github.com/ltltlt/go-source-code@v0.0.0-20190830023027-95be009773aa/internal/poll/sendfile_windows.go (about)

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package poll
     6  
     7  import "syscall"
     8  
     9  // SendFile wraps the TransmitFile call.
    10  func SendFile(fd *FD, src syscall.Handle, n int64) (int64, error) {
    11  	ft, err := syscall.GetFileType(src)
    12  	if err != nil {
    13  		return 0, err
    14  	}
    15  	// TransmitFile does not work with pipes
    16  	if ft == syscall.FILE_TYPE_PIPE {
    17  		return 0, syscall.ESPIPE
    18  	}
    19  
    20  	if err := fd.writeLock(); err != nil {
    21  		return 0, err
    22  	}
    23  	defer fd.writeUnlock()
    24  
    25  	o := &fd.wop
    26  	o.qty = uint32(n)
    27  	o.handle = src
    28  	done, err := wsrv.ExecIO(o, func(o *operation) error {
    29  		return syscall.TransmitFile(o.fd.Sysfd, o.handle, o.qty, 0, &o.o, nil, syscall.TF_WRITE_BEHIND)
    30  	})
    31  	return int64(done), err
    32  }