产生安全散列code为objectgraph [英] generating an safe hashcode for an objectgraph

问题描述

我从文件导入一些数据（XLS，CSV，XML）至极，将导致一个复杂的内存对象图。现在我需要知道这个图是否已被修改，因为它曾经是出口。什么将是一个安全的方法来检查呢？我想我会导出一个哈希code的文件吗？如果是的话会<一href="http://stackoverflow.com/questions/263400/what-is-the-best-algorithm-for-an-overridden-system-object-gethash$c$c">the产生一个对象的哈希值code 足够的标准方法？我应该如何生成散列？我将preFER生成对象图上的散列而非实际的流/文件

I am importing some data from an file (xls, csv, xml) wich will result in a complex in-memory object graph. Now I need to know whether this graph has been modified since it once was exported. What would be a safe way to check this? I suppose I'd export a hashcode with the file? If so would the standard way of generating an object's hashcode suffice? How should I generate the hash? I would prefer to generate the hash on the object graph rather than on the actual stream/file.

推荐答案

我最后做以下（至极似乎工作pretty的好）：

I ended up doing the following (wich seems to work pretty well):

1. 创建一个自定义的整数哈希code，其中包括一个对象的所有简单属性使用<一个href="http://stackoverflow.com/questions/263400/what-is-the-best-algorithm-for-an-overridden-system-object-gethash$c$c">this算法。
2. 所有复杂的对象重复1.此对象引用
3. 在一个众所周知的顺序序列化所有整数哈希code到一个二进制流
4. 创建该流的MD5校验

1. create a custom integer hashcode that include all simple properties of a single object using this algorithm.
2. repeat 1. for all complex objects that this object references
3. serialize all integer hashcode into one binary stream in a well known order
4. create a MD5 checksum of this stream

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