os_str_bytes.rs.html -- source
Description: Source to the Rust file `src/libstd/sys_common/os_str_bytes.rs`.
Keywords: rust, rustlang, rust-lang

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    //! 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::mem;
    use crate::rc::Rc;
    use crate::str;
    use crate::sync::Arc;
    use crate::sys_common::bytestring::debug_fmt_bytestring;
    use crate::sys_common::{AsInner, FromInner, IntoInner};

    use core::str::lossy::Utf8Lossy;

    #[derive(Clone, Hash)]
    pub(crate) struct Buf {
        pub inner: Vec<u8>,
    }

    // FIXME:
    // `Buf::as_slice` current implementation relies
    // on `Slice` being layout-compatible with `[u8]`.
    // When attribute privacy is implemented, `Slice` should be annotated as `#[repr(transparent)]`.
    // Anyway, `Slice` representation and layout are considered implementation detail, are
    // not documented and must not be relied upon.
    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)
        }

        #[inline]
        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 {
        #[inline]
        fn from_u8_slice(s: &[u8]) -> &Slice {
            unsafe { mem::transmute(s) }
        }

        #[inline]
        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 documentation 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 documentation 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 documentation 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 documentation 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 {
        #[inline]
        fn from_bytes(slice: &[u8]) -> &OsStr {
            unsafe { mem::transmute(slice) }
        }
        #[inline]
        fn as_bytes(&self) -> &[u8] {
            &self.as_inner().inner
        }
    }