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//go:build linux
// +build linux
package tools
import (
"io"
"os"
"golang.org/x/sys/unix"
)
// CheckCloneFileSupported runs explicit test of clone file on supplied directory.
// This function creates some (src and dst) file in the directory and remove after test finished.
//
// If check failed (e.g. directory is read-only), returns err.
func CheckCloneFileSupported(dir string) (supported bool, err error) {
src, err := os.CreateTemp(dir, "src")
if err != nil {
return false, err
}
defer func() {
src.Close()
os.Remove(src.Name())
}()
dst, err := os.CreateTemp(dir, "dst")
if err != nil {
return false, err
}
defer func() {
dst.Close()
os.Remove(dst.Name())
}()
if ok, err := CloneFile(dst, src); err != nil {
return false, err
} else {
return ok, nil
}
}
func CloneFile(writer io.Writer, reader io.Reader) (bool, error) {
fdst, fdstFound := writer.(*os.File)
fsrc, fsrcFound := reader.(*os.File)
if fdstFound && fsrcFound {
if err := unix.IoctlFileClone(int(fdst.Fd()), int(fsrc.Fd())); err != nil {
return false, err
}
return true, nil
}
return false, nil
}
func CloneFileByPath(dst, src string) (bool, error) {
srcFile, err := os.Open(src)
if err != nil {
return false, err
}
defer srcFile.Close()
dstFile, err := os.Create(dst) //truncating, it if it already exists.
if err != nil {
return false, err
}
defer dstFile.Close()
return CloneFile(dstFile, srcFile)
}
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