// expandSparse grows the file with zero blocks of 4096
// A small blocksize is chosen to aid in deduplication
func (dm *DagModifier) expandSparse(size int64) error {
r := io.LimitReader(zeroReader{}, size)
spl := chunk.NewSizeSplitter(r, 4096)
blks, errs := chunk.Chan(spl)
nnode, err := dm.appendData(dm.curNode, blks, errs)
if err != nil {
return err
}
_, err = dm.dagserv.Add(nnode)
if err != nil {
return err
}
dm.curNode = nnode
return nil
}
// Add builds a merkledag from the a reader, pinning all objects to the local
// datastore. Returns a key representing the root node.
func Add(n *core.IpfsNode, r io.Reader) (string, error) {
// TODO more attractive function signature importer.BuildDagFromReader
dagNode, err := importer.BuildDagFromReader(
n.DAG,
chunk.NewSizeSplitter(r, chunk.DefaultBlockSize),
importer.BasicPinnerCB(n.Pinning.GetManual()),
)
if err != nil {
return "", err
}
k, err := dagNode.Key()
if err != nil {
return "", err
}
return k.String(), nil
}