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 insertNodeAtPath(ctx context.Context, ds dag.DAGService, root *dag.Node, path []string, toinsert *dag.Node, create func() *dag.Node) (*dag.Node, error) {
if len(path) == 1 {
return addLink(ctx, ds, root, path[0], toinsert)
}
nd, err := root.GetLinkedNode(ctx, ds, path[0])
if err != nil {
// if 'create' is true, we create directories on the way down as needed
if err == dag.ErrNotFound && create != nil {
nd = create()
} else {
return nil, err
}
}
ndprime, err := insertNodeAtPath(ctx, ds, nd, path[1:], toinsert, create)
if err != nil {
return nil, err
}
_ = root.RemoveNodeLink(path[0])
err = root.AddNodeLinkClean(path[0], ndprime)
if err != nil {
return nil, err
}
_, err = ds.Add(root)
if err != nil {
return nil, err
}
return root, nil
}
func rmLink(ctx context.Context, ds dag.DAGService, root *dag.Node, path []string) (*dag.Node, error) {
if len(path) == 1 {
// base case, remove node in question
err := root.RemoveNodeLink(path[0])
if err != nil {
return nil, err
}
_, err = ds.Add(root)
if err != nil {
return nil, err
}
return root, nil
}
nd, err := root.GetLinkedNode(ctx, ds, path[0])
if err != nil {
return nil, err
}
nnode, err := rmLink(ctx, ds, nd, path[1:])
if err != nil {
return nil, err
}
_ = root.RemoveNodeLink(path[0])
err = root.AddNodeLinkClean(path[0], nnode)
if err != nil {
return nil, err
}
_, err = ds.Add(root)
if err != nil {
return nil, err
}
return root, nil
}
func addLink(ctx context.Context, ds dag.DAGService, root *dag.Node, childname string, childnd *dag.Node) (*dag.Node, error) {
if childname == "" {
return nil, errors.New("cannot create link with no name!")
}
// ensure that the node we are adding is in the dagservice
_, err := ds.Add(childnd)
if err != nil {
return nil, err
}
// ensure no link with that name already exists
_ = root.RemoveNodeLink(childname) // ignore error, only option is ErrNotFound
if err := root.AddNodeLinkClean(childname, childnd); err != nil {
return nil, err
}
if _, err := ds.Add(root); err != nil {
return nil, err
}
return root, 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
}