1 files changed, 163 insertions, 0 deletions
diff --git a/storage/vector.go b/storage/vector.go
new file mode 100644
index 0000000..71005e4
--- /dev/null
+++ b/storage/vector.go
@@ -0,0 +1,163 @@
+package storage
+
+import (
+	"gf-lt/models"
+	"errors"
+	"fmt"
+	"unsafe"
+
+	sqlite_vec "github.com/asg017/sqlite-vec-go-bindings/ncruces"
+)
+
+type VectorRepo interface {
+	WriteVector(*models.VectorRow) error
+	SearchClosest(q []float32) ([]models.VectorRow, error)
+	ListFiles() ([]string, error)
+	RemoveEmbByFileName(filename string) error
+}
+
+var (
+	vecTableName5120 = "embeddings_5120"
+	vecTableName384  = "embeddings_384"
+)
+
+func fetchTableName(emb []float32) (string, error) {
+	switch len(emb) {
+	case 5120:
+		return vecTableName5120, nil
+	case 384:
+		return vecTableName384, nil
+	default:
+		return "", fmt.Errorf("no table for the size of %d", len(emb))
+	}
+}
+
+func (p ProviderSQL) WriteVector(row *models.VectorRow) error {
+	tableName, err := fetchTableName(row.Embeddings)
+	if err != nil {
+		return err
+	}
+	stmt, _, err := p.s3Conn.Prepare(
+		fmt.Sprintf("INSERT INTO %s(embedding, slug, raw_text, filename) VALUES (?, ?, ?, ?)", tableName))
+	if err != nil {
+		p.logger.Error("failed to prep a stmt", "error", err)
+		return err
+	}
+	defer stmt.Close()
+	v, err := sqlite_vec.SerializeFloat32(row.Embeddings)
+	if err != nil {
+		p.logger.Error("failed to serialize vector",
+			"emb-len", len(row.Embeddings), "error", err)
+		return err
+	}
+	if v == nil {
+		err = errors.New("empty vector after serialization")
+		p.logger.Error("empty vector after serialization",
+			"emb-len", len(row.Embeddings), "text", row.RawText, "error", err)
+		return err
+	}
+	if err := stmt.BindBlob(1, v); err != nil {
+		p.logger.Error("failed to bind", "error", err)
+		return err
+	}
+	if err := stmt.BindText(2, row.Slug); err != nil {
+		p.logger.Error("failed to bind", "error", err)
+		return err
+	}
+	if err := stmt.BindText(3, row.RawText); err != nil {
+		p.logger.Error("failed to bind", "error", err)
+		return err
+	}
+	if err := stmt.BindText(4, row.FileName); err != nil {
+		p.logger.Error("failed to bind", "error", err)
+		return err
+	}
+	err = stmt.Exec()
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func decodeUnsafe(bs []byte) []float32 {
+	return unsafe.Slice((*float32)(unsafe.Pointer(&bs[0])), len(bs)/4)
+}
+
+func (p ProviderSQL) SearchClosest(q []float32) ([]models.VectorRow, error) {
+	tableName, err := fetchTableName(q)
+	if err != nil {
+		return nil, err
+	}
+	stmt, _, err := p.s3Conn.Prepare(
+		fmt.Sprintf(`SELECT
+			distance,
+			embedding,
+			slug,
+			raw_text,
+			filename
+		FROM %s
+		WHERE embedding MATCH ?
+		ORDER BY distance
+		LIMIT 3
+	`, tableName))
+	if err != nil {
+		return nil, err
+	}
+	query, err := sqlite_vec.SerializeFloat32(q[:])
+	if err != nil {
+		return nil, err
+	}
+	if err := stmt.BindBlob(1, query); err != nil {
+		p.logger.Error("failed to bind", "error", err)
+		return nil, err
+	}
+	resp := []models.VectorRow{}
+	for stmt.Step() {
+		res := models.VectorRow{}
+		res.Distance = float32(stmt.ColumnFloat(0))
+		emb := stmt.ColumnRawText(1)
+		res.Embeddings = decodeUnsafe(emb)
+		res.Slug = stmt.ColumnText(2)
+		res.RawText = stmt.ColumnText(3)
+		res.FileName = stmt.ColumnText(4)
+		resp = append(resp, res)
+	}
+	if err := stmt.Err(); err != nil {
+		return nil, err
+	}
+	err = stmt.Close()
+	if err != nil {
+		return nil, err
+	}
+	return resp, nil
+}
+
+func (p ProviderSQL) ListFiles() ([]string, error) {
+	q := fmt.Sprintf("SELECT filename FROM %s GROUP BY filename", vecTableName384)
+	stmt, _, err := p.s3Conn.Prepare(q)
+	if err != nil {
+		return nil, err
+	}
+	defer stmt.Close()
+	resp := []string{}
+	for stmt.Step() {
+		resp = append(resp, stmt.ColumnText(0))
+	}
+	if err := stmt.Err(); err != nil {
+		return nil, err
+	}
+	return resp, nil
+}
+
+func (p ProviderSQL) RemoveEmbByFileName(filename string) error {
+	q := fmt.Sprintf("DELETE FROM %s WHERE filename = ?", vecTableName384)
+	stmt, _, err := p.s3Conn.Prepare(q)
+	if err != nil {
+		return err
+	}
+	defer stmt.Close()
+	if err := stmt.BindText(1, filename); err != nil {
+		return err
+	}
+	return stmt.Exec()
+}