1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321
//! `read` and `write`, optionally positioned, optionally vectored.
#![allow(unsafe_code)]
use crate::buffer::split_init;
use crate::{backend, io};
use backend::fd::AsFd;
use core::mem::MaybeUninit;
// Declare `IoSlice` and `IoSliceMut`.
#[cfg(not(windows))]
pub use crate::maybe_polyfill::io::{IoSlice, IoSliceMut};
#[cfg(linux_kernel)]
pub use backend::io::types::ReadWriteFlags;
/// `read(fd, buf)`—Reads from a stream.
///
/// This takes a `&mut [u8]` which Rust requires to contain initialized memory.
/// To use an uninitialized buffer, use [`read_uninit`].
///
/// # References
/// - [POSIX]
/// - [Linux]
/// - [Apple]
/// - [FreeBSD]
/// - [NetBSD]
/// - [OpenBSD]
/// - [DragonFly BSD]
/// - [illumos]
/// - [glibc]
///
/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9799919799/functions/read.html
/// [Linux]: https://man7.org/linux/man-pages/man2/read.2.html
/// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/read.2.html
/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=read&sektion=2
/// [NetBSD]: https://man.netbsd.org/read.2
/// [OpenBSD]: https://man.openbsd.org/read.2
/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=read§ion=2
/// [illumos]: https://illumos.org/man/2/read
/// [glibc]: https://www.gnu.org/software/libc/manual/html_node/I_002fO-Primitives.html#index-reading-from-a-file-descriptor
#[inline]
pub fn read<Fd: AsFd>(fd: Fd, buf: &mut [u8]) -> io::Result<usize> {
unsafe { backend::io::syscalls::read(fd.as_fd(), buf.as_mut_ptr(), buf.len()) }
}
/// `read(fd, buf)`—Reads from a stream.
///
/// This is equivalent to [`read`], except that it can read into uninitialized
/// memory. It returns the slice that was initialized by this function and the
/// slice that remains uninitialized.
#[inline]
pub fn read_uninit<Fd: AsFd>(
fd: Fd,
buf: &mut [MaybeUninit<u8>],
) -> io::Result<(&mut [u8], &mut [MaybeUninit<u8>])> {
// Get number of initialized bytes.
let length = unsafe {
backend::io::syscalls::read(fd.as_fd(), buf.as_mut_ptr().cast::<u8>(), buf.len())
};
// Split into the initialized and uninitialized portions.
Ok(unsafe { split_init(buf, length?) })
}
/// `write(fd, buf)`—Writes to a stream.
///
/// # References
/// - [POSIX]
/// - [Linux]
/// - [Apple]
/// - [FreeBSD]
/// - [NetBSD]
/// - [OpenBSD]
/// - [DragonFly BSD]
/// - [illumos]
/// - [glibc]
///
/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9799919799/functions/write.html
/// [Linux]: https://man7.org/linux/man-pages/man2/write.2.html
/// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/write.2.html
/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=write&sektion=2
/// [NetBSD]: https://man.netbsd.org/write.2
/// [OpenBSD]: https://man.openbsd.org/write.2
/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=write§ion=2
/// [illumos]: https://illumos.org/man/2/write
/// [glibc]: https://www.gnu.org/software/libc/manual/html_node/I_002fO-Primitives.html#index-writing-to-a-file-descriptor
#[inline]
pub fn write<Fd: AsFd>(fd: Fd, buf: &[u8]) -> io::Result<usize> {
backend::io::syscalls::write(fd.as_fd(), buf)
}
/// `pread(fd, buf, offset)`—Reads from a file at a given position.
///
/// This takes a `&mut [u8]` which Rust requires to contain initialized memory.
/// To use an uninitialized buffer, use [`pread_uninit`].
///
/// # References
/// - [POSIX]
/// - [Linux]
/// - [Apple]
/// - [FreeBSD]
/// - [NetBSD]
/// - [OpenBSD]
/// - [DragonFly BSD]
/// - [illumos]
///
/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9799919799/functions/pread.html
/// [Linux]: https://man7.org/linux/man-pages/man2/pread.2.html
/// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/pread.2.html
/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=pread&sektion=2
/// [NetBSD]: https://man.netbsd.org/pread.2
/// [OpenBSD]: https://man.openbsd.org/pread.2
/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=pread§ion=2
/// [illumos]: https://illumos.org/man/2/pread
#[inline]
pub fn pread<Fd: AsFd>(fd: Fd, buf: &mut [u8], offset: u64) -> io::Result<usize> {
unsafe { backend::io::syscalls::pread(fd.as_fd(), buf.as_mut_ptr(), buf.len(), offset) }
}
/// `pread(fd, buf, offset)`—Reads from a file at a given position.
///
/// This is equivalent to [`pread`], except that it can read into uninitialized
/// memory. It returns the slice that was initialized by this function and the
/// slice that remains uninitialized.
#[inline]
pub fn pread_uninit<Fd: AsFd>(
fd: Fd,
buf: &mut [MaybeUninit<u8>],
offset: u64,
) -> io::Result<(&mut [u8], &mut [MaybeUninit<u8>])> {
let length = unsafe {
backend::io::syscalls::pread(fd.as_fd(), buf.as_mut_ptr().cast::<u8>(), buf.len(), offset)
};
Ok(unsafe { split_init(buf, length?) })
}
/// `pwrite(fd, bufs)`—Writes to a file at a given position.
///
/// Contrary to POSIX, on many popular platforms including Linux and FreeBSD,
/// if the file is opened in append mode, this ignores the offset appends the
/// data to the end of the file.
///
/// # References
/// - [POSIX]
/// - [Linux]
/// - [Apple]
/// - [FreeBSD]
/// - [NetBSD]
/// - [OpenBSD]
/// - [DragonFly BSD]
/// - [illumos]
///
/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9799919799/functions/pwrite.html
/// [Linux]: https://man7.org/linux/man-pages/man2/pwrite.2.html
/// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/pwrite.2.html
/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=pwrite&sektion=2
/// [NetBSD]: https://man.netbsd.org/pwrite.2
/// [OpenBSD]: https://man.openbsd.org/pwrite.2
/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=pwrite§ion=2
/// [illumos]: https://illumos.org/man/2/pwrite
#[inline]
pub fn pwrite<Fd: AsFd>(fd: Fd, buf: &[u8], offset: u64) -> io::Result<usize> {
backend::io::syscalls::pwrite(fd.as_fd(), buf, offset)
}
/// `readv(fd, bufs)`—Reads from a stream into multiple buffers.
///
/// # References
/// - [POSIX]
/// - [Linux]
/// - [Apple]
/// - [FreeBSD]
/// - [NetBSD]
/// - [OpenBSD]
/// - [DragonFly BSD]
/// - [illumos]
///
/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9799919799/functions/readv.html
/// [Linux]: https://man7.org/linux/man-pages/man2/readv.2.html
/// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/readv.2.html
/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=readv&sektion=2
/// [NetBSD]: https://man.netbsd.org/readv.2
/// [OpenBSD]: https://man.openbsd.org/readv.2
/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=readv§ion=2
/// [illumos]: https://illumos.org/man/2/readv
#[cfg(not(any(target_os = "espidf", target_os = "horizon")))]
#[inline]
pub fn readv<Fd: AsFd>(fd: Fd, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
backend::io::syscalls::readv(fd.as_fd(), bufs)
}
/// `writev(fd, bufs)`—Writes to a stream from multiple buffers.
///
/// # References
/// - [POSIX]
/// - [Linux]
/// - [Apple]
/// - [FreeBSD]
/// - [NetBSD]
/// - [OpenBSD]
/// - [DragonFly BSD]
/// - [illumos]
///
/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9799919799/functions/writev.html
/// [Linux]: https://man7.org/linux/man-pages/man2/writev.2.html
/// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/writev.2.html
/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=writev&sektion=2
/// [NetBSD]: https://man.netbsd.org/writev.2
/// [OpenBSD]: https://man.openbsd.org/writev.2
/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=writev§ion=2
/// [illumos]: https://illumos.org/man/2/writev
#[cfg(not(any(target_os = "espidf", target_os = "horizon")))]
#[inline]
pub fn writev<Fd: AsFd>(fd: Fd, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
backend::io::syscalls::writev(fd.as_fd(), bufs)
}
/// `preadv(fd, bufs, offset)`—Reads from a file at a given position into
/// multiple buffers.
///
/// # References
/// - [Linux]
/// - [FreeBSD]
/// - [NetBSD]
/// - [OpenBSD]
/// - [DragonFly BSD]
/// - [illumos]
///
/// [Linux]: https://man7.org/linux/man-pages/man2/preadv.2.html
/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=preadv&sektion=2
/// [NetBSD]: https://man.netbsd.org/preadv.2
/// [OpenBSD]: https://man.openbsd.org/preadv.2
/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=preadv§ion=2
/// [illumos]: https://illumos.org/man/2/preadv
#[cfg(not(any(
target_os = "espidf",
target_os = "haiku",
target_os = "horizon",
target_os = "nto",
target_os = "redox",
target_os = "solaris",
target_os = "vita"
)))]
#[inline]
pub fn preadv<Fd: AsFd>(fd: Fd, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> {
backend::io::syscalls::preadv(fd.as_fd(), bufs, offset)
}
/// `pwritev(fd, bufs, offset)`—Writes to a file at a given position from
/// multiple buffers.
///
/// Contrary to POSIX, on many popular platforms including Linux and FreeBSD,
/// if the file is opened in append mode, this ignores the offset appends the
/// data to the end of the file.
///
/// # References
/// - [Linux]
/// - [FreeBSD]
/// - [NetBSD]
/// - [OpenBSD]
/// - [DragonFly BSD]
/// - [illumos]
///
/// [Linux]: https://man7.org/linux/man-pages/man2/pwritev.2.html
/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=pwritev&sektion=2
/// [NetBSD]: https://man.netbsd.org/pwritev.2
/// [OpenBSD]: https://man.openbsd.org/pwritev.2
/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=pwritev§ion=2
/// [illumos]: https://illumos.org/man/2/pwritev
#[cfg(not(any(
target_os = "espidf",
target_os = "haiku",
target_os = "horizon",
target_os = "nto",
target_os = "redox",
target_os = "solaris",
target_os = "vita"
)))]
#[inline]
pub fn pwritev<Fd: AsFd>(fd: Fd, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> {
backend::io::syscalls::pwritev(fd.as_fd(), bufs, offset)
}
/// `preadv2(fd, bufs, offset, flags)`—Reads data, with several options.
///
/// An `offset` of `u64::MAX` means to use and update the current file offset.
///
/// # References
/// - [Linux]
///
/// [Linux]: https://man7.org/linux/man-pages/man2/preadv2.2.html
#[cfg(linux_kernel)]
#[inline]
pub fn preadv2<Fd: AsFd>(
fd: Fd,
bufs: &mut [IoSliceMut<'_>],
offset: u64,
flags: ReadWriteFlags,
) -> io::Result<usize> {
backend::io::syscalls::preadv2(fd.as_fd(), bufs, offset, flags)
}
/// `pwritev2(fd, bufs, offset, flags)`—Writes data, with several options.
///
/// An `offset` of `u64::MAX` means to use and update the current file offset.
///
/// # References
/// - [Linux]
///
/// [Linux]: https://man7.org/linux/man-pages/man2/pwritev2.2.html
#[cfg(linux_kernel)]
#[inline]
pub fn pwritev2<Fd: AsFd>(
fd: Fd,
bufs: &[IoSlice<'_>],
offset: u64,
flags: ReadWriteFlags,
) -> io::Result<usize> {
backend::io::syscalls::pwritev2(fd.as_fd(), bufs, offset, flags)
}