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.
13 // maxSendfileSize is the largest chunk size we ask the kernel to copy
15 const maxSendfileSize int = 4 << 20
17 // sendFile copies the contents of r to c using the sendfile
18 // system call to minimize copies.
20 // if handled == true, sendFile returns the number of bytes copied and any
23 // if handled == false, sendFile performed no work.
24 func sendFile(c *netFD, r io.Reader) (written int64, err os.Error, handled bool) {
25 var remain int64 = 1 << 62 // by default, copy until EOF
27 lr, ok := r.(*io.LimitedReader)
29 remain, r = lr.N, lr.R
43 if c.wdeadline_delta > 0 {
44 // This is a little odd that we're setting the timeout
45 // for the entire file but Write has the same issue
46 // (if one slurps the whole file into memory and
47 // do one large Write). At least they're consistent.
48 c.wdeadline = pollserver.Now() + c.wdeadline_delta
57 if int64(n) > remain {
60 n, errno := syscall.Sendfile(dst, src, nil, n)
65 if n == 0 && errno == 0 {
68 if errno == syscall.EAGAIN && c.wdeadline >= 0 {
69 pollserver.WaitWrite(c)
73 // This includes syscall.ENOSYS (no kernel
74 // support) and syscall.EINVAL (fd types which
75 // don't implement sendfile together)
76 err = &OpError{"sendfile", c.net, c.raddr, os.Errno(errno)}
83 return written, err, written > 0