Golang：如何在尚未初始化的结构上使用指针

Question

So I was looking at the file here.

They call record := &accessLog but they don't ever Initialize it as a variable first and if they do it that way if there are multiple simultaneous connections is there a possibility record will get over written with somebody else's data?

type accessLog struct {
ip, method, uri, protocol, host     string
elapsedTime                         time.Duration
}

func LogAccess(w http.ResponseWriter, req *http.Request, duration time.Duration) {
clientIP := req.RemoteAddr

if colon := strings.LastIndex(clientIP, ":"); colon != -1 {
    clientIP = clientIP[:colon]
}

record := &accessLog{
    ip:             clientIP,
    method:         req.Method,
    uri:            req.RequestURI,
    protocol:       req.Proto,
    host:           req.Host,
    elapsedTime:    duration,
}

writeAccessLog(record)
}

Answer 1

Go is a garbage collected language. The struct the pointer is pointing to will be valid as long as there's a reference to it. Multiple connections have nothing to do with this, as this creates a new record every time LogAccess is called, and if you follow the code in question you'll see that the reference lives at least to the end of writeAccessLog, possibly longer depending on the implementation of glog.Infoln.

To be clear &someType { ... fields ...} creates a new (unnamed) instance of someType, and then returns the address of that instance.