From 21470ed28c49787783cbbe799613b2bd92f8a464 Mon Sep 17 00:00:00 2001 From: lacerate551 <128470311+lacerate551@users.noreply.github.com> Date: Sun, 21 Jun 2026 15:37:37 +0800 Subject: [PATCH] =?UTF-8?q?fix:=20=E8=AF=AD=E4=B9=89=E7=BC=93=E5=AD=98?= =?UTF-8?q?=E8=AF=AF=E5=91=BD=E4=B8=AD=E4=BF=AE=E5=A4=8D=20=E2=80=94=20?= =?UTF-8?q?=E4=BA=8C=E6=AC=A1=20Jaccard=20=E9=AA=8C=E8=AF=81=20+=20query-o?= =?UTF-8?q?nly=20embedding?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 问题: 同会话中语义相近但不同的问题(如"总体要求"vs"工作流程和规范要求") 会错误命中缓存，返回上一个问题的答案。 修复: - intent_analyzer: 缓存 embedding 改用 query-only(不含历史)，避免上下文污染 - intent_analyzer + chat_routes: 缓存读取增加字符级 Jaccard 二次验证(阈值0.5) - 缓存写入存储 _raw_query 供二次验证比对 - 兼容旧缓存条目(无 _raw_query 时放行) --- api/chat_routes.py | 66 +++++++++++++++++++++++++---------------- core/intent_analyzer.py | 58 ++++++++++++++++++++++++++++++------ 2 files changed, 89 insertions(+), 35 deletions(-) diff --git a/api/chat_routes.py b/api/chat_routes.py index ee3434a..2bbb380 100644 --- a/api/chat_routes.py +++ b/api/chat_routes.py @@ -2298,32 +2298,45 @@ def rag(): cached = _sc.get(_semantic_cache_emb) # 防御性校验：必须是 RAG 回答缓存（非 intent_analyzer 缓存），且回答非空 if cached is not None and cached.get("cache_type") == "rag_answer" and cached.get("answer"): - logger.info(f"[语义缓存] 命中: {message[:50]}...") - cached_answer = cached.get("answer", "") - # 流式返回缓存的答案 - yield f"data: {json.dumps({'type': 'start', 'message': '正在检索知识库...'}, ensure_ascii=False)}\n\n" - # 分块发送缓存答案 - chunk_size = 20 - for i in range(0, len(cached_answer), chunk_size): - chunk = cached_answer[i:i+chunk_size] - full_answer.append(chunk) - yield f"data: {json.dumps({'type': 'chunk', 'content': chunk}, ensure_ascii=False)}\n\n" - finish_event = { - "type": "finish", - "answer": cached_answer, - "mode": "rag", - "session_id": session_id, - "sources": cached.get("sources", []), - "citations": cached.get("citations", []), - "images": cached.get("images", []), - "tables": cached.get("tables", []), - "sections": [], - "duration_ms": int((_time.time() - start_time) * 1000), - "confidence_score": 1.0, - "semantic_cache_hit": True - } - yield f"data: {json.dumps(finish_event, ensure_ascii=False)}\n\n" - return + # 二次验证：检查原始查询文本相似度，防止语义相近但不同问题误命中 + _cached_query = cached.get("_raw_query", "") + if _cached_query: + _qa, _qb = set(retrieval_query), set(_cached_query) + _jaccard = len(_qa & _qb) / len(_qa | _qb) if (_qa and _qb) else 0 + if _jaccard < 0.5: + logger.info( + f"[语义缓存] 二次验证拒绝 (Jaccard={_jaccard:.2f}): " + f"query='{retrieval_query[:30]}' vs cached='{_cached_query[:30]}'" + ) + cached = None # 拒绝命中，继续正常流程 + # 通过验证（或旧缓存无 _raw_query 字段兼容放行） + if cached is not None and cached.get("cache_type") == "rag_answer" and cached.get("answer"): + logger.info(f"[语义缓存] 命中: {message[:50]}...") + cached_answer = cached.get("answer", "") + # 流式返回缓存的答案 + yield f"data: {json.dumps({'type': 'start', 'message': '正在检索知识库...'}, ensure_ascii=False)}\n\n" + # 分块发送缓存答案 + chunk_size = 20 + for i in range(0, len(cached_answer), chunk_size): + chunk = cached_answer[i:i+chunk_size] + full_answer.append(chunk) + yield f"data: {json.dumps({'type': 'chunk', 'content': chunk}, ensure_ascii=False)}\n\n" + finish_event = { + "type": "finish", + "answer": cached_answer, + "mode": "rag", + "session_id": session_id, + "sources": cached.get("sources", []), + "citations": cached.get("citations", []), + "images": cached.get("images", []), + "tables": cached.get("tables", []), + "sections": [], + "duration_ms": int((_time.time() - start_time) * 1000), + "confidence_score": 1.0, + "semantic_cache_hit": True + } + yield f"data: {json.dumps(finish_event, ensure_ascii=False)}\n\n" + return except Exception as e: logger.warning(f"[语义缓存] 检查失败: {e}") _semantic_cache_emb = None @@ -2886,6 +2899,7 @@ def rag(): "citations": citation_result.get("citations", []), "images": rich_media.get("images", []), "tables": rich_media.get("tables", []), + "_raw_query": retrieval_query, }) logger.debug(f"[语义缓存] 写入成功: {message[:50]}...") except Exception as e: diff --git a/core/intent_analyzer.py b/core/intent_analyzer.py index 78edb0a..296f47d 100644 --- a/core/intent_analyzer.py +++ b/core/intent_analyzer.py @@ -308,18 +308,30 @@ class IntentAnalyzer: return self._exact_cache[exact_key] # 2. 尝试从语义缓存获取 + # 关键：语义缓存只用原始 query 做 embedding（不含历史）， + # 避免同会话中不同问题因历史上下文污染导致误命中 cache = self._get_cache() if cache: - # 使用 query + 历史关键信息作为缓存键 - cache_key = self._build_cache_key(query, history) - cache_emb = self._get_embedding(cache_key) + query_emb = self._get_embedding(query) - if cache_emb is not None: - cached = cache.get(cache_emb) + if query_emb is not None: + cached = cache.get(query_emb) # 确保缓存条目是意图分析结果（非 RAG 回答缓存） if cached and cached.get("cache_type") != "rag_answer": - logger.info(f"意图分析缓存命中: {cached.get('reason', '')[:50]}") - return IntentAnalysis.from_dict(cached) + # 二次验证：检查原始 query 文本相似度 + cached_query = cached.get("_raw_query", "") + if cached_query and self._query_text_similar(query, cached_query): + logger.info(f"意图分析缓存命中: {cached.get('reason', '')[:50]}") + return IntentAnalysis.from_dict(cached) + elif cached_query: + logger.info( + f"意图分析缓存二次验证拒绝: " + f"query='{query[:30]}' vs cached='{cached_query[:30]}'" + ) + else: + # 旧缓存无 _raw_query 字段，兼容放行 + logger.info(f"意图分析缓存命中(无验证): {cached.get('reason', '')[:50]}") + return IntentAnalysis.from_dict(cached) else: logger.debug(f"意图分析缓存未命中，缓存状态: {cache.get_stats()}") else: @@ -388,10 +400,12 @@ class IntentAnalyzer: ) # 存入语义缓存（标记类型，避免与 RAG 回答缓存混淆） - if cache and cache_emb is not None: + # 使用仅含 query 的 embedding，不含历史，防止同会话误命中 + if cache and query_emb is not None: cache_data = analysis.to_dict() cache_data["cache_type"] = "intent_analysis" - cache.set(cache_emb, cache_data) + cache_data["_raw_query"] = query # 供二次验证使用 + cache.set(query_emb, cache_data) # 存入精确匹配缓存 if len(self._exact_cache) < self._exact_cache_max: @@ -431,6 +445,32 @@ class IntentAnalyzer: return " | ".join(parts) + @staticmethod + def _query_text_similar(query: str, cached_query: str, threshold: float = 0.5) -> bool: + """ + 判断两个 query 文本是否足够相似（字符级 Jaccard）。 + 用于语义缓存命中后的二次验证，防止语义相近但实际意图不同的问题误命中。 + + Args: + query: 当前查询 + cached_query: 缓存中的原始查询 + threshold: 相似度阈值，默认 0.5 + + Returns: + True 表示足够相似，可以命中缓存 + """ + # 精确匹配快速路径 + if query.strip() == cached_query.strip(): + return True + # 字符级 Jaccard 相似度 + set_a = set(query) + set_b = set(cached_query) + if not set_a or not set_b: + return False + intersection = len(set_a & set_b) + union = len(set_a | set_b) + return (intersection / union) >= threshold + def _build_history_summary( self, history: List[dict],