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A csharp library to generate short id's. they can be used as primary keys or unique identifiers

License: MIT License

C# 100.00%

csharp shortid id-generation

shortid's Introduction

shortid

About ShortId

A CSharp library to generate completely random short id's. They can be used as primary keys or unique identifiers. This library is different in that you can specify the length of the ids to be generated. This library is thread-safe and can generate millions of unique ids across multiple threads.

Getting Started

To make use of the shortid, add it to your project via the Nuget package manager UI or console via this command:

Package Manager

Install-Package shortid

.NET CLI

> dotnet add package shortid

PackageReference

<PackageReference Include="shortid" />

Usage

Add the following using command to the top of your csharp code file:

using shortid;
using shortid.Configuration;

This gives your code access the classes and methods of the shortid namespace.

To generate a unique id of any length between 8 and 15, you call the Generate method without parameters.

string id = ShortId.Generate();
// id = KXTR_VzGVUoOY

If you want to include numbers in the generated id, then you call the Generate method with options indicating your preference.

var options = new GenerationOptions(useNumbers: true);
string id = ShortId.Generate(options);
// id = O_bBY-YUkJg

If you do not want special characters i.e _ and - in your generated id, then call the Generate method with options indicating your preferences.

var options = new GenerationOptions(useSpecialCharacters: false);
string id = ShortId.Generate(options);
// id = waBfk3z

If you want to specify the length of the generated id, call the Generate method with options indicating your preferences.

var options = new GenerationOptions(length: 9);
string id = ShortId.Generate(options);
// id = M-snXzBkj

Customize ShortId

ShortId has several features that help with customizing the ids generated. Characters sets can be introduced and the random number generator can be seeded.

To change the character set in use, run the following:

string characters = "ⒶⒷⒸⒹⒺⒻⒼⒽⒾⒿⓀⓁⓂⓃⓄⓅⓆⓇⓈⓉⓊⓋⓌⓍⓎⓏⓐⓑⓒⓓⓔⓕⓖⓗⓘⓙⓚⓛⓜⓝⓞⓟⓠⓡⓢⓣⓤⓥⓦⓧⓨⓩ①②③④⑤⑥⑦⑧⑨⑩⑪⑫"; //whatever you want;
ShortId.SetCharacters(characters);

NOTE: the new character set must not be null, an empty string or whitespace. Also, all whitespace and duplicate characters would be removed, finally the character set cannot be less than 50 characters.

ShortId also allows the seed for the random number generator to be set.

To set the seed, run the following:

int seed = 1939048828;
ShortId.SetSeed(seed);

Finally, ShortId allows for all customizations to be reset using the following:

ShortId.Reset();

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shortid's Issues

Are you trying to port dylang's shortid to C#? Problems with approach...

I'm toying with the idea of creating my own port, and I saw your library and thought "maybe I won't need to". Unfortunately, I don't think I can use this as-is -- there are a few issues with your approach compared to node's "shortid" library:

It's stateless. Node's version keeps track of how many times you've asked for a unique ID in a very short period of time. This stateful behavior helps ensure the uniqueness of IDs.
Length is random between 7-14. Node's version only increases the length of the unique ID if you need to, to guarantee uniqueness. The more times you ask for an ID within the same second, the longer the ID becomes.
No support for clusters. Node's version allows up to 16 machines in a cluster to generate unique IDs without the possibility of collisions.

Thoughts?

Emits only "aaaaaa" after some time due to wrong use of Math.Random

I've used your code in a multithreaded server environment, but after some time only "aaaaaaa" is emitted. This is probably due to the fact that you're using the same Math.Random instance across multiple threads. You shouldn't do that: https://msdn.microsoft.com/en-us/library/system.random%28v=vs.110%29.aspx?f=255&MSPPError=-2147217396#ThreadSafety

Especially (bold by me):

Instead of instantiating individual Random objects, we recommend that you create a single Random instance to generate all the random numbers needed by your app. However, Random objects are not thread safe. If your app calls Random methods from multiple threads, you must use a synchronization object to ensure that only one thread can access the random number generator at a time. If you don't ensure that the Random object is accessed in a thread-safe way, calls to methods that return random numbers return 0.

public class ShortIdOptions
{
    public bool IncludeNumbers { get; set; }
    public bool IncludeSpecialCharacters { get; set; }
    public int Length { get; set; }
}

Signature:

public static string Generate(ShortIdOptions options)

Usage:

var options = new ShortIdOptions
{
    IncludeNumbers = true;
    IncludeSpecialCharacters = true;
    Length = 12;
};
string id = ShortId.Generate(options);

Please advice & suggest.

Thanks