准备demo

ReadMe_CN.md

@@ -9,7 +9,14 @@ groupcache是go语言开发的缓存库。用于替换memcache的。
 ```shell
 cd example
 go build
-./main 127.0.0.1:8001 127.0.0.1:8002 127.0.0.1:8003
+./example -addr=:8080 -pool=http:https://127.0.0.1:8080 
+
+# 查询
+curl localhost:8080/color?name=green
+#00FF00
+curl localhost:8080/color?name=red
+#FF0000
+
 ```
 
 ### 分析目的
@@ -19,7 +26,7 @@ go build
 https://segmentfault.com/a/1190000018464029
 
 ### 参考资料
-+ [《groupcache 使用入门》](http:https://betazk.github.io/2014/12/groupcache%E5%A6%82%E4%BD%95%E4%BD%BF%E7%94%A8%E7%9A%84%E4%B8%80%E4%B8%AA%E7%AE%80%E5%8D%95%E4%BE%8B%E5%AD%90/)
++ [《GROUPCACHE EXAMPLE》](https:https://sconedocs.github.io/groupcacheUseCase/)
 + [Playing with groupcache](https://capotej.com/blog/2013/07/28/playing-with-groupcache/)
 
 

example/main.go

@@ -1,77 +1,58 @@
+// Simple groupcache example: https://github.com/golang/groupcache
+// Running 3 instances:
+// go run groupcache.go -addr=:8080 -pool=http:https://127.0.0.1:8080,http:https://127.0.0.1:8081,http:https://127.0.0.1:8082
+// go run groupcache.go -addr=:8081 -pool=http:https://127.0.0.1:8081,http:https://127.0.0.1:8080,http:https://127.0.0.1:8082
+// go run groupcache.go -addr=:8082 -pool=http:https://127.0.0.1:8082,http:https://127.0.0.1:8080,http:https://127.0.0.1:8081
+// Testing:
+// curl localhost:8080/color?name=red
 package main
 
 import (
  "context"
+ "errors"
  "flag"
- "fmt"
- "io/ioutil"
  "log"
  "net/http"
- "os"
- "strconv"
  "strings"
 
  "github.com/golang/groupcache"
 )
 
-var (
- peers_addrs = []string{"127.0.0.1:8001", "127.0.0.1:8002", "127.0.0.1:8003"}
- rpc_addrs = []string{"127.0.0.1:9001", "127.0.0.1:9002", "127.0.0.1:9003"}
- index = flag.Int("index", 0, "peer index")
-)
+var Store = map[string][]byte{
+ "red": []byte("#FF0000"),
+ "green": []byte("#00FF00"),
+ "blue": []byte("#0000FF"),
+}
+
+var Group = groupcache.NewGroup("foobar", 64<<20, groupcache.GetterFunc(
+ func(ctx context.Context, key string, dest groupcache.Sink) error {
+ log.Println("looking up", key)
+ v, ok := Store[key]
+ if !ok {
+ return errors.New("color not found")
+ }
+ dest.SetBytes(v)
+ return nil
+ },
+))
 
 func main() {
+ addr := flag.String("addr", ":8080", "server address")
+ peers := flag.String("pool", "http:https://localhost:8080", "server pool list")
  flag.Parse()
- peers_addrs := make([]string, 3)
- rpc_addrs := make([]string, 3)
- if len(os.Args) > 0 {
- for i := 1; i < 4; i++ {
- peers_addrs[i-1] = os.Args[i]
- rpcaddr := strings.Split(os.Args[i], ":")[1]
- port, _ := strconv.Atoi(rpcaddr)
- rpc_addrs[i-1] = ":" + strconv.Itoa(port+1000)
+ http.HandleFunc("/color", func(w http.ResponseWriter, r *http.Request) {
+ color := r.FormValue("name")
+ var b []byte
+ err := Group.Get(nil, color, groupcache.AllocatingByteSliceSink(&b))
+ if err != nil {
+ http.Error(w, err.Error(), http.StatusNotFound)
+ return
  }
- }
- if *index < 0 || *index >= len(peers_addrs) {
- fmt.Printf("peer_index %d not invalid\n", *index)
- os.Exit(1)
- }
- peers := groupcache.NewHTTPPool(addrToURL(peers_addrs[*index]))
- var stringcache = groupcache.NewGroup("SlowDBCache", 64<<20, groupcache.GetterFunc(
- func(ctx context.Context, key string, dest groupcache.Sink) error {
- result, err := ioutil.ReadFile(key)
- if err != nil {
- log.Fatal(err)
- return err
- }
- fmt.Printf("asking for %s from dbserver\n", key)
- dest.SetBytes([]byte(result))
- return nil
- }))
-
- peers.Set(addrsToURLs(peers_addrs)...)
-
- http.HandleFunc("/zk", func(rw http.ResponseWriter, r *http.Request) {
- log.Println(r.URL.Query().Get("key"))
- var data []byte
- k := r.URL.Query().Get("key")
- fmt.Printf("cli asked for %s from groupcache\n", k)
- stringcache.Get(nil, k, groupcache.AllocatingByteSliceSink(&data))
- rw.Write([]byte(data))
+ w.Write(b)
+ w.Write([]byte{'\n'})
  })
- go http.ListenAndServe(rpc_addrs[*index], nil)
- rpcaddr := strings.Split(os.Args[1], ":")[1]
- log.Fatal(http.ListenAndServe(":"+rpcaddr, peers))
-}
-
-func addrToURL(addr string) string {
- return "http:https://" + addr
-}
-
-func addrsToURLs(addrs []string) []string {
- result := make([]string, 0)
- for _, addr := range addrs {
- result = append(result, addrToURL(addr))
- }
- return result
+ p := strings.Split(*peers, ",")
+ pool := groupcache.NewHTTPPool(p[0])
+ pool.Set(p...)
+ http.ListenAndServe(*addr, nil)
 }