08-27-周三_17-09-29

node_modules/dagre-layout/lib/acyclic.js

@@ -0,0 +1,66 @@
+import _ from 'lodash'
+
+import greedyFAS from './greedy-fas'
+
+function run (g) {
+  const fas = (g.graph().acyclicer === 'greedy'
+    ? greedyFAS(g, weightFn(g))
+    : dfsFAS(g))
+  _.forEach(fas, function (e) {
+    const label = g.edge(e)
+    g.removeEdge(e)
+    label.forwardName = e.name
+    label.reversed = true
+    g.setEdge(e.w, e.v, label, _.uniqueId('rev'))
+  })
+
+  function weightFn (g) {
+    return function (e) {
+      return g.edge(e).weight
+    }
+  }
+}
+
+function dfsFAS (g) {
+  const fas = []
+  const stack = {}
+  const visited = {}
+
+  function dfs (v) {
+    if (_.has(visited, v)) {
+      return
+    }
+    visited[v] = true
+    stack[v] = true
+    _.forEach(g.outEdges(v), function (e) {
+      if (_.has(stack, e.w)) {
+        fas.push(e)
+      } else {
+        dfs(e.w)
+      }
+    })
+    delete stack[v]
+  }
+
+  _.forEach(g.nodes(), dfs)
+  return fas
+}
+
+function undo (g) {
+  _.forEach(g.edges(), function (e) {
+    const label = g.edge(e)
+    if (label.reversed) {
+      g.removeEdge(e)
+
+      const forwardName = label.forwardName
+      delete label.reversed
+      delete label.forwardName
+      g.setEdge(e.w, e.v, label, forwardName)
+    }
+  })
+}
+
+export default {
+  run,
+  undo
+}