src/libstd/sys_common/os_str_bytes.rs

   1 //! The underlying OsString/OsStr implementation on Unix and many other
   2 //! systems: just a `Vec<u8>`/`[u8]`.
   3
   4 use crate::borrow::Cow;
   5 use crate::ffi::{OsStr, OsString};
   6 use crate::fmt;
   7 use crate::mem;
   8 use crate::rc::Rc;
   9 use crate::str;
  10 use crate::sync::Arc;
  11 use crate::sys_common::bytestring::debug_fmt_bytestring;
  12 use crate::sys_common::{AsInner, FromInner, IntoInner};
  13
  14 use core::str::lossy::Utf8Lossy;
  15
  16 #[derive(Clone, Hash)]
  17 pub(crate) struct Buf {
  18     pub inner: Vec<u8>,
  19 }
  20
  21 // FIXME:
  22 // `Buf::as_slice` current implementation relies
  23 // on `Slice` being layout-compatible with `[u8]`.
  24 // When attribute privacy is implemented, `Slice` should be annotated as `#[repr(transparent)]`.
  25 // Anyway, `Slice` representation and layout are considered implementation detail, are
  26 // not documented and must not be relied upon.
  27 pub(crate) struct Slice {
  28     pub inner: [u8],
  29 }
  30
  31 impl fmt::Debug for Slice {
  32     fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
  33         debug_fmt_bytestring(&self.inner, formatter)
  34     }
  35 }
  36
  37 impl fmt::Display for Slice {
  38     fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
  39         fmt::Display::fmt(&Utf8Lossy::from_bytes(&self.inner), formatter)
  40     }
  41 }
  42
  43 impl fmt::Debug for Buf {
  44     fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
  45         fmt::Debug::fmt(self.as_slice(), formatter)
  46     }
  47 }
  48
  49 impl fmt::Display for Buf {
  50     fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
  51         fmt::Display::fmt(self.as_slice(), formatter)
  52     }
  53 }
  54
  55 impl IntoInner<Vec<u8>> for Buf {
  56     fn into_inner(self) -> Vec<u8> {
  57         self.inner
  58     }
  59 }
  60
  61 impl AsInner<[u8]> for Buf {
  62     fn as_inner(&self) -> &[u8] {
  63         &self.inner
  64     }
  65 }
  66
  67 impl Buf {
  68     pub fn from_string(s: String) -> Buf {
  69         Buf { inner: s.into_bytes() }
  70     }
  71
  72     #[inline]
  73     pub fn with_capacity(capacity: usize) -> Buf {
  74         Buf { inner: Vec::with_capacity(capacity) }
  75     }
  76
  77     #[inline]
  78     pub fn clear(&mut self) {
  79         self.inner.clear()
  80     }
  81
  82     #[inline]
  83     pub fn capacity(&self) -> usize {
  84         self.inner.capacity()
  85     }
  86
  87     #[inline]
  88     pub fn reserve(&mut self, additional: usize) {
  89         self.inner.reserve(additional)
  90     }
  91
  92     #[inline]
  93     pub fn reserve_exact(&mut self, additional: usize) {
  94         self.inner.reserve_exact(additional)
  95     }
  96
  97     #[inline]
  98     pub fn shrink_to_fit(&mut self) {
  99         self.inner.shrink_to_fit()
 100     }
 101
 102     #[inline]
 103     pub fn shrink_to(&mut self, min_capacity: usize) {
 104         self.inner.shrink_to(min_capacity)
 105     }
 106
 107     pub fn as_slice(&self) -> &Slice {
 108         unsafe { mem::transmute(&*self.inner) }
 109     }
 110
 111     pub fn into_string(self) -> Result<String, Buf> {
 112         String::from_utf8(self.inner).map_err(|p| Buf { inner: p.into_bytes() })
 113     }
 114
 115     pub fn push_slice(&mut self, s: &Slice) {
 116         self.inner.extend_from_slice(&s.inner)
 117     }
 118
 119     #[inline]
 120     pub fn into_box(self) -> Box<Slice> {
 121         unsafe { mem::transmute(self.inner.into_boxed_slice()) }
 122     }
 123
 124     #[inline]
 125     pub fn from_box(boxed: Box<Slice>) -> Buf {
 126         let inner: Box<[u8]> = unsafe { mem::transmute(boxed) };
 127         Buf { inner: inner.into_vec() }
 128     }
 129
 130     #[inline]
 131     pub fn into_arc(&self) -> Arc<Slice> {
 132         self.as_slice().into_arc()
 133     }
 134
 135     #[inline]
 136     pub fn into_rc(&self) -> Rc<Slice> {
 137         self.as_slice().into_rc()
 138     }
 139 }
 140
 141 impl Slice {
 142     #[inline]
 143     fn from_u8_slice(s: &[u8]) -> &Slice {
 144         unsafe { mem::transmute(s) }
 145     }
 146
 147     #[inline]
 148     pub fn from_str(s: &str) -> &Slice {
 149         Slice::from_u8_slice(s.as_bytes())
 150     }
 151
 152     pub fn to_str(&self) -> Option<&str> {
 153         str::from_utf8(&self.inner).ok()
 154     }
 155
 156     pub fn to_string_lossy(&self) -> Cow<'_, str> {
 157         String::from_utf8_lossy(&self.inner)
 158     }
 159
 160     pub fn to_owned(&self) -> Buf {
 161         Buf { inner: self.inner.to_vec() }
 162     }
 163
 164     #[inline]
 165     pub fn into_box(&self) -> Box<Slice> {
 166         let boxed: Box<[u8]> = self.inner.into();
 167         unsafe { mem::transmute(boxed) }
 168     }
 169
 170     pub fn empty_box() -> Box<Slice> {
 171         let boxed: Box<[u8]> = Default::default();
 172         unsafe { mem::transmute(boxed) }
 173     }
 174
 175     #[inline]
 176     pub fn into_arc(&self) -> Arc<Slice> {
 177         let arc: Arc<[u8]> = Arc::from(&self.inner);
 178         unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Slice) }
 179     }
 180
 181     #[inline]
 182     pub fn into_rc(&self) -> Rc<Slice> {
 183         let rc: Rc<[u8]> = Rc::from(&self.inner);
 184         unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Slice) }
 185     }
 186 }
 187
 188 /// Platform-specific extensions to [`OsString`].
 189 ///
 190 /// [`OsString`]: ../../../../std/ffi/struct.OsString.html
 191 #[stable(feature = "rust1", since = "1.0.0")]
 192 pub trait OsStringExt {
 193     /// Creates an [`OsString`] from a byte vector.
 194     ///
 195     /// See the module documentation for an example.
 196     ///
 197     /// [`OsString`]: ../../../ffi/struct.OsString.html
 198     #[stable(feature = "rust1", since = "1.0.0")]
 199     fn from_vec(vec: Vec<u8>) -> Self;
 200
 201     /// Yields the underlying byte vector of this [`OsString`].
 202     ///
 203     /// See the module documentation for an example.
 204     ///
 205     /// [`OsString`]: ../../../ffi/struct.OsString.html
 206     #[stable(feature = "rust1", since = "1.0.0")]
 207     fn into_vec(self) -> Vec<u8>;
 208 }
 209
 210 #[stable(feature = "rust1", since = "1.0.0")]
 211 impl OsStringExt for OsString {
 212     fn from_vec(vec: Vec<u8>) -> OsString {
 213         FromInner::from_inner(Buf { inner: vec })
 214     }
 215     fn into_vec(self) -> Vec<u8> {
 216         self.into_inner().inner
 217     }
 218 }
 219
 220 /// Platform-specific extensions to [`OsStr`].
 221 ///
 222 /// [`OsStr`]: ../../../../std/ffi/struct.OsStr.html
 223 #[stable(feature = "rust1", since = "1.0.0")]
 224 pub trait OsStrExt {
 225     #[stable(feature = "rust1", since = "1.0.0")]
 226     /// Creates an [`OsStr`] from a byte slice.
 227     ///
 228     /// See the module documentation for an example.
 229     ///
 230     /// [`OsStr`]: ../../../ffi/struct.OsStr.html
 231     fn from_bytes(slice: &[u8]) -> &Self;
 232
 233     /// Gets the underlying byte view of the [`OsStr`] slice.
 234     ///
 235     /// See the module documentation for an example.
 236     ///
 237     /// [`OsStr`]: ../../../ffi/struct.OsStr.html
 238     #[stable(feature = "rust1", since = "1.0.0")]
 239     fn as_bytes(&self) -> &[u8];
 240 }
 241
 242 #[stable(feature = "rust1", since = "1.0.0")]
 243 impl OsStrExt for OsStr {
 244     #[inline]
 245     fn from_bytes(slice: &[u8]) -> &OsStr {
 246         unsafe { mem::transmute(slice) }
 247     }
 248     #[inline]
 249     fn as_bytes(&self) -> &[u8] {
 250         &self.as_inner().inner
 251     }
 252 }