Merge pull request minio#649 from harshavardhana/pr_out_minor_optimiz…

…ation_avoiding_one_unnecessary_copy

Minor optimization avoiding one unnecessary copy

pkg/storage/drivers/memory/memory.go

@@ -277,18 +277,18 @@ func (memory *memoryDriver) createObject(bucket, key, contentType, expectedMD5Su
 	if err != io.EOF {
 		return "", iodine.New(err, nil)
 	}
-	go debug.FreeOSMemory()
 	md5SumBytes := hash.Sum(nil)
 	totalLength := len(readBytes)
 
 	memory.lock.Lock()
 	ok := memory.objects.Set(objectKey, readBytes)
+	// setting up for de-allocation
+	readBytes = nil
+	go debug.FreeOSMemory()
 	memory.lock.Unlock()
 	if !ok {
 		return "", iodine.New(drivers.InternalError{}, nil)
 	}
-	// setting up for de-allocation
-	readBytes = nil
 
 	md5Sum := hex.EncodeToString(md5SumBytes)
 	// Verify if the written object is equal to what is expected, only if it is requested as such

pkg/storage/drivers/memory/memory_multipart.go

@@ -244,9 +244,8 @@ func (memory *memoryDriver) CompleteMultipartUpload(bucket, key, uploadID string
 			memory.lock.Unlock()
 			return "", iodine.New(errors.New("missing part: "+strconv.Itoa(i)), nil)
 		}
-		obj := object
-		size += int64(len(obj))
-		calcMD5Bytes := md5.Sum(obj)
+		size += int64(len(object))
+		calcMD5Bytes := md5.Sum(object)
 		// complete multi part request header md5sum per part is hex encoded
 		recvMD5Bytes, err := hex.DecodeString(strings.Trim(recvMD5, "\""))
 		if err != nil {
@@ -255,10 +254,12 @@ func (memory *memoryDriver) CompleteMultipartUpload(bucket, key, uploadID string
 		if !bytes.Equal(recvMD5Bytes, calcMD5Bytes[:]) {
 			return "", iodine.New(drivers.BadDigest{Md5: recvMD5, Bucket: bucket, Key: getMultipartKey(key, uploadID, i)}, nil)
 		}
-		_, err = io.Copy(&fullObject, bytes.NewBuffer(obj))
+		_, err = io.Copy(&fullObject, bytes.NewBuffer(object))
 		if err != nil {
 			return "", iodine.New(err, nil)
 		}
+		object = nil
+		go debug.FreeOSMemory()
 	}
 	memory.lock.Unlock()
 
@@ -271,6 +272,7 @@ func (memory *memoryDriver) CompleteMultipartUpload(bucket, key, uploadID string
 		// which would in-turn cleanup properly in accordance with S3 Spec
 		return "", iodine.New(err, nil)
 	}
+	fullObject.Reset()
 	memory.cleanupMultiparts(bucket, key, uploadID)
 	memory.cleanupMultipartSession(bucket, key, uploadID)
 	return etag, nil