add sequential file access hint on windows

Author: anastygnome

Cargo.lock

@@ -25,6 +25,9 @@ thiserror = { workspace = true }
 uucore = { workspace = true }
 rustc-hash = { workspace = true }
 
+[target.'cfg(windows)'.dependencies]
+windows-sys = { workspace = true, features = ["Win32_Storage_FileSystem"] }
+
 [target.'cfg(unix)'.dependencies]
 rustix = { workspace = true, features = ["fs"] }
 

src/uu/tsort/Cargo.toml

@@ -57,6 +57,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     if input == "-" {
         process_input(io::stdin().lock(), &mut g)?;
     } else {
+        let mut options;
         // some platforms cannot catch this as read error. Needs additional cost by stat
         #[cfg(windows)]
         {
@@ -66,9 +67,23 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
                     Error::Read(ReadError::IsDir(input.to_string_lossy().to_string())).into(),
                 );
             }
+            // advise the OS we will access the data sequentially if possible (windows)
+
+            use std::os::windows::fs::OpenOptionsExt;
+            use windows_sys::Win32::Storage::FileSystem::FILE_FLAG_SEQUENTIAL_SCAN;
+            options = File::options().custom_flags(FILE_FLAG_SEQUENTIAL_SCAN);
         }
-        let file = File::open(input).map_err_context(|| input.maybe_quote().to_string())?;
-        // advise the OS we will access the data sequentially if possible
+
+        #[cfg(not(windows))]
+        {
+            options = File::options();
+        }
+        let file = options
+            .read(true)
+            .open(input)
+            .map_err_context(|| input.maybe_quote().to_string())?;
+
+        // advise the OS we will access the data sequentially if possible (unix)
         #[cfg(any(target_os = "linux", target_os = "android", target_os = "freebsd"))]
         let _ = rustix::fs::fadvise(&file, 0, None, rustix::fs::Advice::Sequential);