Feat: add rag [wip; skip-ci]

storage/vector.go

@@ -0,0 +1,89 @@
+package storage
+
+import (
+	"elefant/models"
+	"fmt"
+	"log"
+	"unsafe"
+
+	sqlite_vec "github.com/asg017/sqlite-vec-go-bindings/ncruces"
+)
+
+type VectorRepo interface {
+	WriteVector(*models.VectorRow) error
+	SearchClosest(q [5120]float32) (*models.VectorRow, error)
+}
+
+var vecTableName = "embeddings"
+
+func (p ProviderSQL) WriteVector(row *models.VectorRow) error {
+	stmt, _, err := p.s3Conn.Prepare(
+		fmt.Sprintf("INSERT INTO %s(embedding, slug, raw_text) VALUES (?, ?, ?)", vecTableName))
+	defer stmt.Close()
+	if err != nil {
+		p.logger.Error("failed to prep a stmt", "error", err)
+		return err
+	}
+	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
+	}
+	stmt.BindInt(1, int(row.ID))
+	stmt.BindBlob(2, v)
+	stmt.BindText(3, row.Slug)
+	stmt.BindText(4, row.RawText)
+	err = stmt.Exec()
+	if err != nil {
+		p.logger.Error("failed exec a stmt", "error", err)
+		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 [5120]float32) (*models.VectorRow, error) {
+	stmt, _, err := p.s3Conn.Prepare(`
+		SELECT
+			id,
+			distance,
+			embedding,
+			slug,
+			raw_text
+		FROM vec_items
+		WHERE embedding MATCH ?
+		ORDER BY distance
+		LIMIT 4
+	`)
+	if err != nil {
+		log.Fatal(err)
+	}
+	query, err := sqlite_vec.SerializeFloat32(q[:])
+	if err != nil {
+		log.Fatal(err)
+	}
+	stmt.BindBlob(1, query)
+	resp := make([]models.VectorRow, 4)
+	i := 0
+	for stmt.Step() {
+		resp[i].ID = uint32(stmt.ColumnInt64(0))
+		resp[i].Distance = float32(stmt.ColumnFloat(1))
+		emb := stmt.ColumnRawText(2)
+		resp[i].Embeddings = decodeUnsafe(emb)
+		resp[i].Slug = stmt.ColumnText(3)
+		resp[i].RawText = stmt.ColumnText(4)
+		i++
+	}
+	if err := stmt.Err(); err != nil {
+		log.Fatal(err)
+	}
+	err = stmt.Close()
+	if err != nil {
+		log.Fatal(err)
+	}
+	return nil, nil
+}