func MaximalSubGraphs(all store.SubGraphs, nodeAttrs *bptree.BpTree, tempDir string) (<-chan []byte, error) {
labelsBf, err := fmap.CreateBlockFile(path.Join(tempDir, "labels.bptree"))
if err != nil {
return nil, err
}
labels, err := bptree.New(labelsBf, -1, 1)
if err != nil {
return nil, err
}
keys := make(chan []byte)
go func() {
defer labelsBf.Close()
var cur []byte
var had bool = false
for key, sg, next := all.Backward()(); next != nil; key, sg, next = next() {
if cur != nil && !bytes.Equal(key, cur) {
if !had {
keys <- cur
}
had = false
}
has, err := labels.Has(key)
if err != nil {
log.Fatal(err)
}
if has {
had = true
}
if !bytes.Equal(cur, key) {
// add all of the (potential) parents of this node
for eIdx := range sg.E {
nsg, _ := sg.RemoveEdge(eIdx)
addToLabels(labels, nsg.ShortLabel())
}
}
cur = key
}
if !had && cur != nil {
keys <- cur
}
close(keys)
}()
return keys, nil
}
