From 5e77bab66325f9fb2a3b9d8875cadf036646b1b3 Mon Sep 17 00:00:00 2001
From: oech3 <79379754+oech3@users.noreply.github.com>
Date: Wed, 27 May 2026 13:49:20 +0900
Subject: [PATCH] buf_copy: remove thin wrapper & useless conversion

---
 src/uucore/src/lib/features/buf_copy.rs       | 22 +++++++++----
 src/uucore/src/lib/features/buf_copy/linux.rs | 33 -------------------
 src/uucore/src/lib/features/buf_copy/other.rs | 27 ---------------
 3 files changed, 16 insertions(+), 66 deletions(-)
 delete mode 100644 src/uucore/src/lib/features/buf_copy/linux.rs
 delete mode 100644 src/uucore/src/lib/features/buf_copy/other.rs

diff --git a/src/uucore/src/lib/features/buf_copy.rs b/src/uucore/src/lib/features/buf_copy.rs
index 1891a48785f..9943488c7ba 100644
--- a/src/uucore/src/lib/features/buf_copy.rs
+++ b/src/uucore/src/lib/features/buf_copy.rs
@@ -10,17 +10,27 @@
 //! does not handle copying special files (e.g pipes, character/block devices).
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
-pub mod linux;
+use std::os::fd::AsFd;
 #[cfg(any(target_os = "linux", target_os = "android"))]
-pub use linux::*;
+pub fn copy_stream(
+    src: &mut (impl std::io::Read + AsFd),
+    dest: &mut impl AsFd,
+) -> std::io::Result<()> {
+    // try to splice() system call for throughput
+    if crate::pipes::splice_unbounded_auto(src, dest)?.is_err() {
+        // fall back on writing "without buffering", or order of output would be wrong
+        // unrelated for cp /dev/stdin since cp does not have multiple input? <https://github.com/uutils/coreutils/issues/5186>
+        // RawWriter also removes io::copy's specialization slower than our splice
+        std::io::copy(src, &mut crate::io::RawWriter(dest))?;
+    }
+    Ok(())
+}
 
 #[cfg(not(any(target_os = "linux", target_os = "android")))]
-pub mod other;
-#[cfg(not(any(target_os = "linux", target_os = "android")))]
-pub use other::copy_stream;
+pub use std::io::copy as copy_stream;
 
 #[cfg(test)]
-#[cfg(any(target_os = "linux", target_os = "android"))] // copy_stream is a thin wrapper for io::copy. nothing to test...
+#[cfg(any(target_os = "linux", target_os = "android"))] // copy_stream is io::copy on other platforms. nothing to test.
 mod tests {
     use super::*;
     use std::fs::File;
diff --git a/src/uucore/src/lib/features/buf_copy/linux.rs b/src/uucore/src/lib/features/buf_copy/linux.rs
deleted file mode 100644
index 86cbf03696e..00000000000
--- a/src/uucore/src/lib/features/buf_copy/linux.rs
+++ /dev/null
@@ -1,33 +0,0 @@
-// This file is part of the uutils coreutils package.
-//
-// For the full copyright and license information, please view the LICENSE
-// file that was distributed with this source code.
-
-//! Buffer-based copying implementation for Linux and Android.
-use std::os::fd::AsFd;
-
-/// Copy data from `Read` implementor `source` into a `Write` implementor
-/// `dest`. This works by reading a chunk of data from `source` and writing the
-/// data to `dest` in a loop.
-///
-/// This function uses the Linux-specific `splice` call when possible which does
-/// not use any intermediate user-space buffer. It falls backs to
-/// `std::io::copy` when the call fails and is still recoverable.
-///
-/// # Arguments
-/// * `source` - `Read` implementor to copy data from.
-/// * `dest` - `Write` implementor to copy data to.
-pub fn copy_stream(
-    src: &mut (impl std::io::Read + AsFd),
-    dest: &mut impl AsFd,
-) -> crate::error::UResult<()> {
-    // If we're on Linux or Android, try to use the splice() system call
-    // for faster writing. If it works, we're done.
-    if crate::pipes::splice_unbounded_auto(src, dest)?.is_err() {
-        // If the splice() call failed, fall back on writing "without buffering", or order of output would be wrong
-        // unrelated for cp /dev/stdin since cp does not have multiple input? <https://github.com/uutils/coreutils/issues/5186>
-        // RawWriter also removes io::copy's specialization
-        std::io::copy(src, &mut crate::io::RawWriter(dest))?;
-    }
-    Ok(())
-}
diff --git a/src/uucore/src/lib/features/buf_copy/other.rs b/src/uucore/src/lib/features/buf_copy/other.rs
deleted file mode 100644
index 6b435b8d02d..00000000000
--- a/src/uucore/src/lib/features/buf_copy/other.rs
+++ /dev/null
@@ -1,27 +0,0 @@
-// This file is part of the uutils coreutils package.
-//
-// For the full copyright and license information, please view the LICENSE
-// file that was distributed with this source code.
-//!
-//! Buffer-based copying implementation for other platforms.
-
-use std::io::{Read, Write};
-
-use crate::error::UResult;
-
-/// Copy data from `Read` implementor `source` into a `Write` implementor
-/// `dest`. This works by reading a chunk of data from `source` and writing the
-/// data to `dest` in a loop, using std::io::copy. This is implemented for
-/// non-Linux platforms.
-///
-/// # Arguments
-/// * `source` - `Read` implementor to copy data from.
-/// * `dest` - `Write` implementor to copy data to.
-pub fn copy_stream<R, S>(src: &mut R, dest: &mut S) -> UResult<()>
-where
-    R: Read,
-    S: Write,
-{
-    std::io::copy(src, dest)?;
-    Ok(())
-}