将散列与Node.js一起存储

问题描述

我使用Node.js为一个文件生成一个散列，然后当它被修改时，我想在保存之前将它与之前的版本匹配。例如，如果没有发生变化，则不会进行保存。

我尝试下面的代码来完成这个任务（受到）：

  var filename = __dirname +'/ public / team。 HTML; 
 var shasum = crypto.createHash（'sha1'）; 
 
 var s = fs.ReadStream（filename）; 
 s.on（'data'，function（d）{
 shasum.update（d）; 
}）; 
 $ b s.on（'end'，function（）{
 var d = shasum.digest（'hex'）; 
 console.log（d +''+ filename ）; 
}）; 
  

我想知道如何保存文件的哈希值以便后续匹配。任何想法都会受到欢迎。

解决方案

简单的解决方案：将它写入一个文件（每个文件一个附加信息文件

更复杂一点的解决方案：保存一个包含所有哈希（如路径，哈希）的文件。您必须加载文件，解析数据并在每次之后保存。

正确的解决方案：使用数据库。使用SQLite应该很容易，而且不需要单独的数据库服务器。以下是NodeJS驱动程序的一个示例：

I am using Node.js to generate a hash for a file and then when it is changed, I want to match it with the previous version before saving it. For example, if no change has happened, no save will be done.

I try the following code to do the task (inspired by doc of Node.js):

var filename = __dirname + '/public/team.html';
var shasum = crypto.createHash('sha1');

var s = fs.ReadStream(filename);
s.on('data', function(d) {
  shasum.update(d);
});

s.on('end', function() {
  var d = shasum.digest('hex');
  console.log(d + '  ' + filename);
});

I was wondering how I can save the hash of the file in order to match it afterwards. Any ideas would be more than welcome.

解决方案

Simple solution: just write it to a file (one additional info file per file you are saving).

A bit more complex solution: keep one file with all hashes like pairs (path, hash). You have to load the file, parse the data and save it afterwards each time.

Proper solution: use database. It should be very easy with SQLite and you won't need a separate database server. Here's an example of a driver for NodeJS:

https://github.com/developmentseed/node-sqlite3

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