feat: added redis storage (#25)

Co-authored-by: o.musin <o.musin@tinkoff.ru>

Author: Oleg

cache/cache.go

@@ -12,6 +12,8 @@ var (
 	ErrFailedToSaveToCache = errors.New("Failed to save item")
 	// ErrCacheMissed will throw if an item can't be retrieved (due to invalid, or missing)
 	ErrCacheMissed = errors.New("Cache is missing")
+	// ErrStorageInternal will throw when some internal error in storage occurred
+	ErrStorageInternal = errors.New("Internal error in storage")
 )
 
 // Cache storage type

cache/redis/redis.go

@@ -0,0 +1,80 @@
+package redis
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/bxcodec/httpcache/cache"
+	"github.com/go-redis/redis/v8"
+)
+
+// CacheOptions for storing data for Redis connections
+type CacheOptions struct {
+	Addr     string
+	Password string
+	DB       int // 0 for default DB
+}
+
+type redisCache struct {
+	ctx        context.Context
+	cache      *redis.Client
+	expiryTime time.Duration
+}
+
+// NewCache will return the redis cache handler
+func NewCache(ctx context.Context, c *redis.Client, exptime time.Duration) cache.ICacheInteractor {
+	return &redisCache{
+		ctx:        ctx,
+		cache:      c,
+		expiryTime: exptime,
+	}
+}
+
+func (i *redisCache) Set(key string, value cache.CachedResponse) (err error) {
+	valueJSON, _ := json.Marshal(value)
+	set := i.cache.Set(i.ctx, key, string(valueJSON), i.expiryTime*time.Second)
+	if err := set.Err(); err != nil {
+		fmt.Println(err)
+		return cache.ErrStorageInternal
+	}
+	return nil
+}
+
+func (i *redisCache) Get(key string) (res cache.CachedResponse, err error) {
+	get := i.cache.Do(i.ctx, "get", key)
+	if err = get.Err(); err != nil {
+		if err == redis.Nil {
+			return cache.CachedResponse{}, cache.ErrCacheMissed
+		}
+		return cache.CachedResponse{}, cache.ErrStorageInternal
+	}
+	val := get.Val().(string)
+	err = json.Unmarshal([]byte(val), &res)
+	if err != nil {
+		return cache.CachedResponse{}, cache.ErrStorageInternal
+	}
+	return
+}
+
+func (i *redisCache) Delete(key string) (err error) {
+	// deleting in redis equal to setting expiration time for key to 0
+	set := i.cache.Set(i.ctx, key, nil, 0)
+	if err := set.Err(); err != nil {
+		return cache.ErrStorageInternal
+	}
+	return nil
+}
+
+func (i *redisCache) Origin() string {
+	return cache.CacheRedis
+}
+
+func (i *redisCache) Flush() error {
+	flush := i.cache.FlushAll(i.ctx)
+	if err := flush.Err(); err != nil {
+		return cache.ErrStorageInternal
+	}
+	return nil
+}

cache/redis/redis_test.go

@@ -0,0 +1,66 @@
+package redis_test
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/alicebob/miniredis"
+	"github.com/bxcodec/httpcache/cache"
+	rediscache "github.com/bxcodec/httpcache/cache/redis"
+	"github.com/go-redis/redis/v8"
+)
+
+func TestCacheRedis(t *testing.T) {
+	s, err := miniredis.Run()
+	if err != nil {
+		panic(err)
+	}
+	defer s.Close()
+	c := redis.NewClient(&redis.Options{
+		Addr:     s.Addr(),
+		Password: "", // no password set
+		DB:       0,  // use default DB
+	})
+
+	cacheObj := rediscache.NewCache(context.Background(), c, 15)
+	testKey := "KEY"
+	testVal := cache.CachedResponse{
+		DumpedResponse: nil,
+		RequestURI:     "http://bxcodec.io",
+		RequestMethod:  "GET",
+		CachedTime:     time.Now(),
+	}
+
+	// Try to SET item
+	err = cacheObj.Set(testKey, testVal)
+	if err != nil {
+		t.Fatalf("expected %v, got %v", nil, err)
+	}
+
+	// try to GET item from cache
+	res, err := cacheObj.Get(testKey)
+	if err != nil {
+		t.Fatalf("expected %v, got %v", nil, err)
+	}
+	// assert the content
+	if res.RequestURI != testVal.RequestURI {
+		t.Fatalf("expected %v, got %v", testVal.RequestURI, res.RequestURI)
+	}
+	// assert the content
+	if res.RequestMethod != testVal.RequestMethod {
+		t.Fatalf("expected %v, got %v", testVal.RequestMethod, res.RequestMethod)
+	}
+
+	// try to DELETE the item
+	err = cacheObj.Delete(testKey)
+	if err != nil {
+		t.Fatalf("expected %v, got %v", nil, err)
+	}
+
+	// try to re-GET item from cache after deleted
+	res, err = cacheObj.Get(testKey)
+	if err == nil {
+		t.Fatalf("expected %v, got %v", err, nil)
+	}
+}

example_inmemory_storage_test.go example_storages_test.goexample_inmemory_storage_test.go renamed to example_storages_test.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/bxcodec/httpcache"
+	"github.com/bxcodec/httpcache/cache/redis"
 )
 
 func Example_inMemoryStorageDefault() {
@@ -16,27 +17,42 @@ func Example_inMemoryStorageDefault() {
 		log.Fatal(err)
 	}
 
-	for i := 0; i < 100; i++ {
-		startTime := time.Now()
-		req, err := http.NewRequest("GET", "https://bxcodec.io", nil)
-		if err != nil {
-			log.Fatal((err))
-		}
-		res, err := client.Do(req)
-		if err != nil {
-			log.Fatal(err)
-		}
-		fmt.Printf("Response time: %v micro-second\n", time.Since(startTime).Microseconds())
-		fmt.Println("Status Code", res.StatusCode)
-		time.Sleep(time.Second * 1)
-		fmt.Println("Sequence >>> ", i)
-		if i%5 == 0 {
-			err := handler.CacheInteractor.Flush()
-			if err != nil {
-				log.Fatal(err)
-			}
-		}
+	processCachedRequest(client, handler)
+	// Example Output:
+	/*
+		2020/06/21 13:14:51 Cache item's missing failed to retrieve from cache, trying with a live version
+		Response time: 940086 micro-second
+		Status Code 200
+		Sequence >>>  0
+		2020/06/21 13:14:53 Cache item's missing failed to retrieve from cache, trying with a live version
+		Response time: 73679 micro-second
+		Status Code 200
+		Sequence >>>  1
+		Response time: 126 micro-second
+		Status Code 200
+		Sequence >>>  2
+		Response time: 96 micro-second
+		Status Code 200
+		Sequence >>>  3
+		Response time: 102 micro-second
+		Status Code 200
+		Sequence >>>  4
+		Response time: 94 micro-second
+		Status Code 200
+		Sequence >>>  5
+	*/
+}
+
+func Example_redisStorage() {
+	client := &http.Client{}
+	handler, err := httpcache.NewWithRedisCache(client, true, &redis.CacheOptions{
+		Addr: "localhost:6379",
+	}, time.Second*15)
+	if err != nil {
+		log.Fatal(err)
 	}
+
+	processCachedRequest(client, handler)
 	// Example Output:
 	/*
 		2020/06/21 13:14:51 Cache item's missing failed to retrieve from cache, trying with a live version
@@ -61,3 +77,27 @@ func Example_inMemoryStorageDefault() {
 		Sequence >>>  5
 	*/
 }
+
+func processCachedRequest(client *http.Client, handler *httpcache.CacheHandler) {
+	for i := 0; i < 100; i++ {
+		startTime := time.Now()
+		req, err := http.NewRequest("GET", "https://bxcodec.io", nil)
+		if err != nil {
+			log.Fatal((err))
+		}
+		res, err := client.Do(req)
+		if err != nil {
+			log.Fatal(err)
+		}
+		fmt.Printf("Response time: %v micro-second\n", time.Since(startTime).Microseconds())
+		fmt.Println("Status Code", res.StatusCode)
+		time.Sleep(time.Second * 1)
+		fmt.Println("Sequence >>> ", i)
+		if i%5 == 0 {
+			err := handler.CacheInteractor.Flush()
+			if err != nil {
+				log.Fatal(err)
+			}
+		}
+	}
+}

go.mod

@@ -3,7 +3,11 @@ module github.com/bxcodec/httpcache
 go 1.13
 
 require (
+	github.com/alicebob/miniredis v2.5.0+incompatible
+	github.com/alicebob/miniredis/v2 v2.13.0
 	github.com/bxcodec/gotcha v1.0.0-beta.2
+	github.com/go-redis/redis/v8 v8.0.0-beta.5
 	github.com/patrickmn/go-cache v2.1.0+incompatible
-	github.com/stretchr/testify v1.4.0
+	github.com/stretchr/testify v1.5.1
+	golang.org/x/net v0.0.0-20190923162816-aa69164e4478
 )

httpcache.go

@@ -8,6 +8,9 @@ import (
 	inmemcache "github.com/bxcodec/gotcha/cache"
 	"github.com/bxcodec/httpcache/cache"
 	"github.com/bxcodec/httpcache/cache/inmem"
+	rediscache "github.com/bxcodec/httpcache/cache/redis"
+	"github.com/go-redis/redis/v8"
+	"golang.org/x/net/context"
 )
 
 // NewWithCustomStorageCache will initiate the httpcache with your defined cache storage
@@ -40,3 +43,21 @@ func NewWithInmemoryCache(client *http.Client, rfcCompliance bool, duration ...t
 
 	return newClient(client, rfcCompliance, inmem.NewCache(c))
 }
+
+// NewWithRedisCache will create a complete cache-support of HTTP client with using redis cache.
+// If the duration not set, the cache will use LFU algorithm
+func NewWithRedisCache(client *http.Client, rfcCompliance bool, options *rediscache.CacheOptions,
+	duration ...time.Duration) (cachedHandler *CacheHandler, err error) {
+	var ctx = context.Background()
+	var expiryTime time.Duration
+	if len(duration) > 0 {
+		expiryTime = duration[0]
+	}
+	c := redis.NewClient(&redis.Options{
+		Addr:     options.Addr,
+		Password: options.Password,
+		DB:       options.DB,
+	})
+
+	return newClient(client, rfcCompliance, rediscache.NewCache(ctx, c, expiryTime))
+}