blonkus/source/util/ffi.rs

use std::{ffi::CString, os::raw::c_char, ptr::null};

/// Creates a C string from a literal.
#[macro_export]
macro_rules! c_str {
	($s:expr) => {
		std::concat!($s, "\0").as_ptr() as *const std::os::raw::c_char
	};
}

/// An owned null-terminated string vector.
#[derive(Debug)]
pub struct CStringVec {
	sv: Vec<CString>,
	cv: Vec<*const c_char>,
}

impl Default for CStringVec {
	/// Creates a new empty CStringVec.
	#[inline]
	fn default() -> Self {
		Self { sv: Vec::new(), cv: vec![null()] }
	}
}

#[allow(dead_code)]
impl CStringVec {
	/// Creates a new `CStringVec` from an iterator.
	#[inline]
	pub fn new_from_iter<'a, I>(it: I) -> Result<Self, std::ffi::NulError>
	where
		I: Iterator<Item = &'a str>,
	{
		let mut v = Self::default();

		for st in it {
			v.push(CString::new(st)?);
		}

		Ok(v)
	}

	/// Pushes a new `CString`.
	#[inline]
	pub fn push(&mut self, st: CString) {
		self.cv.insert(self.cv.len() - 1, st.as_ptr());
		self.sv.push(st);
	}

	/// Returns the FFI pointer.
	#[inline]
	pub fn as_ptr(&self) -> *const *const c_char {
		self.cv.as_ptr()
	}

	/// Returns the FFI pointer mutably.
	#[inline]
	pub fn as_mut_ptr(&mut self) -> *mut *const c_char {
		self.cv.as_mut_ptr()
	}

	/// Returns the length of the vector.
	#[inline]
	pub fn len(&self) -> usize {
		self.sv.len()
	}
}

// EOF