Example #1
0
        /// <summary>
        /// Add or update edge.
        /// </summary>
        /// <returns></returns>
        public static void AddOrUpdateEdge(this DirectedMetaGraph graph, uint vertex1, uint vertex2, float weight,
                                           bool?direction, uint contractedId, float distance, float time)
        {
            var current         = ContractedEdgeDataSerializer.Serialize(weight, direction);
            var hasExistingEdge = false;
            var hasExistingEdgeOnlySameDirection = true;

            if (graph.UpdateEdge(vertex1, vertex2, (data) =>
            {
                hasExistingEdge = true;
                if (ContractedEdgeDataSerializer.HasDirection(data[0], direction))
                {     // has the same direction.
                    if (weight < ContractedEdgeDataSerializer.DeserializeWeight(data[0]))
                    { // the weight is better, just update.
                        return(true);
                    }
                    return(false);
                }
                hasExistingEdgeOnlySameDirection = false;
                return(false);
            }, new uint[] { current }, ContractedEdgeDataSerializer.SerializeMetaAugmented(contractedId, distance, time)) != Constants.NO_EDGE)
            { // updating the edge succeeded.
                return;
            }
            if (!hasExistingEdge)
            { // no edge exists yet.
                graph.AddEdge(vertex1, vertex2, new uint[] { current }, ContractedEdgeDataSerializer.SerializeMetaAugmented(
                                  contractedId, distance, time));
                return;
            }
            else if (hasExistingEdgeOnlySameDirection)
            { // there is an edge already but it has a better weight.
                return;
            }
            else
            { // see what's there and update if needed.
                var forward              = false;
                var forwardWeight        = float.MaxValue;
                var forwardContractedId  = uint.MaxValue;
                var forwardTime          = float.MaxValue;
                var forwardDistance      = float.MaxValue;
                var backward             = false;
                var backwardWeight       = float.MaxValue;
                var backwardContractedId = uint.MaxValue;
                var backwardTime         = float.MaxValue;
                var backwardDistance     = float.MaxValue;

                if (direction == null || direction.Value)
                {
                    forward             = true;
                    forwardWeight       = weight;
                    forwardContractedId = contractedId;
                    forwardTime         = time;
                    forwardDistance     = distance;
                }
                if (direction == null || !direction.Value)
                {
                    backward             = true;
                    backwardWeight       = weight;
                    backwardContractedId = contractedId;
                    backwardTime         = time;
                    backwardDistance     = distance;
                }

                var edgeEnumerator = graph.GetEdgeEnumerator(vertex1);
                while (edgeEnumerator.MoveNext())
                {
                    if (edgeEnumerator.Neighbour == vertex2)
                    {
                        float localWeight;
                        bool? localDirection;
                        ContractedEdgeDataSerializer.Deserialize(edgeEnumerator.Data0,
                                                                 out localWeight, out localDirection);
                        uint  localContractedId;
                        float localTime;
                        float localDistance;
                        ContractedEdgeDataSerializer.DeserializeMetaAgumented(edgeEnumerator.MetaData, out localContractedId, out localDistance, out localTime);
                        if (localDirection == null || localDirection.Value)
                        {
                            if (localWeight < forwardWeight)
                            {
                                forwardWeight       = localWeight;
                                forward             = true;
                                forwardContractedId = localContractedId;
                                forwardTime         = localTime;
                                forwardDistance     = localDistance;
                            }
                        }
                        if (localDirection == null || !localDirection.Value)
                        {
                            if (localWeight < backwardWeight)
                            {
                                backwardWeight       = localWeight;
                                backward             = true;
                                backwardContractedId = localContractedId;
                                backwardDistance     = localDistance;
                                backwardTime         = localTime;
                            }
                        }
                    }
                }

                graph.RemoveEdge(vertex1, vertex2);

                if (forward && backward &&
                    forwardWeight == backwardWeight &&
                    forwardContractedId == backwardContractedId)
                { // add one bidirectional edge.
                    graph.AddEdge(vertex1, vertex2, forwardWeight, null, forwardContractedId, forwardDistance, forwardTime);
                    //graph.AddEdge(vertex1, vertex2,
                    //    ContractedEdgeDataSerializer.Serialize(forwardWeight, null), forwardContractedId);
                }
                else
                {     // add two unidirectional edges if needed.
                    if (forward)
                    { // there is a forward edge.
                        graph.AddEdge(vertex1, vertex2, forwardWeight, true, forwardContractedId, forwardDistance, forwardTime);
                        //graph.AddEdge(vertex1, vertex2,
                        //    ContractedEdgeDataSerializer.Serialize(forwardWeight, true), forwardContractedId);
                    }
                    if (backward)
                    { // there is a backward edge.
                        graph.AddEdge(vertex1, vertex2, backwardWeight, false, backwardContractedId, backwardDistance, backwardTime);
                    }
                }
            }
        }