From 9f6685152979650214c297ab3ac1b1aa393c3663 Mon Sep 17 00:00:00 2001
From: sbouaram <salim-amine.bou-aram@coopgo.fr>
Date: Mon, 15 May 2023 14:49:00 +0200
Subject: [PATCH] adding groupcache

---
 utils/storage/groupcache.go      | 99 ++++++++++++++++++++++++++++++++
 utils/storage/groupcache_test.go | 75 ++++++++++++++++++++++++
 2 files changed, 174 insertions(+)
 create mode 100644 utils/storage/groupcache.go
 create mode 100644 utils/storage/groupcache_test.go

diff --git a/utils/storage/groupcache.go b/utils/storage/groupcache.go
new file mode 100644
index 0000000..0e81c2d
--- /dev/null
+++ b/utils/storage/groupcache.go
@@ -0,0 +1,99 @@
+package storage
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"log"
+	"net/http"
+	"time"
+
+	"github.com/mailgun/groupcache/v2"
+	"github.com/spf13/viper"
+)
+
+type EtcdGroupCacheHandler struct {
+	EtcdHandler *EtcdHandler
+	Group       *groupcache.Group
+}
+
+func NewEtcdGroupCacheHandler(cfg *viper.Viper) (*EtcdGroupCacheHandler, error) {
+	var endpoint = cfg.GetString("storage.kv.groupcache.endpoint")
+	etcdHandler, err := NewEtcdHandler(cfg)
+	if err != nil {
+		return nil, err
+	}
+	pool := groupcache.NewHTTPPoolOpts("http://"+endpoint, &groupcache.HTTPPoolOptions{})
+	server := http.Server{
+		Addr:    endpoint,
+		Handler: pool,
+	}
+	go func() {
+		log.Printf("Serving....\n")
+		if err := server.ListenAndServe(); err != nil {
+			log.Fatal(err)
+		}
+	}()
+	group := groupcache.NewGroup("data", 3000000, groupcache.GetterFunc(
+		func(ctx context.Context, key string, dest groupcache.Sink) error {
+
+			resp, err := etcdHandler.Get(key)
+			if err != nil {
+				return err
+			}
+			if resp == nil {
+				return errors.New("key not found in ETCD")
+			}
+			decoded, err := base64.StdEncoding.DecodeString(resp.(string))
+			if err != nil {
+				return fmt.Errorf("failed to decode value for key %s: %v", key, err)
+			}
+			dest.SetString(string(decoded), time.Now().Add(time.Minute*5))
+			return nil
+		},
+	))
+
+	return &EtcdGroupCacheHandler{
+		EtcdHandler: etcdHandler,
+		Group:       group,
+	}, nil
+}
+
+func (h *EtcdGroupCacheHandler) Put(k string, v interface{}) error {
+	value, err := json.Marshal(v)
+	if err != nil {
+		return err
+	}
+	return h.EtcdHandler.Put(k, value)
+}
+
+func (h *EtcdGroupCacheHandler) PutWithTTL(k string, v interface{}, duration time.Duration) error {
+	value, err := json.Marshal(v)
+	if err != nil {
+		return err
+	}
+	return h.EtcdHandler.PutWithTTL(k, value, duration)
+}
+
+func (h *EtcdGroupCacheHandler) Get(k string) (interface{}, error) {
+	var value []byte
+	err := h.Group.Get(nil, k, groupcache.AllocatingByteSliceSink(&value))
+	if err != nil {
+		return nil, err
+	}
+	return value, nil
+}
+
+func (h *EtcdGroupCacheHandler) Delete(k string) error {
+	err := h.EtcdHandler.Delete(k)
+	if err != nil {
+		return err
+	}
+	err = h.Group.Remove(context.Background(), k)
+	if err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/utils/storage/groupcache_test.go b/utils/storage/groupcache_test.go
new file mode 100644
index 0000000..fb875c1
--- /dev/null
+++ b/utils/storage/groupcache_test.go
@@ -0,0 +1,75 @@
+package storage
+
+import (
+	"encoding/json"
+	"github.com/spf13/viper"
+	"testing"
+	"time"
+)
+
+func TestEtcdGroupCacheHandler(t *testing.T) {
+	cfg := createConfig()
+	handler, err := NewEtcdGroupCacheHandler(cfg)
+	if err != nil {
+		t.Fatalf("failed to create EtcdGroupCacheHandler: %v", err)
+	}
+
+	key := "test-key"
+	value := map[string]string{"key1": "value1", "key2": "value2"}
+
+	// test Put and Get
+	err = handler.Put(key, value)
+	if err != nil {
+		t.Fatalf("failed to put key: %v", err)
+	}
+	resp, err := handler.Get(key)
+	if err != nil {
+		t.Fatalf("failed to get key: %v", err)
+	}
+	var result map[string]string
+	err = json.Unmarshal(resp.([]byte), &result)
+	if err != nil {
+		t.Fatalf("failed to unmarshal response: %v", err)
+	}
+
+	if len(result) != len(value) || result["key1"] != value["key1"] || result["key2"] != value["key2"] {
+		t.Fatalf("unexpected response: %v", result)
+	}
+
+	// test PutWithTTL and Get
+	err = handler.PutWithTTL(key, value, time.Second*2)
+	if err != nil {
+		t.Fatalf("failed to put key with TTL: %v", err)
+	}
+	resp, err = handler.Get(key)
+	if err != nil {
+		t.Fatalf("failed to get key: %v", err)
+	}
+	err = json.Unmarshal(resp.([]byte), &result)
+	if err != nil {
+		t.Fatalf("failed to unmarshal response: %v", err)
+	}
+	if len(result) != len(value) || result["key1"] != value["key1"] || result["key2"] != value["key2"] {
+		t.Fatalf("unexpected response: %v", result)
+	}
+
+	// test Delete
+	err = handler.Delete(key)
+	if err != nil {
+		t.Fatalf("failed to delete key: %v", err)
+	}
+	resp, err = handler.Get(key)
+	if err == nil {
+		t.Fatalf("expected key to be deleted")
+	}
+}
+
+func createConfig() *viper.Viper {
+	cfg := viper.New()
+	cfg.Set("storage.kv.etcd.endpoints", []string{"localhost:2379"})
+	cfg.Set("storage.kv.etcd.username", "")
+	cfg.Set("storage.kv.etcd.prefix", "parcoursmob/cache/")
+	cfg.Set("storage.kv.etcd.password", "")
+	cfg.Set("storage.kv.groupcache.endpoint", "localhost:8080")
+	return cfg
+}