enhance: Add Sparse Index type enum (#723)

See also #708
Support SparseInverted & SparseWAND

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

entity/columns_sparse.go

@@ -26,6 +26,7 @@ type SparseEmbedding interface {
 	Len() int // the actual items in this vector
 	Get(idx int) (pos uint32, value float32, ok bool)
 	Serialize() []byte
+	FieldType() FieldType
 }
 
 var _ SparseEmbedding = sliceSparseEmbedding{}

entity/index.go

@@ -44,6 +44,10 @@ const (
 	GPUCagra      IndexType = "GPU_CAGRA"
 	GPUBruteForce IndexType = "GPU_BRUTE_FORCE"
 
+	// Sparse
+	SparseInverted IndexType = "SPARSE_INVERTED_INDEX"
+	SparseWAND     IndexType = "SPARSE_WAND"
+
 	// DEPRECATED
 	Scalar IndexType = ""
 
@@ -66,6 +70,7 @@ const (
 
 // index param field tag
 const (
+	tParams     = `params`
 	tIndexType  = `index_type`
 	tMetricType = `metric_type`
 )

entity/index_sparse.go

@@ -0,0 +1,115 @@
+package entity
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/cockroachdb/errors"
+)
+
+var _ Index = (*IndexSparseInverted)(nil)
+
+// IndexSparseInverted index type for SPARSE_INVERTED_INDEX
+type IndexSparseInverted struct {
+	metricType MetricType
+	dropRatio  float64
+}
+
+func (i *IndexSparseInverted) Name() string {
+	return "SparseInverted"
+}
+
+func (i *IndexSparseInverted) IndexType() IndexType {
+	return SparseInverted
+}
+
+func (i *IndexSparseInverted) Params() map[string]string {
+	params := map[string]string{
+		"drop_ratio_build": fmt.Sprintf("%v", i.dropRatio),
+	}
+	bs, _ := json.Marshal(params)
+	return map[string]string{
+		tParams:     string(bs),
+		tIndexType:  string(i.IndexType()),
+		tMetricType: string(i.metricType),
+	}
+}
+
+type IndexSparseInvertedSearchParam struct {
+	baseSearchParams
+}
+
+func NewIndexSparseInvertedSearchParam(dropRatio float64) (*IndexSparseInvertedSearchParam, error) {
+	if dropRatio < 0 || dropRatio >= 1 {
+		return nil, errors.Newf("invalid dropRatio for search: %v, must be in range [0, 1)", dropRatio)
+	}
+	sp := &IndexSparseInvertedSearchParam{
+		baseSearchParams: newBaseSearchParams(),
+	}
+
+	sp.params["drop_ratio_search"] = dropRatio
+	return sp, nil
+}
+
+// IndexSparseInverted index type for SPARSE_INVERTED_INDEX
+func NewIndexSparseInverted(metricType MetricType, dropRatio float64) (*IndexSparseInverted, error) {
+	if dropRatio < 0 || dropRatio >= 1.0 {
+		return nil, errors.Newf("invalid dropRatio for build: %v, must be in range [0, 1)", dropRatio)
+	}
+	return &IndexSparseInverted{
+		metricType: metricType,
+		dropRatio:  dropRatio,
+	}, nil
+}
+
+type IndexSparseWAND struct {
+	metricType MetricType
+	dropRatio  float64
+}
+
+func (i *IndexSparseWAND) Name() string {
+	return "SparseWAND"
+}
+
+func (i *IndexSparseWAND) IndexType() IndexType {
+	return SparseWAND
+}
+
+func (i *IndexSparseWAND) Params() map[string]string {
+	params := map[string]string{
+		"drop_ratio_build": fmt.Sprintf("%v", i.dropRatio),
+	}
+	bs, _ := json.Marshal(params)
+	return map[string]string{
+		tParams:     string(bs),
+		tIndexType:  string(i.IndexType()),
+		tMetricType: string(i.metricType),
+	}
+}
+
+// IndexSparseWAND index type for SPARSE_WAND, weak-and
+func NewIndexSparseWAND(metricType MetricType, dropRatio float64) (*IndexSparseWAND, error) {
+	if dropRatio < 0 || dropRatio >= 1.0 {
+		return nil, errors.Newf("invalid dropRatio for build: %v, must be in range [0, 1)", dropRatio)
+	}
+	return &IndexSparseWAND{
+		metricType: metricType,
+		dropRatio:  dropRatio,
+	}, nil
+}
+
+type IndexSparseWANDSearchParam struct {
+	baseSearchParams
+}
+
+func NewIndexSparseWANDSearchParam(dropRatio float64) (*IndexSparseWANDSearchParam, error) {
+	if dropRatio < 0 || dropRatio >= 1 {
+		return nil, errors.Newf("invalid dropRatio for search: %v, must be in range [0, 1)", dropRatio)
+	}
+	sp := &IndexSparseWANDSearchParam{
+		baseSearchParams: newBaseSearchParams(),
+	}
+
+	sp.params["drop_ratio_search"] = dropRatio
+	return sp, nil
+}

entity/index_sparse_test.go

@@ -0,0 +1,98 @@
+package entity
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+)
+
+type SparseIndexSuite struct {
+	suite.Suite
+}
+
+func (s *SparseIndexSuite) TestSparseInverted() {
+	s.Run("bad_drop_ratio", func() {
+		_, err := NewIndexSparseInverted(IP, -1)
+		s.Error(err)
+
+		_, err = NewIndexSparseInverted(IP, 1.0)
+		s.Error(err)
+	})
+
+	s.Run("normal_case", func() {
+		idx, err := NewIndexSparseInverted(IP, 0.2)
+		s.Require().NoError(err)
+
+		s.Equal("SparseInverted", idx.Name())
+		s.Equal(SparseInverted, idx.IndexType())
+		params := idx.Params()
+
+		s.Equal("SPARSE_INVERTED_INDEX", params[tIndexType])
+		s.Equal("IP", params[tMetricType])
+		paramsVal, has := params[tParams]
+		s.True(has)
+		m := make(map[string]string)
+		err = json.Unmarshal([]byte(paramsVal), &m)
+		s.Require().NoError(err)
+		dropRatio, ok := m["drop_ratio_build"]
+		s.True(ok)
+		s.Equal("0.2", dropRatio)
+	})
+
+	s.Run("search_param", func() {
+		_, err := NewIndexSparseInvertedSearchParam(-1)
+		s.Error(err)
+		_, err = NewIndexSparseInvertedSearchParam(1.0)
+		s.Error(err)
+
+		sp, err := NewIndexSparseInvertedSearchParam(0.2)
+		s.Require().NoError(err)
+		s.EqualValues(0.2, sp.Params()["drop_ratio_search"])
+	})
+}
+
+func (s *SparseIndexSuite) TestSparseWAND() {
+	s.Run("bad_drop_ratio", func() {
+		_, err := NewIndexSparseWAND(IP, -1)
+		s.Error(err)
+
+		_, err = NewIndexSparseWAND(IP, 1.0)
+		s.Error(err)
+	})
+
+	s.Run("normal_case", func() {
+		idx, err := NewIndexSparseWAND(IP, 0.2)
+		s.Require().NoError(err)
+
+		s.Equal("SparseWAND", idx.Name())
+		s.Equal(SparseWAND, idx.IndexType())
+		params := idx.Params()
+
+		s.Equal("SPARSE_WAND", params[tIndexType])
+		s.Equal("IP", params[tMetricType])
+		paramsVal, has := params[tParams]
+		s.True(has)
+		m := make(map[string]string)
+		err = json.Unmarshal([]byte(paramsVal), &m)
+		s.Require().NoError(err)
+		dropRatio, ok := m["drop_ratio_build"]
+		s.True(ok)
+		s.Equal("0.2", dropRatio)
+	})
+
+	s.Run("search_param", func() {
+		_, err := NewIndexSparseWANDSearchParam(-1)
+		s.Error(err)
+		_, err = NewIndexSparseWANDSearchParam(1.0)
+		s.Error(err)
+
+		sp, err := NewIndexSparseWANDSearchParam(0.2)
+		s.Require().NoError(err)
+		s.EqualValues(0.2, sp.Params()["drop_ratio_search"])
+	})
+}
+
+func TestSparseIndex(t *testing.T) {
+	suite.Run(t, new(SparseIndexSuite))
+}