Finalize http go

go-http/httpfastcache.go

@@ -0,0 +1,87 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"github.com/patrickmn/go-cache"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"time"
+)
+
+// ConfigType represents config info
+type ConfigType struct {
+	HostPort   string
+	Stacosys   string
+	CorsOrigin string
+}
+
+var config ConfigType
+var countCache = cache.New(5*time.Minute, 10*time.Minute)
+
+func die(format string, v ...interface{}) {
+	fmt.Fprintln(os.Stderr, fmt.Sprintf(format, v...))
+	os.Exit(1)
+}
+
+func commentsCount(w http.ResponseWriter, r *http.Request) {
+
+	// only GET method is supported
+	if r.Method != "GET" {
+		http.NotFound(w, r)
+		return
+	}
+
+	// set header
+	w.Header().Add("Content-Type", "application/json")
+	w.Header().Add("Access-Control-Allow-Origin", config.CorsOrigin)
+
+	// get cached value
+	cachedBody, found := countCache.Get(r.URL.String())
+	if found {
+		//log.Printf("return cached value")
+		w.Write([]byte(cachedBody.(string)))
+		return
+	}
+
+	// relay request to stacosys
+	response, err := http.Get(config.Stacosys + r.URL.String())
+	if err != nil {
+		http.NotFound(w, r)
+		return
+	}
+	defer response.Body.Close()
+	body, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		http.NotFound(w, r)
+		return
+	}
+
+	// cache body and return response
+	countCache.Set(r.URL.String(), string(body), cache.DefaultExpiration)
+	log.Printf(string(body))
+	w.Write(body)
+}
+
+func main() {
+	pathname := flag.String("config", "", "config pathname")
+	flag.Parse()
+	if *pathname == "" {
+		die("%s --config <pathname>", os.Args[0])
+	}
+	// read config File
+	file, e := ioutil.ReadFile(*pathname)
+	if e != nil {
+		die("File error: %v", e)
+	}
+	fmt.Printf("config: %s\n", string(file))
+
+	config := ConfigType{}
+	json.Unmarshal(file, &config)
+
+	http.HandleFunc("/comments/count", commentsCount)
+	http.ListenAndServe(config.HostPort, nil)
+}