Add LRU cache

.gitignore

@@ -0,0 +1,2 @@
+.idea/
+*.iml

cache.go

@@ -14,6 +14,7 @@ const (
 	Memcache = "memcache"
 	Redis    = "redis"
 	Memory   = "memory"
+	Lru      = "lru"
 )
 
 var (
@@ -66,6 +67,20 @@ func New(uri string) (CacheInterface, error) {
 		}
 
 		return NewMemoryCache(time.Duration(i) * time.Second)
+	case Lru:
+		size := query.Get("size")
+
+		if size == "" {
+			size = "128"
+		}
+
+		i, err := strconv.Atoi(size)
+
+		if err != nil {
+			return nil, err
+		}
+
+		return NewLruCache(i)
 	}
 
 	return nil, ErrInvalidDriver

go.mod

@@ -4,6 +4,7 @@ go 1.12
 
 require (
 	github.com/bradfitz/gomemcache v0.0.0-20190913173617-a41fca850d0b
+	github.com/hashicorp/golang-lru v0.5.3
 	github.com/hoisie/redis v0.0.0-20160730154456-b5c6e81454e0
 	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/vmihailenco/msgpack/v4 v4.2.0

go.sum

@@ -3,6 +3,8 @@ github.com/bradfitz/gomemcache v0.0.0-20190913173617-a41fca850d0b/go.mod h1:H0wQ
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.2 h1:6nsPYzhq5kReh6QImI3k5qWzO4PEbvbIW2cwSfR/6xs=
 github.com/golang/protobuf v1.3.2/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/hashicorp/golang-lru v0.5.3 h1:YPkqC67at8FYaadspW/6uE0COsBxS2656RLEr8Bppgk=
+github.com/hashicorp/golang-lru v0.5.3/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=
 github.com/hoisie/redis v0.0.0-20160730154456-b5c6e81454e0 h1:mjZV3MTu2A5gwfT5G9IIiLGdwZNciyVq5qqnmJJZ2JI=
 github.com/hoisie/redis v0.0.0-20160730154456-b5c6e81454e0/go.mod h1:pMYMxVaKJqCDC1JUg/XbPJ4/fSazB25zORpFzqsIGIc=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=

lru.go

@@ -0,0 +1,46 @@
+package cache
+
+import (
+	"github.com/hashicorp/golang-lru"
+	"time"
+)
+
+type LruCache struct {
+	c *lru.Cache
+}
+
+func NewLruCache(size int) (CacheInterface, error) {
+	c, err := lru.New(size)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &LruCache{c: c}, nil
+}
+
+func (mc *LruCache) Has(key string) bool {
+	_, exists := mc.c.Get(key)
+
+	return exists
+}
+
+func (mc *LruCache) Get(key string, dst ...interface{}) ([]byte, error) {
+	item, exists := mc.c.Get(key)
+
+	if !exists {
+		return nil, ErrMemoryCacheNotExists
+	}
+
+	return memoryCacheGet(item, dst...)
+}
+
+func (mc *LruCache) Set(key string, val interface{}, ttl time.Duration) error {
+	mc.c.Add(key, val)
+	return nil
+}
+
+func (mc *LruCache) Del(key string) error {
+	mc.c.Remove(key)
+	return nil
+}

lru_test.go

@@ -0,0 +1,96 @@
+package cache
+
+import (
+	"testing"
+	"time"
+)
+
+func TestNew_LruURI(t *testing.T) {
+	cache, err := New("lru://")
+
+	if err != nil {
+		t.Fatal("Error creating cache:", err)
+	}
+
+	if _, ok := cache.(*LruCache); !ok {
+		t.Fatal("Cache is not instance of MemoryCache")
+	}
+}
+
+func TestLruCache_Get(t *testing.T) {
+	cache, err := New("lru://")
+
+	if err != nil {
+		t.Fatal("Error creating cache:", err)
+	}
+
+	obj := "test"
+
+	cache.Set("test", obj, time.Minute)
+
+	var new string
+
+	cache.Get("test", &new)
+
+	if obj != new {
+		t.Fatal("Expected", obj, "got", new)
+	}
+}
+
+func TestLruCache_GetRaw(t *testing.T) {
+	cache, err := New("lru://")
+
+	if err != nil {
+		t.Fatal("Error creating cache:", err)
+	}
+
+	obj := "test"
+
+	cache.Set("test", obj, time.Minute)
+
+	v, err := cache.Get("test")
+
+	if err != nil {
+		t.Fatal("Unable to get value:", err)
+	}
+
+	new := string(v)
+
+	if obj != new {
+		t.Fatal("Expected", obj, "got", new)
+	}
+}
+
+func TestLruCache_Has(t *testing.T) {
+	cache, err := New("lru://")
+
+	if err != nil {
+		t.Fatal("Error creating cache:", err)
+	}
+
+	cache.Set("test", "test", time.Minute)
+
+	if !cache.Has("test") {
+		t.Fatal("Expected cache to have object 'test'")
+	}
+}
+
+func TestLruCache_Del(t *testing.T) {
+	cache, err := New("lru://")
+
+	if err != nil {
+		t.Fatal("Error creating cache:", err)
+	}
+
+	cache.Set("test", "test", time.Minute)
+
+	if !cache.Has("test") {
+		t.Fatal("Expected cache to have object 'test'")
+	}
+
+	cache.Del("test")
+
+	if cache.Has("test") {
+		t.Fatal("Cache did not properly delete item")
+	}
+}

memory.go

@@ -35,6 +35,20 @@ func (mc *MemoryCache) Get(key string, dst ...interface{}) ([]byte, error) {
 		return nil, ErrMemoryCacheNotExists
 	}
 
+	return memoryCacheGet(item, dst...)
+}
+
+func (mc *MemoryCache) Set(key string, val interface{}, ttl time.Duration) error {
+	mc.c.Set(key, val, ttl)
+	return nil
+}
+
+func (mc *MemoryCache) Del(key string) error {
+	mc.c.Delete(key)
+	return nil
+}
+
+func memoryCacheGet(item interface{}, dst ...interface{}) ([]byte, error) {
 	if len(dst) == 0 {
 		switch item.(type) {
 		case string:
@@ -165,13 +179,3 @@ func (mc *MemoryCache) Get(key string, dst ...interface{}) ([]byte, error) {
 
 	return nil, nil
 }
-
-func (mc *MemoryCache) Set(key string, val interface{}, ttl time.Duration) error {
-	mc.c.Set(key, val, ttl)
-	return nil
-}
-
-func (mc *MemoryCache) Del(key string) error {
-	mc.c.Delete(key)
-	return nil
-}