cat: move cfg to uucore

Author: oech3

src/uu/cat/src/cat.rs

@@ -497,43 +497,26 @@ fn print_fast<R: FdReadable>(handle: &mut InputHandle<R>) -> CatResult<()> {
 }
 
 #[cfg_attr(any(target_os = "linux", target_os = "android"), inline(never))] // splice fast-path does not require this allocation
-#[cfg(any(unix, target_os = "wasi"))]
 fn print_unbuffered<R: FdReadable>(
     handle: &mut InputHandle<R>,
     stdout: io::Stdout,
 ) -> CatResult<()> {
+    #[cfg(not(any(unix, target_os = "wasi")))]
+    let mut stdout = stdout.lock();
     // todo: since there is no cost by 0-fill, we could use larger heap buffer for throughput
+    #[cfg(any(unix, target_os = "wasi"))]
     let mut buf = [std::mem::MaybeUninit::<u8>::uninit(); 1024 * 64];
-    // use raw syscall to remove buffering
-    loop {
-        match rustix::io::read(&handle.reader, &mut buf) {
-            Ok(([], _)) => return Ok(()),
-            Ok((filled, _)) => {
-                uucore::io::write_all_raw(&stdout, filled).inspect_err(handle_broken_pipe)?;
-            }
-            Err(e) if e.kind() != ErrorKind::Interrupted => return Err(e.into()),
-            _ => {}
-        }
-    }
-}
-
-#[cfg(not(any(unix, target_os = "wasi")))]
-fn print_unbuffered<R: FdReadable>(
-    handle: &mut InputHandle<R>,
-    stdout: io::Stdout,
-) -> CatResult<()> {
-    let mut stdout = stdout.lock();
+    #[cfg(not(any(unix, target_os = "wasi")))]
     let mut buf = [0; 1024 * 64];
     loop {
-        match handle.reader.read(&mut buf) {
-            Ok(0) => return Ok(()),
-            Ok(n) => {
-                stdout
-                    .write_all(&buf[..n])
-                    .inspect_err(handle_broken_pipe)?;
-                // we cannot use rustix::io on Windows
-                // really bad workaround for unbuffered write <https://github.com/uutils/coreutils/issues/12188>
-                stdout.flush().inspect_err(handle_broken_pipe)?;
+        #[cfg(any(unix, target_os = "wasi"))]
+        let res = rustix::io::read(&handle.reader, &mut buf).map(|(f, _)| f);
+        #[cfg(not(any(unix, target_os = "wasi")))]
+        let res = handle.reader.read(&mut buf).map(|n| &buf[..n]);
+        match res {
+            Ok([]) => return Ok(()),
+            Ok(filled) => {
+                uucore::io::write_all_raw(&stdout, filled).inspect_err(handle_broken_pipe)?;
             }
             Err(e) if e.kind() != ErrorKind::Interrupted => return Err(e.into()),
             _ => {}

src/uucore/src/lib/mods/io.rs

@@ -30,7 +30,7 @@ type NativeType = OwnedHandle;
 #[cfg(not(windows))]
 type NativeType = OwnedFd;
 
-// io::write_all but no buffering
+// io::write_all-like function without io::stdout's buffering
 #[inline]
 #[cfg(any(unix, target_os = "wasi"))]
 pub fn write_all_raw(output: impl AsFd, buf: &[u8]) -> io::Result<()> {
@@ -46,6 +46,12 @@ pub fn write_all_raw(output: impl AsFd, buf: &[u8]) -> io::Result<()> {
     Ok(())
 }
 
+#[cfg(not(any(unix, target_os = "wasi")))]
+pub fn write_all_raw<W: io::Write>(mut output: W, buf: &[u8]) -> io::Result<()> {
+    output.write_all(&buf)?;
+    output.flush() // workaround for unbuffered write <https://github.com/uutils/coreutils/issues/12188>
+}
+
 /// abstraction wrapper for native file handle / file descriptor
 // todo: remove clone introducing additional syscall dependency
 pub struct OwnedFileDescriptorOrHandle {