blob: 17a3681064b66df8da5a3f2f3a25f5fd2076c5b8 [file] [log] [blame]
// Copyright 2011 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 poll
import "syscall"
// SendFile wraps the TransmitFile call.
func SendFile(fd *FD, src syscall.Handle, n int64) (int64, error) {
ft, err := syscall.GetFileType(src)
if err != nil {
return 0, err
}
// TransmitFile does not work with pipes
if ft == syscall.FILE_TYPE_PIPE {
return 0, syscall.ESPIPE
}
if err := fd.writeLock(); err != nil {
return 0, err
}
defer fd.writeUnlock()
o := &fd.wop
o.qty = uint32(n)
o.handle = src
// TODO(brainman): skip calling syscall.Seek if OS allows it
curpos, err := syscall.Seek(o.handle, 0, 1)
if err != nil {
return 0, err
}
o.o.Offset = uint32(curpos)
o.o.OffsetHigh = uint32(curpos >> 32)
done, err := wsrv.ExecIO(o, func(o *operation) error {
return syscall.TransmitFile(o.fd.Sysfd, o.handle, o.qty, 0, &o.o, nil, syscall.TF_WRITE_BEHIND)
})
if err == nil {
// Some versions of Windows (Windows 10 1803) do not set
// file position after TransmitFile completes.
// So just use Seek to set file position.
_, err = syscall.Seek(o.handle, curpos+int64(done), 0)
}
return int64(done), err
}