Where to put “defer req.Body.Close()”?
A request body does not need to be closed in the handler. From the http.Request documentation // The Server will close the request body. The ServeHTTP // Handler does not need to.
go
“go build” became very slow after installing a new version of Go
You probably have dependencies that are being recompiled each time. Try go install -a mypackage to rebuild all dependencies. Removing $GOPATH/pkg also helps to ensure you don’t have old object files around. Building with the -x flag will show you if the toolchain is finding incompatible versions.
Gorilla mux custom middleware
Just create a wrapper, it’s rather easy in Go: func HomeHandler(response http.ResponseWriter, request *http.Request) { fmt.Fprintf(response, “Hello home”) } func Middleware(h http.Handler) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { log.Println(“middleware”, r.URL) h.ServeHTTP(w, r) }) } func main() { r := mux.NewRouter() r.HandleFunc(“https://stackoverflow.com/”, HomeHandler) http.Handle(“https://stackoverflow.com/”, Middleware(r)) }
In golang, what is the difference between & and *
Here is a very simple example, that illustrates how & and * are used. Note that * can be used for two different things 1) to declare a variable to be a pointer 2) to dereference a pointer. package main import “fmt” func main() { b := 6 var b_ptr *int // *int is used … Read more
How to sort by time.Time
Go 1.8 and above: sort.Slice(timeSlice, func(i, j int) bool { return timeSlice[i].date.Before(timeSlice[j].date) })
Recursive locking in Go
I’m sorry to not answer your question directly: IMHO, the best way how to implement recursive locks in Go is to not implement them, but rather redesign your code to not need them in the first place. It’s probable, I think, that the desire for them indicates a wrong approach to some (unknown here) problem … Read more
Does Go have something like ThreadLocal from Java?
The Go runtime and standard libraries do not provide goroutine local storage or a goroutine identifier that can be used to implement goroutine local storage. The third party gls package implements goroutine local storage in an interesting way. Some find this package horrifying and others think it’s clever. The Go team recommends passing context explicitly … Read more
Is it best-practice to commit the `vendor` directory?
The dep tool’s FAQ answers this: Should I commit my vendor directory? It’s up to you: Pros It’s the only way to get truly reproducible builds, as it guards against upstream renames, deletes and commit history overwrites. You don’t need an extra dep ensure step to sync vendor/ with Gopkg.lock after most operations, such as … Read more
Why is lint giving a warning ineffectual assignment to (ineffassign)
After the following if statement, cfg is written, thus the value assigned to cfg using cfg := &utils.Config{} is never used. You are using an assignment where a declaration would do. var cfg *utils.Config …
How golang’s “defer” capture closure’s parameter?
The ‘part 2’ closure captures the variable ‘i’. When the code in the closure (later) executes, the variable ‘i’ has the value which it had in the last iteration of the range statement, ie. ‘4’. Hence the 4 4 4 4 4 part of the output. The ‘part 3’ doesn’t capture any outer variables in … Read more