47 lines
1 KiB
Go
47 lines
1 KiB
Go
// 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 net
|
|
|
|
import (
|
|
"internal/poll"
|
|
"io"
|
|
"os"
|
|
"syscall"
|
|
)
|
|
|
|
// sendFile copies the contents of r to c using the TransmitFile
|
|
// system call to minimize copies.
|
|
//
|
|
// if handled == true, sendFile returns the number of bytes copied and any
|
|
// non-EOF error.
|
|
//
|
|
// if handled == false, sendFile performed no work.
|
|
func sendFile(fd *netFD, r io.Reader) (written int64, err error, handled bool) {
|
|
var n int64 = 0 // by default, copy until EOF.
|
|
|
|
lr, ok := r.(*io.LimitedReader)
|
|
if ok {
|
|
n, r = lr.N, lr.R
|
|
if n <= 0 {
|
|
return 0, nil, true
|
|
}
|
|
}
|
|
|
|
f, ok := r.(*os.File)
|
|
if !ok {
|
|
return 0, nil, false
|
|
}
|
|
|
|
written, err = poll.SendFile(&fd.pfd, syscall.Handle(f.Fd()), n)
|
|
if err != nil {
|
|
err = wrapSyscallError("transmitfile", err)
|
|
}
|
|
|
|
// If any byte was copied, regardless of any error
|
|
// encountered mid-way, handled must be set to true.
|
|
handled = written > 0
|
|
|
|
return
|
|
}
|