mirror of
https://github.com/octoleo/syncthing.git
synced 2024-12-22 10:58:57 +00:00
46 lines
1.6 KiB
Go
46 lines
1.6 KiB
Go
|
// Copyright (C) 2019 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"
|
||
|
|
|
||
|
|
"github.com/syncthing/syncthing/lib/sync"
|
||
|
|
)
|
||
|
|
|
||
|
|
var (
|
||
|
|
copyRangeMethods = make(map[CopyRangeMethod]copyRangeImplementation)
|
||
|
|
mut = sync.NewMutex()
|
||
|
|
)
|
||
|
|
|
||
|
|
type copyRangeImplementation func(src, dst File, srcOffset, dstOffset, size int64) error
|
||
|
|
|
||
|
|
func registerCopyRangeImplementation(copyMethod CopyRangeMethod, impl copyRangeImplementation) {
|
||
|
|
mut.Lock()
|
||
|
|
defer mut.Unlock()
|
||
|
|
|
||
|
|
l.Debugln("Registering " + copyMethod.String() + " copyRange method")
|
||
|
|
|
||
|
|
copyRangeMethods[copyMethod] = impl
|
||
|
|
}
|
||
|
|
|
||
|
|
// CopyRange tries to use the specified method to copy data between two files.
|
||
|
|
// Takes size bytes at offset srcOffset from the source file, and copies the data to destination file at offset
|
||
|
|
// dstOffset. If required, adjusts the size of the destination file to fit that much data.
|
||
|
|
//
|
||
|
|
// On Linux/BSD you can ask it to use ioctl and copy_file_range system calls, which if the underlying filesystem supports
|
||
|
|
// it tries referencing existing data in the source file, instead of making a copy and taking up additional space.
|
||
|
|
//
|
||
|
|
// CopyRange does its best to have no effect on src and dst file offsets (copy operation should not affect it).
|
||
|
|
func CopyRange(copyMethod CopyRangeMethod, src, dst File, srcOffset, dstOffset, size int64) error {
|
||
|
|
if impl, ok := copyRangeMethods[copyMethod]; ok {
|
||
|
|
return impl(src, dst, srcOffset, dstOffset, size)
|
||
|
|
}
|
||
|
|
|
||
|
|
return syscall.ENOTSUP
|
||
|
|
}
|