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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
pub use std::ffi::CString;
use std::ffi::OsStr;
use std::os::windows::ffi::OsStrExt;
/// Windows wide strings.
///
/// These are utf16 encoded with a terminating nul character (0).
#[derive(Debug)]
pub struct WideString(Vec<u16>);
/// An error indicating that an interior nul byte was found.
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct NulError(usize, Vec<u16>);
impl std::fmt::Display for NulError {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(f, "nul byte found in provided data at position: {}", self.0)
}
}
impl std::error::Error for NulError {}
impl WideString {
pub fn new(os_str: impl AsRef<OsStr>) -> Result<Self, NulError> {
let mut v: Vec<u16> = os_str.as_ref().encode_wide().collect();
if let Some(p) = v.iter().position(|c| *c == 0) {
Err(NulError(p, v))
} else {
v.push(0);
Ok(WideString(v))
}
}
pub fn pcwstr(&self) -> windows_sys::core::PCWSTR {
self.0.as_ptr()
}
}
/// Iterator over wide characters in a wide string.
///
/// This is useful for wide string constants.
#[derive(Debug)]
pub struct FfiWideCharIterator(*const u16);
impl FfiWideCharIterator {
pub fn new(ptr: *const u16) -> Self {
FfiWideCharIterator(ptr)
}
}
impl Iterator for FfiWideCharIterator {
type Item = u16;
fn next(&mut self) -> Option<Self::Item> {
let c = unsafe { self.0.read() };
if c == 0 {
None
} else {
self.0 = unsafe { self.0.add(1) };
Some(c)
}
}
}
/// Convert a utf16 ptr to an ascii CString.
pub fn utf16_ptr_to_ascii(ptr: *const u16) -> Option<CString> {
char::decode_utf16(FfiWideCharIterator::new(ptr))
// Using try_into() accepts extended ascii as well; we don't care much about the
// distinction here, it'll still be a valid conversion.
.map(|res| res.ok().and_then(|c| c.try_into().ok()))
.collect::<Option<Vec<_>>>()
.map(CString::new)
.and_then(|res| {
if res.is_err() {
log::error!("FfiWideCharIterator provided nul character");
}
res.ok()
})
}