Merge pull request #228 from rustedgrail/master

pass1 and pass2 no longer cause a stack overflow for large graphs
dagrejs · Feb 6, 2018 · c6cacf7 · c6cacf7
2 parents 9596cec + ee72d87
commit c6cacf7
Showing 1 changed file with 37 additions and 26 deletions.
diff --git a/lib/position/bk.js b/lib/position/bk.js
@@ -211,36 +211,47 @@ function horizontalCompaction(g, layering, root, align, reverseSep) {
   // coordinates. The second sweep removes unused space by moving blocks to the
   // greatest coordinates without violating separation.
   var xs = {},
-      blockG = buildBlockGraph(g, layering, root, reverseSep);
-
-  // First pass, assign smallest coordinates via DFS
-  var visited = {};
-  function pass1(v) {
-    if (!_.has(visited, v)) {
-      visited[v] = true;
-      xs[v] = _.reduce(blockG.inEdges(v), function(max, e) {
-        pass1(e.v);
-        return Math.max(max, xs[e.v] + blockG.edge(e));
-      }, 0);
+      blockG = buildBlockGraph(g, layering, root, reverseSep),
+      borderType = reverseSep ? "borderLeft" : "borderRight";
+
+  function iterate(setXsFunc, nextNodesFunc) {
+    var stack = blockG.nodes();
+    var elem = stack.pop();
+    var visited = {};
+    while (elem) {
+      if (visited[elem]) {
+        setXsFunc(elem);
+      } else {
+        visited[elem] = true;
+        stack.push(elem);
+        stack = stack.concat(nextNodesFunc(elem));
+      }
+
+      elem = stack.pop();
     }
   }
-  _.forEach(blockG.nodes(), pass1);
-
-  var borderType = reverseSep ? "borderLeft" : "borderRight";
-  function pass2(v) {
-    if (visited[v] !== 2) {
-      visited[v]++;
-      var node = g.node(v);
-      var min = _.reduce(blockG.outEdges(v), function(min, e) {
-        pass2(e.w);
-        return Math.min(min, xs[e.w] - blockG.edge(e));
-      }, Number.POSITIVE_INFINITY);
-      if (min !== Number.POSITIVE_INFINITY && node.borderType !== borderType) {
-        xs[v] = Math.max(xs[v], min);
-      }
+
+  // First pass, assign smallest coordinates
+  function pass1(elem) {
+    xs[elem] = blockG.inEdges(elem).reduce(function(acc, e) {
+      return Math.max(acc, xs[e.v] + blockG.edge(e));
+    }, 0);
+  }
+
+  // Second pass, assign greatest coordinates
+  function pass2(elem) {
+    var min = blockG.outEdges(elem).reduce(function(acc, e) {
+      return Math.min(acc, xs[e.w] - blockG.edge(e));
+    }, Number.POSITIVE_INFINITY);
+
+    var node = g.node(elem);
+    if (min !== Number.POSITIVE_INFINITY && node.borderType !== borderType) {
+      xs[elem] = Math.max(xs[elem], min);
     }
   }
-  _.forEach(blockG.nodes(), pass2);
+
+  iterate(pass1, _.bind(blockG.predecessors, blockG));
+  iterate(pass2, _.bind(blockG.successors, blockG));
 
   // Assign x coordinates to all nodes
   _.forEach(align, function(v) {