47 lines
1.0 KiB
Go
47 lines
1.0 KiB
Go
// Copyright 2020 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package os
|
|
|
|
import (
|
|
"internal/poll"
|
|
"io"
|
|
)
|
|
|
|
var pollCopyFileRange = poll.CopyFileRange
|
|
|
|
func (f *File) readFrom(r io.Reader) (written int64, handled bool, err error) {
|
|
// copy_file_range(2) does not support destinations opened with
|
|
// O_APPEND, so don't even try.
|
|
if f.appendMode {
|
|
return 0, false, nil
|
|
}
|
|
|
|
remain := int64(1 << 62)
|
|
|
|
lr, ok := r.(*io.LimitedReader)
|
|
if ok {
|
|
remain, r = lr.N, lr.R
|
|
if remain <= 0 {
|
|
return 0, true, nil
|
|
}
|
|
}
|
|
|
|
src, ok := r.(*File)
|
|
if !ok {
|
|
return 0, false, nil
|
|
}
|
|
if src.checkValid("ReadFrom") != nil {
|
|
// Avoid returning the error as we report handled as false,
|
|
// leave further error handling as the responsibility of the caller.
|
|
return 0, false, nil
|
|
}
|
|
|
|
written, handled, err = pollCopyFileRange(&f.pfd, &src.pfd, remain)
|
|
if lr != nil {
|
|
lr.N -= written
|
|
}
|
|
return written, handled, NewSyscallError("copy_file_range", err)
|
|
}
|