Method next

src/fs/raw_dir.rs:202–231

(&mut self)

    #[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(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`].