feat(network): Improve the performance of the network layout engine (#2729)

* Improve the performance of the network layout engine Short-cut the execution of a number of methods in LayoutEngine to make them handle highly-connected graphs better. * Demonstrations of layouts of large networks
8 years ago · 6acc7bdd8c
--- a/examples/network/layout/demo.jsonp
+++ b/examples/network/layout/demo.jsonp
--- a/examples/network/layout/demo_big.jsonp
+++ b/examples/network/layout/demo_big.jsonp
--- a/examples/network/layout/hierarchicalLayoutBigUserDefined.html
+++ b/examples/network/layout/hierarchicalLayoutBigUserDefined.html
@ -0,0 +1,46 @@
 <!doctype html>
 <html>
 <head>
    <title>Network | Hierarchical layout</title>

    <style type="text/css">
        body {
            font: 10pt sans;
        }

        #mynetwork {
            width: 600px;
            height: 600px;
            border: 1px solid lightgray;
        }
    </style>

    <script type="text/javascript" src="../../../dist/vis.js"></script>
    <link href="../../../dist/vis-network.min.css" rel="stylesheet" type="text/css"/>

    <script type="text/javascript">
        var network = null;

        function p(data) {
            var container = document.getElementById('mynetwork');
            var options = {
                layout: {
                    hierarchical: {},
                },
            };
            console.log("starting layout");
            network = new vis.Network(container, data, options);
            console.log("layout complete");
        }
    </script>
 </head>

 <body>
 <h2>Hierarchical Layout</h2>

 <div id="mynetwork"></div>

 <script type="text/javascript" src="./demo.jsonp"></script>

 </body>
 </html>
--- a/lib/network/modules/LayoutEngine.js
+++ b/lib/network/modules/LayoutEngine.js
@ -429,6 +429,9 @@ class LayoutEngine {

    // get a map of all nodes in this branch
    let getBranchNodes = (source, map) => {
      if (map[source.id]) {
        return;
      }
      map[source.id] = true;
      if (this.hierarchicalChildrenReference[source.id]) {
        let children = this.hierarchicalChildrenReference[source.id];
@ -471,16 +474,24 @@ class LayoutEngine {

    // get the maximum level of a branch.
    let getMaxLevel = (nodeId) => {
      let level = this.hierarchicalLevels[nodeId];
      if (this.hierarchicalChildrenReference[nodeId]) {
        let children = this.hierarchicalChildrenReference[nodeId];
        if (children.length > 0) {
          for (let i = 0; i < children.length; i++) {
            level = Math.max(level,getMaxLevel(children[i]));
      let accumulator = {};
      let _getMaxLevel = (nodeId) => {
        if (accumulator[nodeId] !== undefined) {
          return accumulator[nodeId];
        }
        let level = this.hierarchicalLevels[nodeId];
        if (this.hierarchicalChildrenReference[nodeId]) {
          let children = this.hierarchicalChildrenReference[nodeId];
          if (children.length > 0) {
            for (let i = 0; i < children.length; i++) {
              level = Math.max(level,_getMaxLevel(children[i]));
            }
          }
        }
      }
      return level;
        accumulator[nodeId] = level;
        return level;
      };
      return _getMaxLevel(nodeId);
    };

    // check what the maximum level is these nodes have in common.
@ -532,8 +543,8 @@ class LayoutEngine {
        let diffAbs = Math.abs(pos2 - pos1);
        //console.log("NOW CHEcKING:", node1.id, node2.id, diffAbs);
        if (diffAbs > this.options.hierarchical.nodeSpacing) {
          let branchNodes1 = {}; branchNodes1[node1.id] = true;
          let branchNodes2 = {}; branchNodes2[node2.id] = true;
          let branchNodes1 = {};
          let branchNodes2 = {};

          getBranchNodes(node1, branchNodes1);
          getBranchNodes(node2, branchNodes2);
@ -639,7 +650,6 @@ class LayoutEngine {
          // check movable area of the branch
          if (branches[node.id] === undefined) {
            let branchNodes = {};
            branchNodes[node.id] = true;
            getBranchNodes(node, branchNodes);
            branches[node.id] = branchNodes;
          }
@ -1238,17 +1248,25 @@ class LayoutEngine {
   * @private
   */
  _shiftBlock(parentId, diff) {
    if (this.options.hierarchical.direction === 'UD' || this.options.hierarchical.direction === 'DU') {
      this.body.nodes[parentId].x += diff;
    }
    else {
      this.body.nodes[parentId].y += diff;
    }
    if (this.hierarchicalChildrenReference[parentId] !== undefined) {
      for (let i = 0; i < this.hierarchicalChildrenReference[parentId].length; i++) {
        this._shiftBlock(this.hierarchicalChildrenReference[parentId][i], diff);
    let progress = {};
    let shifter = (parentId) => {
      if (progress[parentId]) {
        return;
      }
    }
      progress[parentId] = true;
      if (this.options.hierarchical.direction === 'UD' || this.options.hierarchical.direction === 'DU') {
        this.body.nodes[parentId].x += diff;
      }
      else {
        this.body.nodes[parentId].y += diff;
      }
      if (this.hierarchicalChildrenReference[parentId] !== undefined) {
        for (let i = 0; i < this.hierarchicalChildrenReference[parentId].length; i++) {
          shifter(this.hierarchicalChildrenReference[parentId][i]);
        }
      }
    };
    shifter(parentId);
  }