1234567891011121314151617181920212223242526272829303132333435363738394041424344 |
- // Copyright 2018 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"
- )
- // splice transfers data from r to c using the splice system call to minimize
- // copies from and to userspace. c must be a TCP connection. Currently, splice
- // is only enabled if r is a TCP or a stream-oriented Unix connection.
- //
- // If splice returns handled == false, it has performed no work.
- func splice(c *netFD, r io.Reader) (written int64, err error, handled bool) {
- var remain int64 = 1 << 62 // by default, copy until EOF
- lr, ok := r.(*io.LimitedReader)
- if ok {
- remain, r = lr.N, lr.R
- if remain <= 0 {
- return 0, nil, true
- }
- }
- var s *netFD
- if tc, ok := r.(*TCPConn); ok {
- s = tc.fd
- } else if uc, ok := r.(*UnixConn); ok {
- if uc.fd.net != "unix" {
- return 0, nil, false
- }
- s = uc.fd
- } else {
- return 0, nil, false
- }
- written, handled, sc, err := poll.Splice(&c.pfd, &s.pfd, remain)
- if lr != nil {
- lr.N -= written
- }
- return written, wrapSyscallError(sc, err), handled
- }
|