// EdgeMetadata produces an EdgeMetadata for a given edge.
func (r Reduce) EdgeMetadata(rpt report.Report, localID, remoteID string) report.EdgeMetadata {
metadata := report.EdgeMetadata{}
for _, renderer := range r {
metadata.Merge(renderer.EdgeMetadata(rpt, localID, remoteID))
}
return metadata
}
// EdgeMetadata gives the metadata of an edge from the perspective of the
// srcRenderableID. Since an edgeID can have multiple edges on the address
// level, it uses the supplied mapping function to translate address IDs to
// renderable node (mapped) IDs.
func (m Map) EdgeMetadata(rpt report.Report, srcRenderableID, dstRenderableID string) report.EdgeMetadata {
// First we need to map the ids in this layer into the ids in the underlying layer
_, mapped := m.render(rpt) // this maps from old -> new
inverted := map[string][]string{} // this maps from new -> old(s)
for k, v := range mapped {
existing := inverted[v]
existing = append(existing, k)
inverted[v] = existing
}
// Now work out a slice of edges this edge is constructed from
oldEdges := []struct{ src, dst string }{}
for _, oldSrcID := range inverted[srcRenderableID] {
for _, oldDstID := range inverted[dstRenderableID] {
oldEdges = append(oldEdges, struct{ src, dst string }{oldSrcID, oldDstID})
}
}
// Now recurse for each old edge
output := report.EdgeMetadata{}
for _, edge := range oldEdges {
metadata := m.Renderer.EdgeMetadata(rpt, edge.src, edge.dst)
output.Merge(metadata)
}
return output
}
