MS-507 fix performance issue when set CPU_CACHE to 16 or 64

Former-commit-id: 402b5d91a9866c38bc7dd16be1fa22de5a0b6bf8

cpp/CHANGELOG.md

@@ -5,6 +5,7 @@ Please mark all change in change log and use the ticket from JIRA.
 # Milvus 0.4.0 (2019-07-28)
 
 ## Bug
+- MS-119 - The problem of combining the log files
 - MS-411 - Fix metric unittest linking error
 - MS-412 - Fix gpu cache logical error
 - MS-416 - ExecutionEngineImpl::GpuCache has not return value cause crash
@@ -30,7 +31,7 @@ Please mark all change in change log and use the ticket from JIRA.
 - MS-493 - Knowhere unittest crash
 - MS-453 - GPU search error when nprobe set more than 1024
 - MS-510 - unittest out of memory and crashed
-- MS-119 - The problem of combining the log files
+- MS-507 - Dataset 10m-512, index type sq8，performance in-normal when set CPU_CACHE to 16 or 64
 
 ## Improvement
 - MS-327 - Clean code for milvus

cpp/src/db/engine/ExecutionEngineImpl.cpp

@@ -303,13 +303,15 @@ Status ExecutionEngineImpl::Search(long n,
 }
 
 Status ExecutionEngineImpl::Cache() {
-    zilliz::milvus::cache::CpuCacheMgr::GetInstance()->InsertItem(location_, index_);
+    cache::DataObjPtr obj = std::make_shared<cache::DataObj>(index_, PhysicalSize());
+    zilliz::milvus::cache::CpuCacheMgr::GetInstance()->InsertItem(location_, obj);
 
     return Status::OK();
 }
 
 Status ExecutionEngineImpl::GpuCache(uint64_t gpu_id) {
-    zilliz::milvus::cache::GpuCacheMgr::GetInstance(gpu_id)->InsertItem(location_, index_);
+    cache::DataObjPtr obj = std::make_shared<cache::DataObj>(index_, PhysicalSize());
+    zilliz::milvus::cache::GpuCacheMgr::GetInstance(gpu_id)->InsertItem(location_, obj);
 
     return Status::OK();
 }