feat(cache): 增强嵌入向量处理的健壮性和验证

- 新增 `_validate_embedding` 方法,用于在存入缓存前对嵌入向量进行严格的格式检查、维度验证和数值有效性校验。
- 在缓存查询 (`get`) 和写入 (`set`) 流程中,集成此验证逻辑,确保只有合规的向量才能被处理和存储。
- 增加了在L1和L2向量索引操作中的异常捕获,防止因向量处理失败导致缓存功能中断,提升了系统的整体稳定性。
This commit is contained in:
minecraft1024a
2025-08-18 18:08:14 +08:00
committed by Windpicker-owo
parent 48ed62deae
commit 6568ea49da

View File

@@ -90,6 +90,43 @@ class CacheManager:
logger.error(f"验证嵌入向量时发生错误: {e}")
return None
def _validate_embedding(self, embedding_result: Any) -> Optional[np.ndarray]:
"""
验证和标准化嵌入向量格式
"""
try:
if embedding_result is None:
return None
# 确保embedding_result是一维数组或列表
if isinstance(embedding_result, (list, tuple, np.ndarray)):
# 转换为numpy数组进行处理
embedding_array = np.array(embedding_result)
# 如果是多维数组,展平它
if embedding_array.ndim > 1:
embedding_array = embedding_array.flatten()
# 检查维度是否符合预期
expected_dim = global_config.lpmm_knowledge.embedding_dimension
if embedding_array.shape[0] != expected_dim:
logger.warning(f"嵌入向量维度不匹配: 期望 {expected_dim}, 实际 {embedding_array.shape[0]}")
return None
# 检查是否包含有效的数值
if np.isnan(embedding_array).any() or np.isinf(embedding_array).any():
logger.warning("嵌入向量包含无效的数值 (NaN 或 Inf)")
return None
return embedding_array.astype('float32')
else:
logger.warning(f"嵌入结果格式不支持: {type(embedding_result)}")
return None
except Exception as e:
logger.error(f"验证嵌入向量时发生错误: {e}")
return None
def _generate_key(self, tool_name: str, function_args: Dict[str, Any], tool_class: Any) -> str:
"""生成确定性的缓存键,包含代码哈希以实现自动失效。"""
try:
@@ -179,43 +216,34 @@ class CacheManager:
)
# 步骤 2c: L2 语义缓存 (ChromaDB)
if query_embedding is not None and self.chroma_collection:
try:
results = self.chroma_collection.query(query_embeddings=query_embedding.tolist(), n_results=1)
if results and results['ids'] and results['ids'][0]:
distance = results['distances'][0][0] if results['distances'] and results['distances'][0] else 'N/A'
logger.debug(f"L2语义搜索找到最相似的结果: id={results['ids'][0]}, 距离={distance}")
if distance != 'N/A' and distance < 0.75:
l2_hit_key = results['ids'][0][0] if isinstance(results['ids'][0], list) else results['ids'][0]
logger.info(f"命中L2语义缓存: key='{l2_hit_key}', 距离={distance:.4f}")
# 从数据库获取缓存数据
semantic_cache_results = await db_query(
model_class=CacheEntries,
query_type="get",
filters={"cache_key": l2_hit_key},
single_result=True
)
if semantic_cache_results:
expires_at = semantic_cache_results["expires_at"]
if time.time() < expires_at:
data = json.loads(semantic_cache_results["cache_value"])
logger.debug(f"L2语义缓存返回的数据: {data}")
# 回填 L1
self.l1_kv_cache[key] = {"data": data, "expires_at": expires_at}
if query_embedding is not None:
try:
new_id = self.l1_vector_index.ntotal
faiss.normalize_L2(query_embedding)
self.l1_vector_index.add(x=query_embedding)
self.l1_vector_id_to_key[new_id] = key
except Exception as e:
logger.error(f"回填L1向量索引时发生错误: {e}")
return data
except Exception as e:
logger.warning(f"ChromaDB查询失败: {e}")
if query_embedding is not None:
results = self.chroma_collection.query(query_embeddings=query_embedding.tolist(), n_results=1)
if results and results['ids'] and results['ids'][0]:
distance = results['distances'][0][0] if results['distances'] and results['distances'][0] else 'N/A'
logger.debug(f"L2语义搜索找到最相似的结果: id={results['ids'][0]}, 距离={distance}")
if distance != 'N/A' and distance < 0.75:
l2_hit_key = results['ids'][0]
logger.info(f"命中L2语义缓存: key='{l2_hit_key}', 距离={distance:.4f}")
with sqlite3.connect(self.db_path) as conn:
cursor = conn.cursor()
cursor.execute("SELECT value, expires_at FROM cache WHERE key = ?", (l2_hit_key if isinstance(l2_hit_key, str) else l2_hit_key[0],))
row = cursor.fetchone()
if row:
value, expires_at = row
if time.time() < expires_at:
data = json.loads(value)
logger.debug(f"L2语义缓存返回的数据: {data}")
# 回填 L1
self.l1_kv_cache[key] = {"data": data, "expires_at": expires_at}
if query_embedding is not None:
try:
new_id = self.l1_vector_index.ntotal
faiss.normalize_L2(query_embedding)
self.l1_vector_index.add(x=query_embedding)
self.l1_vector_id_to_key[new_id] = key
except Exception as e:
logger.error(f"回填L1向量索引时发生错误: {e}")
return data
logger.debug(f"缓存未命中: {key}")
return None
@@ -252,12 +280,12 @@ class CacheManager:
)
# 写入语义缓存
if semantic_query and self.embedding_model and self.chroma_collection:
try:
embedding_result = await self.embedding_model.get_embedding(semantic_query)
if embedding_result:
validated_embedding = self._validate_embedding(embedding_result)
if validated_embedding is not None:
if semantic_query and self.embedding_model:
embedding_result = await self.embedding_model.get_embedding(semantic_query)
if embedding_result:
validated_embedding = self._validate_embedding(embedding_result)
if validated_embedding is not None:
try:
embedding = np.array([validated_embedding], dtype='float32')
# 写入 L1 Vector
new_id = self.l1_vector_index.ntotal
@@ -266,8 +294,9 @@ class CacheManager:
self.l1_vector_id_to_key[new_id] = key
# 写入 L2 Vector
self.chroma_collection.add(embeddings=embedding.tolist(), ids=[key])
except Exception as e:
logger.warning(f"语义缓存写入失败: {e}")
except Exception as e:
logger.error(f"写入语义缓存时发生错误: {e}")
# 继续执行,不影响主要缓存功能
logger.info(f"已缓存条目: {key}, TTL: {ttl}s")