Make caching a package trove, and use it inside memory driver

pkg/storage/drivers/memory/memory.go

@@ -34,14 +34,15 @@ import (
 
 	"github.com/minio/minio/pkg/iodine"
 	"github.com/minio/minio/pkg/storage/drivers"
+	"github.com/minio/minio/pkg/storage/trove"
 )
 
 // memoryDriver - local variables
 type memoryDriver struct {
 	storedBuckets    map[string]storedBucket
 	lock             *sync.RWMutex
-	objects          *Cache
-	multiPartObjects *Cache
+	objects          *trove.Cache
+	multiPartObjects *trove.Cache
 }
 
 type storedBucket struct {
@@ -69,8 +70,8 @@ func Start(maxSize uint64, expiration time.Duration) (chan<- string, <-chan erro
 	var memory *memoryDriver
 	memory = new(memoryDriver)
 	memory.storedBuckets = make(map[string]storedBucket)
-	memory.objects = NewCache(maxSize, expiration)
-	memory.multiPartObjects = NewCache(0, time.Duration(0))
+	memory.objects = trove.NewCache(maxSize, expiration)
+	memory.multiPartObjects = trove.NewCache(0, time.Duration(0))
 	memory.lock = new(sync.RWMutex)
 
 	memory.objects.OnExpired = memory.expiredObject
@@ -108,7 +109,7 @@ func (memory *memoryDriver) GetObject(w io.Writer, bucket string, object string)
 		memory.lock.RUnlock()
 		return 0, iodine.New(drivers.ObjectNotFound{Bucket: bucket, Object: object}, nil)
 	}
-	written, err := io.Copy(w, bytes.NewBuffer(data.([]byte)))
+	written, err := io.Copy(w, bytes.NewBuffer(data))
 	memory.lock.RUnlock()
 	return written, iodine.New(err, nil)
 }
@@ -142,7 +143,7 @@ func (memory *memoryDriver) GetPartialObject(w io.Writer, bucket, object string,
 		memory.lock.RUnlock()
 		return 0, iodine.New(drivers.ObjectNotFound{Bucket: bucket, Object: object}, errParams)
 	}
-	written, err := io.CopyN(w, bytes.NewBuffer(data.([]byte)[start:]), length)
+	written, err := io.CopyN(w, bytes.NewBuffer(data[start:]), length)
 	memory.lock.RUnlock()
 	return written, iodine.New(err, nil)
 }

pkg/storage/drivers/memory/memory_multipart.go

@@ -208,11 +208,9 @@ func (memory *memoryDriver) cleanupMultipartSession(bucket, key, uploadID string
 }
 
 func (memory *memoryDriver) cleanupMultiparts(bucket, key, uploadID string) {
-	memory.lock.Lock()
-	defer memory.lock.Unlock()
 	for i := 1; i <= memory.storedBuckets[bucket].multiPartSession[key].totalParts; i++ {
 		objectKey := bucket + "/" + getMultipartKey(key, uploadID, i)
-		memory.multiPartObjects.doDelete(objectKey)
+		memory.multiPartObjects.Delete(objectKey)
 	}
 }
 
@@ -246,7 +244,7 @@ func (memory *memoryDriver) CompleteMultipartUpload(bucket, key, uploadID string
 			memory.lock.Unlock()
 			return "", iodine.New(errors.New("missing part: "+strconv.Itoa(i)), nil)
 		}
-		obj := object.([]byte)
+		obj := object
 		size += int64(len(obj))
 		calcMD5Bytes := md5.Sum(obj)
 		// complete multi part request header md5sum per part is hex encoded

pkg/storage/trove/trove.go

@@ -14,14 +14,15 @@
  * limitations under the License.
  */
 
-package memory
+// Package trove implements in memory caching methods
+package trove
 
 import (
 	"sync"
 	"time"
 )
 
-var zeroExpiration = time.Duration(0)
+var noExpiration = time.Duration(0)
 
 // Cache holds the required variables to compose an in memory cache system
 // which also provides expiring key mechanism and also maxSize
@@ -31,7 +32,7 @@ type Cache struct {
 	sync.Mutex
 
 	// items hold the cached objects
-	items map[string]interface{}
+	items map[string][]byte
 
 	// updatedAt holds the time that related item's updated at
 	updatedAt map[string]time.Time
@@ -68,7 +69,7 @@ type Stats struct {
 // expiration is used for expiration of a key from cache
 func NewCache(maxSize uint64, expiration time.Duration) *Cache {
 	return &Cache{
-		items:      map[string]interface{}{},
+		items:      make(map[string][]byte),
 		updatedAt:  map[string]time.Time{},
 		expiration: expiration,
 		maxSize:    maxSize,
@@ -103,7 +104,7 @@ func (r *Cache) ExpireObjects(gcInterval time.Duration) {
 }
 
 // Get returns a value of a given key if it exists
-func (r *Cache) Get(key string) (interface{}, bool) {
+func (r *Cache) Get(key string) ([]byte, bool) {
 	r.Lock()
 	defer r.Unlock()
 	value, ok := r.items[key]
@@ -115,10 +116,10 @@ func (r *Cache) Get(key string) (interface{}, bool) {
 }
 
 // Set will persist a value to the cache
-func (r *Cache) Set(key string, value interface{}) bool {
+func (r *Cache) Set(key string, value []byte) bool {
 	r.Lock()
 	defer r.Unlock()
-	valueLen := uint64(len(value.([]byte)))
+	valueLen := uint64(len(value))
 	if r.maxSize > 0 {
 		// check if the size of the object is not bigger than the
 		// capacity of the cache
@@ -159,7 +160,7 @@ func (r *Cache) Delete(key string) {
 
 func (r *Cache) doDelete(key string) {
 	if _, ok := r.items[key]; ok {
-		r.currentSize -= uint64(len(r.items[key].([]byte)))
+		r.currentSize -= uint64(len(r.items[key]))
 		delete(r.items, key)
 		delete(r.updatedAt, key)
 		r.totalExpired++
@@ -174,7 +175,7 @@ func (r *Cache) isValid(key string) bool {
 	if !ok {
 		return false
 	}
-	if r.expiration == zeroExpiration {
+	if r.expiration == noExpiration {
 		return true
 	}
 	return updatedAt.Add(r.expiration).After(time.Now())

pkg/storage/trove/trove_test.go

@@ -0,0 +1,45 @@
+/*
+ * Minimalist Object Storage, (C) 2015 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package trove
+
+import (
+	"testing"
+
+	. "github.com/minio/check"
+)
+
+func Test(t *testing.T) { TestingT(t) }
+
+type MySuite struct{}
+
+var _ = Suite(&MySuite{})
+
+func (s *MySuite) TestCache(c *C) {
+	cache := NewCache(1000, 0)
+	data := []byte("Hello, world!")
+	ok := cache.Set("filename", data)
+
+	c.Assert(ok, Equals, true)
+	storedata, ok := cache.Get("filename")
+
+	c.Assert(ok, Equals, true)
+	c.Assert(data, DeepEquals, storedata)
+
+	cache.Delete("filename")
+	_, ok = cache.Get("filename")
+	c.Assert(ok, Equals, false)
+}