feat(reader): remove closed reader from slice

multireader.go

@@ -91,6 +91,31 @@ func (m *MultiReader) shift() {
 	}
 }
 
+func (m *MultiReader) removeReader(id int) {
+	var (
+		pin int
+		nb  []*Reader
+	)
+	for idx := range m.pos {
+		if m.pos[idx].id == id {
+			pin = idx
+			break
+		}
+	}
+
+	nb = make([]*Reader, len(m.pos)-1)
+	if pin == 0 {
+		copy(nb, m.pos[1:])
+	} else if pin == len(m.pos)-1 {
+		copy(nb, m.pos[:len(m.pos)-1])
+	} else {
+		copy(nb, m.pos[:pin])
+		copy(nb[pin:], m.pos[pin+1:])
+	}
+
+	m.pos = nb
+}
+
 func (m *MultiReader) Close() error {
 	m.mtx.Lock()
 	defer m.mtx.Unlock()
@@ -155,6 +180,8 @@ func (r *Reader) seek(offset int, whence int) (int, error) {
 		r.readPos = offset
 	case io.SeekEnd:
 		r.readPos = r.multiReader.lastWritePos - offset
+	default:
+		return 0, ErrUnsupportedWhence
 	}
 
 	r.multiReader.sortLastPos()
@@ -192,5 +219,7 @@ func (r *Reader) Close() error {
 	r.mtx.Lock()
 	defer r.mtx.Unlock()
 	r.closed = true
+
+	r.multiReader.removeReader(r.id)
 	return nil
 }