func AddMetadataTo(n *core.IpfsNode, skey string, m *ft.Metadata) (string, error) {
ukey := key.B58KeyDecode(skey)
nd, err := n.DAG.Get(n.Context(), ukey)
if err != nil {
return "", err
}
mdnode := new(dag.Node)
mdata, err := ft.BytesForMetadata(m)
if err != nil {
return "", err
}
mdnode.Data = mdata
if err := mdnode.AddNodeLinkClean("file", nd); err != nil {
return "", err
}
nk, err := n.DAG.Add(mdnode)
if err != nil {
return "", err
}
return nk.B58String(), nil
}
func nodeFromTemplate(template string) (*dag.Node, error) {
switch template {
case "unixfs-dir":
nd := new(dag.Node)
nd.Data = ft.FolderPBData()
return nd, nil
default:
return nil, fmt.Errorf("template '%s' not found", template)
}
}
// converts the Node object into a real dag.Node
func deserializeNode(node *Node) (*dag.Node, error) {
dagnode := new(dag.Node)
dagnode.Data = []byte(node.Data)
dagnode.Links = make([]*dag.Link, len(node.Links))
for i, link := range node.Links {
hash, err := mh.FromB58String(link.Hash)
if err != nil {
return nil, err
}
dagnode.Links[i] = &dag.Link{
Name: link.Name,
Size: link.Size,
Hash: hash,
}
}
return dagnode, nil
}
func setDataCaller(req cmds.Request, root *dag.Node) (key.Key, error) {
if len(req.Arguments()) < 3 {
return "", fmt.Errorf("not enough arguments for set-data")
}
nd, err := req.InvocContext().GetNode()
if err != nil {
return "", err
}
root.Data = []byte(req.Arguments()[2])
newkey, err := nd.DAG.Add(root)
if err != nil {
return "", err
}
return newkey, nil
}
// dagTruncate truncates the given node to 'size' and returns the modified Node
func dagTruncate(ctx context.Context, nd *mdag.Node, size uint64, ds mdag.DAGService) (*mdag.Node, error) {
if len(nd.Links) == 0 {
// TODO: this can likely be done without marshaling and remarshaling
pbn, err := ft.FromBytes(nd.Data)
if err != nil {
return nil, err
}
nd.Data = ft.WrapData(pbn.Data[:size])
return nd, nil
}
var cur uint64
end := 0
var modified *mdag.Node
ndata := new(ft.FSNode)
for i, lnk := range nd.Links {
child, err := lnk.GetNode(ctx, ds)
if err != nil {
return nil, err
}
childsize, err := ft.DataSize(child.Data)
if err != nil {
return nil, err
}
// found the child we want to cut
if size < cur+childsize {
nchild, err := dagTruncate(ctx, child, size-cur, ds)
if err != nil {
return nil, err
}
ndata.AddBlockSize(size - cur)
modified = nchild
end = i
break
}
cur += childsize
ndata.AddBlockSize(childsize)
}
_, err := ds.Add(modified)
if err != nil {
return nil, err
}
nd.Links = nd.Links[:end]
err = nd.AddNodeLinkClean("", modified)
if err != nil {
return nil, err
}
d, err := ndata.GetBytes()
if err != nil {
return nil, err
}
nd.Data = d
// invalidate cache and recompute serialized data
_, err = nd.Encoded(true)
if err != nil {
return nil, err
}
return nd, nil
}