Unify OsString/OsStr for byte-based implementations

1 files changed, 245 insertions, 0 deletions

diff --git a/src/libstd/sys_common/os_str_bytes.rs b/src/libstd/sys_common/os_str_bytes.rs
new file mode 100644
index 00000000000..5a9235a608c
--- /dev/null
+++ b/src/libstd/sys_common/os_str_bytes.rs
@@ -0,0 +1,245 @@
+//! The underlying OsString/OsStr implementation on Unix and many other
+//! systems: just a `Vec<u8>`/`[u8]`.
+
+use crate::borrow::Cow;
+use crate::ffi::{OsStr, OsString};
+use crate::fmt;
+use crate::str;
+use crate::mem;
+use crate::rc::Rc;
+use crate::sync::Arc;
+use crate::sys_common::{FromInner, IntoInner, AsInner};
+use crate::sys_common::bytestring::debug_fmt_bytestring;
+
+use core::str::lossy::Utf8Lossy;
+
+#[derive(Clone, Hash)]
+pub(crate) struct Buf {
+    pub inner: Vec<u8>
+}
+
+pub(crate) struct Slice {
+    pub inner: [u8]
+}
+
+impl fmt::Debug for Slice {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        debug_fmt_bytestring(&self.inner, formatter)
+    }
+}
+
+impl fmt::Display for Slice {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Display::fmt(&Utf8Lossy::from_bytes(&self.inner), formatter)
+    }
+}
+
+impl fmt::Debug for Buf {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Debug::fmt(self.as_slice(), formatter)
+    }
+}
+
+impl fmt::Display for Buf {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Display::fmt(self.as_slice(), formatter)
+    }
+}
+
+impl IntoInner<Vec<u8>> for Buf {
+    fn into_inner(self) -> Vec<u8> {
+        self.inner
+    }
+}
+
+impl AsInner<[u8]> for Buf {
+    fn as_inner(&self) -> &[u8] {
+        &self.inner
+    }
+}
+
+
+impl Buf {
+    pub fn from_string(s: String) -> Buf {
+        Buf { inner: s.into_bytes() }
+    }
+
+    #[inline]
+    pub fn with_capacity(capacity: usize) -> Buf {
+        Buf {
+            inner: Vec::with_capacity(capacity)
+        }
+    }
+
+    #[inline]
+    pub fn clear(&mut self) {
+        self.inner.clear()
+    }
+
+    #[inline]
+    pub fn capacity(&self) -> usize {
+        self.inner.capacity()
+    }
+
+    #[inline]
+    pub fn reserve(&mut self, additional: usize) {
+        self.inner.reserve(additional)
+    }
+
+    #[inline]
+    pub fn reserve_exact(&mut self, additional: usize) {
+        self.inner.reserve_exact(additional)
+    }
+
+    #[inline]
+    pub fn shrink_to_fit(&mut self) {
+        self.inner.shrink_to_fit()
+    }
+
+    #[inline]
+    pub fn shrink_to(&mut self, min_capacity: usize) {
+        self.inner.shrink_to(min_capacity)
+    }
+
+    pub fn as_slice(&self) -> &Slice {
+        unsafe { mem::transmute(&*self.inner) }
+    }
+
+    pub fn into_string(self) -> Result<String, Buf> {
+        String::from_utf8(self.inner).map_err(|p| Buf { inner: p.into_bytes() } )
+    }
+
+    pub fn push_slice(&mut self, s: &Slice) {
+        self.inner.extend_from_slice(&s.inner)
+    }
+
+    #[inline]
+    pub fn into_box(self) -> Box<Slice> {
+        unsafe { mem::transmute(self.inner.into_boxed_slice()) }
+    }
+
+    #[inline]
+    pub fn from_box(boxed: Box<Slice>) -> Buf {
+        let inner: Box<[u8]> = unsafe { mem::transmute(boxed) };
+        Buf { inner: inner.into_vec() }
+    }
+
+    #[inline]
+    pub fn into_arc(&self) -> Arc<Slice> {
+        self.as_slice().into_arc()
+    }
+
+    #[inline]
+    pub fn into_rc(&self) -> Rc<Slice> {
+        self.as_slice().into_rc()
+    }
+}
+
+impl Slice {
+    fn from_u8_slice(s: &[u8]) -> &Slice {
+        unsafe { mem::transmute(s) }
+    }
+
+    pub fn from_str(s: &str) -> &Slice {
+        Slice::from_u8_slice(s.as_bytes())
+    }
+
+    pub fn to_str(&self) -> Option<&str> {
+        str::from_utf8(&self.inner).ok()
+    }
+
+    pub fn to_string_lossy(&self) -> Cow<str> {
+        String::from_utf8_lossy(&self.inner)
+    }
+
+    pub fn to_owned(&self) -> Buf {
+        Buf { inner: self.inner.to_vec() }
+    }
+
+    #[inline]
+    pub fn into_box(&self) -> Box<Slice> {
+        let boxed: Box<[u8]> = self.inner.into();
+        unsafe { mem::transmute(boxed) }
+    }
+
+    pub fn empty_box() -> Box<Slice> {
+        let boxed: Box<[u8]> = Default::default();
+        unsafe { mem::transmute(boxed) }
+    }
+
+    #[inline]
+    pub fn into_arc(&self) -> Arc<Slice> {
+        let arc: Arc<[u8]> = Arc::from(&self.inner);
+        unsafe { Arc::from_raw(Arc::into_raw(arc) as *const Slice) }
+    }
+
+    #[inline]
+    pub fn into_rc(&self) -> Rc<Slice> {
+        let rc: Rc<[u8]> = Rc::from(&self.inner);
+        unsafe { Rc::from_raw(Rc::into_raw(rc) as *const Slice) }
+    }
+}
+
+/// Platform-specific extensions to [`OsString`].
+///
+/// [`OsString`]: ../../../../std/ffi/struct.OsString.html
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait OsStringExt {
+    /// Creates an [`OsString`] from a byte vector.
+    ///
+    /// See the module docmentation for an example.
+    ///
+    /// [`OsString`]: ../../../ffi/struct.OsString.html
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn from_vec(vec: Vec<u8>) -> Self;
+
+    /// Yields the underlying byte vector of this [`OsString`].
+    ///
+    /// See the module docmentation for an example.
+    ///
+    /// [`OsString`]: ../../../ffi/struct.OsString.html
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn into_vec(self) -> Vec<u8>;
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl OsStringExt for OsString {
+    fn from_vec(vec: Vec<u8>) -> OsString {
+        FromInner::from_inner(Buf { inner: vec })
+    }
+    fn into_vec(self) -> Vec<u8> {
+        self.into_inner().inner
+    }
+}
+
+/// Platform-specific extensions to [`OsStr`].
+///
+/// [`OsStr`]: ../../../../std/ffi/struct.OsStr.html
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait OsStrExt {
+    #[stable(feature = "rust1", since = "1.0.0")]
+    /// Creates an [`OsStr`] from a byte slice.
+    ///
+    /// See the module docmentation for an example.
+    ///
+    /// [`OsStr`]: ../../../ffi/struct.OsStr.html
+    fn from_bytes(slice: &[u8]) -> &Self;
+
+    /// Gets the underlying byte view of the [`OsStr`] slice.
+    ///
+    /// See the module docmentation for an example.
+    ///
+    /// [`OsStr`]: ../../../ffi/struct.OsStr.html
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn as_bytes(&self) -> &[u8];
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl OsStrExt for OsStr {
+    fn from_bytes(slice: &[u8]) -> &OsStr {
+        unsafe { mem::transmute(slice) }
+    }
+    fn as_bytes(&self) -> &[u8] {
+        &self.as_inner().inner
+    }
+}