56 lines
1.3 KiB
Go
56 lines
1.3 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 (
|
|
"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.
|
|
//
|
|
// Note that sendfile for windows does not support >2GB file.
|
|
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
|
|
}
|
|
|
|
if err := fd.writeLock(); err != nil {
|
|
return 0, err, true
|
|
}
|
|
defer fd.writeUnlock()
|
|
|
|
o := &fd.wop
|
|
o.qty = uint32(n)
|
|
o.handle = syscall.Handle(f.Fd())
|
|
done, err := wsrv.ExecIO(o, "TransmitFile", 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 {
|
|
return 0, os.NewSyscallError("transmitfile", err), false
|
|
}
|
|
if lr != nil {
|
|
lr.N -= int64(done)
|
|
}
|
|
return int64(done), nil, true
|
|
}
|