MS-151 Fix topk problem

Former-commit-id: ead499ba9f5f152a6c2f9d0c6e2578f6f3a80f8e

cpp/src/db/FaissExecutionEngine.cpp

@@ -138,7 +138,6 @@ Status FaissExecutionEngine::Search(long n,
     auto start_time = METRICS_NOW_TIME;
 
     std::shared_ptr<faiss::IndexIVF> ivf_index = std::dynamic_pointer_cast<faiss::IndexIVF>(pIndex_);
-    //ENGINE_LOG_DEBUG << "Index nlist: " << ivf_index->nlist << ", ntotal: "<< ivf_index->ntotal;
     if(ivf_index) {
         ENGINE_LOG_DEBUG << "Index type: IVFFLAT nProbe: " << nprobe_;
         ivf_index->nprobe = nprobe_;

cpp/src/db/scheduler/task/SearchTask.cpp

@@ -53,7 +53,7 @@ std::shared_ptr<IScheduleTask> SearchTask::Execute() {
     std::vector<float> output_distence;
     for(auto& context : search_contexts_) {
         //step 1: allocate memory
-        auto inner_k = index_engine_->Count() < context->topk() ? index_engine_->Count() : context->topk();
+        auto inner_k = context->topk();
         output_ids.resize(inner_k*context->nq());
         output_distence.resize(inner_k*context->nq());
 
@@ -67,17 +67,9 @@ std::shared_ptr<IScheduleTask> SearchTask::Execute() {
             //step 3: cluster result
             SearchContext::ResultSet result_set;
             auto spec_k = index_engine_->Count() < context->topk() ? index_engine_->Count() : context->topk();
-            SearchTask::ClusterResult(output_ids, output_distence, context->nq(), spec_k, result_set);
+            ClusterResult(output_ids, output_distence, context->nq(), spec_k, result_set);
             rc.Record("cluster result");
 
-
-            SERVER_LOG_DEBUG << "Query Result: ";
-            for(auto& id2score_vector: result_set) {
-                for(auto& pair: id2score_vector) {
-                    SERVER_LOG_DEBUG << "id: " << pair.first << ", distance: " << pair.second;
-                }
-            }
-
             //step 4: pick up topk result
             SearchTask::TopkResult(result_set, inner_k, context->GetResult());
             rc.Record("reduce topk");