Method doMutate

edgraph/server.go:575–713

(ctx context.Context, qc *queryContext, resp *api.Response)

}

func (s *Server) doMutate(ctx context.Context, qc *queryContext, resp *api.Response) error {
	if len(qc.gmuList) == 0 {
		return nil
	}
	if ctx.Err() != nil {
		return ctx.Err()
	}

	start := time.Now()
	defer func() {
		qc.latency.Processing += time.Since(start)
	}()

	if !isMutationAllowed(ctx) {
		return errors.Errorf("no mutations allowed")
	}

	// update mutations from the query results before assigning UIDs
	if err := updateMutations(qc); err != nil {
		return err
	}

	if err := verifyUniqueWithinMutation(qc); err != nil {
		return err
	}

	newUids, err := query.AssignUids(ctx, qc.gmuList)
	if err != nil {
		return err
	}

	// resp.Uids contains a map of the node name to the uid.
	// 1. For a blank node, like _:foo, the key would be foo.
	// 2. For a uid variable that is part of an upsert query,
	//    like uid(foo), the key would be uid(foo).
	resp.Uids = query.UidsToHex(query.StripBlankNode(newUids))
	edges, err := query.ToDirectedEdges(qc.gmuList, newUids)
	if err != nil {
		return err
	}

	if len(edges) > x.Config.LimitMutationsNquad {
		return errors.Errorf("NQuad count in the request: %d, is more that threshold: %d",
			len(edges), x.Config.LimitMutationsNquad)
	}

	ns, err := x.ExtractNamespace(ctx)
	if err != nil {
		return errors.Wrapf(err, "While doing mutations:")
	}
	predHints := make(map[string]pb.Metadata_HintType)
	for _, gmu := range qc.gmuList {
		for pred, hint := range gmu.Metadata.GetPredHints() {
			pred = x.NamespaceAttr(ns, pred)
			if oldHint := predHints[pred]; oldHint == pb.Metadata_LIST {
				continue
			}
			predHints[pred] = hint