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::str;
   8 use crate::mem;
   9 use crate::rc::Rc;
  10 use crate::sync::Arc;
  11 use crate::sys_common::{FromInner, IntoInner, AsInner};
  12 use crate::sys_common::bytestring::debug_fmt_bytestring;
  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
  68 impl Buf {
  69     pub fn from_string(s: String) -> Buf {
  70         Buf { inner: s.into_bytes() }
  71     }
  72
  73     #[inline]
  74     pub fn with_capacity(capacity: usize) -> Buf {
  75         Buf {
  76             inner: Vec::with_capacity(capacity)
  77         }
  78     }
  79
  80     #[inline]
  81     pub fn clear(&mut self) {
  82         self.inner.clear()
  83     }
  84
  85     #[inline]
  86     pub fn capacity(&self) -> usize {
  87         self.inner.capacity()
  88     }
  89
  90     #[inline]
  91     pub fn reserve(&mut self, additional: usize) {
  92         self.inner.reserve(additional)
  93     }
  94
  95     #[inline]
  96     pub fn reserve_exact(&mut self, additional: usize) {
  97         self.inner.reserve_exact(additional)
  98     }
  99
 100     #[inline]
 101     pub fn shrink_to_fit(&mut self) {
 102         self.inner.shrink_to_fit()
 103     }
 104
 105     #[inline]
 106     pub fn shrink_to(&mut self, min_capacity: usize) {
 107         self.inner.shrink_to(min_capacity)
 108     }
 109
 110     pub fn as_slice(&self) -> &Slice {
 111         unsafe { mem::transmute(&*self.inner) }
 112     }
 113
 114     pub fn into_string(self) -> Result<String, Buf> {
 115         String::from_utf8(self.inner).map_err(|p| Buf { inner: p.into_bytes() } )
 116     }
 117
 118     pub fn push_slice(&mut self, s: &Slice) {
 119         self.inner.extend_from_slice(&s.inner)
 120     }
 121
 122     #[inline]
 123     pub fn into_box(self) -> Box<Slice> {
 124         unsafe { mem::transmute(self.inner.into_boxed_slice()) }
 125     }
 126
 127     #[inline]
 128     pub fn from_box(boxed: Box<Slice>) -> Buf {
 129         let inner: Box<[u8]> = unsafe { mem::transmute(boxed) };
 130         Buf { inner: inner.into_vec() }
 131     }
 132
 133     #[inline]
 134     pub fn into_arc(&self) -> Arc<Slice> {
 135         self.as_slice().into_arc()
 136     }
 137
 138     #[inline]
 139     pub fn into_rc(&self) -> Rc<Slice> {
 140         self.as_slice().into_rc()
 141     }
 142 }
 143
 144 impl Slice {
 145     fn from_u8_slice(s: &[u8]) -> &Slice {
 146         unsafe { mem::transmute(s) }
 147     }
 148
 149     pub fn from_str(s: &str) -> &Slice {
 150         Slice::from_u8_slice(s.as_bytes())
 151     }
 152
 153     pub fn to_str(&self) -> Option<&str> {
 154         str::from_utf8(&self.inner).ok()
 155     }
 156
 157     pub fn to_string_lossy(&self) -> Cow<'_, str> {
 158         String::from_utf8_lossy(&self.inner)
 159     }
 160
 161     pub fn to_owned(&self) -> Buf {
 162         Buf { inner: self.inner.to_vec() }
 163     }
 164
 165     #[inline]
 166     pub fn into_box(&self) -> Box<Slice> {
 167         let boxed: Box<[u8]> = self.inner.into();
 168         unsafe { mem::transmute(boxed) }
 169     }
 170
 171     pub fn empty_box() -> Box<Slice> {
 172         let boxed: Box<[u8]> = Default::default();
 173         unsafe { mem::transmute(boxed) }
 174     }
 175
 176     #[inline]
 177     pub fn into_arc(&self) -> Arc<Slice> {
 178         let arc: Arc<[u8]> = Arc::from(&self.inner);
 179         unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Slice) }
 180     }
 181
 182     #[inline]
 183     pub fn into_rc(&self) -> Rc<Slice> {
 184         let rc: Rc<[u8]> = Rc::from(&self.inner);
 185         unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Slice) }
 186     }
 187 }
 188
 189 /// Platform-specific extensions to [`OsString`].
 190 ///
 191 /// [`OsString`]: ../../../../std/ffi/struct.OsString.html
 192 #[stable(feature = "rust1", since = "1.0.0")]
 193 pub trait OsStringExt {
 194     /// Creates an [`OsString`] from a byte vector.
 195     ///
 196     /// See the module documentation for an example.
 197     ///
 198     /// [`OsString`]: ../../../ffi/struct.OsString.html
 199     #[stable(feature = "rust1", since = "1.0.0")]
 200     fn from_vec(vec: Vec<u8>) -> Self;
 201
 202     /// Yields the underlying byte vector of this [`OsString`].
 203     ///
 204     /// See the module documentation for an example.
 205     ///
 206     /// [`OsString`]: ../../../ffi/struct.OsString.html
 207     #[stable(feature = "rust1", since = "1.0.0")]
 208     fn into_vec(self) -> Vec<u8>;
 209 }
 210
 211 #[stable(feature = "rust1", since = "1.0.0")]
 212 impl OsStringExt for OsString {
 213     fn from_vec(vec: Vec<u8>) -> OsString {
 214         FromInner::from_inner(Buf { inner: vec })
 215     }
 216     fn into_vec(self) -> Vec<u8> {
 217         self.into_inner().inner
 218     }
 219 }
 220
 221 /// Platform-specific extensions to [`OsStr`].
 222 ///
 223 /// [`OsStr`]: ../../../../std/ffi/struct.OsStr.html
 224 #[stable(feature = "rust1", since = "1.0.0")]
 225 pub trait OsStrExt {
 226     #[stable(feature = "rust1", since = "1.0.0")]
 227     /// Creates an [`OsStr`] from a byte slice.
 228     ///
 229     /// See the module documentation for an example.
 230     ///
 231     /// [`OsStr`]: ../../../ffi/struct.OsStr.html
 232     fn from_bytes(slice: &[u8]) -> &Self;
 233
 234     /// Gets the underlying byte view of the [`OsStr`] slice.
 235     ///
 236     /// See the module documentation for an example.
 237     ///
 238     /// [`OsStr`]: ../../../ffi/struct.OsStr.html
 239     #[stable(feature = "rust1", since = "1.0.0")]
 240     fn as_bytes(&self) -> &[u8];
 241 }
 242
 243 #[stable(feature = "rust1", since = "1.0.0")]
 244 impl OsStrExt for OsStr {
 245     #[inline]
 246     fn from_bytes(slice: &[u8]) -> &OsStr {
 247         unsafe { mem::transmute(slice) }
 248     }
 249     #[inline]
 250     fn as_bytes(&self) -> &[u8] {
 251         &self.as_inner().inner
 252     }
 253 }