How to use the HTTP server function in Go language to implement the caching function of dynamic routing?

How to use the HTTP server function in the Go language to implement the caching function of dynamic routing?

Caching is a common method to improve application performance. Caching can avoid frequent calculations or data acquisition, thereby reducing the load on the server and improving response speed. When using the Go language to build web applications, we can use the HTTP server function in the Go language to implement the caching function of dynamic routing. This article will introduce how to use the http package and http.HandlerFunc type of Go language to implement this function, and provide a simple sample code.

Setting up cache

Setting up cache in an HTTP server usually involves two steps: setting response headers and cache control policies.

Set response headers

The response headers determine how the browser handles content returned from the server. We can specify the cache strategy by setting the Cache-Control and Expires fields. Among them, the Cache-Control field is used to specify cache behavior, such as whether it can be cached, cache validity period, etc.; the Expires field is used to specify the cache expiration time.

The following is a sample code for setting the caching policy of the response header:

func setCacheHeaders(w http.ResponseWriter) {
    w.Header().Set("Cache-Control", "public, max-age=3600")
    w.Header().Set("Expires", time.Now().Add(time.Hour).Format(http.TimeFormat))
}

In the above code, we use w.Header().Set(key, value ) method to set the response header, where key is the field name and value is the value of the field. The value of the Cache-Control field is public, max-age=3600, which means that the cache is public and can be cached by the browser, and the cache validity period is 3600 seconds. The value of the Expires field is the current time plus one hour, expressed using time.Now().Add(time.Hour), and using http.TimeFormat Format the time into HTTP standard format.

Cache Control Strategy

In addition to setting the response header, we also need to implement the cache control strategy in the HTTP server function. You can customize a http.HandlerFunc type processing function and implement caching logic in it.

The following is a sample code for implementing the caching function of dynamic routing:

type CacheHandler struct {
    cache map[string]string
    mux   sync.RWMutex
}

func (c *CacheHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    // 检查缓存中是否已存在请求路径的结果
    c.mux.RLock()
    result, ok := c.cache[r.URL.Path]
    c.mux.RUnlock()

    if ok {
        // 如果缓存存在，则直接将结果返回给客户端
        w.WriteHeader(http.StatusOK)
        w.Write([]byte(result))
    } else {
        // 如果缓存不存在，则调用真正的处理逻辑，并将结果存入缓存
        // 除了设置响应头部，还可以在这里添加其他的缓存控制策略，比如ETag、Last-Modified等
        setCacheHeaders(w)
        // 处理逻辑...
        // 这里仅作示例，直接返回请求路径
        c.mux.Lock()
        c.cache[r.URL.Path] = r.URL.Path
        c.mux.Unlock()
        w.WriteHeader(http.StatusOK)
        w.Write([]byte(r.URL.Path))
    }
}

func main() {
    cacheHandler := &CacheHandler{
        cache: make(map[string]string),
    }
    http.Handle("/", cacheHandler)
    http.ListenAndServe(":8080", nil)
}

In the above code, we define a CacheHandler type, which contains a # The ##cache field is used to store cached results, and a mux field is used to ensure concurrency safety. The

CacheHandler type implements the ServeHTTP method, which receives a http.ResponseWriter and a http.Request parameter , used to handle HTTP requests and responses. In the ServeHTTP method, we first check from the cache whether the result of the request path already exists. If the cache exists, the result is returned directly to the client, otherwise, the real processing logic is called and the result is stored in the cache.

In the

main function, we create a CacheHandler instance and register it to the default ## through the http.Handle function #http.ServeMux on. Finally, call the http.ListenAndServe function to start the HTTP server, listening on the :8080 port. Summary

By using the HTTP server function in the Go language, we can easily implement the caching function of dynamic routing. By setting appropriate response headers and cache control policies, the performance and response speed of web applications can be effectively improved. I hope the introduction and sample code of this article can help you understand and use the Go language to implement the caching function of dynamic routing.

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