创建一个简短哈希的最佳方式是什么,类似于小型Url所做的? [英] What's the best way to create a short hash, similar to what tiny Url does?
问题描述
我目前正在使用MD5哈希值,但我想找到一些能够创建一个只使用[a-z] [A-Z] [0-9]的更短的哈希值。它只需要大约5-10个字符。
有没有那样的东西已经做到了?
更新: 我喜欢CRC32散列。有没有一种干净的方式计算它在.NET中?
Update2:
我使用Joe提供的链接中的CRC32函数。如何将uInt转换为上面定义的字符?
.NET字符串对象具有GetHashCode()函数。它返回一个整数。
将它转换为一个十六进制,然后转换为长度为8个字符的字符串。
像这样:
string hashCode = String.Format({0:X},sourceString.GetHashCode());
更多内容: http://msdn.microsoft.com/en-us/library/system.string.gethashcode.aspx
更新:在上面的链接中添加了以下评论:
GetHashCode的行为取决于其实现,
可能会从公共语言运行时的一个版本更改为另一个版本的
。这可能发生的一个原因是提高了GetHashCode的性能
。
如果两个字符串对象相等,则GetHashCode方法返回
个相同的值。但是,对于
每个唯一的字符串值,没有唯一的哈希码值。 不同的字符串可以返回相同的散列码
代码。
$ b 来电者注释
GetHashCode返回的值是平台相关的。它不同于
的.NET Framework的32位和64位版本。
I'm currently using MD5 hashes but I would like to find something that will create a shorter hash that uses just [a-z][A-Z][0-9]. It only needs to be around 5-10 characters long.
Is there something out there that already does this?
Update:
I like the CRC32 hash. Is there a clean way of calculating it in .NET?
Update2:
I'm using the CRC32 function from the link Joe provided. How can I convert the uInt into the characters defined above?
.NET string object has a GetHashCode() function. It returns an integer. Convert it into a hex and then to an 8 characters long string.
Like so:
string hashCode = String.Format("{0:X}", sourceString.GetHashCode());
More on that: http://msdn.microsoft.com/en-us/library/system.string.gethashcode.aspx
UPDATE: Added the remarks from the link above to this answer:
The behavior of GetHashCode is dependent on its implementation, which might change from one version of the common language runtime to another. A reason why this might happen is to improve the performance of GetHashCode.
If two string objects are equal, the GetHashCode method returns identical values. However, there is not a unique hash code value for each unique string value. Different strings can return the same hash code.
Notes to Callers
The value returned by GetHashCode is platform-dependent. It differs on the 32-bit and 64-bit versions of the .NET Framework.
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