From 351c154cb44d90b1db7e3c62aa6500e0fb472969 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Beno=C3=AEt=20du=20Garreau?= Date: Mon, 4 Oct 2021 12:55:50 +0200 Subject: [PATCH] Add vectored positioned I/O on Unix --- library/std/src/os/unix/fs.rs | 34 ++++++++++++++ library/std/src/sys/unix/fd.rs | 82 ++++++++++++++++++++++++++++++++-- library/std/src/sys/unix/fs.rs | 8 ++++ 3 files changed, 121 insertions(+), 3 deletions(-) diff --git a/library/std/src/os/unix/fs.rs b/library/std/src/os/unix/fs.rs index 3fc6cc44ce4c8..edd77c824ad7c 100644 --- a/library/std/src/os/unix/fs.rs +++ b/library/std/src/os/unix/fs.rs @@ -54,6 +54,20 @@ pub trait FileExt { #[stable(feature = "file_offset", since = "1.15.0")] fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result; + /// Like `read_at`, except that it reads into a slice of buffers. + /// + /// Data is copied to fill each buffer in order, with the final buffer + /// written to possibly being only partially filled. This method must behave + /// equivalently to a single call to read with concatenated buffers. + #[unstable(feature = "unix_file_vectored_at", issue = "89517")] + fn read_vectored_at( + &mut self, + bufs: &mut [io::IoSliceMut<'_>], + offset: u64, + ) -> io::Result { + io::default_read_vectored(|b| self.read_at(b, offset), bufs) + } + /// Reads the exact number of byte required to fill `buf` from the given offset. /// /// The offset is relative to the start of the file and thus independent @@ -155,6 +169,16 @@ pub trait FileExt { #[stable(feature = "file_offset", since = "1.15.0")] fn write_at(&self, buf: &[u8], offset: u64) -> io::Result; + /// Like `write_at`, except that it writes from a slice of buffers. + /// + /// Data is copied from each buffer in order, with the final buffer read + /// from possibly being only partially consumed. This method must behave as + /// a call to `write_at` with the buffers concatenated would. + #[unstable(feature = "unix_file_vectored_at", issue = "89517")] + fn write_vectored_at(&mut self, bufs: &[io::IoSlice<'_>], offset: u64) -> io::Result { + io::default_write_vectored(|b| self.write_at(b, offset), bufs) + } + /// Attempts to write an entire buffer starting from a given offset. /// /// The offset is relative to the start of the file and thus independent @@ -218,9 +242,19 @@ impl FileExt for fs::File { fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result { self.as_inner().read_at(buf, offset) } + fn read_vectored_at( + &mut self, + bufs: &mut [io::IoSliceMut<'_>], + offset: u64, + ) -> io::Result { + self.as_inner().read_vectored_at(bufs, offset) + } fn write_at(&self, buf: &[u8], offset: u64) -> io::Result { self.as_inner().write_at(buf, offset) } + fn write_vectored_at(&mut self, bufs: &[io::IoSlice<'_>], offset: u64) -> io::Result { + self.as_inner().write_vectored_at(bufs, offset) + } } /// Unix-specific extensions to [`fs::Permissions`]. diff --git a/library/std/src/sys/unix/fd.rs b/library/std/src/sys/unix/fd.rs index 66c33d58d6ca3..3213f4bf2a0c6 100644 --- a/library/std/src/sys/unix/fd.rs +++ b/library/std/src/sys/unix/fd.rs @@ -92,7 +92,7 @@ impl FileDesc { let ret = cvt(unsafe { libc::readv( self.as_raw_fd(), - bufs.as_ptr() as *const libc::iovec, + bufs.as_mut_ptr() as *mut libc::iovec as *const libc::iovec, cmp::min(bufs.len(), max_iov()) as libc::c_int, ) })?; @@ -101,7 +101,7 @@ impl FileDesc { #[cfg(any(target_os = "espidf", target_os = "horizon"))] pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result { - return crate::io::default_read_vectored(|b| self.read(b), bufs); + io::default_read_vectored(|b| self.read(b), bufs) } #[inline] @@ -147,6 +147,44 @@ impl FileDesc { Ok(()) } + #[cfg(any( + target_os = "android", + target_os = "emscripten", + target_os = "freebsd", + target_os = "fuchsia", + target_os = "illumos", + target_os = "ios", + target_os = "linux", + target_os = "macos", + target_os = "netbsd", + ))] + pub fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result { + let ret = cvt(unsafe { + libc::preadv( + self.as_raw_fd(), + bufs.as_mut_ptr() as *mut libc::iovec as *const libc::iovec, + cmp::min(bufs.len(), max_iov()) as libc::c_int, + offset as _, + ) + })?; + Ok(ret as usize) + } + + #[cfg(not(any( + target_os = "android", + target_os = "emscripten", + target_os = "freebsd", + target_os = "fuchsia", + target_os = "illumos", + target_os = "ios", + target_os = "linux", + target_os = "macos", + target_os = "netbsd", + )))] + pub fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result { + io::default_read_vectored(|b| self.read_at(b, offset), bufs) + } + pub fn write(&self, buf: &[u8]) -> io::Result { let ret = cvt(unsafe { libc::write( @@ -172,7 +210,7 @@ impl FileDesc { #[cfg(any(target_os = "espidf", target_os = "horizon"))] pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result { - return crate::io::default_write_vectored(|b| self.write(b), bufs); + io::default_write_vectored(|b| self.write(b), bufs) } #[inline] @@ -197,6 +235,44 @@ impl FileDesc { } } + #[cfg(any( + target_os = "android", + target_os = "emscripten", + target_os = "freebsd", + target_os = "fuchsia", + target_os = "illumos", + target_os = "ios", + target_os = "linux", + target_os = "macos", + target_os = "netbsd", + ))] + pub fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result { + let ret = cvt(unsafe { + libc::pwritev( + self.as_raw_fd(), + bufs.as_ptr() as *const libc::iovec, + cmp::min(bufs.len(), max_iov()) as libc::c_int, + offset as _, + ) + })?; + Ok(ret as usize) + } + + #[cfg(not(any( + target_os = "android", + target_os = "emscripten", + target_os = "freebsd", + target_os = "fuchsia", + target_os = "illumos", + target_os = "ios", + target_os = "linux", + target_os = "macos", + target_os = "netbsd", + )))] + pub fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result { + io::default_write_vectored(|b| self.write_at(b, offset), bufs) + } + #[cfg(not(any( target_env = "newlib", target_os = "solaris", diff --git a/library/std/src/sys/unix/fs.rs b/library/std/src/sys/unix/fs.rs index 8e1f35d6cc920..ec674801a8ff8 100644 --- a/library/std/src/sys/unix/fs.rs +++ b/library/std/src/sys/unix/fs.rs @@ -1098,6 +1098,10 @@ impl File { self.0.read_buf(cursor) } + pub fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result { + self.0.read_vectored_at(bufs, offset) + } + pub fn write(&self, buf: &[u8]) -> io::Result { self.0.write(buf) } @@ -1115,6 +1119,10 @@ impl File { self.0.write_at(buf, offset) } + pub fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result { + self.0.write_vectored_at(bufs, offset) + } + pub fn flush(&self) -> io::Result<()> { Ok(()) }