2021-12-04 16:42:11 +00:00

99 lines
1.6 KiB
Go

// Copyright 2020 lesismal. All rights reserved.
// Use of this source code is governed by an MIT-style
// license that can be found in the LICENSE file.
//go:build linux
// +build linux
package nbio
import (
"errors"
"os"
"syscall"
)
const maxSendfileSize = 4 << 20
// Sendfile .
func (c *Conn) Sendfile(f *os.File, remain int64) (int64, error) {
if f == nil {
return 0, nil
}
c.mux.Lock()
if c.closed {
c.mux.Unlock()
return -1, errClosed
}
if remain <= 0 {
stat, err := f.Stat()
if err != nil {
return 0, err
}
remain = stat.Size()
}
if len(c.writeBuffer) > 0 {
if c.chWaitWrite == nil {
c.chWaitWrite = make(chan struct{}, 1)
}
c.mux.Unlock()
<-c.chWaitWrite
if c.closed {
c.chWaitWrite = nil
return -1, errClosed
}
c.mux.Lock()
}
c.g.beforeWrite(c)
var (
err error
n int
src = int(f.Fd())
dst = c.fd
total = remain
)
for remain > 0 {
n = maxSendfileSize
if int64(n) > remain {
n = int(remain)
}
n, err = syscall.Sendfile(dst, src, nil, n)
if n > 0 {
remain -= int64(n)
} else if n == 0 && err == nil {
break
}
if errors.Is(err, syscall.EINTR) {
continue
}
if errors.Is(err, syscall.EAGAIN) {
c.modWrite()
if c.chWaitWrite == nil {
c.chWaitWrite = make(chan struct{}, 1)
}
c.mux.Unlock()
<-c.chWaitWrite
c.chWaitWrite = nil
if c.closed {
return total - remain, err
}
c.mux.Lock()
continue
}
if err != nil {
c.closeWithErrorWithoutLock(err)
c.mux.Unlock()
return total - remain, err
}
}
c.chWaitWrite = nil
c.mux.Unlock()
return total - remain, err
}