63 lines
1.5 KiB
Go
63 lines
1.5 KiB
Go
// Copyright (C) 2020 The Syncthing Authors.
|
|
//
|
|
// This Source Code Form is subject to the terms of the Mozilla Public
|
|
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
|
|
// You can obtain one at https://mozilla.org/MPL/2.0/.
|
|
|
|
package fs
|
|
|
|
import (
|
|
"syscall"
|
|
)
|
|
|
|
type copyRangeImplementationBasicFile func(src, dst basicFile, srcOffset, dstOffset, size int64) error
|
|
|
|
func copyRangeImplementationForBasicFile(impl copyRangeImplementationBasicFile) copyRangeImplementation {
|
|
return func(src, dst File, srcOffset, dstOffset, size int64) error {
|
|
src = unwrap(src)
|
|
dst = unwrap(dst)
|
|
// Then see if it's basic files
|
|
srcFile, srcOk := src.(basicFile)
|
|
dstFile, dstOk := dst.(basicFile)
|
|
if !srcOk || !dstOk {
|
|
return syscall.ENOTSUP
|
|
}
|
|
return impl(srcFile, dstFile, srcOffset, dstOffset, size)
|
|
}
|
|
}
|
|
|
|
func withFileDescriptors(first, second basicFile, fn func(first, second uintptr) (int, error)) (int, error) {
|
|
fc, err := first.SyscallConn()
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
sc, err := second.SyscallConn()
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
var n int
|
|
var ferr, serr, fnerr error
|
|
ferr = fc.Control(func(first uintptr) {
|
|
serr = sc.Control(func(second uintptr) {
|
|
n, fnerr = fn(first, second)
|
|
})
|
|
})
|
|
if ferr != nil {
|
|
return n, ferr
|
|
}
|
|
if serr != nil {
|
|
return n, serr
|
|
}
|
|
return n, fnerr
|
|
}
|
|
|
|
func unwrap(f File) File {
|
|
for {
|
|
if wrapped, ok := f.(interface{ unwrap() File }); ok {
|
|
f = wrapped.unwrap()
|
|
} else {
|
|
return f
|
|
}
|
|
}
|
|
}
|