug_assertions, track_caller)]
374 unsafe fn clone_to_uninit(&self, dst: *mut u8) {
375 // SAFETY: we're just a transparent wrapper around [u8]
376 unsafe { self.inner.clone_to_uninit(dest:dst) }
377 }
378}
379