embedded-ffi 0.1.2

//! The underlying OsString/OsStr implementation on Unix and many other
//! systems: just a `Vec<u8>`/`[u8]`.
#[cfg(feature = "alloc")]
use alloc::borrow::Cow;
#[cfg(feature = "alloc")]
use alloc::boxed::Box;
#[cfg(feature = "alloc")]
use alloc::rc::Rc;
#[cfg(feature = "alloc")]
use alloc::string::String;
#[cfg(feature = "alloc")]
use core::mem;
#[cfg(feature = "alloc")]
use alloc::sync::Arc;
use core::fmt;
use core::str;

use crate::lossy::Utf8Lossy;
use crate::os_str::OsStr;
use crate::sys_common::AsInner;
use crate::sys_common::bytestring::debug_fmt_bytestring;

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)
	}
}

#[cfg(feature = "alloc")]
pub mod inner_alloc {
	use alloc::boxed::Box;
	use alloc::rc::Rc;
	use alloc::string::String;
	use alloc::sync::Arc;
	use alloc::vec::Vec;
	use core::fmt;
	use core::mem;

	use crate::os_str::OsString;
	use crate::sys_common::{AsInner, FromInner, IntoInner};

	use super::Slice;

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

	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 { &*(&*self.inner as *const [u8] as *const _) }
		}

		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()
		}
	}

	/// Platform-specific extensions to [`OsString`].
	///
	/// [`OsString`]: ../../../../std/ffi/struct.OsString.html
	pub trait OsStringExt {
		/// Creates an [`OsString`] from a byte vector.
		///
		/// See the module docmentation for an example.
		///
		/// [`OsString`]: ../../../ffi/struct.OsString.html
		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
		fn into_vec(self) -> Vec<u8>;
	}

	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
		}
	}
}

impl Slice {
	fn from_u8_slice(s: &[u8]) -> &Slice {
		unsafe { &*(s as *const [u8] as *const _) }
	}

	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()
	}

	#[cfg(feature = "alloc")]
	pub fn to_string_lossy(&self) -> Cow<'_, str> {
		String::from_utf8_lossy(&self.inner)
	}

	#[cfg(feature = "alloc")]
	pub fn to_owned(&self) -> self::inner_alloc::Buf {
		self::inner_alloc::Buf {
			inner: self.inner.to_vec(),
		}
	}

	#[cfg(feature = "alloc")]
	#[inline]
	pub fn into_box(&self) -> Box<Slice> {
		let boxed: Box<[u8]> = self.inner.into();
		unsafe { mem::transmute(boxed) }
	}

	#[cfg(feature = "alloc")]
	pub fn empty_box() -> Box<Slice> {
		let boxed: Box<[u8]> = Default::default();
		unsafe { mem::transmute(boxed) }
	}

	#[cfg(feature = "alloc")]
	#[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) }
	}

	#[cfg(feature = "alloc")]
	#[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 [`OsStr`].
///
/// [`OsStr`]: ../../../../std/ffi/struct.OsStr.html
pub trait OsStrExt {
	/// 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
	fn as_bytes(&self) -> &[u8];
}

impl OsStrExt for OsStr {
	#[inline]
	fn from_bytes(slice: &[u8]) -> &OsStr {
		unsafe { &*(slice as *const [u8] as *const _) }
	}
	#[inline]
	fn as_bytes(&self) -> &[u8] {
		&self.as_inner().inner
	}
}