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Auto merge of #75272 - the8472:spec-copy, r=KodrAus
specialize io::copy to use copy_file_range, splice or sendfile Fixes #74426. Also covers #60689 but only as an optimization instead of an official API. The specialization only covers std-owned structs so it should avoid the problems with #71091 Currently linux-only but it should be generalizable to other unix systems that have sendfile/sosplice and similar. There is a bit of optimization potential around the syscall count. Right now it may end up doing more syscalls than the naive copy loop when doing short (<8KiB) copies between file descriptors. The test case executes the following: ``` [pid 103776] statx(3, "", AT_STATX_SYNC_AS_STAT|AT_EMPTY_PATH, STATX_ALL, {stx_mask=STATX_ALL|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0644, stx_size=17, ...}) = 0 [pid 103776] write(4, "wxyz", 4) = 4 [pid 103776] write(4, "iklmn", 5) = 5 [pid 103776] copy_file_range(3, NULL, 4, NULL, 5, 0) = 5 ``` 0-1 `stat` calls to identify the source file type. 0 if the type can be inferred from the struct from which the FD was extracted 𝖬 `write` to drain the `BufReader`/`BufWriter` wrappers. only happen when buffers are present. 𝖬 ≾ number of wrappers present. If there is a write buffer it may absorb the read buffer contents first so only result in a single write. Vectored writes would also be an option but that would require more invasive changes to `BufWriter`. 𝖭 `copy_file_range`/`splice`/`sendfile` until file size, EOF or the byte limit from `Take` is reached. This should generally be *much* more efficient than the read-write loop and also have other benefits such as DMA offload or extent sharing. ## Benchmarks ``` OLD test io::tests::bench_file_to_file_copy ... bench: 21,002 ns/iter (+/- 750) = 6240 MB/s [ext4] test io::tests::bench_file_to_file_copy ... bench: 35,704 ns/iter (+/- 1,108) = 3671 MB/s [btrfs] test io::tests::bench_file_to_socket_copy ... bench: 57,002 ns/iter (+/- 4,205) = 2299 MB/s test io::tests::bench_socket_pipe_socket_copy ... bench: 142,640 ns/iter (+/- 77,851) = 918 MB/s NEW test io::tests::bench_file_to_file_copy ... bench: 14,745 ns/iter (+/- 519) = 8889 MB/s [ext4] test io::tests::bench_file_to_file_copy ... bench: 6,128 ns/iter (+/- 227) = 21389 MB/s [btrfs] test io::tests::bench_file_to_socket_copy ... bench: 13,767 ns/iter (+/- 3,767) = 9520 MB/s test io::tests::bench_socket_pipe_socket_copy ... bench: 26,471 ns/iter (+/- 6,412) = 4951 MB/s ```
This commit is contained in:
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commit
30e49a9ead
@ -1656,7 +1656,7 @@ pub fn rename<P: AsRef<Path>, Q: AsRef<Path>>(from: P, to: Q) -> io::Result<()>
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/// the length of the `to` file as reported by `metadata`.
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///
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/// If you’re wanting to copy the contents of one file to another and you’re
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/// working with [`File`]s, see the [`io::copy`] function.
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/// working with [`File`]s, see the [`io::copy()`] function.
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///
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/// # Platform-specific behavior
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///
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88
library/std/src/io/copy.rs
Normal file
88
library/std/src/io/copy.rs
Normal file
@ -0,0 +1,88 @@
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use crate::io::{self, ErrorKind, Read, Write};
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use crate::mem::MaybeUninit;
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/// Copies the entire contents of a reader into a writer.
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///
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/// This function will continuously read data from `reader` and then
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/// write it into `writer` in a streaming fashion until `reader`
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/// returns EOF.
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///
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/// On success, the total number of bytes that were copied from
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/// `reader` to `writer` is returned.
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///
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/// If you’re wanting to copy the contents of one file to another and you’re
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/// working with filesystem paths, see the [`fs::copy`] function.
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///
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/// [`fs::copy`]: crate::fs::copy
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///
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/// # Errors
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///
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/// This function will return an error immediately if any call to [`read`] or
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/// [`write`] returns an error. All instances of [`ErrorKind::Interrupted`] are
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/// handled by this function and the underlying operation is retried.
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///
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/// [`read`]: Read::read
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/// [`write`]: Write::write
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///
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/// # Examples
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///
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/// ```
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/// use std::io;
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///
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/// fn main() -> io::Result<()> {
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/// let mut reader: &[u8] = b"hello";
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/// let mut writer: Vec<u8> = vec![];
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///
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/// io::copy(&mut reader, &mut writer)?;
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///
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/// assert_eq!(&b"hello"[..], &writer[..]);
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/// Ok(())
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/// }
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn copy<R: ?Sized, W: ?Sized>(reader: &mut R, writer: &mut W) -> io::Result<u64>
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where
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R: Read,
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W: Write,
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{
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cfg_if::cfg_if! {
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if #[cfg(any(target_os = "linux", target_os = "android"))] {
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crate::sys::kernel_copy::copy_spec(reader, writer)
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} else {
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generic_copy(reader, writer)
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}
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}
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}
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/// The general read-write-loop implementation of
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/// `io::copy` that is used when specializations are not available or not applicable.
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pub(crate) fn generic_copy<R: ?Sized, W: ?Sized>(reader: &mut R, writer: &mut W) -> io::Result<u64>
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where
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R: Read,
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W: Write,
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{
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let mut buf = MaybeUninit::<[u8; super::DEFAULT_BUF_SIZE]>::uninit();
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// FIXME: #42788
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//
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// - This creates a (mut) reference to a slice of
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// _uninitialized_ integers, which is **undefined behavior**
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//
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// - Only the standard library gets to soundly "ignore" this,
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// based on its privileged knowledge of unstable rustc
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// internals;
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unsafe {
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reader.initializer().initialize(buf.assume_init_mut());
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}
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let mut written = 0;
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loop {
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let len = match reader.read(unsafe { buf.assume_init_mut() }) {
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Ok(0) => return Ok(written),
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Ok(len) => len,
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Err(ref e) if e.kind() == ErrorKind::Interrupted => continue,
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Err(e) => return Err(e),
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};
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writer.write_all(unsafe { &buf.assume_init_ref()[..len] })?;
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written += len as u64;
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}
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}
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@ -266,6 +266,8 @@ pub use self::buffered::IntoInnerError;
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#[stable(feature = "rust1", since = "1.0.0")]
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pub use self::buffered::{BufReader, BufWriter, LineWriter};
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#[stable(feature = "rust1", since = "1.0.0")]
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pub use self::copy::copy;
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#[stable(feature = "rust1", since = "1.0.0")]
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pub use self::cursor::Cursor;
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#[stable(feature = "rust1", since = "1.0.0")]
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pub use self::error::{Error, ErrorKind, Result};
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@ -279,11 +281,12 @@ pub use self::stdio::{_eprint, _print};
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#[doc(no_inline, hidden)]
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pub use self::stdio::{set_panic, set_print, LocalOutput};
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#[stable(feature = "rust1", since = "1.0.0")]
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pub use self::util::{copy, empty, repeat, sink, Empty, Repeat, Sink};
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pub use self::util::{empty, repeat, sink, Empty, Repeat, Sink};
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pub(crate) use self::stdio::clone_io;
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mod buffered;
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pub(crate) mod copy;
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mod cursor;
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mod error;
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mod impls;
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@ -409,6 +409,14 @@ impl Read for Stdin {
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}
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}
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// only used by platform-dependent io::copy specializations, i.e. unused on some platforms
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#[cfg(any(target_os = "linux", target_os = "android"))]
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impl StdinLock<'_> {
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pub(crate) fn as_mut_buf(&mut self) -> &mut BufReader<impl Read> {
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&mut self.inner
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}
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}
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#[stable(feature = "rust1", since = "1.0.0")]
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impl Read for StdinLock<'_> {
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fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
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@ -1,7 +1,7 @@
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use super::{repeat, Cursor, SeekFrom};
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use crate::cmp::{self, min};
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use crate::io::prelude::*;
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use crate::io::{self, IoSlice, IoSliceMut};
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use crate::io::{BufRead, Read, Seek, Write};
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use crate::ops::Deref;
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#[test]
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@ -4,78 +4,7 @@
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mod tests;
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use crate::fmt;
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use crate::io::{self, BufRead, ErrorKind, Initializer, IoSlice, IoSliceMut, Read, Write};
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use crate::mem::MaybeUninit;
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/// Copies the entire contents of a reader into a writer.
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///
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/// This function will continuously read data from `reader` and then
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/// write it into `writer` in a streaming fashion until `reader`
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/// returns EOF.
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///
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/// On success, the total number of bytes that were copied from
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/// `reader` to `writer` is returned.
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///
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/// If you’re wanting to copy the contents of one file to another and you’re
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/// working with filesystem paths, see the [`fs::copy`] function.
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///
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/// [`fs::copy`]: crate::fs::copy
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///
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/// # Errors
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///
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/// This function will return an error immediately if any call to [`read`] or
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/// [`write`] returns an error. All instances of [`ErrorKind::Interrupted`] are
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/// handled by this function and the underlying operation is retried.
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///
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/// [`read`]: Read::read
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/// [`write`]: Write::write
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///
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/// # Examples
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///
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/// ```
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/// use std::io;
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///
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/// fn main() -> io::Result<()> {
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/// let mut reader: &[u8] = b"hello";
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/// let mut writer: Vec<u8> = vec![];
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///
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/// io::copy(&mut reader, &mut writer)?;
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///
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/// assert_eq!(&b"hello"[..], &writer[..]);
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/// Ok(())
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/// }
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn copy<R: ?Sized, W: ?Sized>(reader: &mut R, writer: &mut W) -> io::Result<u64>
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where
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R: Read,
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W: Write,
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{
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let mut buf = MaybeUninit::<[u8; super::DEFAULT_BUF_SIZE]>::uninit();
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// FIXME: #42788
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//
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// - This creates a (mut) reference to a slice of
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// _uninitialized_ integers, which is **undefined behavior**
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//
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// - Only the standard library gets to soundly "ignore" this,
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// based on its privileged knowledge of unstable rustc
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// internals;
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unsafe {
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reader.initializer().initialize(buf.assume_init_mut());
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}
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let mut written = 0;
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loop {
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let len = match reader.read(unsafe { buf.assume_init_mut() }) {
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Ok(0) => return Ok(written),
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Ok(len) => len,
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Err(ref e) if e.kind() == ErrorKind::Interrupted => continue,
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Err(e) => return Err(e),
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||||
};
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writer.write_all(unsafe { &buf.assume_init_ref()[..len] })?;
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written += len as u64;
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}
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}
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use crate::io::{self, BufRead, Initializer, IoSlice, IoSliceMut, Read, Write};
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/// A reader which is always at EOF.
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///
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@ -317,6 +317,7 @@
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#![feature(toowned_clone_into)]
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#![feature(total_cmp)]
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#![feature(trace_macros)]
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#![feature(try_blocks)]
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#![feature(try_reserve)]
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#![feature(unboxed_closures)]
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#![feature(unsafe_block_in_unsafe_fn)]
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@ -1204,88 +1204,19 @@ pub fn copy(from: &Path, to: &Path) -> io::Result<u64> {
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#[cfg(any(target_os = "linux", target_os = "android"))]
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pub fn copy(from: &Path, to: &Path) -> io::Result<u64> {
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use crate::cmp;
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use crate::sync::atomic::{AtomicBool, Ordering};
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// Kernel prior to 4.5 don't have copy_file_range
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// We store the availability in a global to avoid unnecessary syscalls
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static HAS_COPY_FILE_RANGE: AtomicBool = AtomicBool::new(true);
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unsafe fn copy_file_range(
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fd_in: libc::c_int,
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off_in: *mut libc::loff_t,
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fd_out: libc::c_int,
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off_out: *mut libc::loff_t,
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len: libc::size_t,
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flags: libc::c_uint,
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||||
) -> libc::c_long {
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libc::syscall(libc::SYS_copy_file_range, fd_in, off_in, fd_out, off_out, len, flags)
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}
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let (mut reader, reader_metadata) = open_from(from)?;
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let max_len = u64::MAX;
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let (mut writer, _) = open_to_and_set_permissions(to, reader_metadata)?;
|
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|
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let has_copy_file_range = HAS_COPY_FILE_RANGE.load(Ordering::Relaxed);
|
||||
let mut written = 0u64;
|
||||
while written < max_len {
|
||||
let copy_result = if has_copy_file_range {
|
||||
let bytes_to_copy = cmp::min(max_len - written, usize::MAX as u64) as usize;
|
||||
let copy_result = unsafe {
|
||||
// We actually don't have to adjust the offsets,
|
||||
// because copy_file_range adjusts the file offset automatically
|
||||
cvt(copy_file_range(
|
||||
reader.as_raw_fd(),
|
||||
ptr::null_mut(),
|
||||
writer.as_raw_fd(),
|
||||
ptr::null_mut(),
|
||||
bytes_to_copy,
|
||||
0,
|
||||
))
|
||||
};
|
||||
if let Err(ref copy_err) = copy_result {
|
||||
match copy_err.raw_os_error() {
|
||||
Some(libc::ENOSYS | libc::EPERM | libc::EOPNOTSUPP) => {
|
||||
HAS_COPY_FILE_RANGE.store(false, Ordering::Relaxed);
|
||||
}
|
||||
_ => {}
|
||||
}
|
||||
}
|
||||
copy_result
|
||||
} else {
|
||||
Err(io::Error::from_raw_os_error(libc::ENOSYS))
|
||||
};
|
||||
match copy_result {
|
||||
Ok(0) if written == 0 => {
|
||||
// fallback to work around several kernel bugs where copy_file_range will fail to
|
||||
// copy any bytes and return 0 instead of an error if
|
||||
// - reading virtual files from the proc filesystem which appear to have 0 size
|
||||
// but are not empty. noted in coreutils to affect kernels at least up to 5.6.19.
|
||||
// - copying from an overlay filesystem in docker. reported to occur on fedora 32.
|
||||
return io::copy(&mut reader, &mut writer);
|
||||
}
|
||||
Ok(0) => return Ok(written), // reached EOF
|
||||
Ok(ret) => written += ret as u64,
|
||||
Err(err) => {
|
||||
match err.raw_os_error() {
|
||||
Some(
|
||||
libc::ENOSYS | libc::EXDEV | libc::EINVAL | libc::EPERM | libc::EOPNOTSUPP,
|
||||
) => {
|
||||
// Try fallback io::copy if either:
|
||||
// - Kernel version is < 4.5 (ENOSYS)
|
||||
// - Files are mounted on different fs (EXDEV)
|
||||
// - copy_file_range is broken in various ways on RHEL/CentOS 7 (EOPNOTSUPP)
|
||||
// - copy_file_range is disallowed, for example by seccomp (EPERM)
|
||||
// - copy_file_range cannot be used with pipes or device nodes (EINVAL)
|
||||
assert_eq!(written, 0);
|
||||
return io::copy(&mut reader, &mut writer);
|
||||
}
|
||||
_ => return Err(err),
|
||||
}
|
||||
}
|
||||
}
|
||||
use super::kernel_copy::{copy_regular_files, CopyResult};
|
||||
|
||||
match copy_regular_files(reader.as_raw_fd(), writer.as_raw_fd(), max_len) {
|
||||
CopyResult::Ended(result) => result,
|
||||
CopyResult::Fallback(written) => match io::copy::generic_copy(&mut reader, &mut writer) {
|
||||
Ok(bytes) => Ok(bytes + written),
|
||||
Err(e) => Err(e),
|
||||
},
|
||||
}
|
||||
Ok(written)
|
||||
}
|
||||
|
||||
#[cfg(any(target_os = "macos", target_os = "ios"))]
|
||||
|
||||
603
library/std/src/sys/unix/kernel_copy.rs
Normal file
603
library/std/src/sys/unix/kernel_copy.rs
Normal file
@ -0,0 +1,603 @@
|
||||
//! This module contains specializations that can offload `io::copy()` operations on file descriptor
|
||||
//! containing types (`File`, `TcpStream`, etc.) to more efficient syscalls than `read(2)` and `write(2)`.
|
||||
//!
|
||||
//! Specialization is only applied to wholly std-owned types so that user code can't observe
|
||||
//! that the `Read` and `Write` traits are not used.
|
||||
//!
|
||||
//! Since a copy operation involves a reader and writer side where each can consist of different types
|
||||
//! and also involve generic wrappers (e.g. `Take`, `BufReader`) it is not practical to specialize
|
||||
//! a single method on all possible combinations.
|
||||
//!
|
||||
//! Instead readers and writers are handled separately by the `CopyRead` and `CopyWrite` specialization
|
||||
//! traits and then specialized on by the `Copier::copy` method.
|
||||
//!
|
||||
//! `Copier` uses the specialization traits to unpack the underlying file descriptors and
|
||||
//! additional prerequisites and constraints imposed by the wrapper types.
|
||||
//!
|
||||
//! Once it has obtained all necessary pieces and brought any wrapper types into a state where they
|
||||
//! can be safely bypassed it will attempt to use the `copy_file_range(2)`,
|
||||
//! `sendfile(2)` or `splice(2)` syscalls to move data directly between file descriptors.
|
||||
//! Since those syscalls have requirements that cannot be fully checked in advance and
|
||||
//! gathering additional information about file descriptors would require additional syscalls
|
||||
//! anyway it simply attempts to use them one after another (guided by inaccurate hints) to
|
||||
//! figure out which one works and and falls back to the generic read-write copy loop if none of them
|
||||
//! does.
|
||||
//! Once a working syscall is found for a pair of file descriptors it will be called in a loop
|
||||
//! until the copy operation is completed.
|
||||
//!
|
||||
//! Advantages of using these syscalls:
|
||||
//!
|
||||
//! * fewer context switches since reads and writes are coalesced into a single syscall
|
||||
//! and more bytes are transferred per syscall. This translates to higher throughput
|
||||
//! and fewer CPU cycles, at least for sufficiently large transfers to amortize the initial probing.
|
||||
//! * `copy_file_range` creates reflink copies on CoW filesystems, thus moving less data and
|
||||
//! consuming less disk space
|
||||
//! * `sendfile` and `splice` can perform zero-copy IO under some circumstances while
|
||||
//! a naive copy loop would move every byte through the CPU.
|
||||
//!
|
||||
//! Drawbacks:
|
||||
//!
|
||||
//! * copy operations smaller than the default buffer size can under some circumstances, especially
|
||||
//! on older kernels, incur more syscalls than the naive approach would. As mentioned above
|
||||
//! the syscall selection is guided by hints to minimize this possibility but they are not perfect.
|
||||
//! * optimizations only apply to std types. If a user adds a custom wrapper type, e.g. to report
|
||||
//! progress, they can hit a performance cliff.
|
||||
//! * complexity
|
||||
|
||||
use crate::cmp::min;
|
||||
use crate::convert::TryInto;
|
||||
use crate::fs::{File, Metadata};
|
||||
use crate::io::copy::generic_copy;
|
||||
use crate::io::{
|
||||
BufRead, BufReader, BufWriter, Error, Read, Result, StderrLock, StdinLock, StdoutLock, Take,
|
||||
Write,
|
||||
};
|
||||
use crate::mem::ManuallyDrop;
|
||||
use crate::net::TcpStream;
|
||||
use crate::os::unix::fs::FileTypeExt;
|
||||
use crate::os::unix::io::{AsRawFd, FromRawFd, RawFd};
|
||||
use crate::process::{ChildStderr, ChildStdin, ChildStdout};
|
||||
use crate::ptr;
|
||||
use crate::sync::atomic::{AtomicBool, Ordering};
|
||||
use crate::sys::cvt;
|
||||
|
||||
#[cfg(test)]
|
||||
mod tests;
|
||||
|
||||
pub(crate) fn copy_spec<R: Read + ?Sized, W: Write + ?Sized>(
|
||||
read: &mut R,
|
||||
write: &mut W,
|
||||
) -> Result<u64> {
|
||||
let copier = Copier { read, write };
|
||||
SpecCopy::copy(copier)
|
||||
}
|
||||
|
||||
/// This type represents either the inferred `FileType` of a `RawFd` based on the source
|
||||
/// type from which it was extracted or the actual metadata
|
||||
///
|
||||
/// The methods on this type only provide hints, due to `AsRawFd` and `FromRawFd` the inferred
|
||||
/// type may be wrong.
|
||||
enum FdMeta {
|
||||
/// We obtained the FD from a type that can contain any type of `FileType` and queried the metadata
|
||||
/// because it is cheaper than probing all possible syscalls (reader side)
|
||||
Metadata(Metadata),
|
||||
Socket,
|
||||
Pipe,
|
||||
/// We don't have any metadata, e.g. because the original type was `File` which can represent
|
||||
/// any `FileType` and we did not query the metadata either since it did not seem beneficial
|
||||
/// (writer side)
|
||||
NoneObtained,
|
||||
}
|
||||
|
||||
impl FdMeta {
|
||||
fn maybe_fifo(&self) -> bool {
|
||||
match self {
|
||||
FdMeta::Metadata(meta) => meta.file_type().is_fifo(),
|
||||
FdMeta::Socket => false,
|
||||
FdMeta::Pipe => true,
|
||||
FdMeta::NoneObtained => true,
|
||||
}
|
||||
}
|
||||
|
||||
fn potential_sendfile_source(&self) -> bool {
|
||||
match self {
|
||||
// procfs erronously shows 0 length on non-empty readable files.
|
||||
// and if a file is truly empty then a `read` syscall will determine that and skip the write syscall
|
||||
// thus there would be benefit from attempting sendfile
|
||||
FdMeta::Metadata(meta)
|
||||
if meta.file_type().is_file() && meta.len() > 0
|
||||
|| meta.file_type().is_block_device() =>
|
||||
{
|
||||
true
|
||||
}
|
||||
_ => false,
|
||||
}
|
||||
}
|
||||
|
||||
fn copy_file_range_candidate(&self) -> bool {
|
||||
match self {
|
||||
// copy_file_range will fail on empty procfs files. `read` can determine whether EOF has been reached
|
||||
// without extra cost and skip the write, thus there is no benefit in attempting copy_file_range
|
||||
FdMeta::Metadata(meta) if meta.is_file() && meta.len() > 0 => true,
|
||||
FdMeta::NoneObtained => true,
|
||||
_ => false,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
struct CopyParams(FdMeta, Option<RawFd>);
|
||||
|
||||
struct Copier<'a, 'b, R: Read + ?Sized, W: Write + ?Sized> {
|
||||
read: &'a mut R,
|
||||
write: &'b mut W,
|
||||
}
|
||||
|
||||
trait SpecCopy {
|
||||
fn copy(self) -> Result<u64>;
|
||||
}
|
||||
|
||||
impl<R: Read + ?Sized, W: Write + ?Sized> SpecCopy for Copier<'_, '_, R, W> {
|
||||
default fn copy(self) -> Result<u64> {
|
||||
generic_copy(self.read, self.write)
|
||||
}
|
||||
}
|
||||
|
||||
impl<R: CopyRead, W: CopyWrite> SpecCopy for Copier<'_, '_, R, W> {
|
||||
fn copy(self) -> Result<u64> {
|
||||
let (reader, writer) = (self.read, self.write);
|
||||
let r_cfg = reader.properties();
|
||||
let w_cfg = writer.properties();
|
||||
|
||||
// before direct operations on file descriptors ensure that all source and sink buffers are empty
|
||||
let mut flush = || -> crate::io::Result<u64> {
|
||||
let bytes = reader.drain_to(writer, u64::MAX)?;
|
||||
// BufWriter buffered bytes have already been accounted for in earlier write() calls
|
||||
writer.flush()?;
|
||||
Ok(bytes)
|
||||
};
|
||||
|
||||
let mut written = 0u64;
|
||||
|
||||
if let (CopyParams(input_meta, Some(readfd)), CopyParams(output_meta, Some(writefd))) =
|
||||
(r_cfg, w_cfg)
|
||||
{
|
||||
written += flush()?;
|
||||
let max_write = reader.min_limit();
|
||||
|
||||
if input_meta.copy_file_range_candidate() && output_meta.copy_file_range_candidate() {
|
||||
let result = copy_regular_files(readfd, writefd, max_write);
|
||||
|
||||
match result {
|
||||
CopyResult::Ended(Ok(bytes_copied)) => return Ok(bytes_copied + written),
|
||||
CopyResult::Ended(err) => return err,
|
||||
CopyResult::Fallback(bytes) => written += bytes,
|
||||
}
|
||||
}
|
||||
|
||||
// on modern kernels sendfile can copy from any mmapable type (some but not all regular files and block devices)
|
||||
// to any writable file descriptor. On older kernels the writer side can only be a socket.
|
||||
// So we just try and fallback if needed.
|
||||
// If current file offsets + write sizes overflow it may also fail, we do not try to fix that and instead
|
||||
// fall back to the generic copy loop.
|
||||
if input_meta.potential_sendfile_source() {
|
||||
let result = sendfile_splice(SpliceMode::Sendfile, readfd, writefd, max_write);
|
||||
|
||||
match result {
|
||||
CopyResult::Ended(Ok(bytes_copied)) => return Ok(bytes_copied + written),
|
||||
CopyResult::Ended(err) => return err,
|
||||
CopyResult::Fallback(bytes) => written += bytes,
|
||||
}
|
||||
}
|
||||
|
||||
if input_meta.maybe_fifo() || output_meta.maybe_fifo() {
|
||||
let result = sendfile_splice(SpliceMode::Splice, readfd, writefd, max_write);
|
||||
|
||||
match result {
|
||||
CopyResult::Ended(Ok(bytes_copied)) => return Ok(bytes_copied + written),
|
||||
CopyResult::Ended(err) => return err,
|
||||
CopyResult::Fallback(0) => { /* use the fallback below */ }
|
||||
CopyResult::Fallback(_) => {
|
||||
unreachable!("splice should not return > 0 bytes on the fallback path")
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// fallback if none of the more specialized syscalls wants to work with these file descriptors
|
||||
match generic_copy(reader, writer) {
|
||||
Ok(bytes) => Ok(bytes + written),
|
||||
err => err,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#[rustc_specialization_trait]
|
||||
trait CopyRead: Read {
|
||||
/// Implementations that contain buffers (i.e. `BufReader`) must transfer data from their internal
|
||||
/// buffers into `writer` until either the buffers are emptied or `limit` bytes have been
|
||||
/// transferred, whichever occurs sooner.
|
||||
/// If nested buffers are present the outer buffers must be drained first.
|
||||
///
|
||||
/// This is necessary to directly bypass the wrapper types while preserving the data order
|
||||
/// when operating directly on the underlying file descriptors.
|
||||
fn drain_to<W: Write>(&mut self, _writer: &mut W, _limit: u64) -> Result<u64> {
|
||||
Ok(0)
|
||||
}
|
||||
|
||||
/// The minimum of the limit of all `Take<_>` wrappers, `u64::MAX` otherwise.
|
||||
/// This method does not account for data `BufReader` buffers and would underreport
|
||||
/// the limit of a `Take<BufReader<Take<_>>>` type. Thus its result is only valid
|
||||
/// after draining the buffers via `drain_to`.
|
||||
fn min_limit(&self) -> u64 {
|
||||
u64::MAX
|
||||
}
|
||||
|
||||
/// Extracts the file descriptor and hints/metadata, delegating through wrappers if necessary.
|
||||
fn properties(&self) -> CopyParams;
|
||||
}
|
||||
|
||||
#[rustc_specialization_trait]
|
||||
trait CopyWrite: Write {
|
||||
/// Extracts the file descriptor and hints/metadata, delegating through wrappers if necessary.
|
||||
fn properties(&self) -> CopyParams;
|
||||
}
|
||||
|
||||
impl<T> CopyRead for &mut T
|
||||
where
|
||||
T: CopyRead,
|
||||
{
|
||||
fn drain_to<W: Write>(&mut self, writer: &mut W, limit: u64) -> Result<u64> {
|
||||
(**self).drain_to(writer, limit)
|
||||
}
|
||||
|
||||
fn min_limit(&self) -> u64 {
|
||||
(**self).min_limit()
|
||||
}
|
||||
|
||||
fn properties(&self) -> CopyParams {
|
||||
(**self).properties()
|
||||
}
|
||||
}
|
||||
|
||||
impl<T> CopyWrite for &mut T
|
||||
where
|
||||
T: CopyWrite,
|
||||
{
|
||||
fn properties(&self) -> CopyParams {
|
||||
(**self).properties()
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyRead for File {
|
||||
fn properties(&self) -> CopyParams {
|
||||
CopyParams(fd_to_meta(self), Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyRead for &File {
|
||||
fn properties(&self) -> CopyParams {
|
||||
CopyParams(fd_to_meta(*self), Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyWrite for File {
|
||||
fn properties(&self) -> CopyParams {
|
||||
CopyParams(FdMeta::NoneObtained, Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyWrite for &File {
|
||||
fn properties(&self) -> CopyParams {
|
||||
CopyParams(FdMeta::NoneObtained, Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyRead for TcpStream {
|
||||
fn properties(&self) -> CopyParams {
|
||||
// avoid the stat syscall since we can be fairly sure it's a socket
|
||||
CopyParams(FdMeta::Socket, Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyRead for &TcpStream {
|
||||
fn properties(&self) -> CopyParams {
|
||||
// avoid the stat syscall since we can be fairly sure it's a socket
|
||||
CopyParams(FdMeta::Socket, Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyWrite for TcpStream {
|
||||
fn properties(&self) -> CopyParams {
|
||||
// avoid the stat syscall since we can be fairly sure it's a socket
|
||||
CopyParams(FdMeta::Socket, Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyWrite for &TcpStream {
|
||||
fn properties(&self) -> CopyParams {
|
||||
// avoid the stat syscall since we can be fairly sure it's a socket
|
||||
CopyParams(FdMeta::Socket, Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyWrite for ChildStdin {
|
||||
fn properties(&self) -> CopyParams {
|
||||
CopyParams(FdMeta::Pipe, Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyRead for ChildStdout {
|
||||
fn properties(&self) -> CopyParams {
|
||||
CopyParams(FdMeta::Pipe, Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyRead for ChildStderr {
|
||||
fn properties(&self) -> CopyParams {
|
||||
CopyParams(FdMeta::Pipe, Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyRead for StdinLock<'_> {
|
||||
fn drain_to<W: Write>(&mut self, writer: &mut W, outer_limit: u64) -> Result<u64> {
|
||||
let buf_reader = self.as_mut_buf();
|
||||
let buf = buf_reader.buffer();
|
||||
let buf = &buf[0..min(buf.len(), outer_limit.try_into().unwrap_or(usize::MAX))];
|
||||
let bytes_drained = buf.len();
|
||||
writer.write_all(buf)?;
|
||||
buf_reader.consume(bytes_drained);
|
||||
|
||||
Ok(bytes_drained as u64)
|
||||
}
|
||||
|
||||
fn properties(&self) -> CopyParams {
|
||||
CopyParams(fd_to_meta(self), Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyWrite for StdoutLock<'_> {
|
||||
fn properties(&self) -> CopyParams {
|
||||
CopyParams(FdMeta::NoneObtained, Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl CopyWrite for StderrLock<'_> {
|
||||
fn properties(&self) -> CopyParams {
|
||||
CopyParams(FdMeta::NoneObtained, Some(self.as_raw_fd()))
|
||||
}
|
||||
}
|
||||
|
||||
impl<T: CopyRead> CopyRead for Take<T> {
|
||||
fn drain_to<W: Write>(&mut self, writer: &mut W, outer_limit: u64) -> Result<u64> {
|
||||
let local_limit = self.limit();
|
||||
let combined_limit = min(outer_limit, local_limit);
|
||||
let bytes_drained = self.get_mut().drain_to(writer, combined_limit)?;
|
||||
// update limit since read() was bypassed
|
||||
self.set_limit(local_limit - bytes_drained);
|
||||
|
||||
Ok(bytes_drained)
|
||||
}
|
||||
|
||||
fn min_limit(&self) -> u64 {
|
||||
min(Take::limit(self), self.get_ref().min_limit())
|
||||
}
|
||||
|
||||
fn properties(&self) -> CopyParams {
|
||||
self.get_ref().properties()
|
||||
}
|
||||
}
|
||||
|
||||
impl<T: CopyRead> CopyRead for BufReader<T> {
|
||||
fn drain_to<W: Write>(&mut self, writer: &mut W, outer_limit: u64) -> Result<u64> {
|
||||
let buf = self.buffer();
|
||||
let buf = &buf[0..min(buf.len(), outer_limit.try_into().unwrap_or(usize::MAX))];
|
||||
let bytes = buf.len();
|
||||
writer.write_all(buf)?;
|
||||
self.consume(bytes);
|
||||
|
||||
let remaining = outer_limit - bytes as u64;
|
||||
|
||||
// in case of nested bufreaders we also need to drain the ones closer to the source
|
||||
let inner_bytes = self.get_mut().drain_to(writer, remaining)?;
|
||||
|
||||
Ok(bytes as u64 + inner_bytes)
|
||||
}
|
||||
|
||||
fn min_limit(&self) -> u64 {
|
||||
self.get_ref().min_limit()
|
||||
}
|
||||
|
||||
fn properties(&self) -> CopyParams {
|
||||
self.get_ref().properties()
|
||||
}
|
||||
}
|
||||
|
||||
impl<T: CopyWrite> CopyWrite for BufWriter<T> {
|
||||
fn properties(&self) -> CopyParams {
|
||||
self.get_ref().properties()
|
||||
}
|
||||
}
|
||||
|
||||
fn fd_to_meta<T: AsRawFd>(fd: &T) -> FdMeta {
|
||||
let fd = fd.as_raw_fd();
|
||||
let file: ManuallyDrop<File> = ManuallyDrop::new(unsafe { File::from_raw_fd(fd) });
|
||||
match file.metadata() {
|
||||
Ok(meta) => FdMeta::Metadata(meta),
|
||||
Err(_) => FdMeta::NoneObtained,
|
||||
}
|
||||
}
|
||||
|
||||
pub(super) enum CopyResult {
|
||||
Ended(Result<u64>),
|
||||
Fallback(u64),
|
||||
}
|
||||
|
||||
/// linux-specific implementation that will attempt to use copy_file_range for copy offloading
|
||||
/// as the name says, it only works on regular files
|
||||
///
|
||||
/// Callers must handle fallback to a generic copy loop.
|
||||
/// `Fallback` may indicate non-zero number of bytes already written
|
||||
/// if one of the files' cursor +`max_len` would exceed u64::MAX (`EOVERFLOW`).
|
||||
pub(super) fn copy_regular_files(reader: RawFd, writer: RawFd, max_len: u64) -> CopyResult {
|
||||
use crate::cmp;
|
||||
|
||||
// Kernel prior to 4.5 don't have copy_file_range
|
||||
// We store the availability in a global to avoid unnecessary syscalls
|
||||
static HAS_COPY_FILE_RANGE: AtomicBool = AtomicBool::new(true);
|
||||
|
||||
unsafe fn copy_file_range(
|
||||
fd_in: libc::c_int,
|
||||
off_in: *mut libc::loff_t,
|
||||
fd_out: libc::c_int,
|
||||
off_out: *mut libc::loff_t,
|
||||
len: libc::size_t,
|
||||
flags: libc::c_uint,
|
||||
) -> libc::c_long {
|
||||
libc::syscall(libc::SYS_copy_file_range, fd_in, off_in, fd_out, off_out, len, flags)
|
||||
}
|
||||
|
||||
let has_copy_file_range = HAS_COPY_FILE_RANGE.load(Ordering::Relaxed);
|
||||
let mut written = 0u64;
|
||||
while written < max_len {
|
||||
let copy_result = if has_copy_file_range {
|
||||
let bytes_to_copy = cmp::min(max_len - written, usize::MAX as u64);
|
||||
// cap to 1GB chunks in case u64::MAX is passed as max_len and the file has a non-zero seek position
|
||||
// this allows us to copy large chunks without hitting EOVERFLOW,
|
||||
// unless someone sets a file offset close to u64::MAX - 1GB, in which case a fallback would be required
|
||||
let bytes_to_copy = cmp::min(bytes_to_copy as usize, 0x4000_0000usize);
|
||||
let copy_result = unsafe {
|
||||
// We actually don't have to adjust the offsets,
|
||||
// because copy_file_range adjusts the file offset automatically
|
||||
cvt(copy_file_range(
|
||||
reader,
|
||||
ptr::null_mut(),
|
||||
writer,
|
||||
ptr::null_mut(),
|
||||
bytes_to_copy,
|
||||
0,
|
||||
))
|
||||
};
|
||||
if let Err(ref copy_err) = copy_result {
|
||||
match copy_err.raw_os_error() {
|
||||
Some(libc::ENOSYS | libc::EPERM | libc::EOPNOTSUPP) => {
|
||||
HAS_COPY_FILE_RANGE.store(false, Ordering::Relaxed);
|
||||
}
|
||||
_ => {}
|
||||
}
|
||||
}
|
||||
copy_result
|
||||
} else {
|
||||
Err(Error::from_raw_os_error(libc::ENOSYS))
|
||||
};
|
||||
match copy_result {
|
||||
Ok(0) if written == 0 => {
|
||||
// fallback to work around several kernel bugs where copy_file_range will fail to
|
||||
// copy any bytes and return 0 instead of an error if
|
||||
// - reading virtual files from the proc filesystem which appear to have 0 size
|
||||
// but are not empty. noted in coreutils to affect kernels at least up to 5.6.19.
|
||||
// - copying from an overlay filesystem in docker. reported to occur on fedora 32.
|
||||
return CopyResult::Fallback(0);
|
||||
}
|
||||
Ok(0) => return CopyResult::Ended(Ok(written)), // reached EOF
|
||||
Ok(ret) => written += ret as u64,
|
||||
Err(err) => {
|
||||
return match err.raw_os_error() {
|
||||
// when file offset + max_length > u64::MAX
|
||||
Some(libc::EOVERFLOW) => CopyResult::Fallback(written),
|
||||
Some(
|
||||
libc::ENOSYS | libc::EXDEV | libc::EINVAL | libc::EPERM | libc::EOPNOTSUPP,
|
||||
) => {
|
||||
// Try fallback io::copy if either:
|
||||
// - Kernel version is < 4.5 (ENOSYS)
|
||||
// - Files are mounted on different fs (EXDEV)
|
||||
// - copy_file_range is broken in various ways on RHEL/CentOS 7 (EOPNOTSUPP)
|
||||
// - copy_file_range is disallowed, for example by seccomp (EPERM)
|
||||
// - copy_file_range cannot be used with pipes or device nodes (EINVAL)
|
||||
assert_eq!(written, 0);
|
||||
CopyResult::Fallback(0)
|
||||
}
|
||||
_ => CopyResult::Ended(Err(err)),
|
||||
};
|
||||
}
|
||||
}
|
||||
}
|
||||
CopyResult::Ended(Ok(written))
|
||||
}
|
||||
|
||||
#[derive(PartialEq)]
|
||||
enum SpliceMode {
|
||||
Sendfile,
|
||||
Splice,
|
||||
}
|
||||
|
||||
/// performs splice or sendfile between file descriptors
|
||||
/// Does _not_ fall back to a generic copy loop.
|
||||
fn sendfile_splice(mode: SpliceMode, reader: RawFd, writer: RawFd, len: u64) -> CopyResult {
|
||||
static HAS_SENDFILE: AtomicBool = AtomicBool::new(true);
|
||||
static HAS_SPLICE: AtomicBool = AtomicBool::new(true);
|
||||
|
||||
syscall! {
|
||||
fn splice(
|
||||
srcfd: libc::c_int,
|
||||
src_offset: *const i64,
|
||||
dstfd: libc::c_int,
|
||||
dst_offset: *const i64,
|
||||
len: libc::size_t,
|
||||
flags: libc::c_int
|
||||
) -> libc::ssize_t
|
||||
}
|
||||
|
||||
match mode {
|
||||
SpliceMode::Sendfile if !HAS_SENDFILE.load(Ordering::Relaxed) => {
|
||||
return CopyResult::Fallback(0);
|
||||
}
|
||||
SpliceMode::Splice if !HAS_SPLICE.load(Ordering::Relaxed) => {
|
||||
return CopyResult::Fallback(0);
|
||||
}
|
||||
_ => (),
|
||||
}
|
||||
|
||||
let mut written = 0u64;
|
||||
while written < len {
|
||||
// according to its manpage that's the maximum size sendfile() will copy per invocation
|
||||
let chunk_size = crate::cmp::min(len - written, 0x7ffff000_u64) as usize;
|
||||
|
||||
let result = match mode {
|
||||
SpliceMode::Sendfile => {
|
||||
cvt(unsafe { libc::sendfile(writer, reader, ptr::null_mut(), chunk_size) })
|
||||
}
|
||||
SpliceMode::Splice => cvt(unsafe {
|
||||
splice(reader, ptr::null_mut(), writer, ptr::null_mut(), chunk_size, 0)
|
||||
}),
|
||||
};
|
||||
|
||||
match result {
|
||||
Ok(0) => break, // EOF
|
||||
Ok(ret) => written += ret as u64,
|
||||
Err(err) => {
|
||||
return match err.raw_os_error() {
|
||||
Some(libc::ENOSYS | libc::EPERM) => {
|
||||
// syscall not supported (ENOSYS)
|
||||
// syscall is disallowed, e.g. by seccomp (EPERM)
|
||||
match mode {
|
||||
SpliceMode::Sendfile => HAS_SENDFILE.store(false, Ordering::Relaxed),
|
||||
SpliceMode::Splice => HAS_SPLICE.store(false, Ordering::Relaxed),
|
||||
}
|
||||
assert_eq!(written, 0);
|
||||
CopyResult::Fallback(0)
|
||||
}
|
||||
Some(libc::EINVAL) => {
|
||||
// splice/sendfile do not support this particular file descriptor (EINVAL)
|
||||
assert_eq!(written, 0);
|
||||
CopyResult::Fallback(0)
|
||||
}
|
||||
Some(os_err) if mode == SpliceMode::Sendfile && os_err == libc::EOVERFLOW => {
|
||||
CopyResult::Fallback(written)
|
||||
}
|
||||
_ => CopyResult::Ended(Err(err)),
|
||||
};
|
||||
}
|
||||
}
|
||||
}
|
||||
CopyResult::Ended(Ok(written))
|
||||
}
|
||||
213
library/std/src/sys/unix/kernel_copy/tests.rs
Normal file
213
library/std/src/sys/unix/kernel_copy/tests.rs
Normal file
@ -0,0 +1,213 @@
|
||||
use crate::env::temp_dir;
|
||||
use crate::fs::OpenOptions;
|
||||
use crate::io;
|
||||
use crate::io::Result;
|
||||
use crate::io::SeekFrom;
|
||||
use crate::io::{BufRead, Read, Seek, Write};
|
||||
use crate::os::unix::io::AsRawFd;
|
||||
|
||||
#[test]
|
||||
fn copy_specialization() -> Result<()> {
|
||||
use crate::io::{BufReader, BufWriter};
|
||||
|
||||
let path = crate::env::temp_dir();
|
||||
let source_path = path.join("copy-spec.source");
|
||||
let sink_path = path.join("copy-spec.sink");
|
||||
|
||||
let result: Result<()> = try {
|
||||
let mut source = crate::fs::OpenOptions::new()
|
||||
.read(true)
|
||||
.write(true)
|
||||
.create(true)
|
||||
.truncate(true)
|
||||
.open(&source_path)?;
|
||||
source.write_all(b"abcdefghiklmnopqr")?;
|
||||
source.seek(SeekFrom::Start(8))?;
|
||||
let mut source = BufReader::with_capacity(8, source.take(5));
|
||||
source.fill_buf()?;
|
||||
assert_eq!(source.buffer(), b"iklmn");
|
||||
source.get_mut().set_limit(6);
|
||||
source.get_mut().get_mut().seek(SeekFrom::Start(1))?; // "bcdefg"
|
||||
let mut source = source.take(10); // "iklmnbcdef"
|
||||
|
||||
let mut sink = crate::fs::OpenOptions::new()
|
||||
.read(true)
|
||||
.write(true)
|
||||
.create(true)
|
||||
.truncate(true)
|
||||
.open(&sink_path)?;
|
||||
sink.write_all(b"000000")?;
|
||||
let mut sink = BufWriter::with_capacity(5, sink);
|
||||
sink.write_all(b"wxyz")?;
|
||||
assert_eq!(sink.buffer(), b"wxyz");
|
||||
|
||||
let copied = crate::io::copy(&mut source, &mut sink)?;
|
||||
assert_eq!(copied, 10);
|
||||
assert_eq!(sink.buffer().len(), 0);
|
||||
|
||||
let mut sink = sink.into_inner()?;
|
||||
sink.seek(SeekFrom::Start(0))?;
|
||||
let mut copied = Vec::new();
|
||||
sink.read_to_end(&mut copied)?;
|
||||
assert_eq!(&copied, b"000000wxyziklmnbcdef");
|
||||
};
|
||||
|
||||
let rm1 = crate::fs::remove_file(source_path);
|
||||
let rm2 = crate::fs::remove_file(sink_path);
|
||||
|
||||
result.and(rm1).and(rm2)
|
||||
}
|
||||
|
||||
#[bench]
|
||||
fn bench_file_to_file_copy(b: &mut test::Bencher) {
|
||||
const BYTES: usize = 128 * 1024;
|
||||
let src_path = temp_dir().join("file-copy-bench-src");
|
||||
let mut src = crate::fs::OpenOptions::new()
|
||||
.create(true)
|
||||
.truncate(true)
|
||||
.read(true)
|
||||
.write(true)
|
||||
.open(src_path)
|
||||
.unwrap();
|
||||
src.write(&vec![0u8; BYTES]).unwrap();
|
||||
|
||||
let sink_path = temp_dir().join("file-copy-bench-sink");
|
||||
let mut sink = crate::fs::OpenOptions::new()
|
||||
.create(true)
|
||||
.truncate(true)
|
||||
.write(true)
|
||||
.open(sink_path)
|
||||
.unwrap();
|
||||
|
||||
b.bytes = BYTES as u64;
|
||||
b.iter(|| {
|
||||
src.seek(SeekFrom::Start(0)).unwrap();
|
||||
sink.seek(SeekFrom::Start(0)).unwrap();
|
||||
assert_eq!(BYTES as u64, io::copy(&mut src, &mut sink).unwrap());
|
||||
});
|
||||
}
|
||||
|
||||
#[bench]
|
||||
fn bench_file_to_socket_copy(b: &mut test::Bencher) {
|
||||
const BYTES: usize = 128 * 1024;
|
||||
let src_path = temp_dir().join("pipe-copy-bench-src");
|
||||
let mut src = OpenOptions::new()
|
||||
.create(true)
|
||||
.truncate(true)
|
||||
.read(true)
|
||||
.write(true)
|
||||
.open(src_path)
|
||||
.unwrap();
|
||||
src.write(&vec![0u8; BYTES]).unwrap();
|
||||
|
||||
let sink_drainer = crate::net::TcpListener::bind("localhost:0").unwrap();
|
||||
let mut sink = crate::net::TcpStream::connect(sink_drainer.local_addr().unwrap()).unwrap();
|
||||
let mut sink_drainer = sink_drainer.accept().unwrap().0;
|
||||
|
||||
crate::thread::spawn(move || {
|
||||
let mut sink_buf = vec![0u8; 1024 * 1024];
|
||||
loop {
|
||||
sink_drainer.read(&mut sink_buf[..]).unwrap();
|
||||
}
|
||||
});
|
||||
|
||||
b.bytes = BYTES as u64;
|
||||
b.iter(|| {
|
||||
src.seek(SeekFrom::Start(0)).unwrap();
|
||||
assert_eq!(BYTES as u64, io::copy(&mut src, &mut sink).unwrap());
|
||||
});
|
||||
}
|
||||
|
||||
#[cfg(any(target_os = "linux", target_os = "android"))]
|
||||
#[bench]
|
||||
fn bench_socket_pipe_socket_copy(b: &mut test::Bencher) {
|
||||
use super::CopyResult;
|
||||
use crate::io::ErrorKind;
|
||||
use crate::process::{ChildStdin, ChildStdout};
|
||||
use crate::sys_common::FromInner;
|
||||
|
||||
let (read_end, write_end) = crate::sys::pipe::anon_pipe().unwrap();
|
||||
|
||||
let mut read_end = ChildStdout::from_inner(read_end);
|
||||
let write_end = ChildStdin::from_inner(write_end);
|
||||
|
||||
let acceptor = crate::net::TcpListener::bind("localhost:0").unwrap();
|
||||
let mut remote_end = crate::net::TcpStream::connect(acceptor.local_addr().unwrap()).unwrap();
|
||||
|
||||
let local_end = crate::sync::Arc::new(acceptor.accept().unwrap().0);
|
||||
|
||||
// the data flow in this benchmark:
|
||||
//
|
||||
// socket(tx) local_source
|
||||
// remote_end (write) +--------> (splice to)
|
||||
// write_end
|
||||
// +
|
||||
// |
|
||||
// | pipe
|
||||
// v
|
||||
// read_end
|
||||
// remote_end (read) <---------+ (splice to) *
|
||||
// socket(rx) local_end
|
||||
//
|
||||
// * benchmark loop using io::copy
|
||||
|
||||
crate::thread::spawn(move || {
|
||||
let mut sink_buf = vec![0u8; 1024 * 1024];
|
||||
remote_end.set_nonblocking(true).unwrap();
|
||||
loop {
|
||||
match remote_end.write(&mut sink_buf[..]) {
|
||||
Err(err) if err.kind() == ErrorKind::WouldBlock => {}
|
||||
Ok(_) => {}
|
||||
err => {
|
||||
err.expect("write failed");
|
||||
}
|
||||
};
|
||||
match remote_end.read(&mut sink_buf[..]) {
|
||||
Err(err) if err.kind() == ErrorKind::WouldBlock => {}
|
||||
Ok(_) => {}
|
||||
err => {
|
||||
err.expect("read failed");
|
||||
}
|
||||
};
|
||||
}
|
||||
});
|
||||
|
||||
// check that splice works, otherwise the benchmark would hang
|
||||
let probe = super::sendfile_splice(
|
||||
super::SpliceMode::Splice,
|
||||
local_end.as_raw_fd(),
|
||||
write_end.as_raw_fd(),
|
||||
1,
|
||||
);
|
||||
|
||||
match probe {
|
||||
CopyResult::Ended(Ok(1)) => {
|
||||
// splice works
|
||||
}
|
||||
_ => {
|
||||
eprintln!("splice failed, skipping benchmark");
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
let local_source = local_end.clone();
|
||||
crate::thread::spawn(move || {
|
||||
loop {
|
||||
super::sendfile_splice(
|
||||
super::SpliceMode::Splice,
|
||||
local_source.as_raw_fd(),
|
||||
write_end.as_raw_fd(),
|
||||
u64::MAX,
|
||||
);
|
||||
}
|
||||
});
|
||||
|
||||
const BYTES: usize = 128 * 1024;
|
||||
b.bytes = BYTES as u64;
|
||||
b.iter(|| {
|
||||
assert_eq!(
|
||||
BYTES as u64,
|
||||
io::copy(&mut (&mut read_end).take(BYTES as u64), &mut &*local_end).unwrap()
|
||||
);
|
||||
});
|
||||
}
|
||||
@ -51,6 +51,8 @@ pub mod fd;
|
||||
pub mod fs;
|
||||
pub mod futex;
|
||||
pub mod io;
|
||||
#[cfg(any(target_os = "linux", target_os = "android"))]
|
||||
pub mod kernel_copy;
|
||||
#[cfg(target_os = "l4re")]
|
||||
mod l4re;
|
||||
pub mod memchr;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user