1 files changed, 62 insertions, 0 deletions
diff --git a/pkg/merkletree/merkletree_test.go b/pkg/merkletree/merkletree_test.go
new file mode 100644
index 000000000..6221eec07
--- /dev/null
+++ b/pkg/merkletree/merkletree_test.go
@@ -0,0 +1,62 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package merkletree
+
+import (
+	"fmt"
+	"testing"
+
+	"gvisor.dev/gvisor/pkg/usermem"
+)
+
+func TestSize(t *testing.T) {
+	testCases := []struct {
+		dataSize           int64
+		expectedLevelStart []int64
+	}{
+		{
+			dataSize:           100,
+			expectedLevelStart: []int64{0},
+		},
+		{
+			dataSize:           1000000,
+			expectedLevelStart: []int64{0, 2, 3},
+		},
+		{
+			dataSize:           4096 * int64(usermem.PageSize),
+			expectedLevelStart: []int64{0, 32, 33},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(fmt.Sprintf("%d", tc.dataSize), func(t *testing.T) {
+			s := MakeSize(tc.dataSize)
+			if s.blockSize != int64(usermem.PageSize) {
+				t.Errorf("got blockSize %d, want %d", s.blockSize, usermem.PageSize)
+			}
+			if s.digestSize != sha256DigestSize {
+				t.Errorf("got digestSize %d, want %d", s.digestSize, sha256DigestSize)
+			}
+			if len(s.levelStart) != len(tc.expectedLevelStart) {
+				t.Errorf("got levels %d, want %d", len(s.levelStart), len(tc.expectedLevelStart))
+			}
+			for i := 0; i < len(s.levelStart) && i < len(tc.expectedLevelStart); i++ {
+				if s.levelStart[i] != tc.expectedLevelStart[i] {
+					t.Errorf("got levelStart[%d] %d, want %d", i, s.levelStart[i], tc.expectedLevelStart[i])
+				}
+			}
+		})
+	}
+}