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-rw-r--r--third_party/rust/windows-core/src/strings/hstring.rs458
1 files changed, 458 insertions, 0 deletions
diff --git a/third_party/rust/windows-core/src/strings/hstring.rs b/third_party/rust/windows-core/src/strings/hstring.rs
new file mode 100644
index 0000000000..a0a7f59fab
--- /dev/null
+++ b/third_party/rust/windows-core/src/strings/hstring.rs
@@ -0,0 +1,458 @@
+use super::*;
+
+/// A WinRT string ([HSTRING](https://docs.microsoft.com/en-us/windows/win32/winrt/hstring))
+/// is reference-counted and immutable.
+#[repr(transparent)]
+pub struct HSTRING(Option<std::ptr::NonNull<Header>>);
+
+impl HSTRING {
+ /// Create an empty `HSTRING`.
+ ///
+ /// This function does not allocate memory.
+ pub const fn new() -> Self {
+ Self(None)
+ }
+
+ /// Returns `true` if the string is empty.
+ pub const fn is_empty(&self) -> bool {
+ // An empty HSTRING is represented by a null pointer.
+ self.0.is_none()
+ }
+
+ /// Returns the length of the string.
+ pub fn len(&self) -> usize {
+ if let Some(header) = self.get_header() {
+ header.len as usize
+ } else {
+ 0
+ }
+ }
+
+ /// Get the string as 16-bit wide characters (wchars).
+ pub fn as_wide(&self) -> &[u16] {
+ unsafe { std::slice::from_raw_parts(self.as_ptr(), self.len()) }
+ }
+
+ /// Returns a raw pointer to the `HSTRING` buffer.
+ pub fn as_ptr(&self) -> *const u16 {
+ if let Some(header) = self.get_header() {
+ header.data
+ } else {
+ const EMPTY: [u16; 1] = [0];
+ EMPTY.as_ptr()
+ }
+ }
+
+ /// Create a `HSTRING` from a slice of 16 bit characters (wchars).
+ pub fn from_wide(value: &[u16]) -> Result<Self> {
+ unsafe { Self::from_wide_iter(value.iter().copied(), value.len()) }
+ }
+
+ /// Get the contents of this `HSTRING` as a String lossily.
+ pub fn to_string_lossy(&self) -> std::string::String {
+ std::string::String::from_utf16_lossy(self.as_wide())
+ }
+
+ /// Get the contents of this `HSTRING` as a OsString.
+ #[cfg(windows)]
+ pub fn to_os_string(&self) -> std::ffi::OsString {
+ std::os::windows::ffi::OsStringExt::from_wide(self.as_wide())
+ }
+
+ /// # Safety
+ /// len must not be less than the number of items in the iterator.
+ unsafe fn from_wide_iter<I: Iterator<Item = u16>>(iter: I, len: usize) -> Result<Self> {
+ if len == 0 {
+ return Ok(Self::new());
+ }
+
+ let ptr = Header::alloc(len.try_into()?)?;
+
+ // Place each utf-16 character into the buffer and
+ // increase len as we go along.
+ for (index, wide) in iter.enumerate() {
+ debug_assert!(index < len);
+
+ std::ptr::write((*ptr).data.add(index), wide);
+ (*ptr).len = index as u32 + 1;
+ }
+
+ // Write a 0 byte to the end of the buffer.
+ std::ptr::write((*ptr).data.offset((*ptr).len as isize), 0);
+ Ok(Self(std::ptr::NonNull::new(ptr)))
+ }
+
+ fn get_header(&self) -> Option<&Header> {
+ if let Some(header) = &self.0 {
+ unsafe { Some(header.as_ref()) }
+ } else {
+ None
+ }
+ }
+}
+
+impl RuntimeType for HSTRING {
+ const SIGNATURE: crate::imp::ConstBuffer = crate::imp::ConstBuffer::from_slice(b"string");
+}
+
+impl TypeKind for HSTRING {
+ type TypeKind = ValueType;
+}
+
+impl Default for HSTRING {
+ fn default() -> Self {
+ Self::new()
+ }
+}
+
+impl Clone for HSTRING {
+ fn clone(&self) -> Self {
+ if let Some(header) = self.get_header() {
+ Self(std::ptr::NonNull::new(header.duplicate().unwrap()))
+ } else {
+ Self::new()
+ }
+ }
+}
+
+impl Drop for HSTRING {
+ fn drop(&mut self) {
+ if self.is_empty() {
+ return;
+ }
+
+ if let Some(header) = self.0.take() {
+ // REFERENCE_FLAG indicates a string backed by static or stack memory that is
+ // thus not reference-counted and does not need to be freed.
+ unsafe {
+ let header = header.as_ref();
+ if header.flags & REFERENCE_FLAG == 0 && header.count.release() == 0 {
+ crate::imp::heap_free(header as *const _ as *mut _);
+ }
+ }
+ }
+ }
+}
+
+unsafe impl Send for HSTRING {}
+unsafe impl Sync for HSTRING {}
+
+impl std::fmt::Display for HSTRING {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+ write!(f, "{}", Decode(|| std::char::decode_utf16(self.as_wide().iter().cloned())))
+ }
+}
+
+impl std::fmt::Debug for HSTRING {
+ fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+ write!(f, "\"{}\"", self)
+ }
+}
+
+impl std::convert::From<&str> for HSTRING {
+ fn from(value: &str) -> Self {
+ unsafe { Self::from_wide_iter(value.encode_utf16(), value.len()).unwrap() }
+ }
+}
+
+impl std::convert::From<std::string::String> for HSTRING {
+ fn from(value: std::string::String) -> Self {
+ value.as_str().into()
+ }
+}
+
+impl std::convert::From<&std::string::String> for HSTRING {
+ fn from(value: &std::string::String) -> Self {
+ value.as_str().into()
+ }
+}
+
+#[cfg(windows)]
+impl std::convert::From<&std::path::Path> for HSTRING {
+ fn from(value: &std::path::Path) -> Self {
+ value.as_os_str().into()
+ }
+}
+
+#[cfg(windows)]
+impl std::convert::From<&std::ffi::OsStr> for HSTRING {
+ fn from(value: &std::ffi::OsStr) -> Self {
+ unsafe { Self::from_wide_iter(std::os::windows::ffi::OsStrExt::encode_wide(value), value.len()).unwrap() }
+ }
+}
+
+#[cfg(windows)]
+impl std::convert::From<std::ffi::OsString> for HSTRING {
+ fn from(value: std::ffi::OsString) -> Self {
+ value.as_os_str().into()
+ }
+}
+
+#[cfg(windows)]
+impl std::convert::From<&std::ffi::OsString> for HSTRING {
+ fn from(value: &std::ffi::OsString) -> Self {
+ value.as_os_str().into()
+ }
+}
+
+impl Eq for HSTRING {}
+
+impl Ord for HSTRING {
+ fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+ self.as_wide().cmp(other.as_wide())
+ }
+}
+
+impl PartialOrd for HSTRING {
+ fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+ Some(self.cmp(other))
+ }
+}
+
+impl PartialEq for HSTRING {
+ fn eq(&self, other: &Self) -> bool {
+ *self.as_wide() == *other.as_wide()
+ }
+}
+
+impl PartialEq<std::string::String> for HSTRING {
+ fn eq(&self, other: &std::string::String) -> bool {
+ *self == **other
+ }
+}
+
+impl PartialEq<std::string::String> for &HSTRING {
+ fn eq(&self, other: &std::string::String) -> bool {
+ **self == **other
+ }
+}
+
+impl PartialEq<&std::string::String> for HSTRING {
+ fn eq(&self, other: &&std::string::String) -> bool {
+ *self == ***other
+ }
+}
+
+impl PartialEq<str> for HSTRING {
+ fn eq(&self, other: &str) -> bool {
+ self.as_wide().iter().copied().eq(other.encode_utf16())
+ }
+}
+
+impl PartialEq<str> for &HSTRING {
+ fn eq(&self, other: &str) -> bool {
+ **self == *other
+ }
+}
+
+impl PartialEq<&str> for HSTRING {
+ fn eq(&self, other: &&str) -> bool {
+ *self == **other
+ }
+}
+
+impl PartialEq<HSTRING> for str {
+ fn eq(&self, other: &HSTRING) -> bool {
+ *other == *self
+ }
+}
+
+impl PartialEq<HSTRING> for &str {
+ fn eq(&self, other: &HSTRING) -> bool {
+ *other == **self
+ }
+}
+
+impl PartialEq<&HSTRING> for str {
+ fn eq(&self, other: &&HSTRING) -> bool {
+ **other == *self
+ }
+}
+
+impl PartialEq<HSTRING> for std::string::String {
+ fn eq(&self, other: &HSTRING) -> bool {
+ *other == **self
+ }
+}
+
+impl PartialEq<HSTRING> for &std::string::String {
+ fn eq(&self, other: &HSTRING) -> bool {
+ *other == ***self
+ }
+}
+
+impl PartialEq<&HSTRING> for std::string::String {
+ fn eq(&self, other: &&HSTRING) -> bool {
+ **other == **self
+ }
+}
+
+#[cfg(windows)]
+impl PartialEq<std::ffi::OsString> for HSTRING {
+ fn eq(&self, other: &std::ffi::OsString) -> bool {
+ *self == **other
+ }
+}
+
+#[cfg(windows)]
+impl PartialEq<std::ffi::OsString> for &HSTRING {
+ fn eq(&self, other: &std::ffi::OsString) -> bool {
+ **self == **other
+ }
+}
+
+#[cfg(windows)]
+impl PartialEq<&std::ffi::OsString> for HSTRING {
+ fn eq(&self, other: &&std::ffi::OsString) -> bool {
+ *self == ***other
+ }
+}
+
+#[cfg(windows)]
+impl PartialEq<std::ffi::OsStr> for HSTRING {
+ fn eq(&self, other: &std::ffi::OsStr) -> bool {
+ self.as_wide().iter().copied().eq(std::os::windows::ffi::OsStrExt::encode_wide(other))
+ }
+}
+
+#[cfg(windows)]
+impl PartialEq<std::ffi::OsStr> for &HSTRING {
+ fn eq(&self, other: &std::ffi::OsStr) -> bool {
+ **self == *other
+ }
+}
+
+#[cfg(windows)]
+impl PartialEq<&std::ffi::OsStr> for HSTRING {
+ fn eq(&self, other: &&std::ffi::OsStr) -> bool {
+ *self == **other
+ }
+}
+
+#[cfg(windows)]
+impl PartialEq<HSTRING> for std::ffi::OsStr {
+ fn eq(&self, other: &HSTRING) -> bool {
+ *other == *self
+ }
+}
+
+#[cfg(windows)]
+impl PartialEq<HSTRING> for &std::ffi::OsStr {
+ fn eq(&self, other: &HSTRING) -> bool {
+ *other == **self
+ }
+}
+
+#[cfg(windows)]
+impl PartialEq<&HSTRING> for std::ffi::OsStr {
+ fn eq(&self, other: &&HSTRING) -> bool {
+ **other == *self
+ }
+}
+
+#[cfg(windows)]
+impl PartialEq<HSTRING> for std::ffi::OsString {
+ fn eq(&self, other: &HSTRING) -> bool {
+ *other == **self
+ }
+}
+
+#[cfg(windows)]
+impl PartialEq<HSTRING> for &std::ffi::OsString {
+ fn eq(&self, other: &HSTRING) -> bool {
+ *other == ***self
+ }
+}
+
+#[cfg(windows)]
+impl PartialEq<&HSTRING> for std::ffi::OsString {
+ fn eq(&self, other: &&HSTRING) -> bool {
+ **other == **self
+ }
+}
+
+impl<'a> std::convert::TryFrom<&'a HSTRING> for std::string::String {
+ type Error = std::string::FromUtf16Error;
+
+ fn try_from(hstring: &HSTRING) -> std::result::Result<Self, Self::Error> {
+ std::string::String::from_utf16(hstring.as_wide())
+ }
+}
+
+impl std::convert::TryFrom<HSTRING> for std::string::String {
+ type Error = std::string::FromUtf16Error;
+
+ fn try_from(hstring: HSTRING) -> std::result::Result<Self, Self::Error> {
+ std::string::String::try_from(&hstring)
+ }
+}
+
+#[cfg(windows)]
+impl<'a> std::convert::From<&'a HSTRING> for std::ffi::OsString {
+ fn from(hstring: &HSTRING) -> Self {
+ hstring.to_os_string()
+ }
+}
+
+#[cfg(windows)]
+impl std::convert::From<HSTRING> for std::ffi::OsString {
+ fn from(hstring: HSTRING) -> Self {
+ Self::from(&hstring)
+ }
+}
+
+impl IntoParam<PCWSTR> for &HSTRING {
+ fn into_param(self) -> Param<PCWSTR> {
+ Param::Owned(PCWSTR(self.as_ptr()))
+ }
+}
+
+const REFERENCE_FLAG: u32 = 1;
+
+#[repr(C)]
+struct Header {
+ flags: u32,
+ len: u32,
+ _0: u32,
+ _1: u32,
+ data: *mut u16,
+ count: crate::imp::RefCount,
+ buffer_start: u16,
+}
+
+impl Header {
+ fn alloc(len: u32) -> Result<*mut Header> {
+ debug_assert!(len != 0);
+ // Allocate enough space for header and two bytes per character.
+ // The space for the terminating null character is already accounted for inside of `Header`.
+ let alloc_size = std::mem::size_of::<Header>() + 2 * len as usize;
+
+ let header = crate::imp::heap_alloc(alloc_size)? as *mut Header;
+
+ // SAFETY: uses `std::ptr::write` (since `header` is unintialized). `Header` is safe to be all zeros.
+ unsafe {
+ header.write(std::mem::MaybeUninit::<Header>::zeroed().assume_init());
+ (*header).len = len;
+ (*header).count = crate::imp::RefCount::new(1);
+ (*header).data = &mut (*header).buffer_start;
+ }
+ Ok(header)
+ }
+
+ fn duplicate(&self) -> Result<*mut Header> {
+ if self.flags & REFERENCE_FLAG == 0 {
+ // If this is not a "fast pass" string then simply increment the reference count.
+ self.count.add_ref();
+ Ok(self as *const Header as *mut Header)
+ } else {
+ // Otherwise, allocate a new string and copy the value into the new string.
+ let copy = Header::alloc(self.len)?;
+ // SAFETY: since we are duplicating the string it is safe to copy all data from self to the initialized `copy`.
+ // We copy `len + 1` characters since `len` does not account for the terminating null character.
+ unsafe {
+ std::ptr::copy_nonoverlapping(self.data, (*copy).data, self.len as usize + 1);
+ }
+ Ok(copy)
+ }
+ }
+}
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