Remove registry storage testdriver

Signed-off-by: glefloch <glfloch@gmail.com>

registry/storage/driver/inmemory/driver.go

@@ -251,6 +251,8 @@ func (d *driver) Walk(ctx context.Context, path string, f storagedriver.WalkFn)
 type writer struct {
 	d         *driver
 	f         *file
+	buffer    []byte
+	buffSize  int
 	closed    bool
 	committed bool
 	cancelled bool
@@ -274,8 +276,17 @@ func (w *writer) Write(p []byte) (int, error) {
 
 	w.d.mutex.Lock()
 	defer w.d.mutex.Unlock()
+	if cap(w.buffer) < len(p)+w.buffSize {
+		data := make([]byte, len(w.buffer), len(p)+w.buffSize)
+		copy(data, w.buffer)
+		w.buffer = data
+	}
 
-	return w.f.WriteAt(p, int64(len(w.f.data)))
+	w.buffer = w.buffer[:w.buffSize+len(p)]
+	n := copy(w.buffer[w.buffSize:w.buffSize+len(p)], p)
+	w.buffSize += n
+
+	return n, nil
 }
 
 func (w *writer) Size() int64 {
@@ -290,6 +301,8 @@ func (w *writer) Close() error {
 		return fmt.Errorf("already closed")
 	}
 	w.closed = true
+	w.flush()
+
 	return nil
 }
 
@@ -316,5 +329,16 @@ func (w *writer) Commit() error {
 		return fmt.Errorf("already cancelled")
 	}
 	w.committed = true
+	w.flush()
+
 	return nil
 }
+
+func (w *writer) flush() {
+	w.d.mutex.Lock()
+	defer w.d.mutex.Unlock()
+
+	w.f.WriteAt(w.buffer, int64(len(w.f.data)))
+	w.buffer = []byte{}
+	w.buffSize = 0
+}