Redigo Redis Pool是否真的应该是全局变量？

Question

In the example here Redigo Docs for Pool the redis pool is set as a global variable in func main. Is that a kosher way to do things? Should you really be using global varibales left and right or is there a better, more preferred way of accomplishing the same thing?

Answer 1

The only other solution have I seen, for instance in "Passing Context to Interface Methods" is:

create a struct that accepts an embedded context and our handler type, and we still satisfy the http.Handler interface thanks to ServeHTTP.

In your case, the struct would include the pool, and the handler function.

type appContext struct {
    pool Pool
}

type appHandler struct {
    *appContext
    h func(a *appContext, w http.ResponseWriter, r *http.Request) (int, error)
}

func (ah appHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
   ...
}


func main() {
    context := &appContext{
        pool:    ...,
        // any other data
    }
}