Files
CyberStrikeAI/knowledge/retriever.go
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2026-04-19 19:14:53 +08:00

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package knowledge
import (
"context"
"database/sql"
"encoding/json"
"fmt"
"math"
"sort"
"strings"
"sync"
"cyberstrike-ai/internal/config"
"github.com/cloudwego/eino/components/retriever"
"github.com/cloudwego/eino/schema"
"go.uber.org/zap"
)
// Retriever 检索器:SQLite 存向量 + Eino 嵌入,**纯向量检索**(余弦相似度、TopK、阈值),
// 实现语义与 [retriever.Retriever] 适配层 [VectorEinoRetriever] 一致。
type Retriever struct {
db *sql.DB
embedder *Embedder
config *RetrievalConfig
logger *zap.Logger
rerankMu sync.RWMutex
reranker DocumentReranker
}
// RetrievalConfig 检索配置
type RetrievalConfig struct {
TopK int
SimilarityThreshold float64
// SubIndexFilter 非空时仅检索 sub_indexes 包含该标签(逗号分隔之一)的行;空 sub_indexes 的旧行仍保留以兼容。
SubIndexFilter string
PostRetrieve config.PostRetrieveConfig
}
// NewRetriever 创建新的检索器
func NewRetriever(db *sql.DB, embedder *Embedder, config *RetrievalConfig, logger *zap.Logger) *Retriever {
return &Retriever{
db: db,
embedder: embedder,
config: config,
logger: logger,
}
}
// UpdateConfig 更新检索配置
func (r *Retriever) UpdateConfig(cfg *RetrievalConfig) {
if cfg != nil {
r.config = cfg
if r.logger != nil {
r.logger.Info("检索器配置已更新",
zap.Int("top_k", cfg.TopK),
zap.Float64("similarity_threshold", cfg.SimilarityThreshold),
zap.String("sub_index_filter", cfg.SubIndexFilter),
zap.Int("post_retrieve_prefetch_top_k", cfg.PostRetrieve.PrefetchTopK),
zap.Int("post_retrieve_max_context_chars", cfg.PostRetrieve.MaxContextChars),
zap.Int("post_retrieve_max_context_tokens", cfg.PostRetrieve.MaxContextTokens),
)
}
}
}
// SetDocumentReranker 注入可选重排器(并发安全);nil 表示禁用。
func (r *Retriever) SetDocumentReranker(rr DocumentReranker) {
if r == nil {
return
}
r.rerankMu.Lock()
defer r.rerankMu.Unlock()
r.reranker = rr
}
func (r *Retriever) documentReranker() DocumentReranker {
if r == nil {
return nil
}
r.rerankMu.RLock()
defer r.rerankMu.RUnlock()
return r.reranker
}
func cosineSimilarity(a, b []float32) float64 {
if len(a) != len(b) {
return 0.0
}
var dotProduct, normA, normB float64
for i := range a {
dotProduct += float64(a[i] * b[i])
normA += float64(a[i] * a[i])
normB += float64(b[i] * b[i])
}
if normA == 0 || normB == 0 {
return 0.0
}
return dotProduct / (math.Sqrt(normA) * math.Sqrt(normB))
}
// Search 搜索知识库。统一经 [VectorEinoRetriever]Eino retriever.Retriever 边界)。
func (r *Retriever) Search(ctx context.Context, req *SearchRequest) ([]*RetrievalResult, error) {
if req == nil {
return nil, fmt.Errorf("请求不能为空")
}
q := strings.TrimSpace(req.Query)
if q == "" {
return nil, fmt.Errorf("查询不能为空")
}
opts := r.einoRetrieverOptions(req)
docs, err := NewVectorEinoRetriever(r).Retrieve(ctx, q, opts...)
if err != nil {
return nil, err
}
return documentsToRetrievalResults(docs)
}
func (r *Retriever) einoRetrieverOptions(req *SearchRequest) []retriever.Option {
var opts []retriever.Option
if req.TopK > 0 {
opts = append(opts, retriever.WithTopK(req.TopK))
}
dsl := map[string]any{}
if strings.TrimSpace(req.RiskType) != "" {
dsl[DSLRiskType] = strings.TrimSpace(req.RiskType)
}
if req.Threshold > 0 {
dsl[DSLSimilarityThreshold] = req.Threshold
}
if strings.TrimSpace(req.SubIndexFilter) != "" {
dsl[DSLSubIndexFilter] = strings.TrimSpace(req.SubIndexFilter)
}
if len(dsl) > 0 {
opts = append(opts, retriever.WithDSLInfo(dsl))
}
return opts
}
// EinoRetrieve 直接返回 [schema.Document],供 Eino Graph / Chain 使用。
func (r *Retriever) EinoRetrieve(ctx context.Context, query string, opts ...retriever.Option) ([]*schema.Document, error) {
return NewVectorEinoRetriever(r).Retrieve(ctx, query, opts...)
}
func (r *Retriever) knowledgeEmbeddingSelectSQL(riskType, subIndexFilter string) (string, []interface{}) {
q := `SELECT e.id, e.item_id, e.chunk_index, e.chunk_text, e.embedding, e.embedding_model, e.embedding_dim, i.category, i.title
FROM knowledge_embeddings e
JOIN knowledge_base_items i ON e.item_id = i.id
WHERE 1=1`
var args []interface{}
if strings.TrimSpace(riskType) != "" {
q += ` AND TRIM(i.category) = TRIM(?) COLLATE NOCASE`
args = append(args, riskType)
}
if tag := strings.TrimSpace(subIndexFilter); tag != "" {
tag = strings.ToLower(strings.ReplaceAll(tag, " ", ""))
q += ` AND (TRIM(COALESCE(e.sub_indexes,'')) = '' OR INSTR(',' || LOWER(REPLACE(e.sub_indexes,' ','')) || ',', ',' || ? || ',') > 0)`
args = append(args, tag)
}
return q, args
}
// vectorSearch 纯向量检索:余弦相似度排序,按相似度阈值与 TopK 截断(无 BM25、无混合分、无邻块扩展)。
func (r *Retriever) vectorSearch(ctx context.Context, req *SearchRequest) ([]*RetrievalResult, error) {
if req.Query == "" {
return nil, fmt.Errorf("查询不能为空")
}
topK := req.TopK
if topK <= 0 && r.config != nil {
topK = r.config.TopK
}
if topK <= 0 {
topK = 5
}
threshold := req.Threshold
if threshold <= 0 && r.config != nil {
threshold = r.config.SimilarityThreshold
}
if threshold <= 0 {
threshold = 0.7
}
subIdxFilter := strings.TrimSpace(req.SubIndexFilter)
if subIdxFilter == "" && r.config != nil {
subIdxFilter = strings.TrimSpace(r.config.SubIndexFilter)
}
queryText := FormatQueryEmbeddingText(req.RiskType, req.Query)
queryEmbedding, err := r.embedder.EmbedText(ctx, queryText)
if err != nil {
return nil, fmt.Errorf("向量化查询失败: %w", err)
}
queryDim := len(queryEmbedding)
expectedModel := ""
if r.embedder != nil {
expectedModel = r.embedder.EmbeddingModelName()
}
sqlStr, sqlArgs := r.knowledgeEmbeddingSelectSQL(strings.TrimSpace(req.RiskType), subIdxFilter)
rows, err := r.db.QueryContext(ctx, sqlStr, sqlArgs...)
if err != nil {
return nil, fmt.Errorf("查询向量失败: %w", err)
}
defer rows.Close()
type candidate struct {
chunk *KnowledgeChunk
item *KnowledgeItem
similarity float64
}
candidates := make([]candidate, 0)
rowNum := 0
for rows.Next() {
rowNum++
if rowNum%48 == 0 {
select {
case <-ctx.Done():
return nil, ctx.Err()
default:
}
}
var chunkID, itemID, chunkText, embeddingJSON, category, title, rowModel string
var chunkIndex, rowDim int
if err := rows.Scan(&chunkID, &itemID, &chunkIndex, &chunkText, &embeddingJSON, &rowModel, &rowDim, &category, &title); err != nil {
r.logger.Warn("扫描向量失败", zap.Error(err))
continue
}
var embedding []float32
if err := json.Unmarshal([]byte(embeddingJSON), &embedding); err != nil {
r.logger.Warn("解析向量失败", zap.Error(err))
continue
}
if rowDim > 0 && len(embedding) != rowDim {
r.logger.Debug("跳过维度不一致的向量行", zap.String("chunkId", chunkID), zap.Int("rowDim", rowDim), zap.Int("got", len(embedding)))
continue
}
if queryDim > 0 && len(embedding) != queryDim {
r.logger.Debug("跳过与查询维度不一致的向量", zap.String("chunkId", chunkID), zap.Int("queryDim", queryDim), zap.Int("got", len(embedding)))
continue
}
if expectedModel != "" && strings.TrimSpace(rowModel) != "" && strings.TrimSpace(rowModel) != expectedModel {
r.logger.Debug("跳过嵌入模型不一致的行", zap.String("chunkId", chunkID), zap.String("rowModel", rowModel), zap.String("expected", expectedModel))
continue
}
similarity := cosineSimilarity(queryEmbedding, embedding)
candidates = append(candidates, candidate{
chunk: &KnowledgeChunk{
ID: chunkID,
ItemID: itemID,
ChunkIndex: chunkIndex,
ChunkText: chunkText,
Embedding: embedding,
},
item: &KnowledgeItem{
ID: itemID,
Category: category,
Title: title,
},
similarity: similarity,
})
}
sort.Slice(candidates, func(i, j int) bool {
return candidates[i].similarity > candidates[j].similarity
})
filtered := make([]candidate, 0, len(candidates))
for _, c := range candidates {
if c.similarity >= threshold {
filtered = append(filtered, c)
}
}
if len(filtered) > topK {
filtered = filtered[:topK]
}
results := make([]*RetrievalResult, len(filtered))
for i, c := range filtered {
results[i] = &RetrievalResult{
Chunk: c.chunk,
Item: c.item,
Similarity: c.similarity,
Score: c.similarity,
}
}
return results, nil
}
// AsEinoRetriever 将纯向量检索暴露为 Eino [retriever.Retriever]。
func (r *Retriever) AsEinoRetriever() retriever.Retriever {
return NewVectorEinoRetriever(r)
}