Adds storage driver interface, tests, and two basic implementations

storagedriver/storagedriver.go

@@ -0,0 +1,34 @@
+package storagedriver
+
+import (
+	"fmt"
+	"io"
+)
+
+type StorageDriver interface {
+	GetContent(path string) ([]byte, error)
+	PutContent(path string, content []byte) error
+	ReadStream(path string, offset uint64) (io.ReadCloser, error)
+	WriteStream(path string, offset, size uint64, readCloser io.ReadCloser) error
+	ResumeWritePosition(path string) (uint64, error)
+	List(prefix string) ([]string, error)
+	Move(sourcePath string, destPath string) error
+	Delete(path string) error
+}
+
+type PathNotFoundError struct {
+	Path string
+}
+
+func (err PathNotFoundError) Error() string {
+	return fmt.Sprintf("Path not found: %s", err.Path)
+}
+
+type InvalidOffsetError struct {
+	Path   string
+	Offset uint64
+}
+
+func (err InvalidOffsetError) Error() string {
+	return fmt.Sprintf("Invalid offset: %d for path: %s", err.Offset, err.Path)
+}