rclone/vendor/github.com/hanwen/go-fuse/v2/splice/pair.go

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// Copyright 2016 the Go-FUSE 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 splice
import (
"fmt"
"syscall"
)
type Pair struct {
r, w int
size int
}
func (p *Pair) MaxGrow() {
for p.Grow(2*p.size) == nil {
}
}
func (p *Pair) Grow(n int) error {
if n <= p.size {
return nil
}
if !resizable {
return fmt.Errorf("splice: want %d bytes, but not resizable", n)
}
if n > maxPipeSize {
return fmt.Errorf("splice: want %d bytes, max pipe size %d", n, maxPipeSize)
}
newsize, errNo := fcntl(uintptr(p.r), F_SETPIPE_SZ, n)
if errNo != 0 {
return fmt.Errorf("splice: fcntl returned %v", errNo)
}
p.size = newsize
return nil
}
func (p *Pair) Cap() int {
return p.size
}
func (p *Pair) Close() error {
err1 := syscall.Close(p.r)
err2 := syscall.Close(p.w)
if err1 != nil {
return err1
}
return err2
}
func (p *Pair) Read(d []byte) (n int, err error) {
return syscall.Read(p.r, d)
}
func (p *Pair) Write(d []byte) (n int, err error) {
return syscall.Write(p.w, d)
}
func (p *Pair) ReadFd() uintptr {
return uintptr(p.r)
}
func (p *Pair) WriteFd() uintptr {
return uintptr(p.w)
}