Merging upstream version 1.74.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 224 insertions, 0 deletions

diff --git a/vendor/rustix-0.37.6/src/fs/raw_dir.rs b/vendor/rustix-0.37.6/src/fs/raw_dir.rs
new file mode 100644
index 000000000..780ff0e89
--- /dev/null
+++ b/vendor/rustix-0.37.6/src/fs/raw_dir.rs
@@ -0,0 +1,224 @@
+//! `RawDir` and `RawDirEntry`.
+
+use core::fmt;
+use core::mem::{align_of, MaybeUninit};
+use linux_raw_sys::general::linux_dirent64;
+
+use crate::backend::fs::syscalls::getdents_uninit;
+use crate::fd::AsFd;
+use crate::ffi::CStr;
+use crate::fs::FileType;
+use crate::io;
+
+/// A directory iterator implemented with getdents.
+///
+/// Note: This implementation does not handle growing the buffer. If this
+/// functionality is necessary, you'll need to drop the current iterator,
+/// resize the buffer, and then re-create the iterator. The iterator is
+/// guaranteed to continue where it left off provided the file descriptor isn't
+/// changed. See the example in [`RawDir::new`].
+pub struct RawDir<'buf, Fd: AsFd> {
+    fd: Fd,
+    buf: &'buf mut [MaybeUninit<u8>],
+    initialized: usize,
+    offset: usize,
+}
+
+impl<'buf, Fd: AsFd> RawDir<'buf, Fd> {
+    /// Create a new iterator from the given file descriptor and buffer.
+    ///
+    /// Note: the buffer size may be trimmed to accommodate alignment
+    /// requirements.
+    ///
+    /// # Examples
+    ///
+    /// ## Simple but non-portable
+    ///
+    /// These examples are non-portable, because file systems may not have a
+    /// maximum file name length. If you can make assumptions that bound
+    /// this length, then these examples may suffice.
+    ///
+    /// Using the heap:
+    ///
+    /// ```notrust
+    /// # // The `notrust` above can be removed when we can depend on Rust 1.60.
+    /// # use std::mem::MaybeUninit;
+    /// # use rustix::fs::{cwd, Mode, OFlags, openat, RawDir};
+    ///
+    /// let fd = openat(cwd(), ".", OFlags::RDONLY | OFlags::DIRECTORY, Mode::empty()).unwrap();
+    ///
+    /// let mut buf = Vec::with_capacity(8192);
+    /// let mut iter = RawDir::new(fd, buf.spare_capacity_mut());
+    /// while let Some(entry) = iter.next() {
+    ///     let entry = entry.unwrap();
+    ///     dbg!(&entry);
+    /// }
+    /// ```
+    ///
+    /// Using the stack:
+    ///
+    /// ```
+    /// # use std::mem::MaybeUninit;
+    /// # use rustix::fs::{cwd, Mode, OFlags, openat, RawDir};
+    ///
+    /// let fd = openat(
+    ///     cwd(),
+    ///     ".",
+    ///     OFlags::RDONLY | OFlags::DIRECTORY,
+    ///     Mode::empty(),
+    /// )
+    /// .unwrap();
+    ///
+    /// let mut buf = [MaybeUninit::uninit(); 2048];
+    /// let mut iter = RawDir::new(fd, &mut buf);
+    /// while let Some(entry) = iter.next() {
+    ///     let entry = entry.unwrap();
+    ///     dbg!(&entry);
+    /// }
+    /// ```
+    ///
+    /// ## Portable
+    ///
+    /// Heap allocated growing buffer for supporting directory entries with
+    /// arbitrarily large file names:
+    ///
+    /// ```notrust
+    /// # // The `notrust` above can be removed when we can depend on Rust 1.60.
+    /// # use std::mem::MaybeUninit;
+    /// # use rustix::fs::{cwd, Mode, OFlags, openat, RawDir};
+    /// # use rustix::io::Errno;
+    ///
+    /// let fd = openat(cwd(), ".", OFlags::RDONLY | OFlags::DIRECTORY, Mode::empty()).unwrap();
+    ///
+    /// let mut buf = Vec::with_capacity(8192);
+    /// 'read: loop {
+    ///     'resize: {
+    ///         let mut iter = RawDir::new(&fd, buf.spare_capacity_mut());
+    ///         while let Some(entry) = iter.next() {
+    ///             let entry = match entry {
+    ///                 Err(Errno::INVAL) => break 'resize,
+    ///                 r => r.unwrap(),
+    ///             };
+    ///             dbg!(&entry);
+    ///         }
+    ///         break 'read;
+    ///     }
+    ///
+    ///     let new_capacity = buf.capacity() * 2;
+    ///     buf.reserve(new_capacity);
+    /// }
+    /// ```
+    pub fn new(fd: Fd, buf: &'buf mut [MaybeUninit<u8>]) -> Self {
+        Self {
+            fd,
+            buf: {
+                let offset = buf.as_ptr().align_offset(align_of::<linux_dirent64>());
+                if offset < buf.len() {
+                    &mut buf[offset..]
+                } else {
+                    &mut []
+                }
+            },
+            initialized: 0,
+            offset: 0,
+        }
+    }
+}
+
+/// A raw directory entry, similar to `std::fs::DirEntry`.
+///
+/// Note that unlike the std version, this may represent the `.` or `..`
+/// entries.
+pub struct RawDirEntry<'a> {
+    file_name: &'a CStr,
+    file_type: u8,
+    inode_number: u64,
+    next_entry_cookie: i64,
+}
+
+impl<'a> fmt::Debug for RawDirEntry<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut f = f.debug_struct("RawDirEntry");
+        f.field("file_name", &self.file_name());
+        f.field("file_type", &self.file_type());
+        f.field("ino", &self.ino());
+        f.field("next_entry_cookie", &self.next_entry_cookie());
+        f.finish()
+    }
+}
+
+impl<'a> RawDirEntry<'a> {
+    /// Returns the file name of this directory entry.
+    #[inline]
+    pub fn file_name(&self) -> &CStr {
+        self.file_name
+    }
+
+    /// Returns the type of this directory entry.
+    #[inline]
+    pub fn file_type(&self) -> FileType {
+        FileType::from_dirent_d_type(self.file_type)
+    }
+
+    /// Returns the inode number of this directory entry.
+    #[inline]
+    #[doc(alias = "inode_number")]
+    pub fn ino(&self) -> u64 {
+        self.inode_number
+    }
+
+    /// Returns the seek cookie to the next directory entry.
+    #[inline]
+    #[doc(alias = "off")]
+    pub fn next_entry_cookie(&self) -> u64 {
+        self.next_entry_cookie as u64
+    }
+}
+
+impl<'buf, Fd: AsFd> RawDir<'buf, Fd> {
+    /// Identical to [Iterator::next] except that [Iterator::Item] borrows from
+    /// self.
+    ///
+    /// Note: this interface will be broken to implement a stdlib iterator API
+    /// with GAT support once one becomes available.
+    #[allow(unsafe_code)]
+    #[allow(clippy::should_implement_trait)]
+    pub fn next(&mut self) -> Option<io::Result<RawDirEntry>> {
+        if self.is_buffer_empty() {
+            match getdents_uninit(self.fd.as_fd(), self.buf) {
+                Ok(bytes_read) if bytes_read == 0 => return None,
+                Ok(bytes_read) => {
+                    self.initialized = bytes_read;
+                    self.offset = 0;
+                }
+                Err(e) => return Some(Err(e)),
+            }
+        }
+
+        let dirent_ptr = self.buf[self.offset..].as_ptr();
+        // SAFETY:
+        // - This data is initialized by the check above.
+        //   - Assumption: the kernel will not give us partial structs.
+        // - Assumption: the kernel uses proper alignment between structs.
+        // - The starting pointer is aligned (performed in RawDir::new)
+        let dirent = unsafe { &*dirent_ptr.cast::<linux_dirent64>() };
+
+        self.offset += usize::from(dirent.d_reclen);
+
+        Some(Ok(RawDirEntry {
+            file_type: dirent.d_type,
+            inode_number: dirent.d_ino.into(),
+            next_entry_cookie: dirent.d_off.into(),
+            // SAFETY: the kernel guarantees a NUL terminated string.
+            file_name: unsafe { CStr::from_ptr(dirent.d_name.as_ptr().cast()) },
+        }))
+    }
+
+    /// Returns true if the internal buffer is empty and will be refilled when
+    /// calling [`next`].
+    ///
+    /// [`next`]: Self::next
+    pub fn is_buffer_empty(&self) -> bool {
+        self.offset >= self.initialized
+    }
+}