func EnumerateChildrenAsync(ctx context.Context, ds DAGService, root *Node, set key.KeySet) error {
toprocess := make(chan []key.Key, 8)
nodes := make(chan *NodeOption, 8)
ctx, cancel := context.WithCancel(ctx)
defer cancel()
defer close(toprocess)
go fetchNodes(ctx, ds, toprocess, nodes)
nodes <- &NodeOption{Node: root}
live := 1
for {
select {
case opt, ok := <-nodes:
if !ok {
return nil
}
if opt.Err != nil {
return opt.Err
}
nd := opt.Node
// a node has been fetched
live--
var keys []key.Key
for _, lnk := range nd.Links {
k := key.Key(lnk.Hash)
if !set.Has(k) {
set.Add(k)
live++
keys = append(keys, k)
}
}
if live == 0 {
return nil
}
if len(keys) > 0 {
select {
case toprocess <- keys:
case <-ctx.Done():
return ctx.Err()
}
}
case <-ctx.Done():
return ctx.Err()
}
}
}
func Descendants(ctx context.Context, ds dag.DAGService, set key.KeySet, roots []key.Key, bestEffort bool) error {
for _, k := range roots {
set.Add(k)
nd, err := ds.Get(ctx, k)
if err != nil {
return err
}
// EnumerateChildren recursively walks the dag and adds the keys to the given set
err = dag.EnumerateChildren(ctx, ds, nd, set, bestEffort)
if err != nil {
return err
}
}
return nil
}
func Descendants(ds dag.DAGService, set key.KeySet, roots []key.Key) error {
for _, k := range roots {
set.Add(k)
nd, err := ds.Get(context.Background(), k)
if err != nil {
return err
}
// EnumerateChildren recursively walks the dag and adds the keys to the given set
err = dag.EnumerateChildren(context.Background(), ds, nd, set)
if err != nil {
return err
}
}
return nil
}
// EnumerateChildren will walk the dag below the given root node and add all
// unseen children to the passed in set.
// TODO: parallelize to avoid disk latency perf hits?
func EnumerateChildren(ctx context.Context, ds DAGService, root *Node, set key.KeySet) error {
for _, lnk := range root.Links {
k := key.Key(lnk.Hash)
if !set.Has(k) {
set.Add(k)
child, err := ds.Get(ctx, k)
if err != nil {
return err
}
err = EnumerateChildren(ctx, ds, child, set)
if err != nil {
return err
}
}
}
return nil
}
// EnumerateChildren will walk the dag below the given root node and add all
// unseen children to the passed in set.
// TODO: parallelize to avoid disk latency perf hits?
func EnumerateChildren(ctx context.Context, ds DAGService, root *Node, set key.KeySet, bestEffort bool) error {
for _, lnk := range root.Links {
k := key.Key(lnk.Hash)
if !set.Has(k) {
set.Add(k)
child, err := ds.Get(ctx, k)
if err != nil {
if bestEffort && err == ErrNotFound {
continue
} else {
return err
}
}
err = EnumerateChildren(ctx, ds, child, set, bestEffort)
if err != nil {
return err
}
}
}
return nil
}