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//! Shared utility helpers for platform interop.
#[cfg(windows)]
pub mod win {
use std::os::windows::ffi::OsStrExt;
use windows::core::PWSTR;
use windows::Win32::Foundation::{CloseHandle, HANDLE};
use windows::Win32::Security::{FreeSid, PSID};
#[link(name = "Kernel32")]
unsafe extern "system" {
fn LocalFree(h: isize) -> isize;
}
/// Converts a Rust string into a null-terminated UTF-16 buffer.
pub fn to_utf16(s: &str) -> Vec<u16> {
std::ffi::OsStr::new(s)
.encode_wide()
.chain(std::iter::once(0))
.collect()
}
/// Converts a platform string (OsStr) into a null-terminated UTF-16 buffer.
pub fn to_utf16_os(s: &std::ffi::OsStr) -> Vec<u16> {
s.encode_wide().chain(std::iter::once(0)).collect()
}
/// Owned Win32 `HANDLE` that closes on drop.
#[derive(Debug)]
pub struct OwnedHandle(pub(crate) HANDLE);
impl Drop for OwnedHandle {
fn drop(&mut self) {
unsafe {
let _ = CloseHandle(self.0);
}
}
}
impl OwnedHandle {
pub fn as_raw(&self) -> HANDLE {
self.0
}
/// Constructs an `OwnedHandle` from a raw Win32 `HANDLE`.
///
/// # Safety
/// Caller must ensure `handle` is a valid, live HANDLE that is uniquely
/// owned and must be closed exactly once. After calling this, the guard
/// will close it on drop. Do not use the handle elsewhere after passing it here.
pub unsafe fn from_raw(handle: HANDLE) -> Self {
Self(handle)
}
pub fn into_file(self) -> std::fs::File {
use std::os::windows::io::FromRawHandle;
let handle = self.0;
// Prevent Drop from closing the handle twice
std::mem::forget(self);
// SAFETY: transfer ownership of the HANDLE to a File
unsafe { std::fs::File::from_raw_handle(handle.0 as *mut _) }
}
}
/// RAII guard that frees allocations with `LocalFree` when dropped.
#[derive(Debug)]
pub struct LocalFreeGuard<T> {
ptr: *mut T,
}
impl<T> LocalFreeGuard<T> {
/// Creates a new guard from a raw pointer returned by Win32.
///
/// # Safety
/// The pointer must have been allocated by a Win32 API that requires
/// `LocalFree` for release and must be valid for the lifetime of the guard.
/// Do not pass stack or heap pointers that are not `LocalAlloc`-managed.
pub unsafe fn new(ptr: *mut T) -> Self {
Self { ptr }
}
pub fn as_ptr(&self) -> *mut T {
self.ptr
}
pub fn is_null(&self) -> bool {
self.ptr.is_null()
}
/// Releases ownership without freeing.
pub fn into_raw(mut self) -> *mut T {
let ptr = self.ptr;
self.ptr = std::ptr::null_mut();
ptr
}
}
impl<T> Drop for LocalFreeGuard<T> {
fn drop(&mut self) {
if !self.ptr.is_null() {
unsafe {
let _ = LocalFree(self.ptr as isize);
}
self.ptr = std::ptr::null_mut();
}
}
}
impl LocalFreeGuard<u16> {
/// Converts the guarded wide string into UTF-8 (without trailing null).
///
/// # Safety
/// The guarded pointer must reference a valid, NUL-terminated UTF-16
/// buffer allocated by a Win32 API compatible with `LocalFree`.
#[allow(unsafe_op_in_unsafe_fn)]
pub unsafe fn to_string_lossy(&self) -> String {
if self.ptr.is_null() {
return String::new();
}
let mut len = 0usize;
while unsafe { *self.ptr.add(len) } != 0 {
len += 1;
}
let slice = unsafe { std::slice::from_raw_parts(self.ptr, len) };
String::from_utf16_lossy(slice)
}
pub fn as_pwstr(&self) -> PWSTR {
PWSTR(self.ptr)
}
}
/// RAII guard that releases a `PSID` via `FreeSid` on drop.
#[derive(Debug)]
pub struct FreeSidGuard {
psid: PSID,
}
impl FreeSidGuard {
/// Creates a guard that will call `FreeSid` on drop.
///
/// # Safety
/// `psid` must be a valid, heap-allocated SID returned by APIs that
/// require `FreeSid` for release. Do not pass borrowed or invalid pointers.
pub unsafe fn new(psid: PSID) -> Self {
Self { psid }
}
pub fn as_psid(&self) -> PSID {
self.psid
}
pub fn into_raw(mut self) -> PSID {
let psid = self.psid;
self.psid = PSID::default();
psid
}
}
impl Drop for FreeSidGuard {
fn drop(&mut self) {
if !self.psid.0.is_null() {
unsafe {
let _ = FreeSid(self.psid);
}
self.psid = PSID::default();
}
}
}
}
#[cfg(not(windows))]
pub mod win {
/// Non-Windows stub conversion; returns an empty buffer.
pub fn to_utf16(_s: &str) -> Vec<u16> {
Vec::new()
}
pub fn to_utf16_os(_s: &std::ffi::OsStr) -> Vec<u16> {
Vec::new()
}
}
#[cfg(not(windows))]
pub use win::to_utf16;
#[cfg(not(windows))]
pub use win::to_utf16_os;
#[cfg(windows)]
pub use win::{to_utf16, to_utf16_os, FreeSidGuard, LocalFreeGuard, OwnedHandle};