vendor/rustix/src/io/read_write.rs

   1 //! `read` and `write`, optionally positioned, optionally vectored
   2
   3 use crate::{backend, io};
   4 use backend::fd::AsFd;
   5
   6 // Declare `IoSlice` and `IoSliceMut`.
   7 #[cfg(not(windows))]
   8 #[cfg(not(feature = "std"))]
   9 pub use backend::io::io_slice::{IoSlice, IoSliceMut};
  10 #[cfg(not(windows))]
  11 #[cfg(feature = "std")]
  12 pub use std::io::{IoSlice, IoSliceMut};
  13
  14 /// `RWF_*` constants for use with [`preadv2`] and [`pwritev2`].
  15 #[cfg(any(target_os = "android", target_os = "linux"))]
  16 pub use backend::io::types::ReadWriteFlags;
  17
  18 /// `read(fd, buf)`—Reads from a stream.
  19 ///
  20 /// # References
  21 ///  - [POSIX]
  22 ///  - [Linux]
  23 ///  - [Apple]
  24 ///
  25 /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/read.html
  26 /// [Linux]: https://man7.org/linux/man-pages/man2/read.2.html
  27 /// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/read.2.html
  28 #[inline]
  29 pub fn read<Fd: AsFd>(fd: Fd, buf: &mut [u8]) -> io::Result<usize> {
  30     backend::io::syscalls::read(fd.as_fd(), buf)
  31 }
  32
  33 /// `write(fd, buf)`—Writes to a stream.
  34 ///
  35 /// # References
  36 ///  - [POSIX]
  37 ///  - [Linux]
  38 ///  - [Apple]
  39 ///
  40 /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/write.html
  41 /// [Linux]: https://man7.org/linux/man-pages/man2/write.2.html
  42 /// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/write.2.html
  43 #[inline]
  44 pub fn write<Fd: AsFd>(fd: Fd, buf: &[u8]) -> io::Result<usize> {
  45     backend::io::syscalls::write(fd.as_fd(), buf)
  46 }
  47
  48 /// `pread(fd, buf, offset)`—Reads from a file at a given position.
  49 ///
  50 /// # References
  51 ///  - [POSIX]
  52 ///  - [Linux]
  53 ///  - [Apple]
  54 ///
  55 /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/pread.html
  56 /// [Linux]: https://man7.org/linux/man-pages/man2/pread.2.html
  57 /// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/pread.2.html
  58 #[inline]
  59 pub fn pread<Fd: AsFd>(fd: Fd, buf: &mut [u8], offset: u64) -> io::Result<usize> {
  60     backend::io::syscalls::pread(fd.as_fd(), buf, offset)
  61 }
  62
  63 /// `pwrite(fd, bufs)`—Writes to a file at a given position.
  64 ///
  65 /// # References
  66 ///  - [POSIX]
  67 ///  - [Linux]
  68 ///  - [Apple]
  69 ///
  70 /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/pwrite.html
  71 /// [Linux]: https://man7.org/linux/man-pages/man2/pwrite.2.html
  72 /// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/pwrite.2.html
  73 #[inline]
  74 pub fn pwrite<Fd: AsFd>(fd: Fd, buf: &[u8], offset: u64) -> io::Result<usize> {
  75     backend::io::syscalls::pwrite(fd.as_fd(), buf, offset)
  76 }
  77
  78 /// `readv(fd, bufs)`—Reads from a stream into multiple buffers.
  79 ///
  80 /// # References
  81 ///  - [POSIX]
  82 ///  - [Linux]
  83 ///  - [Apple]
  84 ///
  85 /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/readv.html
  86 /// [Linux]: https://man7.org/linux/man-pages/man2/readv.2.html
  87 /// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/readv.2.html
  88 #[inline]
  89 pub fn readv<Fd: AsFd>(fd: Fd, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
  90     backend::io::syscalls::readv(fd.as_fd(), bufs)
  91 }
  92
  93 /// `writev(fd, bufs)`—Writes to a stream from multiple buffers.
  94 ///
  95 /// # References
  96 ///  - [POSIX]
  97 ///  - [Linux]
  98 ///  - [Apple]
  99 ///
 100 /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/writev.html
 101 /// [Linux]: https://man7.org/linux/man-pages/man2/writev.2.html
 102 /// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/writev.2.html
 103 #[inline]
 104 pub fn writev<Fd: AsFd>(fd: Fd, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
 105     backend::io::syscalls::writev(fd.as_fd(), bufs)
 106 }
 107
 108 /// `preadv(fd, bufs, offset)`—Reads from a file at a given position into
 109 /// multiple buffers.
 110 ///
 111 /// # References
 112 ///  - [Linux]
 113 ///
 114 /// [Linux]: https://man7.org/linux/man-pages/man2/preadv.2.html
 115 #[cfg(not(any(target_os = "haiku", target_os = "redox", target_os = "solaris")))]
 116 #[inline]
 117 pub fn preadv<Fd: AsFd>(fd: Fd, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> {
 118     backend::io::syscalls::preadv(fd.as_fd(), bufs, offset)
 119 }
 120
 121 /// `pwritev(fd, bufs, offset)`—Writes to a file at a given position from
 122 /// multiple buffers.
 123 ///
 124 /// # References
 125 ///  - [Linux]
 126 ///
 127 /// [Linux]: https://man7.org/linux/man-pages/man2/pwritev.2.html
 128 #[cfg(not(any(target_os = "haiku", target_os = "redox", target_os = "solaris")))]
 129 #[inline]
 130 pub fn pwritev<Fd: AsFd>(fd: Fd, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> {
 131     backend::io::syscalls::pwritev(fd.as_fd(), bufs, offset)
 132 }
 133
 134 /// `preadv2(fd, bufs, offset, flags)`—Reads data, with several options.
 135 ///
 136 /// An `offset` of `u64::MAX` means to use and update the current file offset.
 137 ///
 138 /// # References
 139 ///  - [Linux]
 140 ///
 141 /// [Linux]: https://man7.org/linux/man-pages/man2/preadv2.2.html
 142 #[cfg(any(target_os = "android", target_os = "linux"))]
 143 #[inline]
 144 pub fn preadv2<Fd: AsFd>(
 145     fd: Fd,
 146     bufs: &mut [IoSliceMut<'_>],
 147     offset: u64,
 148     flags: ReadWriteFlags,
 149 ) -> io::Result<usize> {
 150     backend::io::syscalls::preadv2(fd.as_fd(), bufs, offset, flags)
 151 }
 152
 153 /// `pwritev2(fd, bufs, offset, flags)`—Writes data, with several options.
 154 ///
 155 /// An `offset` of `u64::MAX` means to use and update the current file offset.
 156 ///
 157 /// # References
 158 ///  - [Linux]
 159 ///
 160 /// [Linux]: https://man7.org/linux/man-pages/man2/pwritev2.2.html
 161 #[cfg(any(target_os = "android", target_os = "linux"))]
 162 #[inline]
 163 pub fn pwritev2<Fd: AsFd>(
 164     fd: Fd,
 165     bufs: &[IoSlice<'_>],
 166     offset: u64,
 167     flags: ReadWriteFlags,
 168 ) -> io::Result<usize> {
 169     backend::io::syscalls::pwritev2(fd.as_fd(), bufs, offset, flags)
 170 }