Adding start of inmem donut

pkg/donutbox/donutbox.go

@@ -0,0 +1,26 @@
+package donutbox
+
+import "io"
+
+// DonutBox is an interface specifying how the storage driver should interact with its underlying system.
+type DonutBox interface {
+	// system operations
+	ListBuckets() ([]string, error)
+
+	// bucket operations
+	CreateBucket(bucket string) error
+	ListObjects(bucket, prefix string) ([]string, error)
+	GetBucketMetadata(bucket, name string) (io.Reader, error)
+	SetBucketMetadata(bucket, name string, metadata io.Reader) error
+
+	// object operations
+	GetObjectWriter(bucket, object string, column, blockSize uint) (io.WriteCloser, <-chan Result, error)
+	GetObjectReader(bucket, object string, column int) (io.Reader, error)
+	StoreObjectMetadata(bucket, object, name string, reader io.Reader) error
+	GetObjectMetadata(bucket, object, name string) (io.Reader, error)
+}
+
+// Result is a result for async tasks
+type Result struct {
+	Err error
+}