crypto: Add compact bit array for intended usage in the multisig

This is in a separate PR for ease of review.
2026-09-13 19:44:23 +00:00 · 2018-08-06 15:55:02 -05:00
parent ec3e34efd8
commit 21448bcf4f
2 changed files with 387 additions and 0 deletions
@@ -0,0 +1,169 @@
+package multisig
+
+import (
+	"encoding/json"
+	"math/rand"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	cmn "github.com/tendermint/tendermint/libs/common"
+)
+
+func randCompactBitArray(bits int) (*CompactBitArray, []byte) {
+	numBytes := (bits + 7) / 8
+	src := cmn.RandBytes((bits + 7) / 8)
+	bA := NewCompactBitArray(bits)
+
+	for i := 0; i < numBytes-1; i++ {
+		for j := uint8(0); j < 8; j++ {
+			bA.SetIndex(i*8+int(j), src[i]&(uint8(1)<<(8-j)) > 0)
+		}
+	}
+	// Set remaining bits
+	for i := uint8(0); i < 8-uint8(bA.ExtraBitsStored); i++ {
+		bA.SetIndex(numBytes*8+int(i), src[numBytes-1]&(uint8(1)<<(8-i)) > 0)
+	}
+	return bA, src
+}
+
+func TestNewBitArrayNeverCrashesOnNegatives(t *testing.T) {
+	bitList := []int{-127, -128, -1 << 31}
+	for _, bits := range bitList {
+		_ = NewCompactBitArray(bits)
+	}
+}
+
+func TestJSONMarshalUnmarshal(t *testing.T) {
+
+	bA1 := NewCompactBitArray(0)
+	bA2 := NewCompactBitArray(1)
+
+	bA3 := NewCompactBitArray(1)
+	bA3.SetIndex(0, true)
+
+	bA4 := NewCompactBitArray(5)
+	bA4.SetIndex(0, true)
+	bA4.SetIndex(1, true)
+
+	bA5 := NewCompactBitArray(9)
+	bA5.SetIndex(0, true)
+	bA5.SetIndex(1, true)
+	bA5.SetIndex(8, true)
+
+	bA6 := NewCompactBitArray(16)
+	bA6.SetIndex(0, true)
+	bA6.SetIndex(1, true)
+	bA6.SetIndex(8, false)
+	bA6.SetIndex(15, true)
+
+	testCases := []struct {
+		bA           *CompactBitArray
+		marshalledBA string
+	}{
+		{nil, `null`},
+		{bA1, `null`},
+		{bA2, `"_"`},
+		{bA3, `"x"`},
+		{bA4, `"xx___"`},
+		{bA5, `"xx______x"`},
+		{bA6, `"xx_____________x"`},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.bA.String(), func(t *testing.T) {
+			bz, err := json.Marshal(tc.bA)
+			require.NoError(t, err)
+
+			assert.Equal(t, tc.marshalledBA, string(bz))
+
+			var unmarshalledBA *CompactBitArray
+			err = json.Unmarshal(bz, &unmarshalledBA)
+			require.NoError(t, err)
+
+			if tc.bA == nil {
+				require.Nil(t, unmarshalledBA)
+			} else {
+				require.NotNil(t, unmarshalledBA)
+				assert.EqualValues(t, tc.bA.Elems, unmarshalledBA.Elems)
+				if assert.EqualValues(t, tc.bA.String(), unmarshalledBA.String()) {
+					assert.EqualValues(t, tc.bA.Elems, unmarshalledBA.Elems)
+				}
+			}
+		})
+	}
+}
+
+func TestCompactMarshalUnmarshal(t *testing.T) {
+	bA1 := NewCompactBitArray(0)
+	bA2 := NewCompactBitArray(1)
+
+	bA3 := NewCompactBitArray(1)
+	bA3.SetIndex(0, true)
+
+	bA4 := NewCompactBitArray(5)
+	bA4.SetIndex(0, true)
+	bA4.SetIndex(1, true)
+
+	bA5 := NewCompactBitArray(9)
+	bA5.SetIndex(0, true)
+	bA5.SetIndex(1, true)
+	bA5.SetIndex(8, true)
+
+	bA6 := NewCompactBitArray(16)
+	bA6.SetIndex(0, true)
+	bA6.SetIndex(1, true)
+	bA6.SetIndex(8, false)
+	bA6.SetIndex(15, true)
+
+	testCases := []struct {
+		bA           *CompactBitArray
+		marshalledBA []byte
+	}{
+		{nil, []byte("null")},
+		{bA1, []byte("null")},
+		{bA2, []byte{byte(1), byte(0)}},
+		{bA3, []byte{byte(1), byte(128)}},
+		{bA4, []byte{byte(5), byte(192)}},
+		{bA5, []byte{byte(9), byte(192), byte(128)}},
+		{bA6, []byte{byte(16), byte(192), byte(1)}},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.bA.String(), func(t *testing.T) {
+			bz := tc.bA.CompactMarshal()
+
+			assert.Equal(t, tc.marshalledBA, bz)
+
+			unmarshalledBA, err := CompactUnmarshal(bz)
+			require.NoError(t, err)
+			if tc.bA == nil {
+				require.Nil(t, unmarshalledBA)
+			} else {
+				require.NotNil(t, unmarshalledBA)
+				assert.EqualValues(t, tc.bA.Elems, unmarshalledBA.Elems)
+				if assert.EqualValues(t, tc.bA.String(), unmarshalledBA.String()) {
+					assert.EqualValues(t, tc.bA.Elems, unmarshalledBA.Elems)
+				}
+			}
+		})
+	}
+}
+
+func TestCompactBitArrayGetSetIndex(t *testing.T) {
+	r := rand.New(rand.NewSource(100))
+	numTests := 10
+	numBitsPerArr := 100
+	for i := 0; i < numTests; i++ {
+		bits := r.Intn(1000)
+		bA, _ := randCompactBitArray(bits)
+
+		for j := 0; j < numBitsPerArr; j++ {
+			copy := bA.Copy()
+			index := r.Intn(bits)
+			val := (r.Int63() % 2) == 0
+			bA.SetIndex(index, val)
+			require.Equal(t, val, bA.GetIndex(index), "bA.SetIndex(%d, %v) failed on bit array: %s", index, val, copy)
+		}
+	}
+}