Blame view

node_modules/toposort/index.js 1.45 KB
aaac7fed   liuqimichale   add
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
  
  /**
   * Topological sorting function
   *
   * @param {Array} edges
   * @returns {Array}
   */
  
  module.exports = function(edges){
    return toposort(uniqueNodes(edges), edges)
  }
  
  module.exports.array = toposort
  
  function toposort(nodes, edges) {
    var cursor = nodes.length
      , sorted = new Array(cursor)
      , visited = {}
      , i = cursor
  
    while (i--) {
      if (!visited[i]) visit(nodes[i], i, [])
    }
  
    return sorted
  
    function visit(node, i, predecessors) {
      if(predecessors.indexOf(node) >= 0) {
        var nodeRep 
        try {
          nodeRep = ", node was:" + JSON.stringify(node)
        } catch(e) {
          nodeRep = ""
        }
        throw new Error('Cyclic dependency' + nodeRep)
      }
  
      if (!~nodes.indexOf(node)) {
        throw new Error('Found unknown node. Make sure to provided all involved nodes. Unknown node: '+JSON.stringify(node))
      }
  
      if (visited[i]) return;
      visited[i] = true
  
      // outgoing edges
      var outgoing = edges.filter(function(edge){
        return edge[0] === node
      })
      if (i = outgoing.length) {
        var preds = predecessors.concat(node)
        do {
          var child = outgoing[--i][1]
          visit(child, nodes.indexOf(child), preds)
        } while (i)
      }
  
      sorted[--cursor] = node
    }
  }
  
  function uniqueNodes(arr){
    var res = []
    for (var i = 0, len = arr.length; i < len; i++) {
      var edge = arr[i]
      if (res.indexOf(edge[0]) < 0) res.push(edge[0])
      if (res.indexOf(edge[1]) < 0) res.push(edge[1])
    }
    return res
  }