Current File : /var/www/html/node_modules/toposort/index.js
/**
* 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
// Better data structures make algorithm much faster.
, outgoingEdges = makeOutgoingEdges(edges)
, nodesHash = makeNodesHash(nodes)
// check for unknown nodes
edges.forEach(function(edge) {
if (!nodesHash.has(edge[0]) || !nodesHash.has(edge[1])) {
throw new Error('Unknown node. There is an unknown node in the supplied edges.')
}
})
while (i--) {
if (!visited[i]) visit(nodes[i], i, new Set())
}
return sorted
function visit(node, i, predecessors) {
if(predecessors.has(node)) {
var nodeRep
try {
nodeRep = ", node was:" + JSON.stringify(node)
} catch(e) {
nodeRep = ""
}
throw new Error('Cyclic dependency' + nodeRep)
}
if (!nodesHash.has(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
var outgoing = outgoingEdges.get(node) || new Set()
outgoing = Array.from(outgoing)
if (i = outgoing.length) {
predecessors.add(node)
do {
var child = outgoing[--i]
visit(child, nodesHash.get(child), predecessors)
} while (i)
predecessors.delete(node)
}
sorted[--cursor] = node
}
}
function uniqueNodes(arr){
var res = new Set()
for (var i = 0, len = arr.length; i < len; i++) {
var edge = arr[i]
res.add(edge[0])
res.add(edge[1])
}
return Array.from(res)
}
function makeOutgoingEdges(arr){
var edges = new Map()
for (var i = 0, len = arr.length; i < len; i++) {
var edge = arr[i]
if (!edges.has(edge[0])) edges.set(edge[0], new Set())
if (!edges.has(edge[1])) edges.set(edge[1], new Set())
edges.get(edge[0]).add(edge[1])
}
return edges
}
function makeNodesHash(arr){
var res = new Map()
for (var i = 0, len = arr.length; i < len; i++) {
res.set(arr[i], i)
}
return res
}
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