// SourceFromEntries returns a new Source from the given a set of entries with
// the same source VName.
func SourceFromEntries(entries []*spb.Entry) *Source {
if len(entries) == 0 {
return nil
}
src := &Source{
Ticket: kytheuri.ToString(entries[0].Source),
Facts: make(map[string][]byte),
Edges: make(map[string][]string),
}
edgeTargets := make(map[string]stringset.Set)
for _, e := range entries {
if graphstore.IsEdge(e) {
tgts, ok := edgeTargets[e.EdgeKind]
if !ok {
tgts = stringset.New()
edgeTargets[e.EdgeKind] = tgts
}
tgts.Add(kytheuri.ToString(e.Target))
} else {
src.Facts[e.FactName] = e.FactValue
}
}
for kind, targets := range edgeTargets {
src.Edges[kind] = targets.Slice()
sort.Strings(src.Edges[kind])
}
return src
}
// EnsureReverseEdges checks if gs contains reverse edges. If it doesn't, it
// will scan gs for all forward edges, adding a reverse for each back into the
// GraphStore. This is necessary for a GraphStoreService to work properly.
func EnsureReverseEdges(ctx context.Context, gs graphstore.Service) error {
var edge *spb.Entry
if err := gs.Scan(ctx, &spb.ScanRequest{}, func(e *spb.Entry) error {
if graphstore.IsEdge(e) {
edge = e
return io.EOF
}
return nil
}); err != nil {
return err
}
if edge == nil {
log.Println("No edges found in GraphStore")
return nil
} else if schema.EdgeDirection(edge.EdgeKind) == schema.Reverse {
return nil
}
var foundReverse bool
if err := gs.Read(ctx, &spb.ReadRequest{
Source: edge.Target,
EdgeKind: schema.MirrorEdge(edge.EdgeKind),
}, func(entry *spb.Entry) error {
foundReverse = true
return nil
}); err != nil {
return fmt.Errorf("error checking for reverse edge: %v", err)
}
if foundReverse {
return nil
}
return addReverseEdges(ctx, gs)
}
// AppendEntry adds the given Entry to the Source's facts or edges. It is
// assumed that src.Ticket == kytheuri.ToString(e.Source).
func AppendEntry(src *ipb.Source, e *spb.Entry) {
if graphstore.IsEdge(e) {
kind, ordinal, _ := edges.ParseOrdinal(e.EdgeKind)
group, ok := src.EdgeGroups[kind]
if !ok {
group = &ipb.Source_EdgeGroup{}
src.EdgeGroups[kind] = group
}
ticket := kytheuri.ToString(e.Target)
ord := int32(ordinal)
for _, edge := range group.Edges {
if edge.Ticket == ticket && edge.Ordinal == ord {
// Don't add duplicate edge
return
}
}
group.Edges = append(group.Edges, &ipb.Source_Edge{
Ticket: ticket,
Ordinal: ord,
})
} else {
src.Facts[e.FactName] = e.FactValue
}
}
// NodeFact returns a Node_Fact from the given Entry. If e == nil or e is not a
// node fact, nil is returned.
func NodeFact(e *spb.Entry) *srvpb.Node_Fact {
if e == nil || graphstore.IsEdge(e) {
return nil
}
return &srvpb.Node_Fact{
Name: e.FactName,
Value: e.FactValue,
}
}
// getEdges returns edgeTargets with the given node as their source. Only edge
// entries that return true when applied to pred are returned.
func getEdges(ctx context.Context, gs graphstore.Service, node *spb.VName, pred func(*spb.Entry) bool) ([]*edgeTarget, error) {
var targets []*edgeTarget
if err := gs.Read(ctx, &spb.ReadRequest{
Source: node,
EdgeKind: "*",
}, func(entry *spb.Entry) error {
if graphstore.IsEdge(entry) && pred(entry) {
targets = append(targets, &edgeTarget{entry.EdgeKind, entry.Target})
}
return nil
}); err != nil {
return nil, fmt.Errorf("read error: %v", err)
}
return targets, nil
}
// toTriple converts an Entry to the triple file format. Returns an error if
// the entry is not valid.
func toTriple(entry *spb.Entry) (*rdf.Triple, error) {
if err := graphstore.ValidEntry(entry); err != nil {
return nil, fmt.Errorf("invalid entry {%+v}: %v", entry, err)
}
t := &rdf.Triple{
Subject: kytheuri.FromVName(entry.Source).String(),
}
if graphstore.IsEdge(entry) {
t.Predicate = entry.EdgeKind
t.Object = kytheuri.FromVName(entry.Target).String()
} else {
t.Predicate = entry.FactName
t.Object = string(entry.FactValue)
}
return t, nil
}