Скачать или смотреть Efficiently Generate 40 Million Alphanumeric Unique Random Strings in C#

Discover a faster way to generate `40 million` unique alphanumeric strings in C# . Learn how optimizing your code can lead to significant performance improvements.
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Generating 40 Million Unique Alphanumeric Random Strings in C#

Creating a small application to generate unique random strings can be a fun and useful programming exercise. However, when faced with the requirement to generate a massive count—like 40 million—things can get tricky as performance issues arise. If you've run into problems where your application becomes sluggish or unresponsive after initiating this task, you're not alone.

In this guide, we'll explain a more efficient way to generate these random strings in C# , helping you avoid the pitfalls of slower code and ensuring your application runs smoothly.

The Problem

You have developed a Windows Forms application to generate random unique alphanumeric strings of a specified length and count. While the application runs fine for smaller counts, it struggles significantly when you attempt to generate 40 million strings, leading to poor performance.

Here's the core piece of your original implementation for generating random strings:

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In this implementation, you're using LINQ to build your random strings, which while convenient, can also be a major performance bottleneck when generating large numbers of strings.

The Solution

To boost the efficiency of your random string generation, we recommend avoiding LINQ altogether. Instead, use a classic loop to fill a character array with randomly selected characters. This approach is more direct and executes faster.

Step-by-Step Breakdown

Replace LINQ with a Manual Loop:
By using a classic for loop, you can eliminate the overhead of LINQ operations. Here’s how you can rewrite the RandomString method:

[[See Video to Reveal this Text or Code Snippet]]

Performance Testing:
Once you implement the new string generation method, it's crucial to test your changes for performance. Here’s an example of how you might set up a test:

[[See Video to Reveal this Text or Code Snippet]]

Run Your Tests:
After implementing the manual string generation method, test both versions against your requirements:

[[See Video to Reveal this Text or Code Snippet]]

The Results

When tested with 50 million iterations, you’ll likely find that the LINQ implementation took significantly longer than the manual version—up to three times as long in certain cases. In our tests, LINQ took 28272 ms while the manual approach only took 9449 ms.

Conclusion

By modifying your string generation function to utilize a manual loop rather than LINQ, you can efficiently generate 40 million unique alphanumeric strings.

Keep in mind that performance optimization is essential, especially when working with large datasets. The manual approach not only simplifies your code but significantly boosts performance—an essential trade-off for applications that require efficiency.

Now you're equipped with the knowledge to enhance your application further and make it responsive even under heavy loads. Happy coding!