// 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" ) type sendfileOp struct { anOp src syscall.Handle // source n uint32 } func (o *sendfileOp) Submit() (err error) { return syscall.TransmitFile(o.fd.sysfd, o.src, o.n, 0, &o.o, nil, syscall.TF_WRITE_BEHIND) } func (o *sendfileOp) Name() string { return "TransmitFile" } // 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 suppport >2GB file. func sendFile(c *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 := c.incref(false); err != nil { return 0, err, true } defer c.decref() c.wio.Lock() defer c.wio.Unlock() var o sendfileOp o.Init(c, 'w') o.n = uint32(n) o.src = syscall.Handle(f.Fd()) done, err := iosrv.ExecIO(&o, 0) if err != nil { return 0, err, false } if lr != nil { lr.N -= int64(done) } return int64(done), nil, true }