Created a Custom URL Router in Golang Called Goblin

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#Golang#URL Routing#Router

Overview

I created a custom URL router in Golang and documented the process of its implementation.

Preparation

Here’s a summary of the preparations I made before implementing the URL router.

Data Structures and Algorithms

I considered the logic for how URLs should be matched.

Many libraries use tree structures as their data structure, so I explored which type of tree structure to adopt. Among trees optimized for string searches, radix trees seemed to offer the best time and memory efficiency. However, I found the implementation too challenging and decided to use a simpler and more familiar structure: the trie.

Reading the net/http Code

To implement the router as an extension of the multiplexer in net/http, I needed to understand its internal workings to some extent.

Refer to Code Reading of Golang's HTTP Server.

Reading Implementations of Various Routers

I reviewed various router implementations for reference. See the repository links below.

Others

Here’s an article I wrote previously summarizing URL routing.

bmf-tech.com/posts/tags/URLルーティング

Implementation

Refer to github.com - goblin.

The basic idea was to adapt the trie structure into a more user-friendly form. However, I struggled several times with handling path parameters. Supporting regular expressions wasn’t too difficult; it was just a matter of preparing a DSL, but handling the DSL required some finesse.

During the implementation process, I wrote tests in parallel and repeatedly debugged step-by-step. By constantly tracking how the data structure changed, I felt my debugging skills improved over time.

Since I don’t usually write this kind of logic, it was undoubtedly a good coding exercise.

Future tasks are listed as issues in the repository, and I plan to refine the implementation whenever I have free time.

References

Repositories

Repositories that served as references for design and implementation:

Articles

Articles I referred to during implementation: