gcc/libgo/go/net/sendfile_unix_alt.go
Ian Lance Taylor 4f4a855d82 libgo: update to Go1.12beta2
Reviewed-on: https://go-review.googlesource.com/c/158019

gotools/:
	* Makefile.am (go_cmd_vet_files): Update for Go1.12beta2 release.
	(GOTOOLS_TEST_TIMEOUT): Increase to 600.
	(check-runtime): Export LD_LIBRARY_PATH before computing GOARCH
	and GOOS.
	(check-vet): Copy golang.org/x/tools into check-vet-dir.
	* Makefile.in: Regenerate.

gcc/testsuite/:
	* go.go-torture/execute/names-1.go: Stop using debug/xcoff, which
	is no longer externally visible.

From-SVN: r268084
2019-01-18 19:04:36 +00:00

86 lines
2.0 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.
// +build dragonfly freebsd solaris
package net
import (
"internal/poll"
"io"
"os"
)
// sendFile copies the contents of r to c using the sendfile
// 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(c *netFD, r io.Reader) (written int64, err error, handled bool) {
// FreeBSD, DragonFly and Solaris use 0 as the "until EOF" value.
// If you pass in more bytes than the file contains, it will
// loop back to the beginning ad nauseam until it's sent
// exactly the number of bytes told to. As such, we need to
// know exactly how many bytes to send.
var remain int64 = 0
lr, ok := r.(*io.LimitedReader)
if ok {
remain, r = lr.N, lr.R
if remain <= 0 {
return 0, nil, true
}
}
f, ok := r.(*os.File)
if !ok {
return 0, nil, false
}
if remain == 0 {
fi, err := f.Stat()
if err != nil {
return 0, err, false
}
remain = fi.Size()
}
// The other quirk with FreeBSD/DragonFly/Solaris's sendfile
// implementation is that it doesn't use the current position
// of the file -- if you pass it offset 0, it starts from
// offset 0. There's no way to tell it "start from current
// position", so we have to manage that explicitly.
pos, err := f.Seek(0, io.SeekCurrent)
if err != nil {
return 0, err, false
}
sc, err := f.SyscallConn()
if err != nil {
return 0, nil, false
}
var werr error
err = sc.Read(func(fd uintptr) bool {
written, werr = poll.SendFile(&c.pfd, int(fd), pos, remain)
return true
})
if werr == nil {
werr = err
}
if lr != nil {
lr.N = remain - written
}
_, err1 := f.Seek(written, io.SeekCurrent)
if err1 != nil && err == nil {
return written, err1, written > 0
}
return written, wrapSyscallError("sendfile", err), written > 0
}