libgocryptfs/internal/fusefrontend/file_holes.go
Jakob Unterwurzacher 5f4b16c00f Implement changes proposed by gosimple.
Also delete the unused "dirIVNameStruct", found by deadcode.
2016-09-25 19:48:21 +02:00

31 lines
880 B
Go

package fusefrontend
// Helper functions for sparse files (files with holes)
import (
"github.com/hanwen/go-fuse/fuse"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
// Will a write to offset "off" create a file hole?
func (f *file) createsHole(plainSize uint64, off int64) bool {
nextBlock := f.contentEnc.PlainOffToBlockNo(plainSize)
targetBlock := f.contentEnc.PlainOffToBlockNo(uint64(off))
return targetBlock > nextBlock
}
// Zero-pad the file of size plainSize to the next block boundary
func (f *file) zeroPad(plainSize uint64) fuse.Status {
lastBlockLen := plainSize % f.contentEnc.PlainBS()
missing := f.contentEnc.PlainBS() - lastBlockLen
if missing == 0 {
// Already block-aligned
return fuse.OK
}
pad := make([]byte, missing)
tlog.Debug.Printf("zeroPad: Writing %d bytes\n", missing)
_, status := f.doWrite(pad, int64(plainSize))
return status
}