Exemplo n.º 1
0
        private void MakeConnections(
            Supernode[,] superNodes,
            Supernode[] nodes,
            int columnOffset,
            int nextRow,
            bool toFirstHalf,
            int minLimit,
            int maxLimit,
            int D)
        {
            if (nextRow >= netHeight)
            {
                return;
            }

            var halfLen           = nodes.Length / 2;
            var nextRowFirstHalf  = new Supernode[halfLen];
            var nextRowSecondHalf = new Supernode[halfLen];

            for (int i = 0; i < halfLen; i++)
            {
                nextRowFirstHalf[i]  = superNodes[nextRow, columnOffset + i];
                nextRowSecondHalf[i] = superNodes[nextRow, halfLen + columnOffset + i];
            }

            for (int i = 0; i < halfLen; i++)
            {
                if (CheckSuperNodeSize(nodes[i], nextRowSecondHalf[i], minLimit, maxLimit))
                {
                    nodes[i].ConnectRight(nextRowSecondHalf[i], D);
                }

                if (CheckSuperNodeSize(nodes[halfLen + i], nextRowFirstHalf[i], minLimit, maxLimit))
                {
                    nodes[halfLen + i].ConnectLeft(nextRowFirstHalf[i], D);
                }
            }

            for (int i = 0; i < nodes.Length; i++)
            {
                if (CheckSuperNodeSize(nodes[i], superNodes[nextRow, columnOffset + i], minLimit, maxLimit))
                {
                    if (nodes[i].LowerLeft == null)
                    {
                        nodes[i].ConnectLeft(superNodes[nextRow, columnOffset + i], D);
                    }
                    else
                    {
                        nodes[i].ConnectRight(superNodes[nextRow, columnOffset + i], D);
                    }
                }
            }

            MakeConnections(superNodes, nextRowFirstHalf, columnOffset,
                            nextRow + 1, false, minLimit, maxLimit, D);

            MakeConnections(superNodes, nextRowSecondHalf, columnOffset + halfLen,
                            nextRow + 1, true, minLimit, maxLimit, D);
        }
Exemplo n.º 2
0
        private List <Supernode[]> HashBottomSuperNodes <T>(List <T> dataItems, int B)
        {
            var outputList   = new List <Supernode[]>();
            var lastRowIndex = netHeight - 1;

            foreach (var dataItem in dataItems)
            {
                var hashSuperNodes = new Supernode[B];
                var randomHash     = new Random(dataItem.GetHashCode());
                for (int i = 0; i < B; i++)
                {
                    hashSuperNodes[i] = supernodes[lastRowIndex, randomHash.Next(0, netWidth)];
                }
                outputList.Add(hashSuperNodes);
            }
            return(outputList);
        }
Exemplo n.º 3
0
        private void MakeConnections(Supernode[,] superNodes, int n, int C, int D, double alpha, double beta)
        {
            if (Math.Log(netWidth, 2) != Math.Truncate(Math.Log(netWidth, 2)))
            {
                throw new Exception("Number of rows must be a power of two!");
            }

            var minLimit = (int)Math.Round(alpha * C * Math.Log(n, Math.E));
            var maxLimit = (int)Math.Round(beta * C * Math.Log(n, Math.E));

            var firstRow = new Supernode[netWidth];

            for (int i = 0; i < netWidth; i++)
            {
                firstRow[i] = superNodes[0, i];
            }

            MakeConnections(superNodes, firstRow, 0, 1, false, minLimit, maxLimit, D);
        }
Exemplo n.º 4
0
        private void bn_InitializationFinished(Supernode[,] supernodes)
        {
            // draw the network
            var g = new Graph();

            var numRows = supernodes.GetLength(0);
            var numCols = supernodes.GetLength(1);
            int x, y = 50;
            for (int i = 0; i < numRows; i++)
            {
                x = 30;
                for (int j = 0; j < numCols; j++)
                {
                    var node = supernodes[i, j];
                    g.AddNode(new GraphNode(node.Id.ToString(), x, y));
                    x += 40;
                }
                y += 95;
            }

            for (int i = 0; i < numRows; i++)
            {
                for (int j = 0; j < numCols; j++)
                {
                    var superNode = supernodes[i, j];
                    if (superNode.LowerNodes.Length > 0)
                    {
                        foreach (var lowerNode in superNode.LowerNodes)
                        {
                            g.AddEdge(superNode.Id.ToString(), lowerNode.Id.ToString());
                        }
                    }
                }
            }

            graphViewer.GraphSize = 33;
            graphViewer.Graph = g;
            graphViewer.Refresh();
        }
Exemplo n.º 5
0
        private void MakeExpanderGraph(Supernode toSupernode, int D)
        {
            // construct the expander graph
            foreach (var nodeId in NodeIds)
            {
                var toNodeIds = new List <int>();
                foreach (var toNodeId in randUtils.PickRandomElements(toSupernode.NodeIds, D))
                {
                    toNodeIds.Add(toNodeId);
                }

                if (AddNodeConnection != null)
                {
                    AddNodeConnection(new KeyValuePair <int, NodeConnection>(nodeId,
                                                                             new DownNodeConnection(this.Id, toSupernode.Id, toNodeIds)));

                    foreach (var toNodeId in toNodeIds)
                    {
                        AddNodeConnection(new KeyValuePair <int, NodeConnection>(toNodeId,
                                                                                 new UpNodeConnection(toSupernode.Id, this.Id, nodeId)));
                    }
                }
            }
        }
Exemplo n.º 6
0
 /// <summary>
 /// Connects the supernode to another supernode and constructs a random
 /// constant-degree expander graph between the two sets of nodes.
 /// </summary>
 /// <param name="toNode"></param>
 /// <param name="D">The degree of the constant-degree expander graph.</param>
 public void ConnectRight(Supernode toNode, int D)
 {
     LowerRight = toNode;
     MakeExpanderGraph(toNode, D);
 }
Exemplo n.º 7
0
        /// <summary>
        /// Builds the butterfly network.
        /// </summary>
        /// <param name="n">Total number of nodes.</param>
        /// <param name="C">Every node chooses at random C top supernodes, C bottom supernodes, and Clog(n) middle supernodes to which each the node belongs.</param>
        /// <param name="D">The degree of the random expander graph constructed between two supernodes.</param>
        /// <param name="alpha">An expander graph maybe constructed between two supernodes if both are of size at least alpha*C*ln(n) and no more than beta*C*ln(n).</param>
        /// <param name="beta">An expander graph maybe constructed between two supernodes if both are of size at least alpha*C*ln(n) and no more than beta*C*ln(n).</param>
        internal void Initialize(IEnumerable <int> nodeIds, int n, int B, int C, int D, int T, double alpha, double beta)
        {
            IsInitialized = false;
            this.n        = n;
            this.B        = B;
            this.T        = T;
            this.beta     = beta;
            var netWidthTemp = n / Math.Log(n, 2);

            // round this to the nearest greater power of two
            netWidth  = (int)Math.Pow(2.0, Math.Ceiling(Math.Log(netWidthTemp, 2)));
            netHeight = (int)Math.Log(netWidth, 2) + 1;

            supernodes = new Supernode[netHeight, netWidth];
            for (int i = 0; i < netHeight; i++)
            {
                for (int j = 0; j < netWidth; j++)
                {
                    supernodes[i, j] = new Supernode(i * netWidth + j, randUtils);
                    supernodes[i, j].AddNodeConnection +=
                        new Supernode.AddNodeConnectionHandler(CollectNodeConnections);
                }
            }

            // construct the network
            nodeConnections = new Dictionary <int, SetupMessageData>();
            RegisterNodes(nodeIds, supernodes, C);
            MakeConnections(supernodes, n, C, D, alpha, beta);

            // each node should also point to T top supernodes
            foreach (var nodeId in nodeIds)
            {
                var topSupernodeIds = randUtils.GetRandomPerm(0, netWidth, T);
                foreach (var topSupernodeId in topSupernodeIds)
                {
                    var topSupernode = supernodes[0, topSupernodeId];
                    // -1 means the node is directly connected to a supernode
                    // without belonging to any supernode
                    CollectNodeConnections(
                        new KeyValuePair <int, NodeConnection>(nodeId,
                                                               new DownNodeConnection(-1, topSupernodeId, topSupernode.NodeIds)));

                    foreach (var topNodeId in topSupernode.NodeIds)
                    {
                        // -1 means topNode is connected to an individual node (nodeId) that
                        // doesn't belong to any supernode
                        CollectNodeConnections(
                            new KeyValuePair <int, NodeConnection>(topNodeId,
                                                                   new UpNodeConnection(topSupernode.Id, -1, nodeId)));
                    }
                }
            }

            //// send the network setup information to nodes
            //foreach (var nodeId in nodeIds)
            //{
            //	var msg = new SetupMessage(netHeight, netWidth, B, nodeConnections[nodeId]);
            //	Send(nodeId, msg, 100);
            //}

            IsInitialized = true;
            if (InitFinished != null)
            {
                InitFinished(supernodes);
            }
        }
Exemplo n.º 8
0
 private bool CheckSuperNodeSize(Supernode node1, Supernode node2, int min, int max)
 {
     return(node1.Size >= min && node1.Size <= max &&
            node2.Size >= min && node2.Size <= max);
 }
Exemplo n.º 9
0
        private void MakeExpanderGraph(Supernode toSupernode, int D)
        {
            // construct the expander graph
            foreach (var nodeId in NodeIds)
            {
                var toNodeIds = new List<int>();
                foreach (var toNodeId in randUtils.PickRandomElements(toSupernode.NodeIds, D))
                    toNodeIds.Add(toNodeId);

                if (AddNodeConnection != null)
                {
                    AddNodeConnection(new KeyValuePair<int, NodeConnection>(nodeId,
                            new DownNodeConnection(this.Id, toSupernode.Id, toNodeIds)));

                    foreach (var toNodeId in toNodeIds)
                    {
                        AddNodeConnection(new KeyValuePair<int, NodeConnection>(toNodeId,
                                new UpNodeConnection(toSupernode.Id, this.Id, nodeId)));
                    }
                }
            }
        }
Exemplo n.º 10
0
 /// <summary>
 /// Connects the supernode to another supernode and constructs a random 
 /// constant-degree expander graph between the two sets of nodes.
 /// </summary>
 /// <param name="toNode"></param>
 /// <param name="D">The degree of the constant-degree expander graph.</param>
 public void ConnectRight(Supernode toNode, int D)
 {
     LowerRight = toNode;
     MakeExpanderGraph(toNode, D);
 }