Question

我有一个节点的树结构，我需要能够深度克隆。出于安全原因（以及性能），我希望在服务器上运行。我创建了函数deepClone，它在客户端上运行良好，但当我将其更改为Meteor.method时，调用堆栈范围内的崩溃超出了错误。

Meteor.method代码：

Meteor.methods({
deepClone: function(oldParentNodeID, databaseName) {
if (oldParentNodeID && databaseName)
{
console.log(oldParentNodeID);
console.log(databaseName);
// oldParentNodeID is expected to be the _id of a headerNode with a field called archives[{Major:, Minor:, archivedParentNode}]
// databaseName is the name of the collection where the cloning occurs
if (!(oldParentNodeID))
{
  return;  //need to add error code
}
else
{
  var clonedTree=recursiveClone(oldParentNodeID,databaseName);
  databaseName.update({_id:oldParentNodeID},{$push: {archivedStack: clonedTree}});
}}
}});

var recursiveClone = function(currentNodeID, databaseName) {
//this function clones the node whos ID is passed and all descendents of that node.
var oldParentNode=(databaseName).findOne({_id: currentNodeID});
var archivedParentNode=new Object;
var i, childNode;
jQuery.extend(archivedParentNode,oldParentNode);
delete archivedParentNode._id;
archivedParentNode.subcategories=[];
var retval= databaseName.insert(archivedParentNode);
if ((oldParentNode.subcategories) && (oldParentNode.subcategories.length)){ 
  for (i=0; i< oldParentNode.subcategories.length; i++) {
    childNode=recursiveClone(oldParentNode.subcategories[i],databaseName);
    archivedParentNode.subcategories.push(childNode);
    databaseName.update({_id:retval},{$push: {subcategories: childNode}});
    databaseName.update({_id:childNode},{$set: {parentCategory: retval}});
  }
}
return retval;
};

请注意，子类别是子_id的数组，而parentCategory是父的_id。

运行时出错：

RangeError {stack: "RangeError: Maximum call stack size exceeded↵   a…s?8659e45802513ffad53befd6dbee7e6e80df9da4:425:22", message: "Maximum call stack size exceeded"}
message: "Maximum call stack size exceeded"
stack: "RangeError: Maximum call stack size exceeded↵    at http://localhost:3000    /packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:424:22↵    at     Function._.each._.forEach (http://localhost:3000/packages/underscore.js?0a80a8623e1b40b5df5a05582f288ddd586eaa18:164:22)↵    at Object.EJSON.clone (http://localhost:3000/packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:424:5)↵    at http://localhost:3000/packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:425:22↵    at Function._.each._.forEach (http://localhost:3000/packages/underscore.js?0a80a8623e1b40b5df5a05582f288ddd586eaa18:164:22)↵    at Object.EJSON.clone (http://localhost:3000/packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:424:5)↵    at http://localhost:3000/packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:425:22↵    at Function._.each._.forEach (http://localhost:3000/packages/underscore.js?0a80a8623e1b40b5df5a05582f288ddd586eaa18:164:22)↵    at Object.EJSON.clone (http://localhost:3000/packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:424:5)↵    at http://localhost:3000/packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:425:22"
__proto__: Error
 RangeError: Maximum call stack size exceeded
    at http://localhost:3000/packages    /ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:424:22
at Function._.each._.forEach (http://localhost:3000/packages/underscore.js?0a80a8623e1b40b5df5a05582f288ddd586eaa18:164:22)
at Object.EJSON.clone (http://localhost:3000/packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:424:5)
at http://localhost:3000/packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:425:22
at Function._.each._.forEach (http://localhost:3000/packages/underscore.js?0a80a8623e1b40b5df5a05582f288ddd586eaa18:164:22)
at Object.EJSON.clone (http://localhost:3000/packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:424:5)
at http://localhost:3000/packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:425:22
at Function._.each._.forEach (http://localhost:3000/packages/underscore.js?0a80a8623e1b40b5df5a05582f288ddd586eaa18:164:22)
at Object.EJSON.clone (http://localhost:3000/packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:424:5)
at http://localhost:3000/packages/ejson.js?8659e45802513ffad53befd6dbee7e6e80df9da4:425:22

我怀疑对此有一个简单的解决办法，但它让我望而却步。任何帮助表示赞赏。

Answer 1

树中的某个节点实际上可能指向其中一个祖先，导致在尝试遍历树时出现无限循环。

另一个问题是，您需要确保存储在数据库中或通过DDP发送的任何内容都可以强制转换为EJSON对象。否则，您也可能会看到此错误。

带游标参数的Meteor.call

1 个答案: