Stabilized vectored IO

This renames `std::io::IoVec` to `std::io::IoSlice` and
`std::io::IoVecMut` to `std::io::IoSliceMut`, and stabilizes
`std::io::IoSlice`, `std::io::IoSliceMut`,
`std::io::Read::read_vectored`, and `std::io::Write::write_vectored`.

Closes #58452

Author: sfackler

src/libstd/fs.rs

@@ -11,7 +11,7 @@
 
 use crate::fmt;
 use crate::ffi::OsString;
-use crate::io::{self, SeekFrom, Seek, Read, Initializer, Write, IoVec, IoVecMut};
+use crate::io::{self, SeekFrom, Seek, Read, Initializer, Write, IoSlice, IoSliceMut};
 use crate::path::{Path, PathBuf};
 use crate::sys::fs as fs_imp;
 use crate::sys_common::{AsInnerMut, FromInner, AsInner, IntoInner};
@@ -617,7 +617,7 @@ impl Read for File {
         self.inner.read(buf)
     }
 
-    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         self.inner.read_vectored(bufs)
     }
 
@@ -632,7 +632,7 @@ impl Write for File {
         self.inner.write(buf)
     }
 
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         self.inner.write_vectored(bufs)
     }
 
@@ -650,7 +650,7 @@ impl Read for &File {
         self.inner.read(buf)
     }
 
-    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         self.inner.read_vectored(bufs)
     }
 
@@ -665,7 +665,7 @@ impl Write for &File {
         self.inner.write(buf)
     }
 
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         self.inner.write_vectored(bufs)
     }
 

src/libstd/io/buffered.rs

@@ -5,7 +5,7 @@ use crate::io::prelude::*;
 use crate::cmp;
 use crate::error;
 use crate::fmt;
-use crate::io::{self, Initializer, DEFAULT_BUF_SIZE, Error, ErrorKind, SeekFrom, IoVec, IoVecMut};
+use crate::io::{self, Initializer, DEFAULT_BUF_SIZE, Error, ErrorKind, SeekFrom, IoSlice, IoSliceMut};
 use crate::memchr;
 
 /// The `BufReader` struct adds buffering to any reader.
@@ -249,7 +249,7 @@ impl<R: Read> Read for BufReader<R> {
         Ok(nread)
     }
 
-    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         let total_len = bufs.iter().map(|b| b.len()).sum::<usize>();
         if self.pos == self.cap && total_len >= self.buf.len() {
             self.discard_buffer();
@@ -609,7 +609,7 @@ impl<W: Write> Write for BufWriter<W> {
         }
     }
 
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         let total_len = bufs.iter().map(|b| b.len()).sum::<usize>();
         if self.buf.len() + total_len > self.buf.capacity() {
             self.flush_buf()?;

src/libstd/io/cursor.rs

@@ -1,7 +1,7 @@
 use crate::io::prelude::*;
 
 use crate::cmp;
-use crate::io::{self, Initializer, SeekFrom, Error, ErrorKind, IoVec, IoVecMut};
+use crate::io::{self, Initializer, SeekFrom, Error, ErrorKind, IoSlice, IoSliceMut};
 
 use core::convert::TryInto;
 
@@ -230,7 +230,7 @@ impl<T> Read for Cursor<T> where T: AsRef<[u8]> {
         Ok(n)
     }
 
-    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         let mut nread = 0;
         for buf in bufs {
             let n = self.read(buf)?;
@@ -275,7 +275,7 @@ fn slice_write(pos_mut: &mut u64, slice: &mut [u8], buf: &[u8]) -> io::Result<us
 fn slice_write_vectored(
     pos_mut: &mut u64,
     slice: &mut [u8],
-    bufs: &[IoVec<'_>],
+    bufs: &[IoSlice<'_>],
 ) -> io::Result<usize>
 {
     let mut nwritten = 0;
@@ -319,7 +319,7 @@ fn vec_write(pos_mut: &mut u64, vec: &mut Vec<u8>, buf: &[u8]) -> io::Result<usi
 fn vec_write_vectored(
     pos_mut: &mut u64,
     vec: &mut Vec<u8>,
-    bufs: &[IoVec<'_>],
+    bufs: &[IoSlice<'_>],
 ) -> io::Result<usize>
 {
     let mut nwritten = 0;
@@ -337,7 +337,7 @@ impl Write for Cursor<&mut [u8]> {
     }
 
     #[inline]
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         slice_write_vectored(&mut self.pos, self.inner, bufs)
     }
 
@@ -350,7 +350,7 @@ impl Write for Cursor<&mut Vec<u8>> {
         vec_write(&mut self.pos, self.inner, buf)
     }
 
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         vec_write_vectored(&mut self.pos, self.inner, bufs)
     }
 
@@ -363,7 +363,7 @@ impl Write for Cursor<Vec<u8>> {
         vec_write(&mut self.pos, &mut self.inner, buf)
     }
 
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         vec_write_vectored(&mut self.pos, &mut self.inner, bufs)
     }
 
@@ -378,7 +378,7 @@ impl Write for Cursor<Box<[u8]>> {
     }
 
     #[inline]
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         slice_write_vectored(&mut self.pos, &mut self.inner, bufs)
     }
 
@@ -388,7 +388,7 @@ impl Write for Cursor<Box<[u8]>> {
 #[cfg(test)]
 mod tests {
     use crate::io::prelude::*;
-    use crate::io::{Cursor, SeekFrom, IoVec, IoVecMut};
+    use crate::io::{Cursor, SeekFrom, IoSlice, IoSliceMut};
 
     #[test]
     fn test_vec_writer() {
@@ -397,7 +397,7 @@ mod tests {
         assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3);
         assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4);
         assert_eq!(writer.write_vectored(
-            &[IoVec::new(&[]), IoVec::new(&[8, 9]), IoVec::new(&[10])],
+            &[IoSlice::new(&[]), IoSlice::new(&[8, 9]), IoSlice::new(&[10])],
         ).unwrap(), 3);
         let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
         assert_eq!(writer, b);
@@ -410,7 +410,7 @@ mod tests {
         assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3);
         assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4);
         assert_eq!(writer.write_vectored(
-            &[IoVec::new(&[]), IoVec::new(&[8, 9]), IoVec::new(&[10])],
+            &[IoSlice::new(&[]), IoSlice::new(&[8, 9]), IoSlice::new(&[10])],
         ).unwrap(), 3);
         let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
         assert_eq!(&writer.get_ref()[..], b);
@@ -424,7 +424,7 @@ mod tests {
         assert_eq!(writer.write(&[1, 2, 3]).unwrap(), 3);
         assert_eq!(writer.write(&[4, 5, 6, 7]).unwrap(), 4);
         assert_eq!(writer.write_vectored(
-            &[IoVec::new(&[]), IoVec::new(&[8, 9]), IoVec::new(&[10])],
+            &[IoSlice::new(&[]), IoSlice::new(&[8, 9]), IoSlice::new(&[10])],
         ).unwrap(), 3);
         let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
         assert_eq!(&writer.get_ref()[..], b);
@@ -452,18 +452,18 @@ mod tests {
     fn test_box_slice_writer_vectored() {
         let mut writer = Cursor::new(vec![0u8; 9].into_boxed_slice());
         assert_eq!(writer.position(), 0);
-        assert_eq!(writer.write_vectored(&[IoVec::new(&[0])]).unwrap(), 1);
+        assert_eq!(writer.write_vectored(&[IoSlice::new(&[0])]).unwrap(), 1);
         assert_eq!(writer.position(), 1);
         assert_eq!(
-            writer.write_vectored(&[IoVec::new(&[1, 2, 3]), IoVec::new(&[4, 5, 6, 7])]).unwrap(),
+            writer.write_vectored(&[IoSlice::new(&[1, 2, 3]), IoSlice::new(&[4, 5, 6, 7])]).unwrap(),
             7,
         );
         assert_eq!(writer.position(), 8);
         assert_eq!(writer.write_vectored(&[]).unwrap(), 0);
         assert_eq!(writer.position(), 8);
 
-        assert_eq!(writer.write_vectored(&[IoVec::new(&[8, 9])]).unwrap(), 1);
-        assert_eq!(writer.write_vectored(&[IoVec::new(&[10])]).unwrap(), 0);
+        assert_eq!(writer.write_vectored(&[IoSlice::new(&[8, 9])]).unwrap(), 1);
+        assert_eq!(writer.write_vectored(&[IoSlice::new(&[10])]).unwrap(), 0);
         let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8];
         assert_eq!(&**writer.get_ref(), b);
     }
@@ -495,20 +495,20 @@ mod tests {
         {
             let mut writer = Cursor::new(&mut buf[..]);
             assert_eq!(writer.position(), 0);
-            assert_eq!(writer.write_vectored(&[IoVec::new(&[0])]).unwrap(), 1);
+            assert_eq!(writer.write_vectored(&[IoSlice::new(&[0])]).unwrap(), 1);
             assert_eq!(writer.position(), 1);
             assert_eq!(
                 writer.write_vectored(
-                    &[IoVec::new(&[1, 2, 3]), IoVec::new(&[4, 5, 6, 7])],
+                    &[IoSlice::new(&[1, 2, 3]), IoSlice::new(&[4, 5, 6, 7])],
                 ).unwrap(),
                 7,
             );
             assert_eq!(writer.position(), 8);
             assert_eq!(writer.write_vectored(&[]).unwrap(), 0);
             assert_eq!(writer.position(), 8);
 
-            assert_eq!(writer.write_vectored(&[IoVec::new(&[8, 9])]).unwrap(), 1);
-            assert_eq!(writer.write_vectored(&[IoVec::new(&[10])]).unwrap(), 0);
+            assert_eq!(writer.write_vectored(&[IoSlice::new(&[8, 9])]).unwrap(), 1);
+            assert_eq!(writer.write_vectored(&[IoSlice::new(&[10])]).unwrap(), 0);
         }
         let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8];
         assert_eq!(buf, b);
@@ -578,11 +578,11 @@ mod tests {
     fn test_mem_reader_vectored() {
         let mut reader = Cursor::new(vec![0, 1, 2, 3, 4, 5, 6, 7]);
         let mut buf = [];
-        assert_eq!(reader.read_vectored(&mut [IoVecMut::new(&mut buf)]).unwrap(), 0);
+        assert_eq!(reader.read_vectored(&mut [IoSliceMut::new(&mut buf)]).unwrap(), 0);
         assert_eq!(reader.position(), 0);
         let mut buf = [0];
         assert_eq!(
-            reader.read_vectored(&mut [IoVecMut::new(&mut []), IoVecMut::new(&mut buf)]).unwrap(),
+            reader.read_vectored(&mut [IoSliceMut::new(&mut []), IoSliceMut::new(&mut buf)]).unwrap(),
             1,
         );
         assert_eq!(reader.position(), 1);
@@ -592,7 +592,7 @@ mod tests {
         let mut buf2 = [0; 4];
         assert_eq!(
             reader.read_vectored(
-                &mut [IoVecMut::new(&mut buf1), IoVecMut::new(&mut buf2)],
+                &mut [IoSliceMut::new(&mut buf1), IoSliceMut::new(&mut buf2)],
             ).unwrap(),
             7,
         );
@@ -629,11 +629,11 @@ mod tests {
     fn test_boxed_slice_reader_vectored() {
         let mut reader = Cursor::new(vec![0, 1, 2, 3, 4, 5, 6, 7].into_boxed_slice());
         let mut buf = [];
-        assert_eq!(reader.read_vectored(&mut [IoVecMut::new(&mut buf)]).unwrap(), 0);
+        assert_eq!(reader.read_vectored(&mut [IoSliceMut::new(&mut buf)]).unwrap(), 0);
         assert_eq!(reader.position(), 0);
         let mut buf = [0];
         assert_eq!(
-            reader.read_vectored(&mut [IoVecMut::new(&mut []), IoVecMut::new(&mut buf)]).unwrap(),
+            reader.read_vectored(&mut [IoSliceMut::new(&mut []), IoSliceMut::new(&mut buf)]).unwrap(),
             1,
         );
         assert_eq!(reader.position(), 1);
@@ -643,7 +643,7 @@ mod tests {
         let mut buf2 = [0; 4];
         assert_eq!(
             reader.read_vectored(
-                &mut [IoVecMut::new(&mut buf1), IoVecMut::new(&mut buf2)],
+                &mut [IoSliceMut::new(&mut buf1), IoSliceMut::new(&mut buf2)],
             ).unwrap(),
             7,
         );
@@ -689,10 +689,10 @@ mod tests {
         let in_buf = vec![0, 1, 2, 3, 4, 5, 6, 7];
         let reader = &mut &in_buf[..];
         let mut buf = [];
-        assert_eq!(reader.read_vectored(&mut [IoVecMut::new(&mut buf)]).unwrap(), 0);
+        assert_eq!(reader.read_vectored(&mut [IoSliceMut::new(&mut buf)]).unwrap(), 0);
         let mut buf = [0];
         assert_eq!(
-            reader.read_vectored(&mut [IoVecMut::new(&mut []), IoVecMut::new(&mut buf)]).unwrap(),
+            reader.read_vectored(&mut [IoSliceMut::new(&mut []), IoSliceMut::new(&mut buf)]).unwrap(),
             1,
         );
         assert_eq!(reader.len(), 7);
@@ -702,7 +702,7 @@ mod tests {
         let mut buf2 = [0; 4];
         assert_eq!(
             reader.read_vectored(
-                &mut [IoVecMut::new(&mut buf1), IoVecMut::new(&mut buf2)],
+                &mut [IoSliceMut::new(&mut buf1), IoSliceMut::new(&mut buf2)],
             ).unwrap(),
             7,
         );

src/libstd/io/impls.rs

@@ -1,6 +1,6 @@
 use crate::cmp;
-use crate::io::{self, SeekFrom, Read, Initializer, Write, Seek, BufRead, Error, ErrorKind, IoVecMut,
-         IoVec};
+use crate::io::{self, SeekFrom, Read, Initializer, Write, Seek, BufRead, Error, ErrorKind, IoSliceMut,
+         IoSlice};
 use crate::fmt;
 use crate::mem;
 
@@ -15,7 +15,7 @@ impl<R: Read + ?Sized> Read for &mut R {
     }
 
     #[inline]
-    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         (**self).read_vectored(bufs)
     }
 
@@ -45,7 +45,7 @@ impl<W: Write + ?Sized> Write for &mut W {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> { (**self).write(buf) }
 
     #[inline]
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         (**self).write_vectored(bufs)
     }
 
@@ -94,7 +94,7 @@ impl<R: Read + ?Sized> Read for Box<R> {
     }
 
     #[inline]
-    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         (**self).read_vectored(bufs)
     }
 
@@ -124,7 +124,7 @@ impl<W: Write + ?Sized> Write for Box<W> {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> { (**self).write(buf) }
 
     #[inline]
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         (**self).write_vectored(bufs)
     }
 
@@ -207,7 +207,7 @@ impl Read for &[u8] {
     }
 
     #[inline]
-    fn read_vectored(&mut self, bufs: &mut [IoVecMut<'_>]) -> io::Result<usize> {
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         let mut nread = 0;
         for buf in bufs {
             nread += self.read(buf)?;
@@ -280,7 +280,7 @@ impl Write for &mut [u8] {
     }
 
     #[inline]
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         let mut nwritten = 0;
         for buf in bufs {
             nwritten += self.write(buf)?;
@@ -316,7 +316,7 @@ impl Write for Vec<u8> {
     }
 
     #[inline]
-    fn write_vectored(&mut self, bufs: &[IoVec<'_>]) -> io::Result<usize> {
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         let len = bufs.iter().map(|b| b.len()).sum();
         self.reserve(len);
         for buf in bufs {