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Get Correct Module Name via Trie-Style Structure

Go language supports to put modules under a VCS, such as github. Usually, one git repo contains one go module and multiple packages under this module. However, this is not always correct because Go allows you to put multiple modules under the same module, and Go helps to find these modules via its path. A typical example is repository go.opentelemetry.io/otel, which contains huge amount of modules.

In my real senario, given a list of used modules parsing from go.mod, and a package name retrieving from import declaration, I want to know which module does this package belong to. strings.Contain isn't help at all because module paths have overlapped a lot.

Go Minimal Version Selection Notes

This is a reading note to summarise the build list and dependency requirements of minimal version selection of go. If you want to learn more about minimal version select(MVS), please read the documentation and design docs below.

In short, MVS produces the build list as output, the list of module versions used for a build. The "minimal" in MVS means it selects the minimal version of each module that satisfies all requirements, instead of automatically choosing the highest available version. For example, if the requirements are "v1.1, v1.2, v1.3", the version v1.3 is the minimal version that satisfies all requirements. According to the MVS, v1.3 is selected.

  • in Rust

Rust as_ref and as_mut Usage in the Linked List

Recently, I tried to write leetcode by rust. Everything goes well until I started to write code for linked list. The borrow check is quite verbose and I got stuck by the borrow check when handling Option<Box<LinkedNode>> more than the problem itself.

It's sad to find I don't understand the borrow check well, but it's also a good chance to find these missing knowledge for me.

This blog discusses about as_ref, as_mut and take of the Option.

Troubleshooting: Different Valid Tracing ID are Mingled Together

Last week, users have reported a weird issue because they found:

  • Server has received 10+ same requests to the same API in a single trace, and it's impossible.
  • Server made another RPC call when serving, the egress logging interceptor reports 2 different tracing ID. The first one is set to the context logger after parsing the trace id from client, and the second one is retrieved from the context. They should be the same.
  • The data put inside the context(will be propagated by underlying SDK when RPC) cannot be propagated to the server.

This issue is complicated due to the involved components and the cross services. It takes me a lot of time to troubleshoot and finally I found the root cause successfully. The issue happened because user used gin.Context as context.Context directly inside a spawned go routine, however, gin tries to reuse the gin.Context for another request. As a result, the go routine spawned by previous request will be affected by the new request, and the request id mingles.

gotypesalias=1 does not seem to get used correctly for deps on Go 1.23

Recently, I have help to troubleshooting the Go type alias issue inside packages.Load, which relates x/tools, go list and cmd/compile. My original CL is correct, but I got confused when I found the exportdata contains all aliases regardless gotypealias setting. Then, tim has shepherded my CL by another CL to fix it.

Feel a bit frustrated when I saw the email when I got up. But it helps me a lot to learn how go toolchain and cmd/compile works. Think twice before you act!