libgocryptfs/pathfs_frontend/file_holes.go

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package pathfs_frontend
import (
"github.com/hanwen/go-fuse/fuse"
"github.com/rfjakob/gocryptfs/cryptfs"
)
// Will a write to offset "off" create a file hole?
func (f *file) createsHole(plainSize uint64, off int64) bool {
nextBlock := f.cfs.PlainOffToBlockNo(plainSize)
targetBlock := f.cfs.PlainOffToBlockNo(uint64(off))
if targetBlock > nextBlock {
return true
}
return false
}
// Zero-pad the file of size plainSize to the next block boundary
func (f *file) zeroPad(plainSize uint64) fuse.Status {
lastBlockLen := plainSize % f.cfs.PlainBS()
missing := f.cfs.PlainBS() - lastBlockLen
pad := make([]byte, missing)
cryptfs.Debug.Printf("zeroPad: Writing %d bytes\n", missing)
_, status := f.doWrite(pad, int64(plainSize))
return status
}