Feat (rag): hybrid search attempt

config.example.toml

@@ -29,6 +29,7 @@ AutoCleanToolCallsFromCtx = false
 # rag settings
 RAGBatchSize = 1
 RAGWordLimit = 80
+RAGOverlapWords = 16
 RAGDir = "ragimport"
 # extra tts
 TTS_ENABLED = false

config/config.go

@@ -43,6 +43,7 @@ type Config struct {
 	RAGDir          string `toml:"RAGDir"`
 	RAGBatchSize    int    `toml:"RAGBatchSize"`
 	RAGWordLimit    uint32 `toml:"RAGWordLimit"`
+	RAGOverlapWords uint32 `toml:"RAGOverlapWords"`
 	// deepseek
 	DeepSeekChatAPI       string `toml:"DeepSeekChatAPI"`
 	DeepSeekCompletionAPI string `toml:"DeepSeekCompletionAPI"`

rag/rag.go

@@ -73,6 +73,74 @@ func wordCounter(sentence string) int {
 	return len(strings.Split(strings.TrimSpace(sentence), " "))
 }
 
+func createChunks(sentences []string, wordLimit, overlapWords uint32) []string {
+	if len(sentences) == 0 {
+		return nil
+	}
+	if overlapWords >= wordLimit {
+		overlapWords = wordLimit / 2
+	}
+	var chunks []string
+	i := 0
+	for i < len(sentences) {
+		var chunkWords []string
+		wordCount := 0
+		j := i
+		for j < len(sentences) && wordCount <= int(wordLimit) {
+			sentence := sentences[j]
+			words := strings.Fields(sentence)
+			chunkWords = append(chunkWords, sentence)
+			wordCount += len(words)
+			j++
+			// If this sentence alone exceeds limit, still include it and stop
+			if wordCount > int(wordLimit) {
+				break
+			}
+		}
+		if len(chunkWords) == 0 {
+			break
+		}
+		chunk := strings.Join(chunkWords, " ")
+		chunks = append(chunks, chunk)
+		if j >= len(sentences) {
+			break
+		}
+		// Move i forward by skipping overlap
+		if overlapWords == 0 {
+			i = j
+			continue
+		}
+		// Calculate how many sentences to skip to achieve overlapWords
+		overlapRemaining := int(overlapWords)
+		newI := i
+		for newI < j && overlapRemaining > 0 {
+			words := len(strings.Fields(sentences[newI]))
+			overlapRemaining -= words
+			if overlapRemaining >= 0 {
+				newI++
+			}
+		}
+		if newI == i {
+			newI = j
+		}
+		i = newI
+	}
+	return chunks
+}
+
+func sanitizeFTSQuery(query string) string {
+	// Remove double quotes and other problematic characters for FTS5
+	query = strings.ReplaceAll(query, "\"", " ")
+	query = strings.ReplaceAll(query, "'", " ")
+	query = strings.ReplaceAll(query, ";", " ")
+	query = strings.ReplaceAll(query, "\\", " ")
+	query = strings.TrimSpace(query)
+	if query == "" {
+		return "*" // match all
+	}
+	return query
+}
+
 func (r *RAG) LoadRAG(fpath string) error {
 	r.mu.Lock()
 	defer r.mu.Unlock()
@@ -95,31 +163,8 @@ func (r *RAG) LoadRAG(fpath string) error {
 	for i, s := range sentences {
 		sents[i] = s.Text
 	}
-	// Group sentences into paragraphs based on word limit
-	paragraphs := []string{}
-	par := strings.Builder{}
-	for i := 0; i < len(sents); i++ {
-		if strings.TrimSpace(sents[i]) != "" {
-			if par.Len() > 0 {
-				par.WriteString(" ")
-			}
-			par.WriteString(sents[i])
-		}
-		if wordCounter(par.String()) > int(r.cfg.RAGWordLimit) {
-			paragraph := strings.TrimSpace(par.String())
-			if paragraph != "" {
-				paragraphs = append(paragraphs, paragraph)
-			}
-			par.Reset()
-		}
-	}
-	// Handle any remaining content in the paragraph buffer
-	if par.Len() > 0 {
-		paragraph := strings.TrimSpace(par.String())
-		if paragraph != "" {
-			paragraphs = append(paragraphs, paragraph)
-		}
-	}
+	// Create chunks with overlap
+	paragraphs := createChunks(sents, r.cfg.RAGWordLimit, r.cfg.RAGOverlapWords)
 	// Adjust batch size if needed
 	if len(paragraphs) < r.cfg.RAGBatchSize && len(paragraphs) > 0 {
 		r.cfg.RAGBatchSize = len(paragraphs)
@@ -205,9 +250,15 @@ func (r *RAG) LineToVector(line string) ([]float32, error) {
 	return r.embedder.Embed(line)
 }
 
-func (r *RAG) SearchEmb(emb *models.EmbeddingResp) ([]models.VectorRow, error) {
+func (r *RAG) SearchEmb(emb *models.EmbeddingResp, limit int) ([]models.VectorRow, error) {
 	r.resetIdleTimer()
-	return r.storage.SearchClosest(emb.Embedding)
+	return r.storage.SearchClosest(emb.Embedding, limit)
+}
+
+func (r *RAG) SearchKeyword(query string, limit int) ([]models.VectorRow, error) {
+	r.resetIdleTimer()
+	sanitized := sanitizeFTSQuery(query)
+	return r.storage.SearchKeyword(sanitized, limit)
 }
 
 func (r *RAG) ListLoaded() ([]string, error) {
@@ -393,7 +444,7 @@ func (r *RAG) SynthesizeAnswer(results []models.VectorRow, query string) (string
 		Embedding: emb,
 		Index:     0,
 	}
-	topResults, err := r.SearchEmb(embResp)
+	topResults, err := r.SearchEmb(embResp, 1)
 	if err != nil {
 		r.logger.Error("failed to search for synthesis context", "error", err)
 		return "", err
@@ -422,7 +473,9 @@ func truncateString(s string, maxLen int) string {
 func (r *RAG) Search(query string, limit int) ([]models.VectorRow, error) {
 	refined := r.RefineQuery(query)
 	variations := r.GenerateQueryVariations(refined)
-	allResults := make([]models.VectorRow, 0)
+
+	// Collect embedding search results from all variations
+	var embResults []models.VectorRow
 	seen := make(map[string]bool)
 	for _, q := range variations {
 		emb, err := r.LineToVector(q)
@@ -430,29 +483,78 @@ func (r *RAG) Search(query string, limit int) ([]models.VectorRow, error) {
 			r.logger.Error("failed to embed query variation", "error", err, "query", q)
 			continue
 		}
-
 		embResp := &models.EmbeddingResp{
 			Embedding: emb,
 			Index:     0,
 		}
-
-		results, err := r.SearchEmb(embResp)
+		results, err := r.SearchEmb(embResp, limit*2) // Get more candidates
 		if err != nil {
 			r.logger.Error("failed to search embeddings", "error", err, "query", q)
 			continue
 		}
-
 		for _, row := range results {
 			if !seen[row.Slug] {
 				seen[row.Slug] = true
-				allResults = append(allResults, row)
+				embResults = append(embResults, row)
 			}
 		}
 	}
-	reranked := r.RerankResults(allResults, query)
-	if len(reranked) > limit {
-		reranked = reranked[:limit]
+	// Sort embedding results by distance (lower is better)
+	sort.Slice(embResults, func(i, j int) bool {
+		return embResults[i].Distance < embResults[j].Distance
+	})
+
+	// Perform keyword search
+	kwResults, err := r.SearchKeyword(refined, limit*2)
+	if err != nil {
+		r.logger.Warn("keyword search failed, using only embeddings", "error", err)
+		kwResults = nil
 	}
+	// Sort keyword results by distance (already sorted by BM25 score)
+	// kwResults already sorted by distance (lower is better)
+
+	// Combine using Reciprocal Rank Fusion (RRF)
+	const rrfK = 60
+	type scoredRow struct {
+		row   models.VectorRow
+		score float64
+	}
+	scoreMap := make(map[string]float64)
+	// Add embedding results
+	for rank, row := range embResults {
+		score := 1.0 / (float64(rank) + rrfK)
+		scoreMap[row.Slug] += score
+	}
+	// Add keyword results
+	for rank, row := range kwResults {
+		score := 1.0 / (float64(rank) + rrfK)
+		scoreMap[row.Slug] += score
+		// Ensure row exists in combined results
+		if _, exists := seen[row.Slug]; !exists {
+			embResults = append(embResults, row)
+		}
+	}
+	// Create slice of scored rows
+	scoredRows := make([]scoredRow, 0, len(embResults))
+	for _, row := range embResults {
+		score := scoreMap[row.Slug]
+		scoredRows = append(scoredRows, scoredRow{row: row, score: score})
+	}
+	// Sort by descending RRF score
+	sort.Slice(scoredRows, func(i, j int) bool {
+		return scoredRows[i].score > scoredRows[j].score
+	})
+	// Take top limit
+	if len(scoredRows) > limit {
+		scoredRows = scoredRows[:limit]
+	}
+	// Convert back to VectorRow
+	finalResults := make([]models.VectorRow, len(scoredRows))
+	for i, sr := range scoredRows {
+		finalResults[i] = sr.row
+	}
+	// Apply reranking heuristics
+	reranked := r.RerankResults(finalResults, query)
 	return reranked, nil
 }
 

rag/storage.go

@@ -62,6 +62,18 @@ func (vs *VectorStorage) WriteVector(row *models.VectorRow) error {
 	if err != nil {
 		return err
 	}
+	embeddingSize := len(row.Embeddings)
+
+	// Start transaction
+	tx, err := vs.sqlxDB.Beginx()
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			tx.Rollback()
+		}
+	}()
 
 	// Serialize the embeddings to binary
 	serializedEmbeddings := SerializeVector(row.Embeddings)
@@ -69,10 +81,23 @@ func (vs *VectorStorage) WriteVector(row *models.VectorRow) error {
 		"INSERT INTO %s (embeddings, slug, raw_text, filename) VALUES (?, ?, ?, ?)",
 		tableName,
 	)
-	if _, err := vs.sqlxDB.Exec(query, serializedEmbeddings, row.Slug, row.RawText, row.FileName); err != nil {
+	if _, err := tx.Exec(query, serializedEmbeddings, row.Slug, row.RawText, row.FileName); err != nil {
 		vs.logger.Error("failed to write vector", "error", err, "slug", row.Slug)
 		return err
 	}
+
+	// Insert into FTS table
+	ftsQuery := `INSERT INTO fts_embeddings (slug, raw_text, filename, embedding_size) VALUES (?, ?, ?, ?)`
+	if _, err := tx.Exec(ftsQuery, row.Slug, row.RawText, row.FileName, embeddingSize); err != nil {
+		vs.logger.Error("failed to write to FTS table", "error", err, "slug", row.Slug)
+		return err
+	}
+
+	err = tx.Commit()
+	if err != nil {
+		vs.logger.Error("failed to commit transaction", "error", err)
+		return err
+	}
 	return nil
 }
 
@@ -98,16 +123,15 @@ func (vs *VectorStorage) getTableName(emb []float32) (string, error) {
 }
 
 // SearchClosest finds vectors closest to the query vector using efficient cosine similarity calculation
-func (vs *VectorStorage) SearchClosest(query []float32) ([]models.VectorRow, error) {
+func (vs *VectorStorage) SearchClosest(query []float32, limit int) ([]models.VectorRow, error) {
+	if limit <= 0 {
+		limit = 10
+	}
 	tableName, err := vs.getTableName(query)
 	if err != nil {
 		return nil, err
 	}
 
-	// For better performance, instead of loading all vectors at once,
-	// we'll implement batching and potentially add L2 distance-based pre-filtering
-	// since cosine similarity is related to L2 distance for normalized vectors
-
 	querySQL := "SELECT embeddings, slug, raw_text, filename FROM " + tableName
 	rows, err := vs.sqlxDB.Query(querySQL)
 	if err != nil {
@@ -115,13 +139,11 @@ func (vs *VectorStorage) SearchClosest(query []float32) ([]models.VectorRow, err
 	}
 	defer rows.Close()
 
-	// Use a min-heap or simple slice to keep track of top 3 closest vectors
 	type SearchResult struct {
 		vector   models.VectorRow
 		distance float32
 	}
 	var topResults []SearchResult
-	// Process vectors one by one to avoid loading everything into memory
 	for rows.Next() {
 		var (
 			embeddingsBlob          []byte
@@ -134,10 +156,8 @@ func (vs *VectorStorage) SearchClosest(query []float32) ([]models.VectorRow, err
 		}
 
 		storedEmbeddings := DeserializeVector(embeddingsBlob)
-
-		// Calculate cosine similarity (returns value between -1 and 1, where 1 is most similar)
 		similarity := cosineSimilarity(query, storedEmbeddings)
-		distance := 1 - similarity // Convert to distance where 0 is most similar
+		distance := 1 - similarity
 
 		result := SearchResult{
 			vector: models.VectorRow{
@@ -149,20 +169,15 @@ func (vs *VectorStorage) SearchClosest(query []float32) ([]models.VectorRow, err
 			distance: distance,
 		}
 
-		// Add to top results and maintain only top 3
 		topResults = append(topResults, result)
-
-		// Sort and keep only top 3
 		sort.Slice(topResults, func(i, j int) bool {
 			return topResults[i].distance < topResults[j].distance
 		})
-
-		if len(topResults) > 3 {
-			topResults = topResults[:3] // Keep only closest 3
+		if len(topResults) > limit {
+			topResults = topResults[:limit]
 		}
 	}
 
-	// Convert back to VectorRow slice
 	results := make([]models.VectorRow, 0, len(topResults))
 	for _, result := range topResults {
 		result.vector.Distance = result.distance
@@ -171,6 +186,70 @@ func (vs *VectorStorage) SearchClosest(query []float32) ([]models.VectorRow, err
 	return results, nil
 }
 
+// GetVectorBySlug retrieves a vector row by its slug
+func (vs *VectorStorage) GetVectorBySlug(slug string) (*models.VectorRow, error) {
+	embeddingSizes := []int{384, 768, 1024, 1536, 2048, 3072, 4096, 5120}
+	for _, size := range embeddingSizes {
+		table := fmt.Sprintf("embeddings_%d", size)
+		query := fmt.Sprintf("SELECT embeddings, slug, raw_text, filename FROM %s WHERE slug = ?", table)
+		row := vs.sqlxDB.QueryRow(query, slug)
+		var (
+			embeddingsBlob                   []byte
+			retrievedSlug, rawText, fileName string
+		)
+		if err := row.Scan(&embeddingsBlob, &retrievedSlug, &rawText, &fileName); err != nil {
+			// No row in this table, continue to next size
+			continue
+		}
+		storedEmbeddings := DeserializeVector(embeddingsBlob)
+		return &models.VectorRow{
+			Embeddings: storedEmbeddings,
+			Slug:       retrievedSlug,
+			RawText:    rawText,
+			FileName:   fileName,
+		}, nil
+	}
+	return nil, fmt.Errorf("vector with slug %s not found", slug)
+}
+
+// SearchKeyword performs full-text search using FTS5
+func (vs *VectorStorage) SearchKeyword(query string, limit int) ([]models.VectorRow, error) {
+	// Use FTS5 bm25 ranking. bm25 returns negative values where more negative is better.
+	// We'll order by bm25 (ascending) and limit.
+	ftsQuery := `SELECT slug, raw_text, filename, bm25(fts_embeddings) as score 
+				 FROM fts_embeddings 
+				 WHERE fts_embeddings MATCH ? 
+				 ORDER BY score 
+				 LIMIT ?`
+	rows, err := vs.sqlxDB.Query(ftsQuery, query, limit)
+	if err != nil {
+		return nil, fmt.Errorf("FTS search failed: %w", err)
+	}
+	defer rows.Close()
+	var results []models.VectorRow
+	for rows.Next() {
+		var slug, rawText, fileName string
+		var score float64
+		if err := rows.Scan(&slug, &rawText, &fileName, &score); err != nil {
+			vs.logger.Error("failed to scan FTS row", "error", err)
+			continue
+		}
+		// Convert BM25 score to distance-like metric (lower is better)
+		// BM25 is negative, more negative is better. We'll normalize to positive distance.
+		distance := float32(-score) // Make positive (since score is negative)
+		if distance < 0 {
+			distance = 0
+		}
+		results = append(results, models.VectorRow{
+			Slug:     slug,
+			RawText:  rawText,
+			FileName: fileName,
+			Distance: distance,
+		})
+	}
+	return results, nil
+}
+
 // ListFiles returns a list of all loaded files
 func (vs *VectorStorage) ListFiles() ([]string, error) {
 	fileLists := make([][]string, 0)
@@ -215,6 +294,10 @@ func (vs *VectorStorage) ListFiles() ([]string, error) {
 // RemoveEmbByFileName removes all embeddings associated with a specific filename
 func (vs *VectorStorage) RemoveEmbByFileName(filename string) error {
 	var errors []string
+	// Delete from FTS table first
+	if _, err := vs.sqlxDB.Exec("DELETE FROM fts_embeddings WHERE filename = ?", filename); err != nil {
+		errors = append(errors, err.Error())
+	}
 	embeddingSizes := []int{384, 768, 1024, 1536, 2048, 3072, 4096, 5120}
 	for _, size := range embeddingSizes {
 		table := fmt.Sprintf("embeddings_%d", size)

storage/migrations/003_add_fts.down.sql

@@ -0,0 +1,2 @@
+-- Drop FTS5 virtual table
+DROP TABLE IF EXISTS fts_embeddings;

storage/migrations/003_add_fts.up.sql

@@ -0,0 +1,15 @@
+-- Create FTS5 virtual table for full-text search
+CREATE VIRTUAL TABLE IF NOT EXISTS fts_embeddings USING fts5(
+    slug UNINDEXED,
+    raw_text,
+    filename UNINDEXED,
+    embedding_size UNINDEXED,
+    tokenize='porter unicode61'  -- Use porter stemmer and unicode61 tokenizer
+);
+
+-- Create triggers to maintain FTS table when embeddings are inserted/deleted
+-- Note: We'll handle inserts/deletes programmatically for simplicity
+-- but triggers could be added here if needed.
+
+-- Indexes for performance (FTS5 manages its own indexes)
+-- No additional indexes needed for FTS5 virtual table.

storage/migrations/004_populate_fts.down.sql

@@ -0,0 +1,2 @@
+-- Clear FTS table (optional)
+DELETE FROM fts_embeddings;

storage/migrations/004_populate_fts.up.sql

@@ -0,0 +1,26 @@
+-- Populate FTS table with existing embeddings
+DELETE FROM fts_embeddings;
+
+INSERT INTO fts_embeddings (slug, raw_text, filename, embedding_size)
+SELECT slug, raw_text, filename, 384 FROM embeddings_384;
+
+INSERT INTO fts_embeddings (slug, raw_text, filename, embedding_size)
+SELECT slug, raw_text, filename, 768 FROM embeddings_768;
+
+INSERT INTO fts_embeddings (slug, raw_text, filename, embedding_size)
+SELECT slug, raw_text, filename, 1024 FROM embeddings_1024;
+
+INSERT INTO fts_embeddings (slug, raw_text, filename, embedding_size)
+SELECT slug, raw_text, filename, 1536 FROM embeddings_1536;
+
+INSERT INTO fts_embeddings (slug, raw_text, filename, embedding_size)
+SELECT slug, raw_text, filename, 2048 FROM embeddings_2048;
+
+INSERT INTO fts_embeddings (slug, raw_text, filename, embedding_size)
+SELECT slug, raw_text, filename, 3072 FROM embeddings_3072;
+
+INSERT INTO fts_embeddings (slug, raw_text, filename, embedding_size)
+SELECT slug, raw_text, filename, 4096 FROM embeddings_4096;
+
+INSERT INTO fts_embeddings (slug, raw_text, filename, embedding_size)
+SELECT slug, raw_text, filename, 5120 FROM embeddings_5120;

storage/vector.go

@@ -4,6 +4,7 @@ import (
 	"encoding/binary"
 	"fmt"
 	"gf-lt/models"
+	"sort"
 	"unsafe"
 
 	"github.com/jmoiron/sqlx"
@@ -11,7 +12,7 @@ import (
 
 type VectorRepo interface {
 	WriteVector(*models.VectorRow) error
-	SearchClosest(q []float32) ([]models.VectorRow, error)
+	SearchClosest(q []float32, limit int) ([]models.VectorRow, error)
 	ListFiles() ([]string, error)
 	RemoveEmbByFileName(filename string) error
 	DB() *sqlx.DB
@@ -79,7 +80,7 @@ func (p ProviderSQL) WriteVector(row *models.VectorRow) error {
 	return err
 }
 
-func (p ProviderSQL) SearchClosest(q []float32) ([]models.VectorRow, error) {
+func (p ProviderSQL) SearchClosest(q []float32, limit int) ([]models.VectorRow, error) {
 	tableName, err := fetchTableName(q)
 	if err != nil {
 		return nil, err
@@ -94,7 +95,7 @@ func (p ProviderSQL) SearchClosest(q []float32) ([]models.VectorRow, error) {
 		vector   models.VectorRow
 		distance float32
 	}
-	var topResults []SearchResult
+	var allResults []SearchResult
 	for rows.Next() {
 		var (
 			embeddingsBlob          []byte
@@ -119,28 +120,19 @@ func (p ProviderSQL) SearchClosest(q []float32) ([]models.VectorRow, error) {
 			},
 			distance: distance,
 		}
-
-		// Add to top results and maintain only top results
-		topResults = append(topResults, result)
-
-		// Sort and keep only top results
-		// We'll keep the top 3 closest vectors
-		if len(topResults) > 3 {
-			// Simple sort and truncate to maintain only 3 best matches
-			for i := 0; i < len(topResults); i++ {
-				for j := i + 1; j < len(topResults); j++ {
-					if topResults[i].distance > topResults[j].distance {
-						topResults[i], topResults[j] = topResults[j], topResults[i]
+		allResults = append(allResults, result)
 	}
+	// Sort by distance
+	sort.Slice(allResults, func(i, j int) bool {
+		return allResults[i].distance < allResults[j].distance
+	})
+	// Truncate to limit
+	if len(allResults) > limit {
+		allResults = allResults[:limit]
 	}
-			}
-			topResults = topResults[:3]
-		}
-	}
-
 	// Convert back to VectorRow slice
-	results := make([]models.VectorRow, len(topResults))
-	for i, result := range topResults {
+	results := make([]models.VectorRow, len(allResults))
+	for i, result := range allResults {
 		result.vector.Distance = result.distance
 		results[i] = result.vector
 	}