[#1442] pilorama: Generate timestamp based on node position in the container

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

pkg/local_object_storage/pilorama/util_test.go

@@ -0,0 +1,38 @@
+package pilorama
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestNextTimestamp(t *testing.T) {
+	testCases := []struct {
+		latest    Timestamp
+		pos, size uint64
+		expected  Timestamp
+	}{
+		{0, 0, 1, 1},
+		{2, 0, 1, 3},
+		{0, 0, 2, 2},
+		{0, 1, 2, 1},
+		{10, 0, 4, 12},
+		{11, 0, 4, 12},
+		{12, 0, 4, 16},
+		{10, 1, 4, 13},
+		{11, 1, 4, 13},
+		{12, 1, 4, 13},
+		{10, 2, 4, 14},
+		{11, 2, 4, 14},
+		{12, 2, 4, 14},
+		{10, 3, 4, 11},
+		{11, 3, 4, 15},
+		{12, 3, 4, 15},
+	}
+
+	for _, tc := range testCases {
+		actual := nextTimestamp(tc.latest, tc.pos, tc.size)
+		require.Equal(t, tc.expected, actual,
+			"latest %d, pos %d, size %d", tc.latest, tc.pos, tc.size)
+	}
+}