Files
gf-lt/rag/storage.go
2025-11-22 15:31:46 +03:00

318 lines
8.4 KiB
Go

package rag
import (
"encoding/binary"
"fmt"
"gf-lt/models"
"gf-lt/storage"
"log/slog"
"sort"
"strings"
"unsafe"
"github.com/jmoiron/sqlx"
)
// VectorStorage handles storing and retrieving vectors from SQLite
type VectorStorage struct {
logger *slog.Logger
sqlxDB *sqlx.DB
store storage.FullRepo
}
func NewVectorStorage(logger *slog.Logger, store storage.FullRepo) *VectorStorage {
return &VectorStorage{
logger: logger,
sqlxDB: store.DB(), // Use the new DB() method
store: store,
}
}
// CreateTables creates the necessary tables for vector storage
func (vs *VectorStorage) CreateTables() error {
// Create tables for common embedding dimensions
embeddingSizes := []int{384, 768, 1024, 1536, 2048, 3072, 4096, 5120}
// Pre-allocate queries slice: each embedding size needs 1 table + 3 indexes = 4 queries per size
queries := make([]string, 0, len(embeddingSizes)*4)
// Generate table creation queries for each embedding size
for _, size := range embeddingSizes {
tableName := fmt.Sprintf("embeddings_%d", size)
queries = append(queries,
fmt.Sprintf(`CREATE TABLE IF NOT EXISTS %s (
id INTEGER PRIMARY KEY AUTOINCREMENT,
embeddings BLOB NOT NULL,
slug TEXT NOT NULL,
raw_text TEXT NOT NULL,
filename TEXT NOT NULL,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
)`, tableName),
)
}
// Add indexes for all supported sizes
for _, size := range embeddingSizes {
tableName := fmt.Sprintf("embeddings_%d", size)
queries = append(queries,
fmt.Sprintf(`CREATE INDEX IF NOT EXISTS idx_%s_filename ON %s(filename)`, tableName, tableName),
fmt.Sprintf(`CREATE INDEX IF NOT EXISTS idx_%s_slug ON %s(slug)`, tableName, tableName),
fmt.Sprintf(`CREATE INDEX IF NOT EXISTS idx_%s_created_at ON %s(created_at)`, tableName, tableName),
)
}
for _, query := range queries {
if _, err := vs.sqlxDB.Exec(query); err != nil {
return fmt.Errorf("failed to create table: %w", err)
}
}
return nil
}
// SerializeVector converts []float32 to binary blob
func SerializeVector(vec []float32) []byte {
buf := make([]byte, len(vec)*4) // 4 bytes per float32
for i, v := range vec {
binary.LittleEndian.PutUint32(buf[i*4:], mathFloat32bits(v))
}
return buf
}
// DeserializeVector converts binary blob back to []float32
func DeserializeVector(data []byte) []float32 {
count := len(data) / 4
vec := make([]float32, count)
for i := 0; i < count; i++ {
vec[i] = mathBitsToFloat32(binary.LittleEndian.Uint32(data[i*4:]))
}
return vec
}
// mathFloat32bits and mathBitsToFloat32 are helpers to convert between float32 and uint32
func mathFloat32bits(f float32) uint32 {
return binary.LittleEndian.Uint32((*(*[4]byte)(unsafe.Pointer(&f)))[:4])
}
func mathBitsToFloat32(b uint32) float32 {
return *(*float32)(unsafe.Pointer(&b))
}
// WriteVector stores an embedding vector in the database
func (vs *VectorStorage) WriteVector(row *models.VectorRow) error {
tableName, err := vs.getTableName(row.Embeddings)
if err != nil {
return err
}
// Serialize the embeddings to binary
serializedEmbeddings := SerializeVector(row.Embeddings)
query := fmt.Sprintf(
"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 {
vs.logger.Error("failed to write vector", "error", err, "slug", row.Slug)
return err
}
return nil
}
// getTableName determines which table to use based on embedding size
func (vs *VectorStorage) getTableName(emb []float32) (string, error) {
size := len(emb)
// Check if we support this embedding size
supportedSizes := map[int]bool{
384: true,
768: true,
1024: true,
1536: true,
2048: true,
3072: true,
4096: true,
5120: true,
}
if supportedSizes[size] {
return fmt.Sprintf("embeddings_%d", size), nil
}
return "", fmt.Errorf("no table for embedding size of %d", size)
}
// SearchClosest finds vectors closest to the query vector using efficient cosine similarity calculation
func (vs *VectorStorage) SearchClosest(query []float32) ([]models.VectorRow, error) {
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 {
return nil, 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
slug, rawText, fileName string
)
if err := rows.Scan(&embeddingsBlob, &slug, &rawText, &fileName); err != nil {
vs.logger.Error("failed to scan row", "error", err)
continue
}
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
result := SearchResult{
vector: models.VectorRow{
Embeddings: storedEmbeddings,
Slug: slug,
RawText: rawText,
FileName: fileName,
},
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
}
}
// Convert back to VectorRow slice
results := make([]models.VectorRow, 0, len(topResults))
for _, result := range topResults {
result.vector.Distance = result.distance
results = append(results, result.vector)
}
return results, nil
}
// ListFiles returns a list of all loaded files
func (vs *VectorStorage) ListFiles() ([]string, error) {
fileLists := make([][]string, 0)
// Query all supported tables and combine results
embeddingSizes := []int{384, 768, 1024, 1536, 2048, 3072, 4096, 5120}
for _, size := range embeddingSizes {
table := fmt.Sprintf("embeddings_%d", size)
query := "SELECT DISTINCT filename FROM " + table
rows, err := vs.sqlxDB.Query(query)
if err != nil {
// Continue if one table doesn't exist
continue
}
var files []string
for rows.Next() {
var filename string
if err := rows.Scan(&filename); err != nil {
continue
}
files = append(files, filename)
}
rows.Close()
fileLists = append(fileLists, files)
}
// Combine and deduplicate
fileSet := make(map[string]bool)
var allFiles []string
for _, files := range fileLists {
for _, file := range files {
if !fileSet[file] {
fileSet[file] = true
allFiles = append(allFiles, file)
}
}
}
return allFiles, nil
}
// RemoveEmbByFileName removes all embeddings associated with a specific filename
func (vs *VectorStorage) RemoveEmbByFileName(filename string) error {
var errors []string
embeddingSizes := []int{384, 768, 1024, 1536, 2048, 3072, 4096, 5120}
for _, size := range embeddingSizes {
table := fmt.Sprintf("embeddings_%d", size)
query := fmt.Sprintf("DELETE FROM %s WHERE filename = ?", table)
if _, err := vs.sqlxDB.Exec(query, filename); err != nil {
errors = append(errors, err.Error())
}
}
if len(errors) > 0 {
return fmt.Errorf("errors occurred: %s", strings.Join(errors, "; "))
}
return nil
}
// cosineSimilarity calculates the cosine similarity between two vectors
func cosineSimilarity(a, b []float32) float32 {
if len(a) != len(b) {
return 0.0
}
var dotProduct, normA, normB float32
for i := 0; i < len(a); i++ {
dotProduct += a[i] * b[i]
normA += a[i] * a[i]
normB += b[i] * b[i]
}
if normA == 0 || normB == 0 {
return 0.0
}
return dotProduct / (sqrt(normA) * sqrt(normB))
}
// sqrt returns the square root of a float32
func sqrt(f float32) float32 {
// A simple implementation of square root using Newton's method
if f == 0 {
return 0
}
guess := f / 2
for i := 0; i < 10; i++ { // 10 iterations should be enough for good precision
guess = (guess + f/guess) / 2
}
return guess
}