enhance: [GoSDK] support Bitmap Index (#35585)

See also #32900

Signed-off-by: Congqi Xia <congqi.xia@zilliz.com>

client/index/common.go

@@ -64,4 +64,5 @@ const (
 	Trie     IndexType = "Trie"
 	Sorted   IndexType = "STL_SORT"
 	Inverted IndexType = "INVERTED"
+	BITMAP   IndexType = "BITMAP"
 )

client/index/scalar.go

@@ -54,3 +54,9 @@ func NewSortedIndex() Index {
 		indexType: Sorted,
 	}
 }
+
+func NewBitmapIndex() Index {
+	return scalarIndex{
+		indexType: BITMAP,
+	}
+}

client/index/scalar_test.go

@@ -0,0 +1,63 @@
+// Licensed to the LF AI & Data foundation under one
+// or more contributor license agreements. See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership. The ASF licenses this file
+// to you 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 index
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+)
+
+type ScalarIndexSuite struct {
+	suite.Suite
+}
+
+func (s *ScalarIndexSuite) TestConstructors() {
+	type testCase struct {
+		tag             string
+		input           Index
+		expectIndexType IndexType
+	}
+
+	testcases := []testCase{
+		{tag: "Trie", input: NewTrieIndex(), expectIndexType: Trie},
+		{tag: "Sorted", input: NewSortedIndex(), expectIndexType: Sorted},
+		{tag: "Inverted", input: NewInvertedIndex(), expectIndexType: Inverted},
+		{tag: "Bitmap", input: NewBitmapIndex(), expectIndexType: BITMAP},
+	}
+
+	for _, tc := range testcases {
+		s.Run(fmt.Sprintf("%s_indextype", tc.tag), func() {
+			s.Equal(tc.expectIndexType, tc.input.IndexType())
+		})
+	}
+
+	for _, tc := range testcases {
+		s.Run(fmt.Sprintf("%s_params", tc.tag), func() {
+			params := tc.input.Params()
+			itv, ok := params[IndexTypeKey]
+			if s.True(ok) {
+				s.EqualValues(tc.expectIndexType, itv)
+			}
+		})
+	}
+}
+
+func TestScalarIndexes(t *testing.T) {
+	suite.Run(t, new(ScalarIndexSuite))
+}